[PATCH v6 03/10] crash_core: fold duplicated memblock arch hooks into the weak default
Baoquan He
baoquan.he at linux.dev
Fri Sep 18 01:48:41 PDT 2026
On 09/18/26 at 04:45pm, Wandun wrote:
>
>
> On 9/18/26 15:30, Baoquan He wrote:
> > On 09/02/26 at 03:31pm, Wandun Chen wrote:
> >> From: Wandun Chen <chenwandun at lixiang.com>
> >>
> >> arm64, loongarch and riscv open-code the same memblock walk in
> >> arch_get_system_nr_ranges() and arch_crash_populate_cmem(). Move it into
> >> the __weak defaults in kernel/crash_core.c and delete the arch copies.
> >>
> >> No functional change.
> >
> > In one version, you also tried to remove these functions on x86, I could
> > remember it wrong.
>
> Yes, the x86 implementation can also remove these functions and use the same
> approach as arm64, RISC-V, and LoongArch. However since this change would not
> reduce the vmcore size on x86 at all, I did not include it in the current series.
>
> I plan to refactor this part on x86 after this series.
OK, that's fine. I remember I saw the code, but couldn't find it in this
patch. Thanks for telling.
>
>
>
> >
> > Anyway, this looks good to me.
> >
> > Acked-by: Baoquan He <baoquan.he at linux.dev>
> >
> >>
> >> Signed-off-by: Wandun Chen <chenwandun at lixiang.com>
> >> Tested-by: Meijing Zhao <zhaomeijing at lixiang.com>
> >> ---
> >> arch/arm64/kernel/machine_kexec_file.c | 29 ----------------------
> >> arch/loongarch/kernel/machine_kexec_file.c | 27 --------------------
> >> arch/riscv/kernel/machine_kexec_file.c | 26 -------------------
> >> kernel/crash_core.c | 25 +++++++++++++++++--
> >> 4 files changed, 23 insertions(+), 84 deletions(-)
> >>
> >> diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
> >> index 854d872dfd0f..34d944d3f22f 100644
> >> --- a/arch/arm64/kernel/machine_kexec_file.c
> >> +++ b/arch/arm64/kernel/machine_kexec_file.c
> >> @@ -14,7 +14,6 @@
> >> #include <linux/kernel.h>
> >> #include <linux/kexec.h>
> >> #include <linux/libfdt.h>
> >> -#include <linux/memblock.h>
> >> #include <linux/of.h>
> >> #include <linux/of_fdt.h>
> >> #include <linux/slab.h>
> >> @@ -39,34 +38,6 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
> >> return kexec_image_post_load_cleanup_default(image);
> >> }
> >>
> >> -#ifdef CONFIG_CRASH_DUMP
> >> -unsigned int arch_get_system_nr_ranges(void)
> >> -{
> >> - unsigned int nr_ranges = 2 + crashk_cma_cnt; /* for exclusion of crashkernel region */
> >> - phys_addr_t start, end;
> >> - u64 i;
> >> -
> >> - for_each_mem_range(i, &start, &end)
> >> - nr_ranges++;
> >> -
> >> - return nr_ranges;
> >> -}
> >> -
> >> -int arch_crash_populate_cmem(struct crash_mem *cmem)
> >> -{
> >> - phys_addr_t start, end;
> >> - u64 i;
> >> -
> >> - for_each_mem_range(i, &start, &end) {
> >> - cmem->ranges[cmem->nr_ranges].start = start;
> >> - cmem->ranges[cmem->nr_ranges].end = end - 1;
> >> - cmem->nr_ranges++;
> >> - }
> >> -
> >> - return 0;
> >> -}
> >> -#endif
> >> -
> >> /*
> >> * Tries to add the initrd and DTB to the image. If it is not possible to find
> >> * valid locations, this function will undo changes to the image and return non
> >> diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c
> >> index 5412aa9f3568..481b8f906a56 100644
> >> --- a/arch/loongarch/kernel/machine_kexec_file.c
> >> +++ b/arch/loongarch/kernel/machine_kexec_file.c
> >> @@ -13,7 +13,6 @@
> >> #include <linux/ioport.h>
> >> #include <linux/kernel.h>
> >> #include <linux/kexec.h>
> >> -#include <linux/memblock.h>
> >> #include <linux/slab.h>
> >> #include <linux/string.h>
> >> #include <linux/types.h>
> >> @@ -56,32 +55,6 @@ static void cmdline_add_initrd(struct kimage *image, unsigned long *cmdline_tmpl
> >> }
> >>
> >> #ifdef CONFIG_CRASH_DUMP
> >> -unsigned int arch_get_system_nr_ranges(void)
> >> -{
> >> - int nr_ranges = 2; /* for exclusion of crashkernel region */
> >> - phys_addr_t start, end;
> >> - uint64_t i;
> >> -
> >> - for_each_mem_range(i, &start, &end)
> >> - nr_ranges++;
> >> -
> >> - return nr_ranges;
> >> -}
> >> -
> >> -int arch_crash_populate_cmem(struct crash_mem *cmem)
> >> -{
> >> - phys_addr_t start, end;
> >> - uint64_t i;
> >> -
> >> - for_each_mem_range(i, &start, &end) {
> >> - cmem->ranges[cmem->nr_ranges].start = start;
> >> - cmem->ranges[cmem->nr_ranges].end = end - 1;
> >> - cmem->nr_ranges++;
> >> - }
> >> -
> >> - return 0;
> >> -}
> >> -
> >> /*
> >> * Add the "mem=size at start" command line parameter to command line, indicating the
> >> * memory region the new kernel can use to boot into.
