diff options
author | Liao Chang | 2022-04-08 18:09:11 +0800 |
---|---|---|
committer | Palmer Dabbelt | 2022-05-19 12:14:18 -0700 |
commit | 6261586e0c91db14c34f894f4bc48f2300cff1d4 (patch) | |
tree | 0bac89b95a140653c0051982eaf0a9cc4743645c | |
parent | b7fb4d78a6ade6026d9e5cf438c2a46ab962e032 (diff) |
RISC-V: Add kexec_file support
This patch adds support for kexec_file on RISC-V. I tested it on riscv64
QEMU with busybear-linux and single core along with the OpenSBI firmware
fw_jump.bin for generic platform.
On SMP system, it depends on CONFIG_{HOTPLUG_CPU, RISCV_SBI} to
resume/stop hart through OpenSBI firmware, it also needs a OpenSBI that
support the HSM extension.
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Li Zhengyu <lizhengyu3@huawei.com>
Link: https://lore.kernel.org/r/20220408100914.150110-4-lizhengyu3@huawei.com
[Palmer: Make 64-bit only]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
-rw-r--r-- | arch/riscv/Kconfig | 14 | ||||
-rw-r--r-- | arch/riscv/include/asm/kexec.h | 4 | ||||
-rw-r--r-- | arch/riscv/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/riscv/kernel/elf_kexec.c | 180 | ||||
-rw-r--r-- | arch/riscv/kernel/machine_kexec_file.c | 14 |
5 files changed, 213 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 00fd9c548f26..860817a56af6 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -383,6 +383,20 @@ config KEXEC The name comes from the similarity to the exec system call. +config KEXEC_FILE + bool "kexec file based systmem call" + select KEXEC_CORE + select KEXEC_ELF + select HAVE_IMA_KEXEC if IMA + depends on 64BIT + help + This is new version of kexec system call. This system call is + file based and takes file descriptors as system call argument + for kernel and initramfs as opposed to list of segments as + accepted by previous system call. + + If you don't know what to do here, say Y. + config CRASH_DUMP bool "Build kdump crash kernel" help diff --git a/arch/riscv/include/asm/kexec.h b/arch/riscv/include/asm/kexec.h index e4e291d40759..206217b23301 100644 --- a/arch/riscv/include/asm/kexec.h +++ b/arch/riscv/include/asm/kexec.h @@ -53,4 +53,8 @@ typedef void (*riscv_kexec_method)(unsigned long first_ind_entry, extern riscv_kexec_method riscv_kexec_norelocate; +#ifdef CONFIG_KEXEC_FILE +extern const struct kexec_file_ops elf_kexec_ops; +#endif + #endif diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 87adbe47bc15..6673c50c58e2 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -64,6 +64,7 @@ endif obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_KEXEC) += kexec_relocate.o crash_save_regs.o machine_kexec.o +obj-$(CONFIG_KEXEC_FILE) += elf_kexec.o machine_kexec_file.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o diff --git a/arch/riscv/kernel/elf_kexec.c b/arch/riscv/kernel/elf_kexec.c new file mode 100644 index 000000000000..2d442a849871 --- /dev/null +++ b/arch/riscv/kernel/elf_kexec.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Load ELF vmlinux file for the kexec_file_load syscall. + * + * Copyright (C) 2021 Huawei Technologies Co, Ltd. + * + * Author: Liao Chang (liaochang1@huawei.com) + * + * Based on kexec-tools' kexec-elf-riscv.c, heavily modified + * for kernel. + */ + +#define pr_fmt(fmt) "kexec_image: " fmt + +#include <linux/elf.h> +#include <linux/kexec.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/libfdt.h> +#include <linux/types.h> + +static int riscv_kexec_elf_load(struct kimage *image, struct elfhdr *ehdr, + struct kexec_elf_info *elf_info, unsigned long old_pbase, + unsigned long new_pbase) +{ + int i; + int ret = 0; + size_t size; + struct kexec_buf kbuf; + const struct elf_phdr *phdr; + + kbuf.image = image; + + for (i = 0; i < ehdr->e_phnum; i++) { + phdr = &elf_info->proghdrs[i]; + if (phdr->p_type != PT_LOAD) + continue; + + size = phdr->p_filesz; + if (size > phdr->p_memsz) + size = phdr->p_memsz; + + kbuf.buffer = (void *) elf_info->buffer + phdr->p_offset; + kbuf.bufsz = size; + kbuf.buf_align = phdr->p_align; + kbuf.mem = phdr->p_paddr - old_pbase + new_pbase; + kbuf.memsz = phdr->p_memsz; + kbuf.top_down = false; + ret = kexec_add_buffer(&kbuf); + if (ret) + break; + } + + return ret; +} + +/* + * Go through the available phsyical memory regions and find one that hold + * an image of the specified size. + */ +static int elf_find_pbase(struct kimage *image, unsigned long kernel_len, + struct elfhdr *ehdr, struct kexec_elf_info *elf_info, + unsigned long *old_pbase, unsigned long *new_pbase) +{ + int i; + int ret; + struct kexec_buf kbuf; + const struct elf_phdr *phdr; + unsigned long lowest_paddr = ULONG_MAX; + unsigned long lowest_vaddr = ULONG_MAX; + + for (i = 0; i < ehdr->e_phnum; i++) { + phdr = &elf_info->proghdrs[i]; + if (phdr->p_type != PT_LOAD) + continue; + + if (lowest_paddr > phdr->p_paddr) + lowest_paddr = phdr->p_paddr; + + if (lowest_vaddr > phdr->p_vaddr) + lowest_vaddr = phdr->p_vaddr; + } + + kbuf.image = image; + kbuf.buf_min = lowest_paddr; + kbuf.buf_max = ULONG_MAX; + kbuf.buf_align = PAGE_SIZE; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz = ALIGN(kernel_len, PAGE_SIZE); + kbuf.top_down = false; + ret = arch_kexec_locate_mem_hole(&kbuf); + if (!ret) { + *old_pbase = lowest_paddr; + *new_pbase = kbuf.mem; + image->start = ehdr->e_entry - lowest_vaddr + kbuf.mem; + } + return ret; +} + +static void *elf_kexec_load(struct kimage *image, char *kernel_buf, + unsigned long kernel_len, char *initrd, + unsigned long initrd_len, char *cmdline, + unsigned long cmdline_len) +{ + int ret; + unsigned long old_kernel_pbase = ULONG_MAX; + unsigned long new_kernel_pbase = 0UL; + unsigned long initrd_pbase = 0UL; + void *fdt; + struct elfhdr ehdr; + struct kexec_buf kbuf; + struct kexec_elf_info elf_info; + + ret = kexec_build_elf_info(kernel_buf, kernel_len, &ehdr, &elf_info); + if (ret) + return ERR_PTR(ret); + + ret = elf_find_pbase(image, kernel_len, &ehdr, &elf_info, + &old_kernel_pbase, &new_kernel_pbase); + if (ret) + goto out; + pr_notice("The entry point of kernel at 0x%lx\n", image->start); + + /* Add the kernel binary to the image */ + ret = riscv_kexec_elf_load(image, &ehdr, &elf_info, + old_kernel_pbase, new_kernel_pbase); + if (ret) + goto out; + + kbuf.image = image; + kbuf.buf_min = new_kernel_pbase + kernel_len; + kbuf.buf_max = ULONG_MAX; + /* Add the initrd to the image */ + if (initrd != NULL) { + kbuf.buffer = initrd; + kbuf.bufsz = kbuf.memsz = initrd_len; + kbuf.buf_align = PAGE_SIZE; + kbuf.top_down = false; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + ret = kexec_add_buffer(&kbuf); + if (ret) + goto out; + initrd_pbase = kbuf.mem; + pr_notice("Loaded initrd at 0x%lx\n", initrd_pbase); + } + + /* Add the DTB to the image */ + fdt = of_kexec_alloc_and_setup_fdt(image, initrd_pbase, + initrd_len, cmdline, 0); + if (!fdt) { + pr_err("Error setting up the new device tree.\n"); + ret = -EINVAL; + goto out; + } + + fdt_pack(fdt); + kbuf.buffer = fdt; + kbuf.bufsz = kbuf.memsz = fdt_totalsize(fdt); + kbuf.buf_align = PAGE_SIZE; + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf.top_down = true; + ret = kexec_add_buffer(&kbuf); + if (ret) { + pr_err("Error add DTB kbuf ret=%d\n", ret); + goto out_free_fdt; + } + pr_notice("Loaded device tree at 0x%lx\n", kbuf.mem); + goto out; + +out_free_fdt: + kvfree(fdt); +out: + kexec_free_elf_info(&elf_info); + return ret ? ERR_PTR(ret) : NULL; +} + +const struct kexec_file_ops elf_kexec_ops = { + .probe = kexec_elf_probe, + .load = elf_kexec_load, +}; diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c new file mode 100644 index 000000000000..b0bf8c1722c0 --- /dev/null +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * kexec_file for riscv, use vmlinux as the dump-capture kernel image. + * + * Copyright (C) 2021 Huawei Technologies Co, Ltd. + * + * Author: Liao Chang (liaochang1@huawei.com) + */ +#include <linux/kexec.h> + +const struct kexec_file_ops * const kexec_file_loaders[] = { + &elf_kexec_ops, + NULL +}; |