diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/Makefile | 2 | ||||
| -rw-r--r-- | drivers/remoteproc/Kconfig | 28 | ||||
| -rw-r--r-- | drivers/remoteproc/Makefile | 9 | ||||
| -rw-r--r-- | drivers/remoteproc/omap_remoteproc.c | 229 | ||||
| -rw-r--r-- | drivers/remoteproc/omap_remoteproc.h | 69 | ||||
| -rw-r--r-- | drivers/remoteproc/remoteproc_core.c | 1586 | ||||
| -rw-r--r-- | drivers/remoteproc/remoteproc_debugfs.c | 179 | ||||
| -rw-r--r-- | drivers/remoteproc/remoteproc_internal.h | 44 | ||||
| -rw-r--r-- | drivers/remoteproc/remoteproc_virtio.c | 289 | ||||
| -rw-r--r-- | drivers/rpmsg/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/rpmsg/Makefile | 1 | ||||
| -rw-r--r-- | drivers/rpmsg/virtio_rpmsg_bus.c | 1054 |
13 files changed, 3504 insertions, 0 deletions
diff --git a/drivers/Kconfig b/drivers/Kconfig index decf8e420856..6f0459cb745b 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -130,6 +130,10 @@ source "drivers/clocksource/Kconfig" source "drivers/iommu/Kconfig" +source "drivers/remoteproc/Kconfig" + +source "drivers/rpmsg/Kconfig" + source "drivers/virt/Kconfig" source "drivers/devfreq/Kconfig" diff --git a/drivers/Makefile b/drivers/Makefile index 932e8bf20356..262b19d6b627 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -125,6 +125,8 @@ obj-y += clk/ obj-$(CONFIG_HWSPINLOCK) += hwspinlock/ obj-$(CONFIG_NFC) += nfc/ obj-$(CONFIG_IOMMU_SUPPORT) += iommu/ +obj-$(CONFIG_REMOTEPROC) += remoteproc/ +obj-$(CONFIG_RPMSG) += rpmsg/ # Virtualization drivers obj-$(CONFIG_VIRT_DRIVERS) += virt/ diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig new file mode 100644 index 000000000000..24d880e78ec6 --- /dev/null +++ b/drivers/remoteproc/Kconfig @@ -0,0 +1,28 @@ +menu "Remoteproc drivers (EXPERIMENTAL)" + +# REMOTEPROC gets selected by whoever wants it +config REMOTEPROC + tristate + depends on EXPERIMENTAL + +config OMAP_REMOTEPROC + tristate "OMAP remoteproc support" + depends on ARCH_OMAP4 + depends on OMAP_IOMMU + select REMOTEPROC + select OMAP_MBOX_FWK + select RPMSG + help + Say y here to support OMAP's remote processors (dual M3 + and DSP on OMAP4) via the remote processor framework. + + Currently only supported on OMAP4. + + Usually you want to say y here, in order to enable multimedia + use-cases to run on your platform (multimedia codecs are + offloaded to remote DSP processors using this framework). + + It's safe to say n here if you're not interested in multimedia + offloading or just want a bare minimum kernel. + +endmenu diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile new file mode 100644 index 000000000000..5445d9b23294 --- /dev/null +++ b/drivers/remoteproc/Makefile @@ -0,0 +1,9 @@ +# +# Generic framework for controlling remote processors +# + +obj-$(CONFIG_REMOTEPROC) += remoteproc.o +remoteproc-y := remoteproc_core.o +remoteproc-y += remoteproc_debugfs.o +remoteproc-y += remoteproc_virtio.o +obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c new file mode 100644 index 000000000000..69425c4e86f3 --- /dev/null +++ b/drivers/remoteproc/omap_remoteproc.c @@ -0,0 +1,229 @@ +/* + * OMAP Remote Processor driver + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen <ohad@wizery.com> + * Brian Swetland <swetland@google.com> + * Fernando Guzman Lugo <fernando.lugo@ti.com> + * Mark Grosen <mgrosen@ti.com> + * Suman Anna <s-anna@ti.com> + * Hari Kanigeri <h-kanigeri2@ti.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/dma-mapping.h> +#include <linux/remoteproc.h> + +#include <plat/mailbox.h> +#include <plat/remoteproc.h> + +#include "omap_remoteproc.h" +#include "remoteproc_internal.h" + +/** + * struct omap_rproc - omap remote processor state + * @mbox: omap mailbox handle + * @nb: notifier block that will be invoked on inbound mailbox messages + * @rproc: rproc handle + */ +struct omap_rproc { + struct omap_mbox *mbox; + struct notifier_block nb; + struct rproc *rproc; +}; + +/** + * omap_rproc_mbox_callback() - inbound mailbox message handler + * @this: notifier block + * @index: unused + * @data: mailbox payload + * + * This handler is invoked by omap's mailbox driver whenever a mailbox + * message is received. Usually, the mailbox payload simply contains + * the index of the virtqueue that is kicked by the remote processor, + * and we let remoteproc core handle it. + * + * In addition to virtqueue indices, we also have some out-of-band values + * that indicates different events. Those values are deliberately very + * big so they don't coincide with virtqueue indices. + */ +static int omap_rproc_mbox_callback(struct notifier_block *this, + unsigned long index, void *data) +{ + mbox_msg_t msg = (mbox_msg_t) data; + struct omap_rproc *oproc = container_of(this, struct omap_rproc, nb); + struct device *dev = oproc->rproc->dev; + const char *name = oproc->rproc->name; + + dev_dbg(dev, "mbox msg: 0x%x\n", msg); + + switch (msg) { + case RP_MBOX_CRASH: + /* just log this for now. later, we'll also do recovery */ + dev_err(dev, "omap rproc %s crashed\n", name); + break; + case RP_MBOX_ECHO_REPLY: + dev_info(dev, "received echo reply from %s\n", name); + break; + default: + /* msg contains the index of the triggered vring */ + if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE) + dev_dbg(dev, "no message was found in vqid %d\n", msg); + } + + return NOTIFY_DONE; +} + +/* kick a virtqueue */ +static void omap_rproc_kick(struct rproc *rproc, int vqid) +{ + struct omap_rproc *oproc = rproc->priv; + int ret; + + /* send the index of the triggered virtqueue in the mailbox payload */ + ret = omap_mbox_msg_send(oproc->mbox, vqid); + if (ret) + dev_err(rproc->dev, "omap_mbox_msg_send failed: %d\n", ret); +} + +/* + * Power up the remote processor. + * + * This function will be invoked only after the firmware for this rproc + * was loaded, parsed successfully, and all of its resource requirements + * were met. + */ +static int omap_rproc_start(struct rproc *rproc) +{ + struct omap_rproc *oproc = rproc->priv; + struct platform_device *pdev = to_platform_device(rproc->dev); + struct omap_rproc_pdata *pdata = pdev->dev.platform_data; + int ret; + + oproc->nb.notifier_call = omap_rproc_mbox_callback; + + /* every omap rproc is assigned a mailbox instance for messaging */ + oproc->mbox = omap_mbox_get(pdata->mbox_name, &oproc->nb); + if (IS_ERR(oproc->mbox)) { + ret = PTR_ERR(oproc->mbox); + dev_err(rproc->dev, "omap_mbox_get failed: %d\n", ret); + return ret; + } + + /* + * Ping the remote processor. this is only for sanity-sake; + * there is no functional effect whatsoever. + * + * Note that the reply will _not_ arrive immediately: this message + * will wait in the mailbox fifo until the remote processor is booted. + */ + ret = omap_mbox_msg_send(oproc->mbox, RP_MBOX_ECHO_REQUEST); + if (ret) { + dev_err(rproc->dev, "omap_mbox_get failed: %d\n", ret); + goto put_mbox; + } + + ret = pdata->device_enable(pdev); + if (ret) { + dev_err(rproc->dev, "omap_device_enable failed: %d\n", ret); + goto put_mbox; + } + + return 0; + +put_mbox: + omap_mbox_put(oproc->mbox, &oproc->nb); + return ret; +} + +/* power off the remote processor */ +static int omap_rproc_stop(struct rproc *rproc) +{ + struct platform_device *pdev = to_platform_device(rproc->dev); + struct omap_rproc_pdata *pdata = pdev->dev.platform_data; + struct omap_rproc *oproc = rproc->priv; + int ret; + + ret = pdata->device_shutdown(pdev); + if (ret) + return ret; + + omap_mbox_put(oproc->mbox, &oproc->nb); + + return 0; +} + +static struct rproc_ops omap_rproc_ops = { + .start = omap_rproc_start, + .stop = omap_rproc_stop, + .kick = omap_rproc_kick, +}; + +static int __devinit omap_rproc_probe(struct platform_device *pdev) +{ + struct omap_rproc_pdata *pdata = pdev->dev.platform_data; + struct omap_rproc *oproc; + struct rproc *rproc; + int ret; + + ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32)); + if (ret) { + dev_err(pdev->dev.parent, "dma_set_coherent_mask: %d\n", ret); + return ret; + } + + rproc = rproc_alloc(&pdev->dev, pdata->name, &omap_rproc_ops, + pdata->firmware, sizeof(*oproc)); + if (!rproc) + return -ENOMEM; + + oproc = rproc->priv; + oproc->rproc = rproc; + + platform_set_drvdata(pdev, rproc); + + ret = rproc_register(rproc); + if (ret) + goto free_rproc; + + return 0; + +free_rproc: + rproc_free(rproc); + return ret; +} + +static int __devexit omap_rproc_remove(struct platform_device *pdev) +{ + struct rproc *rproc = platform_get_drvdata(pdev); + + return rproc_unregister(rproc); +} + +static struct platform_driver omap_rproc_driver = { + .probe = omap_rproc_probe, + .remove = __devexit_p(omap_rproc_remove), + .driver = { + .name = "omap-rproc", + .owner = THIS_MODULE, + }, +}; + +module_platform_driver(omap_rproc_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("OMAP Remote Processor control driver"); diff --git a/drivers/remoteproc/omap_remoteproc.h b/drivers/remoteproc/omap_remoteproc.h new file mode 100644 index 000000000000..f6d2036d383d --- /dev/null +++ b/drivers/remoteproc/omap_remoteproc.h @@ -0,0 +1,69 @@ +/* + * Remote processor messaging + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name Texas Instruments nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _OMAP_RPMSG_H +#define _OMAP_RPMSG_H + +/* + * enum - Predefined Mailbox Messages + * + * @RP_MBOX_READY: informs the M3's that we're up and running. this is + * part of the init sequence sent that the M3 expects to see immediately + * after it is booted. + * + * @RP_MBOX_PENDING_MSG: informs the receiver that there is an inbound + * message waiting in its own receive-side vring. please note that currently + * this message is optional: alternatively, one can explicitly send the index + * of the triggered virtqueue itself. the preferred approach will be decided + * as we progress and experiment with those two different approaches. + * + * @RP_MBOX_CRASH: this message is sent if BIOS crashes + * + * @RP_MBOX_ECHO_REQUEST: a mailbox-level "ping" message. + * + * @RP_MBOX_ECHO_REPLY: a mailbox-level reply to a "ping" + * + * @RP_MBOX_ABORT_REQUEST: a "please crash" request, used for testing the + * recovery mechanism (to some extent). + */ +enum omap_rp_mbox_messages { + RP_MBOX_READY = 0xFFFFFF00, + RP_MBOX_PENDING_MSG = 0xFFFFFF01, + RP_MBOX_CRASH = 0xFFFFFF02, + RP_MBOX_ECHO_REQUEST = 0xFFFFFF03, + RP_MBOX_ECHO_REPLY = 0xFFFFFF04, + RP_MBOX_ABORT_REQUEST = 0xFFFFFF05, +}; + +#endif /* _OMAP_RPMSG_H */ diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c new file mode 100644 index 000000000000..ee15c68fb519 --- /dev/null +++ b/drivers/remoteproc/remoteproc_core.c @@ -0,0 +1,1586 @@ +/* + * Remote Processor Framework + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen <ohad@wizery.com> + * Brian Swetland <swetland@google.com> + * Mark Grosen <mgrosen@ti.com> + * Fernando Guzman Lugo <fernando.lugo@ti.com> + * Suman Anna <s-anna@ti.com> + * Robert Tivy <rtivy@ti.com> + * Armando Uribe De Leon <x0095078@ti.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/dma-mapping.h> +#include <linux/firmware.h> +#include <linux/string.h> +#include <linux/debugfs.h> +#include <linux/remoteproc.h> +#include <linux/iommu.h> +#include <linux/klist.h> +#include <linux/elf.