diff options
| -rw-r--r-- | arch/powerpc/include/asm/crashdump-ppc64.h | 19 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kexec.h | 7 | ||||
| -rw-r--r-- | arch/powerpc/kexec/elf_64.c | 9 | ||||
| -rw-r--r-- | arch/powerpc/kexec/file_load_64.c | 93 | ||||
| -rw-r--r-- | arch/powerpc/purgatory/trampoline_64.S | 38 |
5 files changed, 159 insertions, 7 deletions
diff --git a/arch/powerpc/include/asm/crashdump-ppc64.h b/arch/powerpc/include/asm/crashdump-ppc64.h new file mode 100644 index 000000000000..68d9717cc5ee --- /dev/null +++ b/arch/powerpc/include/asm/crashdump-ppc64.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _ASM_POWERPC_CRASHDUMP_PPC64_H +#define _ASM_POWERPC_CRASHDUMP_PPC64_H + +/* + * Backup region - first 64KB of System RAM + * + * If ever the below macros are to be changed, please be judicious. + * The implicit assumptions are: + * - start, end & size are less than UINT32_MAX. + * - start & size are at least 8 byte aligned. + * + * For implementation details: arch/powerpc/purgatory/trampoline_64.S + */ +#define BACKUP_SRC_START 0 +#define BACKUP_SRC_END 0xffff +#define BACKUP_SRC_SIZE (BACKUP_SRC_END - BACKUP_SRC_START + 1) + +#endif /* __ASM_POWERPC_CRASHDUMP_PPC64_H */ diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 639f31e13593..807bb58ed8fa 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -105,6 +105,9 @@ extern const struct kexec_file_ops kexec_elf64_ops; struct kimage_arch { struct crash_mem *exclude_ranges; + unsigned long backup_start; + void *backup_buf; + #ifdef CONFIG_IMA_KEXEC phys_addr_t ima_buffer_addr; size_t ima_buffer_size; @@ -120,6 +123,10 @@ int setup_new_fdt(const struct kimage *image, void *fdt, int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size); #ifdef CONFIG_PPC64 +struct kexec_buf; + +int load_crashdump_segments_ppc64(struct kimage *image, + struct kexec_buf *kbuf); int setup_purgatory_ppc64(struct kimage *image, const void *slave_code, const void *fdt, unsigned long kernel_load_addr, unsigned long fdt_load_addr); diff --git a/arch/powerpc/kexec/elf_64.c b/arch/powerpc/kexec/elf_64.c index 64c15a5a280b..76e2fc7e6dc3 100644 --- a/arch/powerpc/kexec/elf_64.c +++ b/arch/powerpc/kexec/elf_64.c @@ -68,6 +68,15 @@ static void *elf64_load(struct kimage *image, char *kernel_buf, pr_debug("Loaded purgatory at 0x%lx\n", pbuf.mem); + /* Load additional segments needed for panic kernel */ + if (image->type == KEXEC_TYPE_CRASH) { + ret = load_crashdump_segments_ppc64(image, &kbuf); + if (ret) { + pr_err("Failed to load kdump kernel segments\n"); + goto out; + } + } + if (initrd != NULL) { kbuf.buffer = initrd; kbuf.bufsz = kbuf.memsz = initrd_len; diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c index f94660874765..a81bffb72cc5 100644 --- a/arch/powerpc/kexec/file_load_64.c +++ b/arch/powerpc/kexec/file_load_64.c @@ -20,8 +20,10 @@ #include <linux/of_device.h> #include <linux/memblock.h> #include <linux/slab.h> +#include <linux/vmalloc.h> #include <asm/drmem.h> #include <asm/kexec_ranges.h> +#include <asm/crashdump-ppc64.h> struct umem_info { u64 *buf; /* data buffer for usable-memory property */ @@ -606,6 +608,70 @@ out: } /** + * load_backup_segment - Locate a memory hole to place the backup region. + * @image: Kexec image. + * @kbuf: Buffer contents and memory parameters. + * + * Returns 0 on success, negative errno on error. + */ +static int load_backup_segment(struct kimage *image, struct kexec_buf *kbuf) +{ + void *buf; + int ret; + + /* + * Setup a source buffer for backup segment. + * + * A source buffer has no meaning for backup region as data will + * be copied from backup source, after crash, in the purgatory. + * But as load segment code doesn't recognize such segments, + * setup a dummy source buffer to keep it happy for now. + */ + buf = vzalloc(BACKUP_SRC_SIZE); + if (!buf) + return -ENOMEM; + + kbuf->buffer = buf; + kbuf->mem = KEXEC_BUF_MEM_UNKNOWN; + kbuf->bufsz = kbuf->memsz = BACKUP_SRC_SIZE; + kbuf->top_down = false; + + ret = kexec_add_buffer(kbuf); + if (ret) { + vfree(buf); + return ret; + } + + image->arch.backup_buf = buf; + image->arch.backup_start = kbuf->mem; + return 