From a149cf00b158e1793a8dd89ca492379c366300d2 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Wed, 16 Nov 2022 20:10:43 +0800 Subject: arm64: kdump: Provide default size when crashkernel=Y,low is not specified Try to allocate at least 128 MiB low memory automatically for the case that crashkernel=,high is explicitly specified, while crashkenrel=,low is omitted. This allows users to focus more on the high memory requirements of their business rather than the low memory requirements of the crash kernel booting. Signed-off-by: Zhen Lei Acked-by: Baoquan He Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20221116121044.1690-2-thunder.leizhen@huawei.com Signed-off-by: Will Deacon --- arch/arm64/mm/init.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'arch/arm64/mm/init.c') diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 4b4651ee47f2..ba7227179822 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -96,6 +96,8 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1; #define CRASH_ADDR_LOW_MAX arm64_dma_phys_limit #define CRASH_ADDR_HIGH_MAX (PHYS_MASK + 1) +#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20) + static int __init reserve_crashkernel_low(unsigned long long low_size) { unsigned long long low_base; @@ -147,7 +149,9 @@ static void __init reserve_crashkernel(void) * is not allowed. */ ret = parse_crashkernel_low(cmdline, 0, &crash_low_size, &crash_base); - if (ret && (ret != -ENOENT)) + if (ret == -ENOENT) + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE; + else if (ret) return; crash_max = CRASH_ADDR_HIGH_MAX; @@ -170,7 +174,7 @@ static void __init reserve_crashkernel(void) return; } - if ((crash_base >= CRASH_ADDR_LOW_MAX) && + if ((crash_base > CRASH_ADDR_LOW_MAX - crash_low_size) && crash_low_size && reserve_crashkernel_low(crash_low_size)) { memblock_phys_free(crash_base, crash_size); return; -- cgit v1.2.3