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_ring.h> +#include <asm/byteorder.h> + +#include "remoteproc_internal.h" + +static void klist_rproc_get(struct klist_node *n); +static void klist_rproc_put(struct klist_node *n); + +/* + * klist of the available remote processors. + * + * We need this in order to support name-based lookups (needed by the + * rproc_get_by_name()). + * + * That said, we don't use rproc_get_by_name() at this point. + * The use cases that do require its existence should be + * scrutinized, and hopefully migrated to rproc_boot() using device-based + * binding. + * + * If/when this materializes, we could drop the klist (and the by_name + * API). + */ +static DEFINE_KLIST(rprocs, klist_rproc_get, klist_rproc_put); + +typedef int (*rproc_handle_resources_t)(struct rproc *rproc, + struct resource_table *table, int len); +typedef int (*rproc_handle_resource_t)(struct rproc *rproc, void *, int avail); + +/* + * This is the IOMMU fault handler we register with the IOMMU API + * (when relevant; not all remote processors access memory through + * an IOMMU). + * + * IOMMU core will invoke this handler whenever the remote processor + * will try to access an unmapped device address. + * + * Currently this is mostly a stub, but it will be later used to trigger + * the recovery of the remote processor. + */ +static int rproc_iommu_fault(struct iommu_domain *domain, struct device *dev, + unsigned long iova, int flags) +{ + dev_err(dev, "iommu fault: da 0x%lx flags 0x%x\n", iova, flags); + + /* + * Let the iommu core know we're not really handling this fault; + * we just plan to use this as a recovery trigger. + */ + return -ENOSYS; +} + +static int rproc_enable_iommu(struct rproc *rproc) +{ + struct iommu_domain *domain; + struct device *dev = rproc->dev; + int ret; + + /* + * We currently use iommu_present() to decide if an IOMMU + * setup is needed. + * + * This works for simple cases, but will easily fail with + * platforms that do have an IOMMU, but not for this specific + * rproc. + * + * This will be easily solved by introducing hw capabilities + * that will be set by the remoteproc driver. + */ + if (!iommu_present(dev->bus)) { + dev_dbg(dev, "iommu not found\n"); + return 0; + } + + domain = iommu_domain_alloc(dev->bus); + if (!domain) { + dev_err(dev, "can't alloc iommu domain\n"); + return -ENOMEM; + } + + iommu_set_fault_handler(domain, rproc_iommu_fault); + + ret = iommu_attach_device(domain, dev); + if (ret) { + dev_err(dev, "can't attach iommu device: %d\n", ret); + goto free_domain; + } + + rproc->domain = domain; + + return 0; + +free_domain: + iommu_domain_free(domain); + return ret; +} + +static void rproc_disable_iommu(struct rproc *rproc) +{ + struct iommu_domain *domain = rproc->domain; + struct device *dev = rproc->dev; + + if (!domain) + return; + + iommu_detach_device(domain, dev); + iommu_domain_free(domain); + + return; +} + +/* + * Some remote processors will ask us to allocate them physically contiguous + * memory regions (which we call "carveouts"), and map them to specific + * device addresses (which are hardcoded in the firmware). + * + * They may then ask us to copy objects into specific device addresses (e.g. + * code/data sections) or expose us certain symbols in other device address + * (e.g. their trace buffer). + * + * This function is an internal helper with which we can go over the allocated + * carveouts and translate specific device address to kernel virtual addresses + * so we can access the referenced memory. + * + * Note: phys_to_virt(iommu_iova_to_phys(rproc->domain, da)) will work too, + * but only on kernel direct mapped RAM memory. Instead, we're just using + * here the output of the DMA API, which should be more correct. + */ +static void *rproc_da_to_va(struct rproc *rproc, u64 da, int len) +{ + struct rproc_mem_entry *carveout; + void *ptr = NULL; + + list_for_each_entry(carveout, &rproc->carveouts, node) { + int offset = da - carveout->da; + + /* try next carveout if da is too small */ + if (offset < 0) + continue; + + /* try next carveout if da is too large */ + if (offset + len > carveout->len) + continue; + + ptr = carveout->va + offset; + + break; + } + + return ptr; +} + +/** + * rproc_load_segments() - load firmware segments to memory + * @rproc: remote processor which will be booted using these fw segments + * @elf_data: the content of the ELF firmware image + * @len: firmware size (in bytes) + * + * This function loads the firmware segments to memory, where the remote + * processor expects them. + * + * Some remote processors will expect their code and data to be placed + * in specific device addresses, and can't have them dynamically assigned. + * + * We currently support only those kind of remote processors, and expect + * the program header's paddr member to contain those addresses. We then go + * through the physically contiguous "carveout" memory regions which we + * allocated (and mapped) earlier on behalf of the remote processor, + * and "translate" device address to kernel addresses, so we can copy the + * segments where they are expected. + * + * Currently we only support remote processors that required carveout + * allocations and got them mapped onto their iommus. Some processors + * might be different: they might not have iommus, and would prefer to + * directly allocate memory for every segment/resource. This is not yet + * supported, though. + */ +static int +rproc_load_segments(struct rproc *rproc, const u8 *elf_data, size_t len) +{ + struct device *dev = rproc->dev; + struct elf32_hdr *ehdr; + struct elf32_phdr *phdr; + int i, ret = 0; + + ehdr = (struct elf32_hdr *)elf_data; + phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff); + + /* go through the available ELF segments */ + for (i = 0; i < ehdr->e_phnum; i++, phdr++) { + u32 da = phdr->p_paddr; + u32 memsz = phdr->p_memsz; + u32 filesz = phdr->p_filesz; + u32 offset = phdr->p_offset; + void *ptr; + + if (phdr->p_type != PT_LOAD) + continue; + + dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n", + phdr->p_type, da, memsz, filesz); + + if (filesz > memsz) { + dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n", + filesz, memsz); + ret = -EINVAL; + break; + } + + if (offset + filesz > len) { + dev_err(dev, "truncated fw: need 0x%x avail 0x%x\n", + offset + filesz, len); + ret = -EINVAL; + break; + } + + /* grab the kernel address for this device address */ + ptr = rproc_da_to_va(rproc, da, memsz); + if (!ptr) { + dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz); + ret = -EINVAL; + break; + } + + /* put the segment where the remote processor expects it */ + if (phdr->p_filesz) + memcpy(ptr, elf_data + phdr->p_offset, filesz); + + /* + * Zero out remaining memory for this segment. + * + * This isn't strictly required since dma_alloc_coherent already + * did this for us. albeit harmless, we may consider removing + * this. + */ + if (memsz > filesz) + memset(ptr + filesz, 0, memsz - filesz); + } + + return ret; +} + +static int +__rproc_handle_vring(struct rproc_vdev *rvdev, struct fw_rsc_vdev *rsc, int i) +{ + struct rproc *rproc = rvdev->rproc; + struct device *dev = rproc->dev; + struct fw_rsc_vdev_vring *vring = &rsc->vring[i]; + dma_addr_t dma; + void *va; + int ret, size, notifyid; + + dev_dbg(dev, "vdev rsc: vring%d: da %x, qsz %d, align %d\n", + i, vring->da, vring->num, vring->align); + + /* make sure reserved bytes are zeroes */ + if (vring->reserved) { + dev_err(dev, "vring rsc has non zero reserved bytes\n"); + return -EINVAL; + } + + /* verify queue size and vring alignment are sane */ + if (!vring->num || !vring->align) { + dev_err(dev, "invalid qsz (%d) or alignment (%d)\n", + vring->num, vring->align); + return -EINVAL; + } + + /* actual size of vring (in bytes) */ + size = PAGE_ALIGN(vring_size(vring->num, vring->align)); + + if (!idr_pre_get(&rproc->notifyids, GFP_KERNEL)) { + dev_err(dev, "idr_pre_get failed\n"); + return -ENOMEM; + } + + /* + * Allocate non-cacheable memory for the vring. In the future + * this call will also configure the IOMMU for us + */ + va = dma_alloc_coherent(dev, size, &dma, GFP_KERNEL); + if (!va) { + dev_err(dev, "dma_alloc_coherent failed\n"); + return -EINVAL; + } + + /* assign an rproc-wide unique index for this vring */ + /* TODO: assign a notifyid for rvdev updates as well */ + ret = idr_get_new(&rproc->notifyids, &rvdev->vring[i], ¬ifyid); + if (ret) { + dev_err(dev, "idr_get_new failed: %d\n", ret); + dma_free_coherent(dev, size, va, dma); + return ret; + } + + /* let the rproc know the da and notifyid of this vring */ + /* TODO: expose this to remote processor */ + vring->da = dma; + vring->notifyid = notifyid; + + dev_dbg(dev, "vring%d: va %p dma %x size %x idr %d\n", i, va, + dma, size, notifyid); + + rvdev->vring[i].len = vring->num; + rvdev->vring[i].align = vring->align; + rvdev->vring[i].va = va; + rvdev->vring[i].dma = dma; + rvdev->vring[i].notifyid = notifyid; + rvdev->vring[i].rvdev = rvdev; + + return 0; +} + +static void __rproc_free_vrings(struct rproc_vdev *rvdev, int i) +{ + struct rproc *rproc = rvdev->rproc; + + for (i--; i > 0; i--) { + struct rproc_vring *rvring = &rvdev->vring[i]; + int size = PAGE_ALIGN(vring_size(rvring->len, rvring->align)); + + dma_free_coherent(rproc->dev, size, rvring->va, rvring->dma); + idr_remove(&rproc->notifyids, rvring->notifyid); + } +} + +/** + * rproc_handle_vdev() - handle a vdev fw resource + * @rproc: the remote processor + * @rsc: the vring resource descriptor + * @avail: size of available data (for sanity checking the image) + * + * This resource entry requests the host to statically register a virtio + * device (vdev), and setup everything needed to support it. It contains + * everything needed to make it possible: the virtio device id, virtio + * device features, vrings information, virtio config space, etc... + * + * Before registering the vdev, the vrings are allocated from non-cacheable + * physically contiguous memory. Currently we only support two vrings per + * remote processor (temporary limitation). We might also want to consider + * doing the vring allocation only later when ->find_vqs() is invoked, and + * then release them upon ->del_vqs(). + * + * Note: @da is currently not really handled correctly: we dynamically + * allocate it using the DMA API, ignoring requested hard coded addresses, + * and we don't take care of any required IOMMU programming. This is all + * going to be taken care of when the generic iommu-based DMA API will be + * merged. Meanwhile, statically-addressed iommu-based firmware images should + * use RSC_DEVMEM resource entries to map their required @da to the physical + * address of their base CMA region (ouch, hacky!). + * + * Returns 0 on success, or an appropriate error code otherwise + */ +static int rproc_handle_vdev(struct rproc *rproc, struct fw_rsc_vdev *rsc, + int avail) +{ + struct device *dev = rproc->dev; + struct rproc_vdev *rvdev; + int i, ret; + + /* make sure resource isn't truncated */ + if (sizeof(*rsc) + rsc->num_of_vrings * sizeof(struct fw_rsc_vdev_vring) + + rsc->config_len > avail) { + dev_err(rproc->dev, "vdev rsc is truncated\n"); + return -EINVAL; + } + + /* make sure reserved bytes are zeroes */ + if (rsc->reserved[0] || rsc->reserved[1]) { + dev_err(dev, "vdev rsc has non zero reserved bytes\n"); + return -EINVAL; + } + + dev_dbg(dev, "vdev rsc: id %d, dfeatures %x, cfg len %d, %d vrings\n", + rsc->id, rsc->dfeatures, rsc->config_len, rsc->num_of_vrings); + + /* we currently support only two vrings per rvdev */ + if (rsc->num_of_vrings > ARRAY_SIZE(rvdev->vring)) { + dev_err(dev, "too many vrings: %d\n", rsc->num_of_vrings); + return -EINVAL; + } + + rvdev = kzalloc(sizeof(struct rproc_vdev), GFP_KERNEL); + if (!rvdev) + return -ENOMEM; + + rvdev->rproc = rproc; + + /* allocate the vrings */ + for (i = 0; i < rsc->num_of_vrings; i++) { + ret = __rproc_handle_vring(rvdev, rsc, i); + if (ret) + goto free_vrings; + } + + /* remember the device features */ + rvdev->dfeatures = rsc->dfeatures; + + list_add_tail(&rvdev->node, &rproc->rvdevs); + + /* it is now safe to add the virtio device */ + ret = rproc_add_virtio_dev(rvdev, rsc->id); + if (ret) + goto free_vrings; + + return 0; + +free_vrings: + __rproc_free_vrings(rvdev, i); + kfree(rvdev); + return ret; +} + +/** + * rproc_handle_trace() - handle a shared trace buffer resource + * @rproc: the remote processor + * @rsc: the trace resource descriptor + * @avail: size of available data (for sanity checking the image) + * + * In case the remote processor dumps trace logs into memory, + * export it via debugfs. + * + * Currently, the 'da' member of @rsc should contain the device address + * where the remote processor is dumping the traces. Later we could also + * support dynamically allocating this address using the generic + * DMA API (but currently there isn't a use case for that). + * + * Returns 0 on success, or an appropriate error code otherwise + */ +static int rproc_handle_trace(struct rproc *rproc, struct fw_rsc_trace *rsc, + int avail) +{ + struct rproc_mem_entry *trace; + struct device *dev = rproc->dev; + void *ptr; + char name[15]; + + if (sizeof(*rsc) > avail) { + dev_err(rproc->dev, "trace rsc is truncated\n"); + return -EINVAL; + } + + /* make sure reserved bytes are zeroes */ + if (rsc->reserved) { + dev_err(dev, "trace rsc has non zero reserved bytes\n"); + return -EINVAL; + } + + /* what's the kernel address of this resource ? */ + ptr = rproc_da_to_va(rproc, rsc->da, rsc->len); + if (!ptr) { + dev_err(dev, "erroneous trace resource entry\n"); + return -EINVAL; + } + + trace = kzalloc(sizeof(*trace), GFP_KERNEL); + if (!trace) { + dev_err(dev, "kzalloc trace failed\n"); + return -ENOMEM; + } + + /* set the trace buffer dma properties */ + trace->len = rsc->len; + trace->va = ptr; + + /* make sure snprintf always null terminates, even if truncating */ + snprintf(name, sizeof(name), "trace%d", rproc->num_traces); + + /* create the debugfs entry */ + trace->priv = rproc_create_trace_file(name, rproc, trace); + if (!trace->priv) { + trace->va = NULL; + kfree(trace); + return -EINVAL; + } + + list_add_tail(&trace->node, &rproc->traces); + + rproc->num_traces++; + + dev_dbg(dev, "%s added: va %p, da 0x%x, len 0x%x\n", name, ptr, + rsc->da, rsc->len); + + return 0; +} + +/** + * rproc_handle_devmem() - handle devmem resource entry + * @rproc: remote processor handle + * @rsc: the devmem resource entry + * @avail: size of available data (for sanity checking the image) + * + * Remote processors commonly need to access certain on-chip peripherals. + * + * Some of these remote processors access memory via an iommu device, + * and might require us to configure their iommu before they can access + * the on-chip peripherals they need. + * + * This resource entry is a request to map such a peripheral device. + * + * These devmem entries will contain the physical address of the device in + * the 'pa' member. If a specific device address is expected, then 'da' will + * contain it (currently this is the only use case supported). 