0; +} + +/** + * load_crashdump_segments_ppc64 - Initialize the additional segements needed + * to load kdump kernel. + * @image: Kexec image. + * @kbuf: Buffer contents and memory parameters. + * + * Returns 0 on success, negative errno on error. + */ +int load_crashdump_segments_ppc64(struct kimage *image, + struct kexec_buf *kbuf) +{ + int ret; + + /* Load backup segment - first 64K bytes of the crashing kernel */ + ret = load_backup_segment(image, kbuf); + if (ret) { + pr_err("Failed to load backup segment\n"); + return ret; + } + pr_debug("Loaded the backup region at 0x%lx\n", kbuf->mem); + + return 0; +} + +/** * setup_purgatory_ppc64 - initialize PPC64 specific purgatory's global * variables and call setup_purgatory() to initialize * common global variable. @@ -643,6 +709,11 @@ int setup_purgatory_ppc64(struct kimage *image, const void *slave_code, goto out; } + /* Tell purgatory where to look for backup region */ + ret = kexec_purgatory_get_set_symbol(image, "backup_start", + &image->arch.backup_start, + sizeof(image->arch.backup_start), + false); out: if (ret) pr_err("Failed to setup purgatory symbols"); @@ -674,7 +745,7 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, /* * Restrict memory usage for kdump kernel by setting up - * usable memory ranges. + * usable memory ranges and memory reserve map. */ if (image->type == KEXEC_TYPE_CRASH) { ret = get_usable_memory_ranges(&umem); @@ -687,13 +758,26 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, goto out; } - /* Ensure we don't touch crashed kernel's memory */ - ret = fdt_add_mem_rsv(fdt, 0, crashk_res.start); + /* + * Ensure we don't touch crashed kernel's memory except the + * first 64K of RAM, which will be backed up. + */ + ret = fdt_add_mem_rsv(fdt, BACKUP_SRC_END + 1, + crashk_res.start - BACKUP_SRC_SIZE); if (ret) { pr_err("Error reserving crash memory: %s\n", fdt_strerror(ret)); goto out; } + + /* Ensure backup region is not used by kdump/capture kernel */ + ret = fdt_add_mem_rsv(fdt, image->arch.backup_start, + BACKUP_SRC_SIZE); + if (ret) { + pr_err("Error reserving memory for backup: %s\n", + fdt_strerror(ret)); + goto out; + } } out: @@ -800,5 +884,8 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image) kfree(image->arch.exclude_ranges); image->arch.exclude_ranges = NULL; + vfree(image->arch.backup_buf); + image->arch.backup_buf = NULL; + return kexec_image_post_load_cleanup_default(image); } diff --git a/arch/powerpc/purgatory/trampoline_64.S b/arch/powerpc/purgatory/trampoline_64.S index a5a83c3f53e6..b567da56dde1 100644 --- a/arch/powerpc/purgatory/trampoline_64.S +++ b/arch/powerpc/purgatory/trampoline_64.S @@ -10,6 +10,7 @@ */ #include <asm/asm-compat.h> +#include <asm/crashdump-ppc64.h> .machine ppc64 .balign 256 @@ -43,14 +44,39 @@ master: mr %r17,%r3 /* save cpu id to r17 */ mr %r15,%r4 /* save physical address in reg15 */ + /* Work out where we're running */ + bcl 20, 31, 0f +0: mflr %r18 + + /* + * Copy BACKUP_SRC_SIZE bytes from BACKUP_SRC_START to + * backup_start 8 bytes at a time. + * + * Use r3 = dest, r4 = src, r5 = size, r6 = count + */ + ld %r3, (backup_start - 0b)(%r18) + cmpdi %cr0, %r3, 0 + beq .Lskip_copy /* skip if there is no backup region */ + lis %r5, BACKUP_SRC_SIZE@h + ori %r5, %r5, BACKUP_SRC_SIZE@l + cmpdi %cr0, %r5, 0 + beq .Lskip_copy /* skip if copy size is zero */ + lis %r4, BACKUP_SRC_START@h + ori %r4, %r4, BACKUP_SRC_START@l + li %r6, 0 +.Lcopy_loop: + ldx %r0, %r6, %r4 + stdx %r0, %r6, %r3 + addi %r6, %r6, 8 + cmpld %cr0, %r6, %r5 + blt .Lcopy_loop + +.Lskip_copy: or %r3,%r3,%r3 /* ok now to high priority, lets boot */ lis %r6,0x1 mtctr %r6 /* delay a bit for slaves to catch up */ bdnz . /* before we overwrite 0-100 again */ - bl 0f /* Work out where we're running */ -0: mflr %r18 - /* load device-tree address */ ld %r3, (dt_offset - 0b)(%r18) mr %r16,%r3 /* save dt address in reg16 */ @@ -89,7 +115,6 @@ master: rfid /* update MSR and start kernel */ - .balign 8 .globl kernel kernel: @@ -102,6 +127,11 @@ dt_offset: .8byte 0x0 .size dt_offset, . - dt_offset + .balign 8 + .globl backup_start +backup_start: + .8byte 0x0 + .size backup_start, . - backup_start .data .balign 8 |