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. This allows the kernel to dynamically allocate
contiguous memory for crash dumping when needed, rather than permanently
reserving a fixed region at boot time.So extend crashkernel CMA reservation support to riscv. The following changes are made to enable CMA reservation: - 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 for kdump kernel to use. - Exclude the CMA-reserved ranges from the crash kernel memory to prevent them from being exported through /proc/vmcore, which is already done in the crash core. Update kernel-parameters.txt to document CMA support for crashkernel on riscv architecture. Signed-off-by: Jinjie Ruan <[email protected]> --- Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++-------- arch/riscv/kernel/machine_kexec_file.c | 10 ++++++++-- arch/riscv/mm/init.c | 5 +++-- 3 files changed, 19 insertions(+), 12 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 36bb642a7edd..3b92324d3a03 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1119,14 +1119,14 @@ Kernel parameters It will be ignored when crashkernel=X,high is not used or memory reserved is below 4G. crashkernel=size[KMG],cma - [KNL, X86, ARM64, ppc] Reserve additional crash kernel memory from - CMA. This reservation is usable by the first system's - userspace memory and kernel movable allocations (memory - balloon, zswap). Pages allocated from this memory range - will not be included in the vmcore so this should not - be used if dumping of userspace memory is intended and - it has to be expected that some movable kernel pages - may be missing from the dump. + [KNL, X86, ARM64, RISCV, ppc] Reserve additional crash + kernel memory from CMA. This reservation is usable by + the first system's userspace memory and kernel movable + allocations (memory balloon, zswap). Pages allocated + from this memory range will not be included in the vmcore + so this should not be used if dumping of userspace memory + is intended and it has to be expected that some movable + kernel pages may be missing from the dump. A standard crashkernel reservation, as described above, is still needed to hold the crash kernel and initrd. diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c index fec3622a13c9..0e4ac70d5a9a 100644 --- a/arch/riscv/kernel/machine_kexec_file.c +++ b/arch/riscv/kernel/machine_kexec_file.c @@ -59,9 +59,9 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) { struct crash_mem *cmem; unsigned int nr_ranges; - int ret; + int ret, i; - nr_ranges = 1; /* For exclusion of crashkernel region */ + nr_ranges = 1 + crashk_cma_cnt; /* For exclusion of crashkernel region */ walk_system_ram_res(0, -1, &nr_ranges, get_nr_ram_ranges_callback); cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL); @@ -74,6 +74,12 @@ static int prepare_elf_headers(void **addr, unsigned long *sz) if (ret) goto out; + for (i = 0; i < crashk_cma_cnt; i++) { + cmem->ranges[cmem->nr_ranges].start = crashk_cma_ranges[i].start; + cmem->ranges[cmem->nr_ranges].end = crashk_cma_ranges[i].end; + cmem->nr_ranges++; + } + ret = crash_prepare_elf64_headers(cmem, true, addr, sz); out: diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index addb8a9305be..074d2d5f79ee 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1404,7 +1404,7 @@ static inline void setup_vm_final(void) */ static void __init arch_reserve_crashkernel(void) { - unsigned long long low_size = 0; + unsigned long long low_size = 0, cma_size = 0; unsigned long long crash_base, crash_size; bool high = false; int ret; @@ -1414,11 +1414,12 @@ static void __init arch_reserve_crashkernel(void) ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), &crash_size, &crash_base, - &low_size, NULL, &high); + &low_size, &cma_size, &high); if (ret) return; reserve_crashkernel_generic(crash_size, crash_base, low_size, high); + reserve_crashkernel_cma(cma_size); } void __init paging_init(void) -- 2.34.1