'len' will + * contain the size of the physical region we need to map. + * + * Currently we just "trust" those devmem entries to contain valid physical + * addresses, but this is going to change: we want the implementations to + * tell us ranges of physical addresses the firmware is allowed to request, + * and not allow firmwares to request access to physical addresses that + * are outside those ranges. + */ +static int rproc_handle_devmem(struct rproc *rproc, struct fw_rsc_devmem *rsc, + int avail) +{ + struct rproc_mem_entry *mapping; + int ret; + + /* no point in handling this resource without a valid iommu domain */ + if (!rproc->domain) + return -EINVAL; + + if (sizeof(*rsc) > avail) { + dev_err(rproc->dev, "devmem rsc is truncated\n"); + return -EINVAL; + } + + /* make sure reserved bytes are zeroes */ + if (rsc->reserved) { + dev_err(rproc->dev, "devmem rsc has non zero reserved bytes\n"); + return -EINVAL; + } + + mapping = kzalloc(sizeof(*mapping), GFP_KERNEL); + if (!mapping) { + dev_err(rproc->dev, "kzalloc mapping failed\n"); + return -ENOMEM; + } + + ret = iommu_map(rproc->domain, rsc->da, rsc->pa, rsc->len, rsc->flags); + if (ret) { + dev_err(rproc->dev, "failed to map devmem: %d\n", ret); + goto out; + } + + /* + * We'll need this info later when we'll want to unmap everything + * (e.g. on shutdown). + * + * We can't trust the remote processor not to change the resource + * table, so we must maintain this info independently. + */ + mapping->da = rsc->da; + mapping->len = rsc->len; + list_add_tail(&mapping->node, &rproc->mappings); + + dev_dbg(rproc->dev, "mapped devmem pa 0x%x, da 0x%x, len 0x%x\n", + rsc->pa, rsc->da, rsc->len); + + return 0; + +out: + kfree(mapping); + return ret; +} + +/** + * rproc_handle_carveout() - handle phys contig memory allocation requests + * @rproc: rproc handle + * @rsc: the resource entry + * @avail: size of available data (for image validation) + * + * This function will handle firmware requests for allocation of physically + * contiguous memory regions. + * + * These request entries should come first in the firmware's resource table, + * as other firmware entries might request placing other data objects inside + * these memory regions (e.g. data/code segments, trace resource entries, ...). + * + * Allocating memory this way helps utilizing the reserved physical memory + * (e.g. CMA) more efficiently, and also minimizes the number of TLB entries + * needed to map it (in case @rproc is using an IOMMU). Reducing the TLB + * pressure is important; it may have a substantial impact on performance. + */ +static int rproc_handle_carveout(struct rproc *rproc, + struct fw_rsc_carveout *rsc, int avail) +{ + struct rproc_mem_entry *carveout, *mapping; + struct device *dev = rproc->dev; + dma_addr_t dma; + void *va; + int ret; + + if (sizeof(*rsc) > avail) { + dev_err(rproc->dev, "carveout rsc is truncated\n"); + return -EINVAL; + } + + /* make sure reserved bytes are zeroes */ + if (rsc->reserved) { + dev_err(dev, "carveout rsc has non zero reserved bytes\n"); + return -EINVAL; + } + + dev_dbg(dev, "carveout rsc: da %x, pa %x, len %x, flags %x\n", + rsc->da, rsc->pa, rsc->len, rsc->flags); + + mapping = kzalloc(sizeof(*mapping), GFP_KERNEL); + if (!mapping) { + dev_err(dev, "kzalloc mapping failed\n"); + return -ENOMEM; + } + + carveout = kzalloc(sizeof(*carveout), GFP_KERNEL); + if (!carveout) { + dev_err(dev, "kzalloc carveout failed\n"); + ret = -ENOMEM; + goto free_mapping; + } + + va = dma_alloc_coherent(dev, rsc->len, &dma, GFP_KERNEL); + if (!va) { + dev_err(dev, "failed to dma alloc carveout: %d\n", rsc->len); + ret = -ENOMEM; + goto free_carv; + } + + dev_dbg(dev, "carveout va %p, dma %x, len 0x%x\n", va, dma, rsc->len); + + /* + * Ok, this is non-standard. + * + * Sometimes we can't rely on the generic iommu-based DMA API + * to dynamically allocate the device address and then set the IOMMU + * tables accordingly, because some remote processors might + * _require_ us to use hard coded device addresses that their + * firmware was compiled with. + * + * In this case, we must use the IOMMU API directly and map + * the memory to the device address as expected by the remote + * processor. + * + * Obviously such remote processor devices should not be configured + * to use the iommu-based DMA API: we expect 'dma' to contain the + * physical address in this case. + */ + if (rproc->domain) { + ret = iommu_map(rproc->domain, rsc->da, dma, rsc->len, + rsc->flags); + if (ret) { + dev_err(dev, "iommu_map failed: %d\n", ret); + goto dma_free; + } + + /* + * We'll need this info later when we'll want to unmap + * everything (e.g. on shutdown). + * + * We can't trust the remote processor not to change the + * resource table, so we must maintain this info independently. + */ + mapping->da = rsc->da; + mapping->len = rsc->len; + list_add_tail(&mapping->node, &rproc->mappings); + + dev_dbg(dev, "carveout mapped 0x%x to 0x%x\n", rsc->da, dma); + + /* + * Some remote processors might need to know the pa + * even though they are behind an IOMMU. E.g., OMAP4's + * remote M3 processor needs this so it can control + * on-chip hardware accelerators that are not behind + * the IOMMU, and therefor must know the pa. + * + * Generally we don't want to expose physical addresses + * if we don't have to (remote processors are generally + * _not_ trusted), so we might want to do this only for + * remote processor that _must_ have this (e.g. OMAP4's + * dual M3 subsystem). + */ + rsc->pa = dma; + } + + carveout->va = va; + carveout->len = rsc->len; + carveout->dma = dma; + carveout->da = rsc->da; + + list_add_tail(&carveout->node, &rproc->carveouts); + + return 0; + +dma_free: + dma_free_coherent(dev, rsc->len, va, dma); +free_carv: + kfree(carveout); +free_mapping: + kfree(mapping); + return ret; +} + +/* + * A lookup table for resource handlers. The indices are defined in + * enum fw_resource_type. + */ +static rproc_handle_resource_t rproc_handle_rsc[] = { + [RSC_CARVEOUT] = (rproc_handle_resource_t)rproc_handle_carveout, + [RSC_DEVMEM] = (rproc_handle_resource_t)rproc_handle_devmem, + [RSC_TRACE] = (rproc_handle_resource_t)rproc_handle_trace, + [RSC_VDEV] = NULL, /* VDEVs were handled upon registrarion */ +}; + +/* handle firmware resource entries before booting the remote processor */ +static int +rproc_handle_boot_rsc(struct rproc *rproc, struct resource_table *table, int len) +{ + struct device *dev = rproc->dev; + rproc_handle_resource_t handler; + int ret = 0, i; + + for (i = 0; i < table->num; i++) { + int offset = table->offset[i]; + struct fw_rsc_hdr *hdr = (void *)table + offset; + int avail = len - offset - sizeof(*hdr); + void *rsc = (void *)hdr + sizeof(*hdr); + + /* make sure table isn't truncated */ + if (avail < 0) { + dev_err(dev, "rsc table is truncated\n"); + return -EINVAL; + } + + dev_dbg(dev, "rsc: type %d\n", hdr->type); + + if (hdr->type >= RSC_LAST) { + dev_warn(dev, "unsupported resource %d\n", hdr->type); + continue; + } + + handler = rproc_handle_rsc[hdr->type]; + if (!handler) + continue; + + ret = handler(rproc, rsc, avail); + if (ret) + break; + } + + return ret; +} + +/* handle firmware resource entries while registering the remote processor */ +static int +rproc_handle_virtio_rsc(struct rproc *rproc, struct resource_table *table, int len) +{ + struct device *dev = rproc->dev; + int ret = 0, i; + + for (i = 0; i < table->num; i++) { + int offset = table->offset[i]; + struct fw_rsc_hdr *hdr = (void *)table + offset; + int avail = len - offset - sizeof(*hdr); + struct fw_rsc_vdev *vrsc; + + /* make sure table isn't truncated */ + if (avail < 0) { + dev_err(dev, "rsc table is truncated\n"); + return -EINVAL; + } + + dev_dbg(dev, "%s: rsc type %d\n", __func__, hdr->type); + + if (hdr->type != RSC_VDEV) + continue; + + vrsc = (struct fw_rsc_vdev *)hdr->data; + + ret = rproc_handle_vdev(rproc, vrsc, avail); + if (ret) + break; + } + + return ret; +} + +/** + * rproc_find_rsc_table() - find the resource table + * @rproc: the rproc handle + * @elf_data: the content of the ELF firmware image + * @len: firmware size (in bytes) + * @tablesz: place holder for providing back the table size + * + * This function finds the resource table inside the remote processor's + * firmware. It is used both upon the registration of @rproc (in order + * to look for and register the supported virito devices), and when the + * @rproc is booted. + * + * Returns the pointer to the resource table if it is found, and write its + * size into @tablesz. If a valid table isn't found, NULL is returned + * (and @tablesz isn't set). + */ +static struct resource_table * +rproc_find_rsc_table(struct rproc *rproc, const u8 *elf_data, size_t len, + int *tablesz) +{ + struct elf32_hdr *ehdr; + struct elf32_shdr *shdr; + const char *name_table; + struct device *dev = rproc->dev; + struct resource_table *table = NULL; + int i; + + ehdr = (struct elf32_hdr *)elf_data; + shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff); + name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset; + + /* look for the resource table and handle it */ + for (i = 0; i < ehdr->e_shnum; i++, shdr++) { + int size = shdr->sh_size; + int offset = shdr->sh_offset; + + if (strcmp(name_table + shdr->sh_name, ".resource_table")) + continue; + + table = (struct resource_table *)(elf_data + offset); + + /* make sure we have the entire table */ + if (offset + size > len) { + dev_err(dev, "resource table truncated\n"); + return NULL; + } + + /* make sure table has at least the header */ + if (sizeof(struct resource_table) > size) { + dev_err(dev, "header-less resource table\n"); + return NULL; + } + + /* we don't support any version beyond the first */ + if (table->ver != 1) { + dev_err(dev, "unsupported fw ver: %d\n", table->ver); + return NULL; + } + + /* make sure reserved bytes are zeroes */ + if (table->reserved[0] || table->reserved[1]) { + dev_err(dev, "non zero reserved bytes\n"); + return NULL; + } + + /* make sure the offsets array isn't truncated */ + if (table->num * sizeof(table->offset[0]) + + sizeof(struct resource_table) > size) { + dev_err(dev, "resource table incomplete\n"); + return NULL; + } + + *tablesz = shdr->sh_size; + break; + } + + return table; +} + +/** + * rproc_resource_cleanup() - clean up and free all acquired resources + * @rproc: rproc handle + * + * This function will free all resources acquired for @rproc, and it + * is called whenever @rproc either shuts down or fails to boot. + */ +static void rproc_resource_cleanup(struct rproc *rproc) +{ + struct rproc_mem_entry *entry, *tmp; + struct device *dev = rproc->dev; + + /* clean up debugfs trace entries */ + list_for_each_entry_safe(entry, tmp, &rproc->traces, node) { + rproc_remove_trace_file(entry->priv); + rproc->num_traces--; + list_del(&entry->node); + kfree(entry); + } + + /* clean up carveout allocations */ + list_for_each_entry_safe(entry, tmp, &rproc->carveouts, node) { + dma_free_coherent(dev, entry->len, entry->va, entry->dma); + list_del(&entry->node); + kfree(entry); + } + + /* clean up iommu mapping entries */ + list_for_each_entry_safe(entry, tmp, &rproc->mappings, node) { + size_t