> >> diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
> >> index 808e872f4063..fdc6695e8588 100644
> >> --- a/arch/riscv/kernel/machine_kexec_file.c
> >> +++ b/arch/riscv/kernel/machine_kexec_file.c
> >> @@ -37,32 +37,6 @@ int arch_kimage_file_post_load_cleanup(struct kimage *image)
> >> }
> >>
> >> #ifdef CONFIG_CRASH_DUMP
> >> -unsigned int arch_get_system_nr_ranges(void)
> >> -{
> >> - unsigned int nr_ranges = 2 + crashk_cma_cnt; /* For exclusion of crashkernel region */
> >> - u64 i;
> >> - phys_addr_t start, end;
> >> -
> >> - for_each_mem_range(i, &start, &end)
> >> - nr_ranges++;
> >> -
> >> - return nr_ranges;
> >> -}
> >> -
> >> -int arch_crash_populate_cmem(struct crash_mem *cmem)
> >> -{
> >> - u64 i;
> >> - phys_addr_t start, end;
> >> -
> >> - for_each_mem_range(i, &start, &end) {
> >> - cmem->ranges[cmem->nr_ranges].start = start;
> >> - cmem->ranges[cmem->nr_ranges].end = end - 1;
> >> - cmem->nr_ranges++;
> >> - }
> >> -
> >> - return 0;
> >> -}
> >> -
> >> static char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
> >> unsigned long cmdline_len)
> >> {
> >> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> >> index 2b36aa9fade0..77285ae3ce60 100644
> >> --- a/kernel/crash_core.c
> >> +++ b/kernel/crash_core.c
> >> @@ -281,8 +281,29 @@ static struct crash_mem *alloc_cmem(unsigned int nr_ranges)
> >> return cmem;
> >> }
> >>
> >> -unsigned int __weak arch_get_system_nr_ranges(void) { return 0; }
> >> -int __weak arch_crash_populate_cmem(struct crash_mem *cmem) { return -1; }
> >> +unsigned int __weak arch_get_system_nr_ranges(void)
> >> +{
> >> + unsigned int nr_ranges = 2 + crashk_cma_cnt; /* crashk_res + crashk_low_res, +CMA splits */
> >> + phys_addr_t start, end;
> >> + u64 i;
> >> +
> >> + for_each_mem_range(i, &start, &end)
> >> + nr_ranges++;
> >> + return nr_ranges;
> >> +}
> >> +
> >> +int __weak arch_crash_populate_cmem(struct crash_mem *cmem)
> >> +{
> >> + phys_addr_t start, end;
> >> + u64 i;
> >> +
> >> + for_each_mem_range(i, &start, &end) {
> >> + cmem->ranges[cmem->nr_ranges].start = start;
> >> + cmem->ranges[cmem->nr_ranges].end = end - 1;
> >> + cmem->nr_ranges++;
> >> + }
> >> + return 0;
> >> +}
> >> int __weak arch_crash_exclude_ranges(struct crash_mem *cmem) { return 0; }
> >>
> >> int __weak arch_crash_exclude_mem_range(struct crash_mem **mem,
> >> --
> >> 2.43.0
> >>
>
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