Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the
crashkernel= command line option") and commit ab475510e042 ("kdump:
implement reserve_crashkernel_cma") added CMA support for kdump
crashkernel reservation.Extend crashkernel CMA reservation support to powerpc. The following changes are made to enable CMA reservation on powerpc: - Parse and obtain the CMA reservation size along with other crashkernel parameters - Call reserve_crashkernel_cma() to allocate the CMA region for kdump - Include the CMA-reserved ranges in the usable memory ranges for the kdump kernel to use. - Exclude the CMA-reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore. With the introduction of the CMA crashkernel regions, crash_exclude_mem_range() needs to be called multiple times to exclude both crashk_res and crashk_cma_ranges from the crash memory ranges. To avoid repetitive logic for validating mem_ranges size and handling reallocation when required, this functionality is moved to a new wrapper function crash_exclude_mem_range_guarded(). To ensure proper CMA reservation, reserve_crashkernel_cma() is called after pageblock_order is initialized. Cc: Jiri Bohac <[email protected]> Cc: Hari Bathini <[email protected]> Cc: Madhavan Srinivasan <[email protected]> Cc: Mahesh Salgaonkar <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Ritesh Harjani (IBM) <[email protected]> Cc: Shivang Upadhyay <[email protected]> Signed-off-by: Sourabh Jain <[email protected]> --- Changlog: v1 -> v2: - Fix build warnings, ensure kernel build when CONFIG_CMA is disabled v2 -> v3 - While excluding crashk_cma_ranges, reallocate mem_ranges if there is insufficient space to split crash memory range - Added a wrapper, crash_exclude_mem_range_guarded(), to simplify the logic for checking mem_ranges size and handling reallocation --- arch/powerpc/include/asm/kexec.h | 2 ++ arch/powerpc/kernel/setup-common.c | 4 ++- arch/powerpc/kexec/core.c | 10 ++++++- arch/powerpc/kexec/ranges.c | 44 ++++++++++++++++++++++-------- 4 files changed, 47 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index 4bbf9f699aaa..bd4a6c42a5f3 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -115,9 +115,11 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, struct crash_mem #ifdef CONFIG_CRASH_RESERVE int __init overlaps_crashkernel(unsigned long start, unsigned long size); extern void arch_reserve_crashkernel(void); +extern void kdump_cma_reserve(void); #else static inline void arch_reserve_crashkernel(void) {} static inline int overlaps_crashkernel(unsigned long start, unsigned long size) { return 0; } +static inline void kdump_cma_reserve(void) { } #endif #if defined(CONFIG_CRASH_DUMP) diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 68d47c53876c..c8c42b419742 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -35,6 +35,7 @@ #include <linux/of_irq.h> #include <linux/hugetlb.h> #include <linux/pgtable.h> +#include <asm/kexec.h> #include <asm/io.h> #include <asm/paca.h> #include <asm/processor.h> @@ -995,11 +996,12 @@ void __init setup_arch(char **cmdline_p) initmem_init(); /* - * Reserve large chunks of memory for use by CMA for fadump, KVM and + * Reserve large chunks of memory for use by CMA for kdump, fadump, KVM and * hugetlb. These must be called after initmem_init(), so that * pageblock_order is initialised. */ fadump_cma_init(); + kdump_cma_reserve(); kvm_cma_reserve(); gigantic_hugetlb_cma_reserve(); diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c index d1a2d755381c..25744737eff5 100644 --- a/arch/powerpc/kexec/core.c +++ b/arch/powerpc/kexec/core.c @@ -33,6 +33,8 @@ void machine_kexec_cleanup(struct kimage *image) { } +unsigned long long cma_size; + /* * Do not allocate memory (or fail in any way) in machine_kexec(). * We are past the point of no return, committed to rebooting now. @@ -110,7 +112,7 @@ void __init arch_reserve_crashkernel(void) /* use common parsing */ ret = parse_crashkernel(boot_command_line, total_mem_sz, &crash_size, - &crash_base, NULL, NULL, NULL); + &crash_base, NULL, &cma_size, NULL); if (ret) return; @@ -130,6 +132,12 @@ void __init arch_reserve_crashkernel(void) reserve_crashkernel_generic(crash_size, crash_base, 0, false); } +void __init kdump_cma_reserve(void) +{ + if (cma_size) + reserve_crashkernel_cma(cma_size); +} + int __init overlaps_crashkernel(unsigned long start, unsigned long size) { return (start + size) > crashk_res.start && start <= crashk_res.end; diff --git a/arch/powerpc/kexec/ranges.c b/arch/powerpc/kexec/ranges.c index 3702b0bdab14..c61aa96f0942 100644 --- a/arch/powerpc/kexec/ranges.c +++ b/arch/powerpc/kexec/ranges.c @@ -515,7 +515,7 @@ int get_exclude_memory_ranges(struct crash_mem **mem_ranges) */ int get_usable_memory_ranges(struct crash_mem **mem_ranges) { - int ret; + int ret, i; /* * Early boot failure observed on guests when low memory (first memory @@ -528,6 +528,13 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges) if (ret) goto out; + for (i = 0; i < crashk_cma_cnt; i++) { + ret = add_mem_range(mem_ranges, crashk_cma_ranges[i].start, + crashk_cma_ranges[i].end); + if (ret) + goto out; + } + ret = add_rtas_mem_range(mem_ranges); if (ret) goto out; @@ -546,6 +553,23 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges) #endif /* CONFIG_KEXEC_FILE */ #ifdef CONFIG_CRASH_DUMP +static int crash_exclude_mem_range_guarded(struct crash_mem **mem_ranges, + unsigned long long mstart, + unsigned long long mend) +{ + struct crash_mem *tmem = *mem_ranges; + + /* Reallocate memory ranges if there is no space to split ranges */ + tmem = *mem_ranges; + if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) { + tmem = realloc_mem_ranges(mem_ranges); + if (!tmem) + return -ENOMEM; + } + + return crash_exclude_mem_range(tmem, crashk_res.start, crashk_res.end); +} + /** * get_crash_memory_ranges - Get crash memory ranges. This list includes * first/crashing kernel's memory regions that @@ -557,7 +581,6 @@ int get_usable_memory_ranges(struct crash_mem **mem_ranges) int get_crash_memory_ranges(struct crash_mem **mem_ranges) { phys_addr_t base, end; - struct crash_mem *tmem; u64 i; int ret; @@ -582,19 +605,18 @@ int get_crash_memory_ranges(struct crash_mem **mem_ranges) sort_memory_ranges(*mem_ranges, true); } - /* Reallocate memory ranges if there is no space to split ranges */ - tmem = *mem_ranges; - if (tmem && (tmem->nr_ranges == tmem->max_nr_ranges)) { - tmem = realloc_mem_ranges(mem_ranges); - if (!tmem) - goto out; - } - /* Exclude crashkernel region */ - ret = crash_exclude_mem_range(tmem, crashk_res.start, crashk_res.end); + ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_res.start, crashk_res.end); if (ret) goto out; + for (i = 0; i < crashk_cma_cnt; ++i) { + ret = crash_exclude_mem_range_guarded(mem_ranges, crashk_cma_ranges[i].start, + crashk_cma_ranges[i].end); + if (ret) + goto out; + } + /* * FIXME: For now, stay in parity with kexec-tools but if RTAS/OPAL * regions are exported to save their context at the time of -- 2.51.0