unmapped; + + unmapped = iommu_unmap(rproc->domain, entry->da, entry->len); + if (unmapped != entry->len) { + /* nothing much to do besides complaining */ + dev_err(dev, "failed to unmap %u/%u\n", entry->len, + unmapped); + } + + list_del(&entry->node); + kfree(entry); + } +} + +/* make sure this fw image is sane */ +static int rproc_fw_sanity_check(struct rproc *rproc, const struct firmware *fw) +{ + const char *name = rproc->firmware; + struct device *dev = rproc->dev; + struct elf32_hdr *ehdr; + char class; + + if (!fw) { + dev_err(dev, "failed to load %s\n", name); + return -EINVAL; + } + + if (fw->size < sizeof(struct elf32_hdr)) { + dev_err(dev, "Image is too small\n"); + return -EINVAL; + } + + ehdr = (struct elf32_hdr *)fw->data; + + /* We only support ELF32 at this point */ + class = ehdr->e_ident[EI_CLASS]; + if (class != ELFCLASS32) { + dev_err(dev, "Unsupported class: %d\n", class); + return -EINVAL; + } + + /* We assume the firmware has the same endianess as the host */ +# ifdef __LITTLE_ENDIAN + if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) { +# else /* BIG ENDIAN */ + if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) { +# endif + dev_err(dev, "Unsupported firmware endianess\n"); + return -EINVAL; + } + + if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) { + dev_err(dev, "Image is too small\n"); + return -EINVAL; + } + + if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) { + dev_err(dev, "Image is corrupted (bad magic)\n"); + return -EINVAL; + } + + if (ehdr->e_phnum == 0) { + dev_err(dev, "No loadable segments\n"); + return -EINVAL; + } + + if (ehdr->e_phoff > fw->size) { + dev_err(dev, "Firmware size is too small\n"); + return -EINVAL; + } + + return 0; +} + +/* + * take a firmware and boot a remote processor with it. + */ +static int rproc_fw_boot(struct rproc *rproc, const struct firmware *fw) +{ + struct device *dev = rproc->dev; + const char *name = rproc->firmware; + struct elf32_hdr *ehdr; + struct resource_table *table; + int ret, tablesz; + + ret = rproc_fw_sanity_check(rproc, fw); + if (ret) + return ret; + + ehdr = (struct elf32_hdr *)fw->data; + + dev_info(dev, "Booting fw image %s, size %d\n", name, fw->size); + + /* + * if enabling an IOMMU isn't relevant for this rproc, this is + * just a nop + */ + ret = rproc_enable_iommu(rproc); + if (ret) { + dev_err(dev, "can't enable iommu: %d\n", ret); + return ret; + } + + /* + * The ELF entry point is the rproc's boot addr (though this is not + * a configurable property of all remote processors: some will always + * boot at a specific hardcoded address). + */ + rproc->bootaddr = ehdr->e_entry; + + /* look for the resource table */ + table = rproc_find_rsc_table(rproc, fw->data, fw->size, &tablesz); + if (!table) + goto clean_up; + + /* handle fw resources which are required to boot rproc */ + ret = rproc_handle_boot_rsc(rproc, table, tablesz); + if (ret) { + dev_err(dev, "Failed to process resources: %d\n", ret); + goto clean_up; + } + + /* load the ELF segments to memory */ + ret = rproc_load_segments(rproc, fw->data, fw->size); + if (ret) { + dev_err(dev, "Failed to load program segments: %d\n", ret); + goto clean_up; + } + + /* power up the remote processor */ + ret = rproc->ops->start(rproc); + if (ret) { + dev_err(dev, "can't start rproc %s: %d\n", rproc->name, ret); + goto clean_up; + } + + rproc->state = RPROC_RUNNING; + + dev_info(dev, "remote processor %s is now up\n", rproc->name); + + return 0; + +clean_up: + rproc_resource_cleanup(rproc); + rproc_disable_iommu(rproc); + return ret; +} + +/* + * take a firmware and look for virtio devices to register. + * + * Note: this function is called asynchronously upon registration of the + * remote processor (so we must wait until it completes before we try + * to unregister the device. one other option is just to use kref here, + * that might be cleaner). + */ +static void rproc_fw_config_virtio(const struct firmware *fw, void *context) +{ + struct rproc *rproc = context; + struct resource_table *table; + int ret, tablesz; + + if (rproc_fw_sanity_check(rproc, fw) < 0) + goto out; + + /* look for the resource table */ + table = rproc_find_rsc_table(rproc, fw->data, fw->size, &tablesz); + if (!table) + goto out; + + /* look for virtio devices and register them */ + ret = rproc_handle_virtio_rsc(rproc, table, tablesz); + if (ret) + goto out; + +out: + if (fw) + release_firmware(fw); + /* allow rproc_unregister() contexts, if any, to proceed */ + complete_all(&rproc->firmware_loading_complete); +} + +/** + * rproc_boot() - boot a remote processor + * @rproc: handle of a remote processor + * + * Boot a remote processor (i.e. load its firmware, power it on, ...). + * + * If the remote processor is already powered on, this function immediately + * returns (successfully). + * + * Returns 0 on success, and an appropriate error value otherwise. + */ +int rproc_boot(struct rproc *rproc) +{ + const struct firmware *firmware_p; + struct device *dev; + int ret; + + if (!rproc) { + pr_err("invalid rproc handle\n"); + return -EINVAL; + } + + dev = rproc->dev; + + ret = mutex_lock_interruptible(&rproc->lock); + if (ret) { + dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret); + return ret; + } + + /* loading a firmware is required */ + if (!rproc->firmware) { + dev_err(dev, "%s: no firmware to load\n", __func__); + ret = -EINVAL; + goto unlock_mutex; + } + + /* prevent underlying implementation from being removed */ + if (!try_module_get(dev->driver->owner)) { + dev_err(dev, "%s: can't get owner\n", __func__); + ret = -EINVAL; + goto unlock_mutex; + } + + /* skip the boot process if rproc is already powered up */ + if (atomic_inc_return(&rproc->power) > 1) { + ret = 0; + goto unlock_mutex; + } + + dev_info(dev, "powering up %s\n", rproc->name); + + /* load firmware */ + ret = request_firmware(&firmware_p, rproc->firmware, dev); + if (ret < 0) { + dev_err(dev, "request_firmware failed: %d\n", ret); + goto downref_rproc; + } + + ret = rproc_fw_boot(rproc, firmware_p); + + release_firmware(firmware_p); + +downref_rproc: + if (ret) { + module_put(dev->driver->owner); + atomic_dec(&rproc->power); + } +unlock_mutex: + mutex_unlock(&rproc->lock); + return ret; +} +EXPORT_SYMBOL(rproc_boot); + +/** + * rproc_shutdown() - power off the remote processor + * @rproc: the remote processor + * + * Power off a remote processor (previously booted with rproc_boot()). + * + * In case @rproc is still being used by an additional user(s), then + * this function will just decrement the power refcount and exit, + * without really powering off the device. + * + * Every call to rproc_boot() must (eventually) be accompanied by a call + * to rproc_shutdown(). Calling rproc_shutdown() redundantly is a bug. + * + * Notes: + * - we're not decrementing the rproc's refcount, only the power refcount. + * which means that the @rproc handle stays valid even after rproc_shutdown() + * returns, and users can still use it with a subsequent rproc_boot(), if + * needed. + * - don't call rproc_shutdown() to unroll rproc_get_by_name(), exactly + * because rproc_shutdown() _does not_ decrement the refcount of @rproc. + * To decrement the refcount of @rproc, use rproc_put() (but _only_ if + * you acquired @rproc using rproc_get_by_name()). + */ +void rproc_shutdown(struct rproc *rproc) +{ + struct device *dev = rproc->dev; + int ret; + + ret = mutex_lock_interruptible(&rproc->lock); + if (ret) { + dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, ret); + return; + } + + /* if the remote proc is still needed, bail out */ + if (!atomic_dec_and_test(&rproc->power)) + goto out; + + /* power off the remote processor */ + ret = rproc->ops->stop(rproc); + if (ret) { + atomic_inc(&rproc->power); + dev_err(dev, "can't stop rproc: %d\n", ret); + goto out; + } + + /* clean up all acquired resources */ + rproc_resource_cleanup(rproc); + + rproc_disable_iommu(rproc); + + rproc->state = RPROC_OFFLINE; + + dev_info(dev, "stopped remote processor %s\n", rproc->name); + +out: + mutex_unlock(&rproc->lock); + if (!ret) + module_put(dev->driver->owner); +} +EXPORT_SYMBOL(rproc_shutdown); + +/** + * rproc_release() - completely deletes the existence of a remote processor + * @kref: the rproc's kref + * + * This function should _never_ be called directly. + * + * The only reasonable location to use it is as an argument when kref_put'ing + * @rproc's refcount. + * + * This way it will be called when no one holds a valid pointer to this @rproc + * anymore (and obviously after it is removed from the rprocs klist). + * + * Note: this function is not static because rproc_vdev_release() needs it when + * it decrements @rproc's refcount. + */ +void rproc_release(struct kref *kref) +{ + struct rproc *rproc = container_of(kref, struct rproc, refcount); + struct rproc_vdev *rvdev, *rvtmp; + + dev_info(rproc->dev, "removing %s\n", rproc->name); + + rproc_delete_debug_dir(rproc); + + /* clean up remote vdev entries */ + list_for_each_entry_safe(rvdev, rvtmp, &rproc->rvdevs, node) { + __rproc_free_vrings(rvdev, RVDEV_NUM_VRINGS); + list_del(&rvdev->node); + } + + /* + * At this point no one holds a reference to rproc anymore, + * so we can directly unroll rproc_alloc() + */ + rproc_free(rproc); +} + +/* will be called when an rproc is added to the rprocs klist */ +static void klist_rproc_get(struct klist_node *n) +{ + struct rproc *rproc = container_of(n, struct rproc, node); + + kref_get(&rproc->refcount); +} + +/* will be called when an rproc is removed from the rprocs klist */ +static void klist_rproc_put(struct klist_node *n) +{ + struct rproc *rproc = container_of(n, struct rproc, node); + + kref_put(&rproc->refcount, rproc_release); +} + +static struct rproc *next_rproc(struct klist_iter *i) +{ + struct klist_node *n; + + n = klist_next(i); + if (!n) + return NULL; + + return container_of(n, struct rproc, node); +} + +/** + * rproc_get_by_name() - find a remote processor by name and boot it + * @name: name of the remote processor + * + * Finds an rproc handle using the remote processor's name, and then + * boot it. If it's already powered on, then just immediately return + * (successfully). + * + * Returns the rproc handle on success, and NULL on failure. + * + * This function increments the remote processor's refcount, so always + * use rproc_put() to decrement it back once rproc isn't needed anymore. + * + * Note: currently this function (and its counterpart rproc_put()) are not + * being used. We need to scrutinize the use cases + * that still need them, and see if we can migrate them to use the non + * name-based boot/shutdown interface. + */ +struct rproc *rproc_get_by_name(const char *name) +{ + struct rproc *rproc; + struct klist_iter i; + int ret; + + /* find the remote processor, and upref its refcount */ + klist_iter_init(&rprocs, &i); + while ((rproc = next_rproc(&i)) != NULL) + if (!strcmp(rproc->name, name)) { + kref_get(&rproc->refcount); + break; + } + klist_iter_exit(&i); + + /* can't find this rproc ? */ + if (!rproc) { + pr_err("can't find remote processor %s\n", name); + return NULL; + } + + ret = rproc_boot(rproc); + if (ret < 0) { + kref_put(&rproc->refcount, rproc_release); + return NULL; + } + + return rproc; +} +EXPORT_SYMBOL(rproc_get_by_name); + +/** + * rproc_put() - decrement the refcount of a remote processor, and shut it down + * @rproc: the remote processor + * + * This function tries to shutdown @rproc, and it then decrements its + * refcount. + * + * After this function returns, @rproc may _not_ be used anymore, and its + * handle should be considered invalid. + * + * This function should be called _iff_ the @rproc handle was grabbed by + * calling rproc_get_by_name(). + */ +void rproc_put(struct rproc *rproc) +{ + /* try to power off the remote processor */ + rproc_shutdown(rproc); + + /* downref rproc's refcount */ + kref_put(&rproc->refcount, rproc_release); +} +EXPORT_SYMBOL(rproc_put); + +/** + * rproc_register() - register a remote processor + * @rproc: the remote processor handle to register + * + * Registers @rproc with the remoteproc framework, after it has been + * allocated with rproc_alloc(). + * + * This is called by the platform-specific rproc implementation, whenever + * a new remote processor device is probed. + * + * Returns 0 on success and an appropriate error code otherwise. + * + * Note: this function initiates an asynchronous firmware loading + * context, which will look for virtio devices supported by the rproc's + * firmware. + * + * If found, those virtio devices will be created and added, so as a result + * of registering this remote processor, additional virtio drivers might be + * probed. + */ +int rproc_register(struct rproc *rproc) +{ + struct device *dev = rproc->dev; + int ret = 0; + + /* expose to rproc_get_by_name users */ + klist_add_tail(&rproc->node, &rprocs); + + dev_info(rproc->dev, "%s is available\n", rproc->name); + + dev_info(dev, "Note: remoteproc is still under development and considered experimental.