[PATCH v5 6/8] crash_core: fold duplicated memblock arch hooks into the weak default

Wandun Chen <[email protected]> Thu, 6 Aug 2026 17:35:17 +0800
Newsgroups dev.linux.lists.iommu,dev.linux.lists.loongarch,org.infradead.lists.kexec,org.infradead.lists.linux-arm-kernel,org.infradead.lists.linux-riscv,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel,org.kvack.linux-mm
Message-ID <[email protected]>
From: Wandun Chen <[email protected]>

The weak defaults are only consumed by crash_prepare_headers(), which is
called only by arm64, riscv, loongarch (via the weak default) and x86
(via its own non-weak override).

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.

Signed-off-by: Wandun Chen <[email protected]>
Tested-by: Meijing Zhao <[email protected]>
---
 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@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