diff options
Diffstat (limited to 'drivers/thunderbolt/ctl.c')
| -rw-r--r-- | drivers/thunderbolt/ctl.c | 731 |
1 files changed, 731 insertions, 0 deletions
diff --git a/drivers/thunderbolt/ctl.c b/drivers/thunderbolt/ctl.c new file mode 100644 index 000000000000..9b0120bede51 --- /dev/null +++ b/drivers/thunderbolt/ctl.c @@ -0,0 +1,731 @@ +/* + * Thunderbolt Cactus Ridge driver - control channel and configuration commands + * + * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> + */ + +#include <linux/crc32.h> +#include <linux/slab.h> +#include <linux/pci.h> +#include <linux/dmapool.h> +#include <linux/workqueue.h> +#include <linux/kfifo.h> + +#include "ctl.h" + + +struct ctl_pkg { + struct tb_ctl *ctl; + void *buffer; + struct ring_frame frame; +}; + +#define TB_CTL_RX_PKG_COUNT 10 + +/** + * struct tb_cfg - thunderbolt control channel + */ +struct tb_ctl { + struct tb_nhi *nhi; + struct tb_ring *tx; + struct tb_ring *rx; + + struct dma_pool *frame_pool; + struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT]; + DECLARE_KFIFO(response_fifo, struct ctl_pkg*, 16); + struct completion response_ready; + + hotplug_cb callback; + void *callback_data; +}; + + +#define tb_ctl_WARN(ctl, format, arg...) \ + dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg) + +#define tb_ctl_err(ctl, format, arg...) \ + dev_err(&(ctl)->nhi->pdev->dev, format, ## arg) + +#define tb_ctl_warn(ctl, format, arg...) \ + dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg) + +#define tb_ctl_info(ctl, format, arg...) \ + dev_info(&(ctl)->nhi->pdev->dev, format, ## arg) + + +/* configuration packets definitions */ + +enum tb_cfg_pkg_type { + TB_CFG_PKG_READ = 1, + TB_CFG_PKG_WRITE = 2, + TB_CFG_PKG_ERROR = 3, + TB_CFG_PKG_NOTIFY_ACK = 4, + TB_CFG_PKG_EVENT = 5, + TB_CFG_PKG_XDOMAIN_REQ = 6, + TB_CFG_PKG_XDOMAIN_RESP = 7, + TB_CFG_PKG_OVERRIDE = 8, + TB_CFG_PKG_RESET = 9, + TB_CFG_PKG_PREPARE_TO_SLEEP = 0xd, +}; + +/* common header */ +struct tb_cfg_header { + u32 route_hi:22; + u32 unknown:10; /* highest order bit is set on replies */ + u32 route_lo; +} __packed; + +/* additional header for read/write packets */ +struct tb_cfg_address { + u32 offset:13; /* in dwords */ + u32 length:6; /* in dwords */ + u32 port:6; + enum tb_cfg_space space:2; + u32 seq:2; /* sequence number */ + u32 zero:3; +} __packed; + +/* TB_CFG_PKG_READ, response for TB_CFG_PKG_WRITE */ +struct cfg_read_pkg { + struct tb_cfg_header header; + struct tb_cfg_address addr; +} __packed; + +/* TB_CFG_PKG_WRITE, response for TB_CFG_PKG_READ */ +struct cfg_write_pkg { + struct tb_cfg_header header; + struct tb_cfg_address addr; + u32 data[64]; /* maximum size, tb_cfg_address.length has 6 bits */ +} __packed; + +/* TB_CFG_PKG_ERROR */ +struct cfg_error_pkg { + struct tb_cfg_header header; + enum tb_cfg_error error:4; + u32 zero1:4; + u32 port:6; + u32 zero2:2; /* Both should be zero, still they are different fields. */ + u32 zero3:16; +} __packed; + +/* TB_CFG_PKG_EVENT */ +struct cfg_event_pkg { + struct tb_cfg_header header; + u32 port:6; + u32 zero:25; + bool unplug:1; +} __packed; + +/* TB_CFG_PKG_RESET */ +struct cfg_reset_pkg { + struct tb_cfg_header header; +} __packed; + +/* TB_CFG_PKG_PREPARE_TO_SLEEP */ +struct cfg_pts_pkg { + struct tb_cfg_header header; + u32 data; +} __packed; + + +/* utility functions */ + +static u64 get_route(struct tb_cfg_header header) +{ + return (u64) header.route_hi << 32 | header.route_lo; +} + +static struct tb_cfg_header make_header(u64 route) +{ + struct tb_cfg_header header = { + .route_hi = route >> 32, + .route_lo = route, + }; + /* check for overflow, route_hi is not 32 bits! */ + WARN_ON(get_route(header) != route); + return header; +} + +static int check_header(struct ctl_pkg *pkg, u32 len, enum tb_cfg_pkg_type type, + u64 route) +{ + struct tb_cfg_header *header = pkg->buffer; + + /* check frame, TODO: frame flags */ + if (WARN(len != pkg->frame.size, + "wrong framesize (expected %#x, got %#x)\n", + len, pkg->frame.size)) + return -EIO; + if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n", + type, pkg->frame.eof)) + return -EIO; + if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n", + pkg->frame.sof)) + return -EIO; + + /* check header */ + if (WARN(header->unknown != 1 << 9, + "header->unknown is %#x\n", header->unknown)) + return -EIO; + if (WARN(route != get_route(*header), + "wrong route (expected %llx, got %llx)", + route, get_route(*header))) + return -EIO; + return 0; +} + +static int check_config_address(struct tb_cfg_address addr, + enum tb_cfg_space space, u32 offset, + u32 length) +{ + if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero)) + return -EIO; + if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)", + space, addr.space)) + return -EIO; + if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)", + offset, addr.offset)) + return -EIO; + if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)", + length, addr.length)) + return -EIO; + if (WARN(addr.seq, "addr.seq is %#x\n", addr.seq)) + return -EIO; + /* + * We cannot check addr->port as it is set to the upstream port of the + * sender. + */ + return 0; +} + +static struct tb_cfg_result decode_error(struct ctl_pkg *response) +{ + struct cfg_error_pkg *pkg = response->buffer; + struct tb_cfg_result res = { 0 }; + res.response_route = get_route(pkg->header); + res.response_port = 0; + res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR, + get_route(pkg->header)); + if (res.err) + return res; + + WARN(pkg->zero1, "pkg->zero1 is %#x\n", pkg->zero1); + WARN(pkg->zero2, "pkg->zero1 is %#x\n", pkg->zero1); + WARN(pkg->zero3, "pkg->zero1 is %#x\n", pkg->zero1); + res.err = 1; + res.tb_error = pkg->error; + res.response_port = pkg->port; + return res; + +} + +static struct tb_cfg_result parse_header(struct ctl_pkg *pkg, u32 len, + enum tb_cfg_pkg_type type, u64 route) +{ + struct tb_cfg_header *header = pkg->buffer; + struct tb_cfg_result res = { 0 }; + + if (pkg->frame.eof == TB_CFG_PKG_ERROR) + return decode_error(pkg); + + res.response_port = 0; /* will be updated later for cfg_read/write */ + res.response_route = get_route(*header); + res.err = check_header(pkg, len, type, route); + return res; +} + +static void tb_cfg_print_error(struct tb_ctl *ctl, + const struct tb_cfg_result *res) +{ + WARN_ON(res->err != 1); + switch (res->tb_error) { + case TB_CFG_ERROR_PORT_NOT_CONNECTED: + /* Port is not connected. This can happen during surprise + * removal. Do not warn. */ + return; + case TB_CFG_ERROR_INVALID_CONFIG_SPACE: + /* + * Invalid cfg_space/offset/length combination in + * cfg_read/cfg_write. + */ + tb_ctl_WARN(ctl, + "CFG_ERROR(%llx:%x): Invalid config space of offset\n", + res->response_route, res->response_port); + return; + case TB_CFG_ERROR_NO_SUCH_PORT: + /* + * - The route contains a non-existent port. + * - The route contains a non-PHY port (e.g. PCIe). + * - The port in cfg_read/cfg_write does not exist. + */ + tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n", + res->response_route, res->response_port); + return; + case TB_CFG_ERROR_LOOP: + tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n", + res->response_route, res->response_port); + return; + default: + /* 5,6,7,9 and 11 are also valid error codes */ + tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n", + res->response_route, res->response_port); + return; + } +} + +static void cpu_to_be32_array(__be32 *dst, u32 *src, size_t len) +{ + int i; + for (i = 0; i < len; i++) + dst[i] = cpu_to_be32(src[i]); +} + +static void be32_to_cpu_array(u32 *dst, __be32 *src, size_t len) +{ + int i; + for (i = 0; i < len; i++) + dst[i] = be32_to_cpu(src[i]); +} + +static __be32 tb_crc(void *data, size_t len) +{ + return cpu_to_be32(~__crc32c_le(~0, data, len)); +} + +static void tb_ctl_pkg_free(struct ctl_pkg *pkg) +{ + if (pkg) { + dma_pool_free(pkg->ctl->frame_pool, + pkg->buffer, pkg->frame.buffer_phy); + kfree(pkg); + } +} + +static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl) +{ + struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL); + if (!pkg) + return 0; + pkg->ctl = ctl; + pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL, + &pkg->frame.buffer_phy); + if (!pkg->buffer) { + kfree(pkg); + return 0; + } + return pkg; +} + + +/* RX/TX handling */ + +static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame, + bool canceled) +{ + struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); + tb_ctl_pkg_free(pkg); +} + +/** + * tb_cfg_tx() - transmit a packet on the control channel + * + * len must be a multiple of four. + * + * Return: Returns 0 on success or an error code on failure. + */ +static int tb_ctl_tx(struct tb_ctl *ctl, void *data, size_t len, + enum tb_cfg_pkg_type type) +{ + int res; + struct ctl_pkg *pkg; + if (len % 4 != 0) { /* required for le->be conversion */ + tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len); + return -EINVAL; + } + if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */ + tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n", + len, TB_FRAME_SIZE - 4); + return -EINVAL; + } + pkg = tb_ctl_pkg_alloc(ctl); + if (!pkg) + return -ENOMEM; + pkg->frame.callback = tb_ctl_tx_callback; + pkg->frame.size = len + 4; + pkg->frame.sof = type; + pkg->frame.eof = type; + cpu_to_be32_array(pkg->buffer, data, len / 4); + *(u32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len); + + res = ring_tx(ctl->tx, &pkg->frame); + if (res) /* ring is stopped */ + tb_ctl_pkg_free(pkg); + return res; +} + +/** + * tb_ctl_handle_plug_event() - acknowledge a plug event, invoke ctl->callback + */ +static void tb_ctl_handle_plug_event(struct tb_ctl *ctl, + struct ctl_pkg *response) +{ + struct cfg_event_pkg *pkg = response->buffer; + u64 route = get_route(pkg->header); + + if (check_header(response, sizeof(*pkg), TB_CFG_PKG_EVENT, route)) { + tb_ctl_warn(ctl, "malformed TB_CFG_PKG_EVENT\n"); + return; + } + + if (tb_cfg_error(ctl, route, pkg->port, TB_CFG_ERROR_ACK_PLUG_EVENT)) + tb_ctl_warn(ctl, "could not ack plug event on %llx:%x\n", + route, pkg->port); + WARN(pkg->zero, "pkg->zero is %#x\n", pkg->zero); + ctl->callback(ctl->callback_data, route, pkg->port, pkg->unplug); +} + +static void tb_ctl_rx_submit(struct ctl_pkg *pkg) +{ + ring_rx(pkg->ctl->rx, &pkg->frame); /* + * We ignore failures during stop. + * All rx packets are referenced + * from ctl->rx_packets, so we do + * not loose them. + */ +} + +static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame, + bool canceled) +{ + struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); + + if (canceled) + return; /* + * ring is stopped, packet is referenced from + * ctl->rx_packets. + */ + + if (frame->size < 4 || frame->size % 4 != 0) { + tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n", + frame->size); + goto rx; + } + + frame->size -= 4; /* remove checksum */ + if (*(u32 *) (pkg->buffer + frame->size) + != tb_crc(pkg->buffer, frame->size)) { + tb_ctl_err(pkg->ctl, + "RX: checksum mismatch, dropping packet\n"); + goto rx; + } + be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4); + + if (frame->eof == TB_CFG_PKG_EVENT) { + tb_ctl_handle_plug_event(pkg->ctl, pkg); + goto rx; + } + if (!kfifo_put(&pkg->ctl->response_fifo, pkg)) { + tb_ctl_err(pkg->ctl, "RX: fifo is full\n"); + goto rx; + } + complete(&pkg->ctl->response_ready); + return; +rx: + tb_ctl_rx_submit(pkg); +} + +/** + * tb_ctl_rx() - receive