\n"); + dev_info(dev, "THE BINARY FORMAT IS NOT YET FINALIZED, and backward compatibility isn't yet guaranteed.\n"); + + /* create debugfs entries */ + rproc_create_debug_dir(rproc); + + /* rproc_unregister() calls must wait until async loader completes */ + init_completion(&rproc->firmware_loading_complete); + + /* + * We must retrieve early virtio configuration info from + * the firmware (e.g. whether to register a virtio device, + * what virtio features does it support, ...). + * + * We're initiating an asynchronous firmware loading, so we can + * be built-in kernel code, without hanging the boot process. + */ + ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG, + rproc->firmware, dev, GFP_KERNEL, + rproc, rproc_fw_config_virtio); + if (ret < 0) { + dev_err(dev, "request_firmware_nowait failed: %d\n", ret); + complete_all(&rproc->firmware_loading_complete); + klist_remove(&rproc->node); + } + + return ret; +} +EXPORT_SYMBOL(rproc_register); + +/** + * rproc_alloc() - allocate a remote processor handle + * @dev: the underlying device + * @name: name of this remote processor + * @ops: platform-specific handlers (mainly start/stop) + * @firmware: name of firmware file to load + * @len: length of private data needed by the rproc driver (in bytes) + * + * Allocates a new remote processor handle, but does not register + * it yet. + * + * This function should be used by rproc implementations during initialization + * of the remote processor. + * + * After creating an rproc handle using this function, and when ready, + * implementations should then call rproc_register() to complete + * the registration of the remote processor. + * + * On success the new rproc is returned, and on failure, NULL. + * + * Note: _never_ directly deallocate @rproc, even if it was not registered + * yet. Instead, if you just need to unroll rproc_alloc(), use rproc_free(). + */ +struct rproc *rproc_alloc(struct device *dev, const char *name, + const struct rproc_ops *ops, + const char *firmware, int len) +{ + struct rproc *rproc; + + if (!dev || !name || !ops) + return NULL; + + rproc = kzalloc(sizeof(struct rproc) + len, GFP_KERNEL); + if (!rproc) { + dev_err(dev, "%s: kzalloc failed\n", __func__); + return NULL; + } + + rproc->dev = dev; + rproc->name = name; + rproc->ops = ops; + rproc->firmware = firmware; + rproc->priv = &rproc[1]; + + atomic_set(&rproc->power, 0); + + kref_init(&rproc->refcount); + + mutex_init(&rproc->lock); + + idr_init(&rproc->notifyids); + + INIT_LIST_HEAD(&rproc->carveouts); + INIT_LIST_HEAD(&rproc->mappings); + INIT_LIST_HEAD(&rproc->traces); + INIT_LIST_HEAD(&rproc->rvdevs); + + rproc->state = RPROC_OFFLINE; + + return rproc; +} +EXPORT_SYMBOL(rproc_alloc); + +/** + * rproc_free() - free an rproc handle that was allocated by rproc_alloc + * @rproc: the remote processor handle + * + * This function should _only_ be used if @rproc was only allocated, + * but not registered yet. + * + * If @rproc was already successfully registered (by calling rproc_register()), + * then use rproc_unregister() instead. + */ +void rproc_free(struct rproc *rproc) +{ + idr_remove_all(&rproc->notifyids); + idr_destroy(&rproc->notifyids); + + kfree(rproc); +} +EXPORT_SYMBOL(rproc_free); + +/** + * rproc_unregister() - unregister a remote processor + * @rproc: rproc handle to unregister + * + * Unregisters a remote processor, and decrements its refcount. + * If its refcount drops to zero, then @rproc will be freed. If not, + * it will be freed later once the last reference is dropped. + * + * This function should be called when the platform specific rproc + * implementation decides to remove the rproc device. it should + * _only_ be called if a previous invocation of rproc_register() + * has completed successfully. + * + * After rproc_unregister() returns, @rproc is _not_ valid anymore and + * it shouldn't be used. More specifically, don't call rproc_free() + * or try to directly free @rproc after rproc_unregister() returns; + * none of these are needed, and calling them is a bug. + * + * Returns 0 on success and -EINVAL if @rproc isn't valid. + */ +int rproc_unregister(struct rproc *rproc) +{ + struct rproc_vdev *rvdev; + + if (!rproc) + return -EINVAL; + + /* if rproc is just being registered, wait */ + wait_for_completion(&rproc->firmware_loading_complete); + + /* clean up remote vdev entries */ + list_for_each_entry(rvdev, &rproc->rvdevs, node) + rproc_remove_virtio_dev(rvdev); + + /* the rproc is downref'ed as soon as it's removed from the klist */ + klist_del(&rproc->node); + + /* the rproc will only be released after its refcount drops to zero */ + kref_put(&rproc->refcount, rproc_release); + + return 0; +} +EXPORT_SYMBOL(rproc_unregister); + +static int __init remoteproc_init(void) +{ + rproc_init_debugfs(); + return 0; +} +module_init(remoteproc_init); + +static void __exit remoteproc_exit(void) +{ + rproc_exit_debugfs(); +} +module_exit(remoteproc_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Generic Remote Processor Framework"); diff --git a/drivers/remoteproc/remoteproc_debugfs.c b/drivers/remoteproc/remoteproc_debugfs.c new file mode 100644 index 000000000000..70277a530133 --- /dev/null +++ b/drivers/remoteproc/remoteproc_debugfs.c @@ -0,0 +1,179 @@ +/* + * Remote Processor Framework + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen <ohad@wizery.com> + * Mark Grosen <mgrosen@ti.com> + * Brian Swetland <swetland@google.com> + * Fernando Guzman Lugo <fernando.lugo@ti.com> + * Suman Anna <s-anna@ti.com> + * Robert Tivy <rtivy@ti.com> + * Armando Uribe De Leon <x0095078@ti.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include <linux/kernel.h> +#include <linux/debugfs.h> +#include <linux/remoteproc.h> +#include <linux/device.h> + +/* remoteproc debugfs parent dir */ +static struct dentry *rproc_dbg; + +/* + * Some remote processors may support dumping trace logs into a shared + * memory buffer. We expose this trace buffer using debugfs, so users + * can easily tell what's going on remotely. + * + * We will most probably improve the rproc tracing facilities later on, + * but this kind of lightweight and simple mechanism is always good to have, + * as it provides very early tracing with little to no dependencies at all. + */ +static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct rproc_mem_entry *trace = filp->private_data; + int len = strnlen(trace->va, trace->len); + + return simple_read_from_buffer(userbuf, count, ppos, trace->va, len); +} + +static int rproc_open_generic(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + + return 0; +} + +static const struct file_operations trace_rproc_ops = { + .read = rproc_trace_read, + .open = rproc_open_generic, + .llseek = generic_file_llseek, +}; + +/* + * A state-to-string lookup table, for exposing a human readable state + * via debugfs. Always keep in sync with enum rproc_state + */ +static const char * const rproc_state_string[] = { + "offline", + "suspended", + "running", + "crashed", + "invalid", +}; + +/* expose the state of the remote processor via debugfs */ +static ssize_t rproc_state_read(struct file *filp, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct rproc *rproc = filp->private_data; + unsigned int state; + char buf[30]; + int i; + + state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state; + + i = snprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state], + rproc->state); + + return simple_read_from_buffer(userbuf, count, ppos, buf, i); +} + +static const struct file_operations rproc_state_ops = { + .read = rproc_state_read, + .open = rproc_open_generic, + .llseek = generic_file_llseek, +}; + +/* expose the name of the remote processor via debugfs */ +static ssize_t rproc_name_read(struct file *filp, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct rproc *rproc = filp->private_data; + /* need room for the name, a newline and a terminating null */ + char buf[100]; + int i; + + i = snprintf(buf, sizeof(buf), "%.98s\n", rproc->name); + + return simple_read_from_buffer(userbuf, count, ppos, buf, i); +} + +static const struct file_operations rproc_name_ops = { + .read = rproc_name_read, + .open = rproc_open_generic, + .llseek = generic_file_llseek, +}; + +void rproc_remove_trace_file(struct dentry *tfile) +{ + debugfs_remove(tfile); +} + +struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc, + struct rproc_mem_entry *trace) +{ + struct dentry *tfile; + + tfile = debugfs_create_file(name, 0400, rproc->dbg_dir, + trace, &trace_rproc_ops); + if (!tfile) { + dev_err(rproc->dev, "failed to create debugfs trace entry\n"); + return NULL; + } + + return tfile; +} + +void rproc_delete_debug_dir(struct rproc *rproc) +{ + if (!rproc->dbg_dir) + return; + + debugfs_remove_recursive(rproc->dbg_dir); +} + +void rproc_create_debug_dir(struct rproc *rproc) +{ + struct device *dev = rproc->dev; + + if (!rproc_dbg) + return; + + rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg); + if (!rproc->dbg_dir) + return; + + debugfs_create_file("name", 0400, rproc->dbg_dir, + rproc, &rproc_name_ops); + debugfs_create_file("state", 0400, rproc->dbg_dir, + rproc, &rproc_state_ops); +} + +void __init rproc_init_debugfs(void) +{ + if (debugfs_initialized()) { + rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL); + if (!rproc_dbg) + pr_err("can't create debugfs dir\n"); + } +} + +void __exit rproc_exit_debugfs(void) +{ + if (rproc_dbg) + debugfs_remove(rproc_dbg); +} diff --git a/drivers/remoteproc/remoteproc_internal.h b/drivers/remoteproc/remoteproc_internal.h new file mode 100644 index 000000000000..9f336d6bdef3 --- /dev/null +++ b/drivers/remoteproc/remoteproc_internal.h @@ -0,0 +1,44 @@ +/* + * Remote processor framework + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen <ohad@wizery.com> + * Brian Swetland <swetland@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef REMOTEPROC_INTERNAL_H +#define REMOTEPROC_INTERNAL_H + +#include <linux/irqreturn.h> + +struct rproc; + +/* from remoteproc_core.c */ +void rproc_release(struct kref *kref); +irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id); + +/* from remoteproc_virtio.c */ +int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id); +void rproc_remove_virtio_dev(struct rproc_vdev *rvdev); + +/* from remoteproc_debugfs.c */ +void rproc_remove_trace_file(struct dentry *tfile); +struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc, + struct rproc_mem_entry *trace); +void rproc_delete_debug_dir(struct rproc *rproc); +void rproc_create_debug_dir(struct rproc *rproc); +void rproc_init_debugfs(void); +void rproc_exit_debugfs(void); + +#endif /* REMOTEPROC_INTERNAL_H */ diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c new file mode 100644 index 000000000000..ecf612130750 --- /dev/null +++ b/drivers/remoteproc/remoteproc_virtio.c @@ -0,0 +1,289 @@ +/* + * Remote processor messaging transport (OMAP platform-specific bits) + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen <ohad@wizery.com> + * Brian Swetland <swetland@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/export.h> +#include <linux/remoteproc.h> +#include <linux/virtio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_ring.h> +#include <linux/err.h> +#include <linux/kref.h> +#include <linux/slab.h> + +#include "remoteproc_internal.h" + +/* kick the remote processor, and let it know which virtqueue to poke at */ +static void rproc_virtio_notify(struct virtqueue *vq) +{ + struct rproc_vring *rvring = vq->priv; + struct rproc *rproc = rvring->rvdev->rproc; + int notifyid = rvring->notifyid; + + dev_dbg(rproc->dev, "kicking vq index: %d\n", notifyid); + + rproc->ops->kick(rproc, notifyid); +} + +/** + * rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted + * @rproc: handle to the remote processor + * @notifyid: index of the signalled virtqueue (unique per this @rproc) + * + * This function should be called by the platform-specific rproc driver, + * when