From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Tue, 12 Jul 2016 14:05:07 +0900 Subject: [PATCH v22 1/8] arm64: kdump: reserve memory for crash dump kernel In-Reply-To: <20160712050514.22307-1-takahiro.akashi@linaro.org> References: <20160712050514.22307-1-takahiro.akashi@linaro.org> Message-ID: <20160712050514.22307-2-takahiro.akashi@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On the startup of primary kernel, the memory region used by crash dump kernel must be specified by "crashkernel=" kernel parameter. reserve_crashkernel() will allocate and reserve the region for later use. User space tools, like kexec-tools, will be able to find that region as - "Crash kernel" in /proc/iomem, or - "linux,crashkernel-base" and "linux,crashkernel-size" under /sys/firmware/devicetree/base/chosen Signed-off-by: AKASHI Takahiro Signed-off-by: Mark Salter Signed-off-by: Pratyush Anand Reviewed-by: James Morse --- arch/arm64/kernel/setup.c | 7 ++- arch/arm64/mm/init.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 121 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index c1509e6..cb5eee0 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -31,7 +31,6 @@ #include #include #include -#include #include #include #include @@ -222,6 +221,12 @@ static void __init request_standard_resources(void) kernel_data.end <= res->end) request_resource(res, &kernel_data); } + +#ifdef CONFIG_KEXEC_CORE + /* User space tools will find "Crash kernel" region in /proc/iomem. */ + if (crashk_res.end) + insert_resource(&iomem_resource, &crashk_res); +#endif } u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID }; diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 2ade7a6..51b1302 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -29,11 +29,13 @@ #include #include #include +#include #include #include #include #include #include +#include #include #include @@ -76,6 +78,117 @@ static int __init early_initrd(char *p) early_param("initrd", early_initrd); #endif +#ifdef CONFIG_KEXEC_CORE +static unsigned long long crash_size, crash_base; +static struct property crash_base_prop = { + .name = "linux,crashkernel-base", + .length = sizeof(u64), + .value = &crash_base +}; +static struct property crash_size_prop = { + .name = "linux,crashkernel-size", + .length = sizeof(u64), + .value = &crash_size, +}; + +static int __init export_crashkernel(void) +{ + struct device_node *node; + int ret; + + if (!crashk_res.end) + return 0; + + crash_base = cpu_to_be64(crashk_res.start); + crash_size = cpu_to_be64(crashk_res.end - crashk_res.start + 1); + + /* Add /chosen/linux,crashkernel-* properties */ + node = of_find_node_by_path("/chosen"); + if (!node) + return -ENOENT; + + /* + * There might be existing crash kernel properties, but we can't + * be sure what's in them, so remove them. + */ + of_remove_property(node, of_find_property(node, + "linux,crashkernel-base", NULL)); + of_remove_property(node, of_find_property(node, + "linux,crashkernel-size", NULL)); + + ret = of_add_property(node, &crash_base_prop); + if (ret) + goto ret_err; + + ret = of_add_property(node, &crash_size_prop); + if (ret) + goto ret_err; + + return 0; + +ret_err: + pr_warn("Exporting crashkernel region to device tree failed\n"); + return ret; +} +late_initcall(export_crashkernel); + +/* + * 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) +{ + 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; + + if (crash_base == 0) { + /* Current arm64 boot protocol requires 2MB alignment */ + crash_base = memblock_find_in_range(0, + MEMBLOCK_ALLOC_ACCESSIBLE, crash_size, SZ_2M); + if (crash_base == 0) { + pr_warn("Unable to allocate crashkernel (size:%llx)\n", + crash_size); + return; + } + memblock_reserve(crash_base, crash_size); + + } else { + /* User specifies base address explicitly. */ + if (!memblock_is_region_memory(crash_base, crash_size) || + memblock_is_region_reserved(crash_base, crash_size)) { + pr_warn("crashkernel has wrong address or size\n"); + return; + } + + if (!IS_ALIGNED(crash_base, SZ_2M)) { + pr_warn("crashkernel base address is not 2MB aligned\n"); + return; + } + + memblock_reserve(crash_base, crash_size); + } + + pr_info("Reserving %lldMB of memory at %lldMB for crashkernel\n", + crash_size >> 20, crash_base >> 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 @@ -289,6 +402,8 @@ void __init arm64_memblock_init(void) } #endif + reserve_crashkernel(); + early_init_fdt_scan_reserved_mem(); /* 4GB maximum for 32-bit only capable devices */ -- 2.9.0