| Message ID | d0486ff8419e38844ecb524d0ac86ea81a6ec67d.1466120418.git.geoff@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 17/06/16 00:48, Geoff Levand wrote: > From: AKASHI Takahiro <takahiro.akashi@linaro.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 marked > as "Crash kernel" in /proc/iomem. > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index d45f862..45f1319 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -34,6 +34,7 @@ > #include <linux/dma-contiguous.h> > #include <linux/efi.h> > #include <linux/swiotlb.h> > +#include <linux/kexec.h> > > #include <asm/boot.h> > #include <asm/fixmap.h> > @@ -76,6 +77,65 @@ 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_size = 0, crash_base = 0; > + int ret; > + > + ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), > + &crash_size, &crash_base); > + /* no crashkernel= or invalid value specified */ > + if (!crash_size) > + return; Should we check ret too? > + > + 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); What if memblock_reserve() fails? > + > + } 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)) { !IS_ALIGNED()... > + pr_warn("crashkernel base address is not 2MB aligned\n"); > + return; > + } > + > + memblock_reserve(crash_base, crash_size); What if memblock_reserve() fails? > + } > + > + 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 > @@ -291,6 +351,8 @@ void __init arm64_memblock_init(void) > } > #endif > > + reserve_crashkernel(); > + > early_init_fdt_scan_reserved_mem(); > > /* 4GB maximum for 32-bit only capable devices */ > With those, Reviewed-by: James Morse <james.morse@arm.com> Thanks, James
On Mon, Jun 20, 2016 at 05:07:11PM +0100, James Morse wrote: > Hi, > > On 17/06/16 00:48, Geoff Levand wrote: > > From: AKASHI Takahiro <takahiro.akashi@linaro.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 marked > > as "Crash kernel" in /proc/iomem. > > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > > index d45f862..45f1319 100644 > > --- a/arch/arm64/mm/init.c > > +++ b/arch/arm64/mm/init.c > > @@ -34,6 +34,7 @@ > > #include <linux/dma-contiguous.h> > > #include <linux/efi.h> > > #include <linux/swiotlb.h> > > +#include <linux/kexec.h> > > > > #include <asm/boot.h> > > #include <asm/fixmap.h> > > @@ -76,6 +77,65 @@ 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_size = 0, crash_base = 0; > > + int ret; > > + > > + ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), > > + &crash_size, &crash_base); > > + /* no crashkernel= or invalid value specified */ > > + if (!crash_size) > > + return; > > Should we check ret too? I thought that it was almost OK, but there is the only erroneous case, "crashkernel=SIZE@". Will fix it. > > > + > > + 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); > > What if memblock_reserve() fails? I don't think it fails because the region has been allocated by memblock_find_in_range() just before. > > > + > > + } 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)) { > > !IS_ALIGNED()... Oops, will fix it. > > > + pr_warn("crashkernel base address is not 2MB aligned\n"); > > + return; > > + } > > + > > + memblock_reserve(crash_base, crash_size); > > What if memblock_reserve() fails? The region has been checked with memblock_is_region_reserved(). > > > + } > > + > > + 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 > > @@ -291,6 +351,8 @@ void __init arm64_memblock_init(void) > > } > > #endif > > > > + reserve_crashkernel(); > > + > > early_init_fdt_scan_reserved_mem(); > > > > /* 4GB maximum for 32-bit only capable devices */ > > > > > With those, > Reviewed-by: James Morse <james.morse@arm.com> Thanks, -Takahiro AKASHI > > Thanks, > > James >
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 3279def..e411957 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -31,7 +31,6 @@ #include <linux/screen_info.h> #include <linux/init.h> #include <linux/kexec.h> -#include <linux/crash_dump.h> #include <linux/root_dev.h> #include <linux/cpu.h> #include <linux/interrupt.h> @@ -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 d45f862..45f1319 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -34,6 +34,7 @@ #include <linux/dma-contiguous.h> #include <linux/efi.h> #include <linux/swiotlb.h> +#include <linux/kexec.h> #include <asm/boot.h> #include <asm/fixmap.h> @@ -76,6 +77,65 @@ 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_size = 0, crash_base = 0; + int ret; + + ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), + &crash_size, &crash_base); + /* no crashkernel= or invalid value specified */ + if (!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 @@ -291,6 +351,8 @@ void __init arm64_memblock_init(void) } #endif + reserve_crashkernel(); + early_init_fdt_scan_reserved_mem(); /* 4GB maximum for 32-bit only capable devices */