the remote processor signals that a specific virtqueue has pending + * messages available. + * + * Returns IRQ_NONE if no message was found in the @notifyid virtqueue, + * and otherwise returns IRQ_HANDLED. + */ +irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int notifyid) +{ + struct rproc_vring *rvring; + + dev_dbg(rproc->dev, "vq index %d is interrupted\n", notifyid); + + rvring = idr_find(&rproc->notifyids, notifyid); + if (!rvring || !rvring->vq) + return IRQ_NONE; + + return vring_interrupt(0, rvring->vq); +} +EXPORT_SYMBOL(rproc_vq_interrupt); + +static struct virtqueue *rp_find_vq(struct virtio_device *vdev, + unsigned id, + void (*callback)(struct virtqueue *vq), + const char *name) +{ + struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); + struct rproc *rproc = vdev_to_rproc(vdev); + struct rproc_vring *rvring; + struct virtqueue *vq; + void *addr; + int len, size; + + /* we're temporarily limited to two virtqueues per rvdev */ + if (id >= ARRAY_SIZE(rvdev->vring)) + return ERR_PTR(-EINVAL); + + rvring = &rvdev->vring[id]; + + addr = rvring->va; + len = rvring->len; + + /* zero vring */ + size = vring_size(len, rvring->align); + memset(addr, 0, size); + + dev_dbg(rproc->dev, "vring%d: va %p qsz %d notifyid %d\n", + id, addr, len, rvring->notifyid); + + /* + * Create the new vq, and tell virtio we're not interested in + * the 'weak' smp barriers, since we're talking with a real device. + */ + vq = vring_new_virtqueue(len, rvring->align, vdev, false, addr, + rproc_virtio_notify, callback, name); + if (!vq) { + dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name); + return ERR_PTR(-ENOMEM); + } + + rvring->vq = vq; + vq->priv = rvring; + + return vq; +} + +static void rproc_virtio_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + struct rproc *rproc = vdev_to_rproc(vdev); + struct rproc_vring *rvring; + + /* power down the remote processor before deleting vqs */ + rproc_shutdown(rproc); + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) { + rvring = vq->priv; + rvring->vq = NULL; + vring_del_virtqueue(vq); + } +} + +static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char *names[]) +{ + struct rproc *rproc = vdev_to_rproc(vdev); + int i, ret; + + for (i = 0; i < nvqs; ++i) { + vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]); + if (IS_ERR(vqs[i])) { + ret = PTR_ERR(vqs[i]); + goto error; + } + } + + /* now that the vqs are all set, boot the remote processor */ + ret = rproc_boot(rproc); + if (ret) { + dev_err(rproc->dev, "rproc_boot() failed %d\n", ret); + goto error; + } + + return 0; + +error: + rproc_virtio_del_vqs(vdev); + return ret; +} + +/* + * We don't support yet real virtio status semantics. + * + * The plan is to provide this via the VDEV resource entry + * which is part of the firmware: this way the remote processor + * will be able to access the status values as set by us. + */ +static u8 rproc_virtio_get_status(struct virtio_device *vdev) +{ + return 0; +} + +static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status) +{ + dev_dbg(&vdev->dev, "status: %d\n", status); +} + +static void rproc_virtio_reset(struct virtio_device *vdev) +{ + dev_dbg(&vdev->dev, "reset !\n"); +} + +/* provide the vdev features as retrieved from the firmware */ +static u32 rproc_virtio_get_features(struct virtio_device *vdev) +{ + struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); + + return rvdev->dfeatures; +} + +static void rproc_virtio_finalize_features(struct virtio_device *vdev) +{ + struct rproc_vdev *rvdev = vdev_to_rvdev(vdev); + + /* Give virtio_ring a chance to accept features */ + vring_transport_features(vdev); + + /* + * Remember the finalized features of our vdev, and provide it + * to the remote processor once it is powered on. + * + * Similarly to the status field, we don't expose yet the negotiated + * features to the remote processors at this point. This will be + * fixed as part of a small resource table overhaul and then an + * extension of the virtio resource entries. + */ + rvdev->gfeatures = vdev->features[0]; +} + +static struct virtio_config_ops rproc_virtio_config_ops = { + .get_features = rproc_virtio_get_features, + .finalize_features = rproc_virtio_finalize_features, + .find_vqs = rproc_virtio_find_vqs, + .del_vqs = rproc_virtio_del_vqs, + .reset = rproc_virtio_reset, + .set_status = rproc_virtio_set_status, + .get_status = rproc_virtio_get_status, +}; + +/* + * This function is called whenever vdev is released, and is responsible + * to decrement the remote processor's refcount taken when vdev was + * added. + * + * Never call this function directly; it will be called by the driver + * core when needed. + */ +static void rproc_vdev_release(struct device *dev) +{ + struct virtio_device *vdev = dev_to_virtio(dev); + struct rproc *rproc = vdev_to_rproc(vdev); + + kref_put(&rproc->refcount, rproc_release); +} + +/** + * rproc_add_virtio_dev() - register an rproc-induced virtio device + * @rvdev: the remote vdev + * + * This function registers a virtio device. This vdev's partent is + * the rproc device. + * + * Returns 0 on success or an appropriate error value otherwise. + */ +int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id) +{ + struct rproc *rproc = rvdev->rproc; + struct device *dev = rproc->dev; + struct virtio_device *vdev = &rvdev->vdev; + int ret; + + vdev->id.device = id, + vdev->config = &rproc_virtio_config_ops, + vdev->dev.parent = dev; + vdev->dev.release = rproc_vdev_release; + + /* + * We're indirectly making a non-temporary copy of the rproc pointer + * here, because drivers probed with this vdev will indirectly + * access the wrapping rproc. + * + * Therefore we must increment the rproc refcount here, and decrement + * it _only_ when the vdev is released. + */ + kref_get(&rproc->refcount); + + ret = register_virtio_device(vdev); + if (ret) { + kref_put(&rproc->refcount, rproc_release); + dev_err(dev, "failed to register vdev: %d\n", ret); + goto out; + } + + dev_info(dev, "registered %s (type %d)\n", dev_name(&vdev->dev), id); + +out: + return ret; +} + +/** + * rproc_remove_virtio_dev() - remove an rproc-induced virtio device + * @rvdev: the remote vdev + * + * This function unregisters an existing virtio device. + */ +void rproc_remove_virtio_dev(struct rproc_vdev *rvdev) +{ + unregister_virtio_device(&rvdev->vdev); +} diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig new file mode 100644 index 000000000000..32aead65735a --- /dev/null +++ b/drivers/rpmsg/Kconfig @@ -0,0 +1,10 @@ +menu "Rpmsg drivers (EXPERIMENTAL)" + +# RPMSG always gets selected by whoever wants it +config RPMSG + tristate + select VIRTIO + select VIRTIO_RING + depends on EXPERIMENTAL + +endmenu diff --git a/drivers/rpmsg/Makefile b/drivers/rpmsg/Makefile new file mode 100644 index 000000000000..7617fcb8259f --- /dev/null +++ b/drivers/rpmsg/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_RPMSG) += virtio_rpmsg_bus.o diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c new file mode 100644 index 000000000000..75506ec2840e --- /dev/null +++ b/drivers/rpmsg/virtio_rpmsg_bus.c @@ -0,0 +1,1054 @@ +/* + * Virtio-based remote processor messaging bus + * + * Copyright (C) 2011 Texas Instruments, Inc. + * Copyright (C) 2011 Google, Inc. + * + * Ohad Ben-Cohen <ohad@wizery.com> + * Brian Swetland <swetland@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/virtio.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_config.h> +#include <linux/scatterlist.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> +#include <linux/idr.h> +#include <linux/jiffies.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/rpmsg.h> +#include <linux/mutex.h> + +/** + * struct virtproc_info - virtual remote processor state + * @vdev: the virtio device + * @rvq: rx virtqueue + * @svq: tx virtqueue + * @rbufs: kernel address of rx buffers + * @sbufs: kernel address of tx buffers + * @last_sbuf: index of last tx buffer used + * @bufs_dma: dma base addr of the buffers + * @tx_lock: protects svq, sbufs and sleepers, to allow concurrent senders. + * sending a message might require waking up a dozing remote + * processor, which involves sleeping, hence the mutex. + * @endpoints: idr of local endpoints, allows fast retrieval + * @endpoints_lock: lock of the endpoints set + * @sendq: wait queue of sending contexts waiting for a tx buffers + * @sleepers: number of senders that are waiting for a tx buffer + * @ns_ept: the bus's name service endpoint + * + * This structure stores the rpmsg state of a given virtio remote processor + * device (there might be several virtio proc devices for each physical + * remote processor). + */ +struct virtproc_info { + struct virtio_device *vdev; + struct virtqueue *rvq, *svq; + void *rbufs, *sbufs; + int last_sbuf; + dma_addr_t bufs_dma; + struct mutex tx_lock; + struct idr endpoints; + struct mutex endpoints_lock; + wait_queue_head_t sendq; + atomic_t sleepers; + struct rpmsg_endpoint *ns_ept; +}; + +/** + * struct rpmsg_channel_info - internal channel info representation + * @name: name of service + * @src: local address + * @dst: destination address + */ +struct rpmsg_channel_info { + char name[RPMSG_NAME_SIZE]; + u32 src; + u32 dst; +}; + +#define to_rpmsg_channel(d) container_of(d, struct rpmsg_channel, dev) +#define to_rpmsg_driver(d) container_of(d, struct rpmsg_driver, drv) + +/* + * We're allocating 512 buffers of 512 bytes for communications, and then + * using the first 256 buffers for RX, and the last 256 buffers for TX. + * + * Each buffer will have 16 bytes for the msg header and 496 bytes for + * the payload. + * + * This will require a total space of 256KB for the buffers. + * + * We might also want to add support for user-provided buffers in time. + * This will allow bigger buffer size flexibility, and can also be used + * to achieve zero-copy messaging. + * + * Note that these numbers are purely a decision of this driver - we + * can change this without changing anything in the firmware of the remote + * processor. + */ +#define RPMSG_NUM_BUFS (512) +#define RPMSG_BUF_SIZE (512) +#define RPMSG_TOTAL_BUF_SPACE (RPMSG_NUM_BUFS * RPMSG_BUF_SIZE) + +/* + * Local addresses are dynamically allocated on-demand. + * We do not dynamically assign addresses from the low 1024 range, + * in order to reserve that address range for predefined services. + */ +#define RPMSG_RESERVED_ADDRESSES (1024) + +/* Address 53 is reserved for advertising remote services */ +#define RPMSG_NS_ADDR (53) + +/* sysfs show configuration fields */ +#define rpmsg_show_attr(field, path, format_string) \ +static ssize_t \ +field##_show(struct device *dev, \ + struct device_attribute *attr, char *buf) \ +{ \ + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); \ + \ + return sprintf(buf, format_string, rpdev->path); \ +} + +/* for more info, see Documentation/ABI/testing/sysfs-bus-rpmsg */ +rpmsg_show_attr(name, id.name, "%s\n"); +rpmsg_show_attr(src, src, "0x%x\n"); +rpmsg_show_attr(dst, dst, "0x%x\n"); +rpmsg_show_attr(announce, announce ? "true" : "false", "%s\n"); + +/* + * Unique (and free running) index for rpmsg devices. + * + * Yeah, we're not recycling those numbers (yet?). will be easy + * to change if/when we want to. + */ +static unsigned int rpmsg_dev_index; + +static ssize_t modalias_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); + + return sprintf(buf, RPMSG_DEVICE_MODALIAS_FMT "\n", rpdev->id.name); +} + +static struct device_attribute rpmsg_dev_attrs[] = { + __ATTR_RO(name), + __ATTR_RO(modalias), + __ATTR_RO(dst), + __ATTR_RO(src), + __ATTR_RO(announce), + __ATTR_NULL +}; + +/* rpmsg devices and drivers are matched using the service name */ +static inline int rpmsg_id_match(const struct rpmsg_channel *rpdev, + const struct rpmsg_device_id *id) +{ + return strncmp(id->name, rpdev->id.name, RPMSG_NAME_SIZE) == 0; +} + +/* match rpmsg channel and rpmsg driver */ +static int rpmsg_dev_match(struct device *dev, struct device_driver *drv) +{ + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); + struct rpmsg_driver *rpdrv = to_rpmsg_driver(drv); + const struct rpmsg_device_id *ids = rpdrv->id_table; + unsigned int i; + + for (i = 0; ids[i].name[0]; i++) + if (rpmsg_id_match(rpdev, &ids[i])) + return 1; + + return 0; +} + +static int rpmsg_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); + + return add_uevent_var(env, "MODALIAS=" RPMSG_DEVICE_MODALIAS_FMT, + rpdev->id.name); +} + +/* for more info, see below