From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Mon, 3 Apr 2017 11:24:32 +0900 Subject: [PATCH v35 04/14] arm64: kdump: reserve memory for crash dump kernel In-Reply-To: <20170403022139.12383-1-takahiro.akashi@linaro.org> References: <20170403022139.12383-1-takahiro.akashi@linaro.org> Message-ID: <20170403022440.12515-2-takahiro.akashi@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org "crashkernel=" kernel parameter specifies the size (and optionally the start address) of the system ram to be used by crash dump kernel. reserve_crashkernel() will allocate and reserve that memory at boot time of primary kernel. The memory range will be exposed to userspace as a resource named "Crash kernel" in /proc/iomem. Signed-off-by: AKASHI Takahiro Signed-off-by: Mark Salter Signed-off-by: Pratyush Anand Reviewed-by: James Morse Acked-by: Catalin Marinas Reviewed-by: Ard Biesheuvel --- arch/arm64/kernel/setup.c | 7 ++++- arch/arm64/mm/init.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 42274bda0ccb..28855ec1be95 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -31,7 +31,6 @@ #include #include #include -#include #include #include #include @@ -226,6 +225,12 @@ static void __init request_standard_resources(void) if (kernel_data.start >= res->start && kernel_data.end <= res->end) request_resource(res, &kernel_data); +#ifdef CONFIG_KEXEC_CORE + /* Userspace will find "Crash kernel" region in /proc/iomem. */ + if (crashk_res.end && crashk_res.start >= res->start && + crashk_res.end <= res->end) + request_resource(res, &crashk_res); +#endif } } diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 290794b1a0f1..09d19207362d 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -37,6 +38,7 @@ #include #include #include +#include #include #include @@ -77,6 +79,67 @@ static int __init early_initrd(char *p) early_param("initrd", early_initrd); #endif +#ifdef CONFIG_KEXEC_CORE +/* + * reserve_crashkernel() - reserves memory for crash kernel + * + * This function reserves memory area given in "crashkernel=" kernel command + * line parameter. The memory reserved is used by dump capture kernel when + * primary kernel is crashing. + */ +static void __init reserve_crashkernel(void) +{ + unsigned long long crash_base, crash_size; + int ret; + + ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), + &crash_size, &crash_base); + /* no crashkernel= or invalid value specified */ + if (ret || !crash_size) + return; + + crash_size = PAGE_ALIGN(crash_size); + + if (crash_base == 0) { + /* Current arm64 boot protocol requires 2MB alignment */ + crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, + crash_size, SZ_2M); + if (crash_base == 0) { + pr_warn("cannot allocate crashkernel (size:0x%llx)\n", + crash_size); + return; + } + } else { + /* User specifies base address explicitly. */ + if (!memblock_is_region_memory(crash_base, crash_size)) { + pr_warn("cannot reserve crashkernel: region is not memory\n"); + return; + } + + if (memblock_is_region_reserved(crash_base, crash_size)) { + pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n"); + return; + } + + if (!IS_ALIGNED(crash_base, SZ_2M)) { + pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n"); + return; + } + } + memblock_reserve(crash_base, crash_size); + + pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", + crash_base, crash_base + crash_size, crash_size >> 20); + + crashk_res.start = crash_base; + crashk_res.end = crash_base + crash_size - 1; +} +#else +static void __init reserve_crashkernel(void) +{ +} +#endif /* CONFIG_KEXEC_CORE */ + /* * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It * currently assumes that for memory starting above 4G, 32-bit devices will @@ -332,6 +395,9 @@ void __init arm64_memblock_init(void) arm64_dma_phys_limit = max_zone_dma_phys(); else arm64_dma_phys_limit = PHYS_MASK + 1; + + reserve_crashkernel(); + dma_contiguous_reserve(arm64_dma_phys_limit); memblock_allow_resize(); -- 2.11.1