Currently, there is only one crash kernel region on arm64, we add another region "crash kernel low" used for crash dump kernel devices.
To do this, we add DT property "linux,low-memory-range" to crash dump kernel's dtb to pass the low region. Signed-off-by: Chen Zhou <chenzho...@huawei.com> --- For "support reserving crashkernel above 4G on arm64 kdump", we need to modify the kexec-tools. I will post patch series "[PATCH v6 0/4] support reserving crashkernel above 4G on arm64 kdump". This version is much different from the previous one and the kexec-tools part neeed to be modified. Changes since [v1]: - Add another DT property "linux,low-memory-range" to crash dump kernel's dtb to pass the low region instead of reusing "linux,usable-memory-range". [1]: http://lists.infradead.org/pipermail/kexec/2019-April/022792.html --- kexec/arch/arm64/crashdump-arm64.c | 29 +++++++++++++++++++++++++++-- kexec/arch/arm64/crashdump-arm64.h | 2 ++ kexec/arch/arm64/iomem.h | 1 + kexec/arch/arm64/kexec-arm64.c | 27 +++++++++++++++++++++++++++ 4 files changed, 57 insertions(+), 2 deletions(-) diff --git a/kexec/arch/arm64/crashdump-arm64.c b/kexec/arch/arm64/crashdump-arm64.c index 4fd7aa8..a8be036 100644 --- a/kexec/arch/arm64/crashdump-arm64.c +++ b/kexec/arch/arm64/crashdump-arm64.c @@ -39,6 +39,14 @@ struct memory_ranges usablemem_rgns = { .ranges = &crash_reserved_mem, }; +/* memory range reserved for crashkernel low, optional */ +struct memory_range crash_reserved_low_mem; +struct memory_ranges lowmem_rgns = { + .size = 0, + .max_size = 1, + .ranges = &crash_reserved_low_mem, +}; + struct memory_range elfcorehdr_mem; static struct crash_elf_info elf_info = { @@ -89,7 +97,10 @@ static int iomem_range_callback(void *UNUSED(data), int UNUSED(nr), char *str, unsigned long long base, unsigned long long length) { - if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0) + if (strncmp(str, CRASH_KERNEL_LOW, strlen(CRASH_KERNEL_LOW)) == 0) + return mem_regions_add(&lowmem_rgns, + base, length, RANGE_RAM); + else if (strncmp(str, CRASH_KERNEL, strlen(CRASH_KERNEL)) == 0) return mem_regions_add(&usablemem_rgns, base, length, RANGE_RAM); else if (strncmp(str, SYSTEM_RAM, strlen(SYSTEM_RAM)) == 0) @@ -129,7 +140,7 @@ static int crash_get_memory_ranges(void) if (!usablemem_rgns.size) kexec_iomem_for_each_line(NULL, iomem_range_callback, NULL); - /* allow only a single region for crash dump kernel */ + /* allow only a single usablemem region for crash dump kernel */ if (usablemem_rgns.size != 1) return -EINVAL; @@ -141,6 +152,20 @@ static int crash_get_memory_ranges(void) return -ENOMEM; } + /* lowmem region for crash dump kernel is optional, at most one region */ + if (lowmem_rgns.size > 1) + return -EINVAL; + + if (lowmem_rgns.size) { + dbgprint_mem_range("Reserved low memory range", &crash_reserved_low_mem, + 1); + + if (mem_regions_exclude(&system_memory_rgns, &crash_reserved_low_mem)) { + fprintf(stderr, + "Error: Number of crash memory ranges excedeed the max limit\n"); + return -ENOMEM; + } + } /* * Make sure that the memory regions are sorted. */ diff --git a/kexec/arch/arm64/crashdump-arm64.h b/kexec/arch/arm64/crashdump-arm64.h index 880b83a..f185534 100644 --- a/kexec/arch/arm64/crashdump-arm64.h +++ b/kexec/arch/arm64/crashdump-arm64.h @@ -18,6 +18,8 @@ extern struct memory_ranges usablemem_rgns; extern struct memory_range crash_reserved_mem; +extern struct memory_ranges lowmem_rgns; +extern struct memory_range crash_reserved_low_mem; extern struct memory_range elfcorehdr_mem; extern int load_crashdump_segments(struct kexec_info *info); diff --git a/kexec/arch/arm64/iomem.h b/kexec/arch/arm64/iomem.h index d4864bb..45d7953 100644 --- a/kexec/arch/arm64/iomem.h +++ b/kexec/arch/arm64/iomem.h @@ -4,6 +4,7 @@ #define SYSTEM_RAM "System RAM\n" #define KERNEL_CODE "Kernel code\n" #define KERNEL_DATA "Kernel data\n" +#define CRASH_KERNEL_LOW "Crash kernel (low)\n" #define CRASH_KERNEL "Crash kernel\n" #define IOMEM_RESERVED "reserved\n" diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c index eb3a3a3..dddec23 100644 --- a/kexec/arch/arm64/kexec-arm64.c +++ b/kexec/arch/arm64/kexec-arm64.c @@ -38,6 +38,7 @@ #define PROP_SIZE_CELLS "#size-cells" #define PROP_ELFCOREHDR "linux,elfcorehdr" #define PROP_USABLE_MEM_RANGE "linux,usable-memory-range" +#define PROP_LOW_MEM_RANGE "linux,low-memory-range" #define PAGE_OFFSET_36 ((0xffffffffffffffffUL) << 36) #define PAGE_OFFSET_39 ((0xffffffffffffffffUL) << 39) @@ -466,12 +467,24 @@ static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) goto on_error; } + if (lowmem_rgns.size) { + if (!cells_size_fitted(address_cells, size_cells, + &crash_reserved_low_mem)) { + fprintf(stderr, "kexec: low memory range doesn't fit cells-size.\n"); + result = -EINVAL; + goto on_error; + } + } + /* duplicate dt blob */ range_len = sizeof(uint32_t) * (address_cells + size_cells); new_size = fdt_totalsize(dtb->buf) + fdt_prop_len(PROP_ELFCOREHDR, range_len) + fdt_prop_len(PROP_USABLE_MEM_RANGE, range_len); + if (lowmem_rgns.size) + new_size += fdt_prop_len(PROP_LOW_MEM_RANGE, range_len); + new_buf = xmalloc(new_size); result = fdt_open_into(dtb->buf, new_buf, new_size); if (result) { @@ -575,6 +588,20 @@ static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) result = -EINVAL; goto on_error; } + + /* add linux,low-memory-range */ + if (lowmem_rgns.size) { + nodeoffset = fdt_path_offset(new_buf, "/chosen"); + result = fdt_setprop_range(new_buf, nodeoffset, + PROP_LOW_MEM_RANGE, &crash_reserved_low_mem, + address_cells, size_cells); + if (result) { + dbgprintf("%s: fdt_setprop failed: %s\n", __func__, + fdt_strerror(result)); + result = -EINVAL; + goto on_error; + } + } } fdt_pack(new_buf); -- 2.7.4 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