documentation of rpmsg_create_ept() */ +static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, + struct rpmsg_channel *rpdev, rpmsg_rx_cb_t cb, + void *priv, u32 addr) +{ + int err, tmpaddr, request; + struct rpmsg_endpoint *ept; + struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev; + + if (!idr_pre_get(&vrp->endpoints, GFP_KERNEL)) + return NULL; + + ept = kzalloc(sizeof(*ept), GFP_KERNEL); + if (!ept) { + dev_err(dev, "failed to kzalloc a new ept\n"); + return NULL; + } + + ept->rpdev = rpdev; + ept->cb = cb; + ept->priv = priv; + + /* do we need to allocate a local address ? */ + request = addr == RPMSG_ADDR_ANY ? RPMSG_RESERVED_ADDRESSES : addr; + + mutex_lock(&vrp->endpoints_lock); + + /* bind the endpoint to an rpmsg address (and allocate one if needed) */ + err = idr_get_new_above(&vrp->endpoints, ept, request, &tmpaddr); + if (err) { + dev_err(dev, "idr_get_new_above failed: %d\n", err); + goto free_ept; + } + + /* make sure the user's address request is fulfilled, if relevant */ + if (addr != RPMSG_ADDR_ANY && tmpaddr != addr) { + dev_err(dev, "address 0x%x already in use\n", addr); + goto rem_idr; + } + + ept->addr = tmpaddr; + + mutex_unlock(&vrp->endpoints_lock); + + return ept; + +rem_idr: + idr_remove(&vrp->endpoints, request); +free_ept: + mutex_unlock(&vrp->endpoints_lock); + kfree(ept); + return NULL; +} + +/** + * rpmsg_create_ept() - create a new rpmsg_endpoint + * @rpdev: rpmsg channel device + * @cb: rx callback handler + * @priv: private data for the driver's use + * @addr: local rpmsg address to bind with @cb + * + * Every rpmsg address in the system is bound to an rx callback (so when + * inbound messages arrive, they are dispatched by the rpmsg bus using the + * appropriate callback handler) by means of an rpmsg_endpoint struct. + * + * This function allows drivers to create such an endpoint, and by that, + * bind a callback, and possibly some private data too, to an rpmsg address + * (either one that is known in advance, or one that will be dynamically + * assigned for them). + * + * Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint + * is already created for them when they are probed by the rpmsg bus + * (using the rx callback provided when they registered to the rpmsg bus). + * + * So things should just work for simple drivers: they already have an + * endpoint, their rx callback is bound to their rpmsg address, and when + * relevant inbound messages arrive (i.e. messages which their dst address + * equals to the src address of their rpmsg channel), the driver's handler + * is invoked to process it. + * + * That said, more complicated drivers might do need to allocate + * additional rpmsg addresses, and bind them to different rx callbacks. + * To accomplish that, those drivers need to call this function. + * + * Drivers should provide their @rpdev channel (so the new endpoint would belong + * to the same remote processor their channel belongs to), an rx callback + * function, an optional private data (which is provided back when the + * rx callback is invoked), and an address they want to bind with the + * callback. If @addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will + * dynamically assign them an available rpmsg address (drivers should have + * a very good reason why not to always use RPMSG_ADDR_ANY here). + * + * Returns a pointer to the endpoint on success, or NULL on error. + */ +struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *rpdev, + rpmsg_rx_cb_t cb, void *priv, u32 addr) +{ + return __rpmsg_create_ept(rpdev->vrp, rpdev, cb, priv, addr); +} +EXPORT_SYMBOL(rpmsg_create_ept); + +/** + * __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint + * @vrp: virtproc which owns this ept + * @ept: endpoing to destroy + * + * An internal function which destroy an ept without assuming it is + * bound to an rpmsg channel. This is needed for handling the internal + * name service endpoint, which isn't bound to an rpmsg channel. + * See also __rpmsg_create_ept(). + */ +static void +__rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept) +{ + mutex_lock(&vrp->endpoints_lock); + idr_remove(&vrp->endpoints, ept->addr); + mutex_unlock(&vrp->endpoints_lock); + + kfree(ept); +} + +/** + * rpmsg_destroy_ept() - destroy an existing rpmsg endpoint + * @ept: endpoing to destroy + * + * Should be used by drivers to destroy an rpmsg endpoint previously + * created with rpmsg_create_ept(). + */ +void rpmsg_destroy_ept(struct rpmsg_endpoint *ept) +{ + __rpmsg_destroy_ept(ept->rpdev->vrp, ept); +} +EXPORT_SYMBOL(rpmsg_destroy_ept); + +/* + * when an rpmsg driver is probed with a channel, we seamlessly create + * it an endpoint, binding its rx callback to a unique local rpmsg + * address. + * + * if we need to, we also announce about this channel to the remote + * processor (needed in case the driver is exposing an rpmsg service). + */ +static int rpmsg_dev_probe(struct device *dev) +{ + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); + struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); + struct virtproc_info *vrp = rpdev->vrp; + struct rpmsg_endpoint *ept; + int err; + + ept = rpmsg_create_ept(rpdev, rpdrv->callback, NULL, rpdev->src); + if (!ept) { + dev_err(dev, "failed to create endpoint\n"); + err = -ENOMEM; + goto out; + } + + rpdev->ept = ept; + rpdev->src = ept->addr; + + err = rpdrv->probe(rpdev); + if (err) { + dev_err(dev, "%s: failed: %d\n", __func__, err); + rpmsg_destroy_ept(ept); + goto out; + } + + /* need to tell remote processor's name service about this channel ? */ + if (rpdev->announce && + virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { + struct rpmsg_ns_msg nsm; + + strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); + nsm.addr = rpdev->src; + nsm.flags = RPMSG_NS_CREATE; + + err = rpmsg_sendto(rpdev, &nsm, sizeof(nsm), RPMSG_NS_ADDR); + if (err) + dev_err(dev, "failed to announce service %d\n", err); + } + +out: + return err; +} + +static int rpmsg_dev_remove(struct device *dev) +{ + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); + struct rpmsg_driver *rpdrv = to_rpmsg_driver(rpdev->dev.driver); + struct virtproc_info *vrp = rpdev->vrp; + int err = 0; + + /* tell remote processor's name service we're removing this channel */ + if (rpdev->announce && + virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { + struct rpmsg_ns_msg nsm; + + strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); + nsm.addr = rpdev->src; + nsm.flags = RPMSG_NS_DESTROY; + + err = rpmsg_sendto(rpdev, &nsm, sizeof(nsm), RPMSG_NS_ADDR); + if (err) + dev_err(dev, "failed to announce service %d\n", err); + } + + rpdrv->remove(rpdev); + + rpmsg_destroy_ept(rpdev->ept); + + return err; +} + +static struct bus_type rpmsg_bus = { + .name = "rpmsg", + .match = rpmsg_dev_match, + .dev_attrs = rpmsg_dev_attrs, + .uevent = rpmsg_uevent, + .probe = rpmsg_dev_probe, + .remove = rpmsg_dev_remove, +}; + +/** + * register_rpmsg_driver() - register an rpmsg driver with the rpmsg bus + * @rpdrv: pointer to a struct rpmsg_driver + * + * Returns 0 on success, and an appropriate error value on failure. + */ +int register_rpmsg_driver(struct rpmsg_driver *rpdrv) +{ + rpdrv->drv.bus = &rpmsg_bus; + return driver_register(&rpdrv->drv); +} +EXPORT_SYMBOL(register_rpmsg_driver); + +/** + * unregister_rpmsg_driver() - unregister an rpmsg driver from the rpmsg bus + * @rpdrv: pointer to a struct rpmsg_driver + * + * Returns 0 on success, and an appropriate error value on failure. + */ +void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv) +{ + driver_unregister(&rpdrv->drv); +} +EXPORT_SYMBOL(unregister_rpmsg_driver); + +static void rpmsg_release_device(struct device *dev) +{ + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); + + kfree(rpdev); +} + +/* + * match an rpmsg channel with a channel info struct. + * this is used to make sure we're not creating rpmsg devices for channels + * that already exist. + */ +static int rpmsg_channel_match(struct device *dev, void *data) +{ + struct rpmsg_channel_info *chinfo = data; + struct rpmsg_channel *rpdev = to_rpmsg_channel(dev); + + if (chinfo->src != RPMSG_ADDR_ANY && chinfo->src != rpdev->src) + return 0; + + if (chinfo->dst != RPMSG_ADDR_ANY && chinfo->dst != rpdev->dst) + return 0; + + if (strncmp(chinfo->name, rpdev->id.name, RPMSG_NAME_SIZE)) + return 0; + + /* found a match ! */ + return 1; +} + +/* + * create an rpmsg channel using its name and address info. + * this function will be used to create both static and dynamic + * channels. + */ +static struct rpmsg_channel *rpmsg_create_channel(struct virtproc_info *vrp, + struct rpmsg_channel_info *chinfo) +{ + struct rpmsg_channel *rpdev; + struct device *tmp, *dev = &vrp->vdev->dev; + int ret; + + /* make sure a similar channel doesn't already exist */ + tmp = device_find_child(dev, chinfo, rpmsg_channel_match); + if (tmp) { + /* decrement the matched device's refcount back */ + put_device(tmp); + dev_err(dev, "channel %s:%x:%x already exist\n", + chinfo->name, chinfo->src, chinfo->dst); + return NULL; + } + + rpdev = kzalloc(sizeof(struct rpmsg_channel), GFP_KERNEL); + if (!rpdev) { + pr_err("kzalloc failed\n"); + return NULL; + } + + rpdev->vrp = vrp; + rpdev->src = chinfo->src; + rpdev->dst = chinfo->dst; + + /* + * rpmsg server channels has predefined local address (for now), + * and their existence needs to be announced remotely + */ + rpdev->announce = rpdev->src != RPMSG_ADDR_ANY ? true : false; + + strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE); + + /* very simple device indexing plumbing which is enough for now */ + dev_set_name(&rpdev->dev, "rpmsg%d", rpmsg_dev_index++); + + rpdev->dev.parent = &vrp->vdev->dev; + rpdev->dev.bus = &rpmsg_bus; + rpdev->dev.release = rpmsg_release_device; + + ret = device_register(&rpdev->dev); + if (ret) { + dev_err(dev, "device_register failed: %d\n", ret); + put_device(&rpdev->dev); + return NULL; + } + + return rpdev; +} + +/* + * find an existing channel using its name + address properties, + * and destroy it + */ +static int rpmsg_destroy_channel(struct virtproc_info *vrp, + struct rpmsg_channel_info *chinfo) +{ + struct virtio_device *vdev = vrp->vdev; + struct device *dev; + + dev = device_find_child(&vdev->dev, chinfo, rpmsg_channel_match); + if (!dev) + return -EINVAL; + + device_unregister(dev); + + put_device(dev); + + return 0; +} + +/* super simple buffer "allocator" that is just enough for now */ +static void *get_a_tx_buf(struct virtproc_info *vrp) +{ + unsigned int len; + void *ret; + + /* support multiple concurrent senders */ + mutex_lock(&vrp->tx_lock); + + /* + * either pick the next unused tx buffer + * (half of our buffers are used for sending messages) + */ + if (vrp->last_sbuf < RPMSG_NUM_BUFS / 2) + ret = vrp->sbufs + RPMSG_BUF_SIZE * vrp->last_sbuf++; + /* or recycle a used one */ + else + ret = virtqueue_get_buf(vrp->svq, &len); + + mutex_unlock(&vrp->tx_lock); + + return ret; +} + +/** + * rpmsg_upref_sleepers() - enable "tx-complete" interrupts, if needed + * @vrp: virtual remote processor state + * + * This function is called before a sender is blocked, waiting for + * a tx buffer to become available. + * + * If we already have blocking senders, this function merely increases + * the "sleepers" reference count, and exits. + * + * Otherwise, if this is the first sender to block, we also enable + * virtio's tx callbacks, so we'd be immediately notified when a tx + * buffer is consumed (we rely on virtio's tx callback in order + * to wake up sleeping senders as soon as a tx buffer is used by the + * remote processor). + */ +static void rpmsg_upref_sleepers(struct virtproc_info *vrp) +{ + /* support multiple concurrent senders */ + mutex_lock(&vrp->tx_lock); + + /* are we the first sleeping context waiting for tx buffers ? */ + if (atomic_inc_return(&vrp->sleepers) == 1) + /* enable "tx-complete" interrupts before dozing off */ + virtqueue_enable_cb(vrp->svq); + + mutex_unlock(&vrp->tx_lock); +} + +/** + * rpmsg_downref_sleepers() - disable "tx-complete" interrupts, if needed + * @vrp: virtual remote processor state + * + * This function is called after a sender, that waited for a tx buffer + * to become available, is unblocked. + * + * If we still have blocking senders, this function merely decreases + * the "sleepers" reference count, and exits. + * + * Otherwise, if there are no more blocking senders, we also disable + * virtio's tx callbacks, to avoid the overhead incurred with