a packet from the control channel + */ +static struct tb_cfg_result tb_ctl_rx(struct tb_ctl *ctl, void *buffer, + size_t length, int timeout_msec, + u8 route, enum tb_cfg_pkg_type type) +{ + struct tb_cfg_result res; + struct ctl_pkg *pkg; + + if (!wait_for_completion_timeout(&ctl->response_ready, + msecs_to_jiffies(timeout_msec))) { + tb_ctl_WARN(ctl, "RX: timeout\n"); + return (struct tb_cfg_result) { .err = -ETIMEDOUT }; + } + if (!kfifo_get(&ctl->response_fifo, &pkg)) { + tb_ctl_WARN(ctl, "empty kfifo\n"); + return (struct tb_cfg_result) { .err = -EIO }; + } + + res = parse_header(pkg, length, type, route); + if (!res.err) + memcpy(buffer, pkg->buffer, length); + tb_ctl_rx_submit(pkg); + return res; +} + + +/* public interface, alloc/start/stop/free */ + +/** + * tb_ctl_alloc() - allocate a control channel + * + * cb will be invoked once for every hot plug event. + * + * Return: Returns a pointer on success or NULL on failure. + */ +struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, hotplug_cb cb, void *cb_data) +{ + int i; + struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL); + if (!ctl) + return NULL; + ctl->nhi = nhi; + ctl->callback = cb; + ctl->callback_data = cb_data; + + init_completion(&ctl->response_ready); + INIT_KFIFO(ctl->response_fifo); + ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev, + TB_FRAME_SIZE, 4, 0); + if (!ctl->frame_pool) + goto err; + + ctl->tx = ring_alloc_tx(nhi, 0, 10); + if (!ctl->tx) + goto err; + + ctl->rx = ring_alloc_rx(nhi, 0, 10); + if (!ctl->rx) + goto err; + + for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) { + ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl); + if (!ctl->rx_packets[i]) + goto err; + ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback; + } + + tb_ctl_info(ctl, "control channel created\n"); + return ctl; +err: + tb_ctl_free(ctl); + return NULL; +} + +/** + * tb_ctl_free() - free a control channel + * + * Must be called after tb_ctl_stop. + * + * Must NOT be called from ctl->callback. + */ +void tb_ctl_free(struct tb_ctl *ctl) +{ + int i; + if (ctl->rx) + ring_free(ctl->rx); + if (ctl->tx) + ring_free(ctl->tx); + + /* free RX packets */ + for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) + tb_ctl_pkg_free(ctl->rx_packets[i]); + + + if (ctl->frame_pool) + dma_pool_destroy(ctl->frame_pool); + kfree(ctl); +} + +/** + * tb_cfg_start() - start/resume the control channel + */ +void tb_ctl_start(struct tb_ctl *ctl) +{ + int i; + tb_ctl_info(ctl, "control channel starting...\n"); + ring_start(ctl->tx); /* is used to ack hotplug packets, start first */ + ring_start(ctl->rx); + for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) + tb_ctl_rx_submit(ctl->rx_packets[i]); +} + +/** + * control() - pause the control channel + * + * All invocations of ctl->callback will have finished after this method + * returns. + * + * Must NOT be called from ctl->callback. + */ +void tb_ctl_stop(struct tb_ctl *ctl) +{ + ring_stop(ctl->rx); + ring_stop(ctl->tx); + + if (!kfifo_is_empty(&ctl->response_fifo)) + tb_ctl_WARN(ctl, "dangling response in response_fifo\n"); + kfifo_reset(&ctl->response_fifo); + tb_ctl_info(ctl, "control channel stopped\n"); +} + +/* public interface, commands */ + +/** + * tb_cfg_error() - send error packet + * + * Return: Returns 0 on success or an error code on failure. + */ +int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port, + enum tb_cfg_error error) +{ + struct cfg_error_pkg pkg = { + .header = make_header(route), + .port = port, + .error = error, + }; + tb_ctl_info(ctl, "resetting error on %llx:%x.