diff options
| author | Jiri Bohac <jbohac@suse.cz> | 2025-06-12 12:16:39 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-07-19 19:08:23 -0700 |
| commit | ab475510e0422bb5672d465f9d0f523d72fdb7f1 (patch) | |
| tree | 4b8674dc85cf5c44d7a0665cf32dd0ae45b6681a | |
| parent | Add a new optional ",cma" suffix to the crashkernel= command line option (diff) | |
| download | linux-ab475510e0422bb5672d465f9d0f523d72fdb7f1.tar.gz linux-ab475510e0422bb5672d465f9d0f523d72fdb7f1.zip | |
kdump: implement reserve_crashkernel_cma
reserve_crashkernel_cma() reserves CMA ranges for the crash kernel. If
allocating the requested size fails, try to reserve in smaller blocks.
Store the reserved ranges in the crashk_cma_ranges array and the number of
ranges in crashk_cma_cnt.
Link: https://lkml.kernel.org/r/aEqpBwOy_ekm0gw9@dwarf.suse.cz
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Donald Dutile <ddutile@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Tao Liu <ltao@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | include/linux/crash_reserve.h | 12 | ||||
| -rw-r--r-- | kernel/crash_reserve.c | 52 |
2 files changed, 64 insertions, 0 deletions
diff --git a/include/linux/crash_reserve.h b/include/linux/crash_reserve.h index e784aaff2f5a..7b44b41d0a20 100644 --- a/include/linux/crash_reserve.h +++ b/include/linux/crash_reserve.h @@ -13,12 +13,24 @@ */ extern struct resource crashk_res; extern struct resource crashk_low_res; +extern struct range crashk_cma_ranges[]; +#if defined(CONFIG_CMA) && defined(CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION) +#define CRASHKERNEL_CMA +#define CRASHKERNEL_CMA_RANGES_MAX 4 +extern int crashk_cma_cnt; +#else +#define crashk_cma_cnt 0 +#define CRASHKERNEL_CMA_RANGES_MAX 0 +#endif + int __init parse_crashkernel(char *cmdline, unsigned long long system_ram, unsigned long long *crash_size, unsigned long long *crash_base, unsigned long long *low_size, unsigned long long *cma_size, bool *high); +void __init reserve_crashkernel_cma(unsigned long long cma_size); + #ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION #ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE #define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20) diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c index 86ae1365d04e..87bf4d41eabb 100644 --- a/kernel/crash_reserve.c +++ b/kernel/crash_reserve.c @@ -14,6 +14,8 @@ #include <linux/cpuhotplug.h> #include <linux/memblock.h> #include <linux/kmemleak.h> +#include <linux/cma.h> +#include <linux/crash_reserve.h> #include <asm/page.h> #include <asm/sections.h> @@ -469,6 +471,56 @@ retry: #endif } +struct range crashk_cma_ranges[CRASHKERNEL_CMA_RANGES_MAX]; +#ifdef CRASHKERNEL_CMA +int crashk_cma_cnt; +void __init reserve_crashkernel_cma(unsigned long long cma_size) +{ + unsigned long long request_size = roundup(cma_size, PAGE_SIZE); + unsigned long long reserved_size = 0; + + if (!cma_size) + return; + + while (cma_size > reserved_size && + crashk_cma_cnt < CRASHKERNEL_CMA_RANGES_MAX) { + + struct cma *res; + + if (cma_declare_contiguous(0, request_size, 0, 0, 0, false, + "crashkernel", &res)) { + /* reservation failed, try half-sized blocks */ + if (request_size <= PAGE_SIZE) + break; + + request_size = roundup(request_size / 2, PAGE_SIZE); + continue; + } + + crashk_cma_ranges[crashk_cma_cnt].start = cma_get_base(res); + crashk_cma_ranges[crashk_cma_cnt].end = + crashk_cma_ranges[crashk_cma_cnt].start + + cma_get_size(res) - 1; + ++crashk_cma_cnt; + reserved_size += request_size; + } + + if (cma_size > reserved_size) + pr_warn("crashkernel CMA reservation failed: %lld MB requested, %lld MB reserved in %d ranges\n", + cma_size >> 20, reserved_size >> 20, crashk_cma_cnt); + else + pr_info("crashkernel CMA reserved: %lld MB in %d ranges\n", + reserved_size >> 20, crashk_cma_cnt); +} + +#else /* CRASHKERNEL_CMA */ +void __init reserve_crashkernel_cma(unsigned long long cma_size) +{ + if (cma_size) + pr_warn("crashkernel CMA reservation not supported\n"); +} +#endif + #ifndef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY static __init int insert_crashkernel_resources(void) { |