handling + * those (now redundant) interrupts. + */ +static void rpmsg_downref_sleepers(struct virtproc_info *vrp) +{ + /* support multiple concurrent senders */ + mutex_lock(&vrp->tx_lock); + + /* are we the last sleeping context waiting for tx buffers ? */ + if (atomic_dec_and_test(&vrp->sleepers)) + /* disable "tx-complete" interrupts */ + virtqueue_disable_cb(vrp->svq); + + mutex_unlock(&vrp->tx_lock); +} + +/** + * rpmsg_send_offchannel_raw() - send a message across to the remote processor + * @rpdev: the rpmsg channel + * @src: source address + * @dst: destination address + * @data: payload of message + * @len: length of payload + * @wait: indicates whether caller should block in case no TX buffers available + * + * This function is the base implementation for all of the rpmsg sending API. + * + * It will send @data of length @len to @dst, and say it's from @src. The + * message will be sent to the remote processor which the @rpdev channel + * belongs to. + * + * The message is sent using one of the TX buffers that are available for + * communication with this remote processor. + * + * If @wait is true, the caller will be blocked until either a TX buffer is + * available, or 15 seconds elapses (we don't want callers to + * sleep indefinitely due to misbehaving remote processors), and in that + * case -ERESTARTSYS is returned. The number '15' itself was picked + * arbitrarily; there's little point in asking drivers to provide a timeout + * value themselves. + * + * Otherwise, if @wait is false, and there are no TX buffers available, + * the function will immediately fail, and -ENOMEM will be returned. + * + * Normally drivers shouldn't use this function directly; instead, drivers + * should use the appropriate rpmsg_{try}send{to, _offchannel} API + * (see include/linux/rpmsg.h). + * + * Returns 0 on success and an appropriate error value on failure. + */ +int rpmsg_send_offchannel_raw(struct rpmsg_channel *rpdev, u32 src, u32 dst, + void *data, int len, bool wait) +{ + struct virtproc_info *vrp = rpdev->vrp; + struct device *dev = &rpdev->dev; + struct scatterlist sg; + struct rpmsg_hdr *msg; + int err; + + /* bcasting isn't allowed */ + if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) { + dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst); + return -EINVAL; + } + + /* + * We currently use fixed-sized buffers, and therefore the payload + * length is limited. + * + * One of the possible improvements here is either to support + * user-provided buffers (and then we can also support zero-copy + * messaging), or to improve the buffer allocator, to support + * variable-length buffer sizes. + */ + if (len > RPMSG_BUF_SIZE - sizeof(struct rpmsg_hdr)) { + dev_err(dev, "message is too big (%d)\n", len); + return -EMSGSIZE; + } + + /* grab a buffer */ + msg = get_a_tx_buf(vrp); + if (!msg && !wait) + return -ENOMEM; + + /* no free buffer ? wait for one (but bail after 15 seconds) */ + while (!msg) { + /* enable "tx-complete" interrupts, if not already enabled */ + rpmsg_upref_sleepers(vrp); + + /* + * sleep until a free buffer is available or 15 secs elapse. + * the timeout period is not configurable because there's + * little point in asking drivers to specify that. + * if later this happens to be required, it'd be easy to add. + */ + err = wait_event_interruptible_timeout(vrp->sendq, + (msg = get_a_tx_buf(vrp)), + msecs_to_jiffies(15000)); + + /* disable "tx-complete" interrupts if we're the last sleeper */ + rpmsg_downref_sleepers(vrp); + + /* timeout ? */ + if (!err) { + dev_err(dev, "timeout waiting for a tx buffer\n"); + return -ERESTARTSYS; + } + } + + msg->len = len; + msg->flags = 0; + msg->src = src; + msg->dst = dst; + msg->reserved = 0; + memcpy(msg->data, data, len); + + dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n", + msg->src, msg->dst, msg->len, + msg->flags, msg->reserved); + print_hex_dump(KERN_DEBUG, "rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1, + msg, sizeof(*msg) + msg->len, true); + + sg_init_one(&sg, msg, sizeof(*msg) + len); + + mutex_lock(&vrp->tx_lock); + + /* add message to the remote processor's virtqueue */ + err = virtqueue_add_buf(vrp->svq, &sg, 1, 0, msg, GFP_KERNEL); + if (err < 0) { + /* + * need to reclaim the buffer here, otherwise it's lost + * (memory won't leak, but rpmsg won't use it again for TX). + * this will wait for a buffer management overhaul. + */ + dev_err(dev, "virtqueue_add_buf failed: %d\n", err); + goto out; + } + + /* tell the remote processor it has a pending message to read */ + virtqueue_kick(vrp->svq); + + err = 0; +out: + mutex_unlock(&vrp->tx_lock); + return err; +} +EXPORT_SYMBOL(rpmsg_send_offchannel_raw); + +/* called when an rx buffer is used, and it's time to digest a message */ +static void rpmsg_recv_done(struct virtqueue *rvq) +{ + struct rpmsg_hdr *msg; + unsigned int len; + struct rpmsg_endpoint *ept; + struct scatterlist sg; + struct virtproc_info *vrp = rvq->vdev->priv; + struct device *dev = &rvq->vdev->dev; + int err; + + msg = virtqueue_get_buf(rvq, &len); + if (!msg) { + dev_err(dev, "uhm, incoming signal, but no used buffer ?\n"); + return; + } + + dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n", + msg->src, msg->dst, msg->len, + msg->flags, msg->reserved); + print_hex_dump(KERN_DEBUG, "rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1, + msg, sizeof(*msg) + msg->len, true); + + /* + * We currently use fixed-sized buffers, so trivially sanitize + * the reported payload length. + */ + if (len > RPMSG_BUF_SIZE || + msg->len > (len - sizeof(struct rpmsg_hdr))) { + dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg->len); + return; + } + + /* use the dst addr to fetch the callback of the appropriate user */ + mutex_lock(&vrp->endpoints_lock); + ept = idr_find(&vrp->endpoints, msg->dst); + mutex_unlock(&vrp->endpoints_lock); + + if (ept && ept->cb) + ept->cb(ept->rpdev, msg->data, msg->len, ept->priv, msg->src); + else + dev_warn(dev, "msg received with no recepient\n"); + + /* publish the real size of the buffer */ + sg_init_one(&sg, msg, RPMSG_BUF_SIZE); + + /* add the buffer back to the remote processor's virtqueue */ + err = virtqueue_add_buf(vrp->rvq, &sg, 0, 1, msg, GFP_KERNEL); + if (err < 0) { + dev_err(dev, "failed to add a virtqueue buffer: %d\n", err); + return; + } + + /* tell the remote processor we added another available rx buffer */ + virtqueue_kick(vrp->rvq); +} + +/* + * This is invoked whenever the remote processor completed processing + * a TX msg we just sent it, and the buffer is put back to the used ring. + * + * Normally, though, we suppress this "tx complete" interrupt in order to + * avoid the incurred overhead. + */ +static void rpmsg_xmit_done(struct virtqueue *svq) +{ + struct virtproc_info *vrp = svq->vdev->priv; + + dev_dbg(&svq->vdev->dev, "%s\n", __func__); + + /* wake up potential senders that are waiting for a tx buffer */ + wake_up_interruptible(&vrp->sendq); +} + +/* invoked when a name service announcement arrives */ +static void rpmsg_ns_cb(struct rpmsg_channel *rpdev, void *data, int len, + void *priv, u32 src) +{ + struct rpmsg_ns_msg *msg = data; + struct rpmsg_channel *newch; + struct rpmsg_channel_info chinfo; + struct virtproc_info *vrp = priv; + struct device *dev = &vrp->vdev->dev; + int ret; + + print_hex_dump(KERN_DEBUG, "NS announcement: ", + DUMP_PREFIX_NONE, 16, 1, + data, len, true); + + if (len != sizeof(*msg)) { + dev_err(dev, "malformed ns msg (%d)\n", len); + return; + } + + /* + * the name service ept does _not_ belong to a real rpmsg channel, + * and is handled by the rpmsg bus itself. + * for sanity reasons, make sure a valid rpdev has _not_ sneaked + * in somehow. + */ + if (rpdev) { + dev_err(dev, "anomaly: ns ept has an rpdev handle\n"); + return; + } + + /* don't trust the remote processor for null terminating the name */ + msg->name[RPMSG_NAME_SIZE - 1] = '\0'; + + dev_info(dev, "%sing channel %s addr 0x%x\n", + msg->flags & RPMSG_NS_DESTROY ? "destroy" : "creat", + msg->name, msg->addr); + + strncpy(chinfo.name, msg->name, sizeof(chinfo.name)); + chinfo.src = RPMSG_ADDR_ANY; + chinfo.dst = msg->addr; + + if (msg->flags & RPMSG_NS_DESTROY) { + ret = rpmsg_destroy_channel(vrp, &chinfo); + if (ret) + dev_err(dev, "rpmsg_destroy_channel failed: %d\n", ret); + } else { + newch = rpmsg_create_channel(vrp, &chinfo); + if (!newch) + dev_err(dev, "rpmsg_create_channel failed\n"); + } +} + +static int rpmsg_probe(struct virtio_device *vdev) +{ + vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done }; + const char *names[] = { "input", "output" }; + struct virtqueue *vqs[2]; + struct virtproc_info *vrp; + void *bufs_va; + int err = 0, i; + + vrp = kzalloc(sizeof(*vrp), GFP_KERNEL); + if (!vrp) + return -ENOMEM; + + vrp->vdev = vdev; + + idr_init(&vrp->endpoints); + mutex_init(&vrp->endpoints_lock); + mutex_init(&vrp->tx_lock); + init_waitqueue_head(&vrp->sendq); + + /* We expect two virtqueues, rx and tx (and in this order) */ + err = vdev->config->find_vqs(vdev, 2, vqs, vq_cbs, names); + if (err) + goto free_vrp; + + vrp->rvq = vqs[0]; + vrp->svq = vqs[1]; + + /* allocate coherent memory for the buffers */ + bufs_va = dma_alloc_coherent(vdev->dev.parent, RPMSG_TOTAL_BUF_SPACE, + &vrp->bufs_dma, GFP_KERNEL); + if (!bufs_va) + goto vqs_del; + + dev_dbg(&vdev->dev, "buffers: va %p, dma 0x%llx\n", bufs_va, + (unsigned long long)vrp->bufs_dma); + + /* half of the buffers is dedicated for RX */ + vrp->rbufs = bufs_va; + + /* and half is dedicated for TX */ + vrp->sbufs = bufs_va + RPMSG_TOTAL_BUF_SPACE / 2; + + /* set up the receive buffers */ + for (i = 0; i < RPMSG_NUM_BUFS / 2; i++) { + struct scatterlist sg; + void *cpu_addr = vrp->rbufs + i * RPMSG_BUF_SIZE; + + sg_init_one(&sg, cpu_addr, RPMSG_BUF_SIZE); + + err = virtqueue_add_buf(vrp->rvq, &sg, 0, 1, cpu_addr, + GFP_KERNEL); + WARN_ON(err < 0); /* sanity check; this can't really happen */ + } + + /* suppress "tx-complete" interrupts */ + virtqueue_disable_cb(vrp->svq); + + vdev->priv = vrp; + + /* if supported by the remote processor, enable the name service */ + if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) { + /* a dedicated endpoint handles the name service msgs */ + vrp->ns_ept = __rpmsg_create_ept(vrp, NULL, rpmsg_ns_cb, + vrp, RPMSG_NS_ADDR); + if (!vrp->ns_ept) { + dev_err(&vdev->dev, "failed to create the ns ept\n"); + err = -ENOMEM; + goto free_coherent; + } + } + + /* tell the remote processor it can start sending messages */ + virtqueue_kick(vrp->rvq); + + dev_info(&vdev->dev, "rpmsg host is online\n"); + + return 0; + +free_coherent: + dma_free_coherent(vdev->dev.parent, RPMSG_TOTAL_BUF_SPACE, bufs_va, + vrp->bufs_dma); +vqs_del: + vdev->config->del_vqs(vrp->vdev); +free_vrp: + kfree(vrp); + return err; +} + +static int rpmsg_remove_device(struct device *dev, void *data) +{ + device_unregister(dev); + + return 0; +} + +static void __devexit rpmsg_remove(struct virtio_device *vdev) +{ + struct virtproc_info *vrp = vdev->priv; + int ret; + + vdev->config->reset(vdev); + + ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device); + if (ret) + dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret); + + if (vrp->ns_ept) + __rpmsg_destroy_ept(vrp, vrp->ns_ept); + + idr_remove_all(&vrp->endpoints); + idr_destroy(&vrp->endpoints); + + vdev->config->del_vqs(vrp->vdev); + + dma_free_coherent(vdev->dev.parent, RPMSG_TOTAL_BUF_SPACE, + vrp->rbufs, vrp->bufs_dma); + + kfree(vrp); +} + +static struct virtio_device_id id_table[] = { + { VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static unsigned int features[] = { + VIRTIO_RPMSG_F_NS, +}; + +static struct virtio_driver virtio_ipc_driver = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .id_table = id_table, + .probe = rpmsg_probe, + .remove = __devexit_p(rpmsg_remove), +}; + +static int __init rpmsg_init(void) +{ + int ret; + + ret = bus_register(&rpmsg_bus); + if (ret) { + pr_err("failed to register rpmsg bus: %d\n", ret); + return ret; + } + + ret = register_virtio_driver(&virtio_ipc_driver); + if (ret) { + pr_err("failed to register virtio driver: %d\n", ret); + bus_unregister(&rpmsg_bus); + } + + return ret; +} +module_init(rpmsg_init); + +static void __exit rpmsg_fini(void) +{ + unregister_virtio_driver(&virtio_ipc_driver); + bus_unregister(&rpmsg_bus); +} +module_exit(rpmsg_fini); + +MODULE_DEVICE_TABLE(virtio, id_table); +MODULE_DESCRIPTION("Virtio-based remote processor messaging bus"); +MODULE_LICENSE("GPL v2"); |