\n", route, port); + return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR); +} + +/** + * tb_cfg_reset() - send a reset packet and wait for a response + * + * If the switch at route is incorrectly configured then we will not receive a + * reply (even though the switch will reset). The caller should check for + * -ETIMEDOUT and attempt to reconfigure the switch. + */ +struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route, + int timeout_msec) +{ + int err; + struct cfg_reset_pkg request = { .header = make_header(route) }; + struct tb_cfg_header reply; + + err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_RESET); + if (err) + return (struct tb_cfg_result) { .err = err }; + + return tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route, + TB_CFG_PKG_RESET); +} + +/** + * tb_cfg_read() - read from config space into buffer + * + * Offset and length are in dwords. + */ +struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer, + u64 route, u32 port, enum tb_cfg_space space, + u32 offset, u32 length, int timeout_msec) +{ + struct tb_cfg_result res = { 0 }; + struct cfg_read_pkg request = { + .header = make_header(route), + .addr = { + .port = port, + .space = space, + .offset = offset, + .length = length, + }, + }; + struct cfg_write_pkg reply; + + res.err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_READ); + if (res.err) + return res; + + res = tb_ctl_rx(ctl, &reply, 12 + 4 * length, timeout_msec, route, + TB_CFG_PKG_READ); + if (res.err) + return res; + + res.response_port = reply.addr.port; + res.err = check_config_address(reply.addr, space, offset, length); + if (!res.err) + memcpy(buffer, &reply.data, 4 * length); + return res; +} + +/** + * tb_cfg_write() - write from buffer into config space + * + * Offset and length are in dwords. + */ +struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, void *buffer, + u64 route, u32 port, enum tb_cfg_space space, + u32 offset, u32 length, int timeout_msec) +{ + struct tb_cfg_result res = { 0 }; + struct cfg_write_pkg request = { + .header = make_header(route), + .addr = { + .port = port, + .space = space, + .offset = offset, + .length = length, + }, + }; + struct cfg_read_pkg reply; + + memcpy(&request.data, buffer, length * 4); + + res.err = tb_ctl_tx(ctl, &request, 12 + 4 * length, TB_CFG_PKG_WRITE); + if (res.err) + return res; + + res = tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route, + TB_CFG_PKG_WRITE); + if (res.err) + return res; + + res.response_port = reply.addr.port; + res.err = check_config_address(reply.addr, space, offset, length); + return res; +} + +int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, + enum tb_cfg_space space, u32 offset, u32 length) +{ + struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port, + space, offset, length, TB_CFG_DEFAULT_TIMEOUT); + if (res.err == 1) { + tb_cfg_print_error(ctl, &res); + return -EIO; + } + WARN(res.err, "tb_cfg_read: %d\n", res.err); + return res.err; +} + +int tb_cfg_write(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, + enum tb_cfg_space space, u32 offset, u32 length) +{ + struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port, + space, offset, length, TB_CFG_DEFAULT_TIMEOUT); + if (res.err == 1) { + tb_cfg_print_error(ctl, &res); + return -EIO; + } + WARN(res.err, "tb_cfg_write: %d\n", res.err); + return res.err; +} + +/** + * tb_cfg_get_upstream_port() - get upstream port number of switch at route + * + * Reads the first dword from the switches TB_CFG_SWITCH config area and + * returns the port number from which the reply originated. + * + * Return: Returns the upstream port number on success or an error code on + * failure. + */ +int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route) +{ + u32 dummy; + struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0, + TB_CFG_SWITCH, 0, 1, + TB_CFG_DEFAULT_TIMEOUT); + if (res.err == 1) + return -EIO; + if (res.err) + return res.err; + return res.response_port; +} |