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| author | AKASHI Takahiro <takahiro.akashi@linaro.org> | 2016-08-22 08:55:24 +0200 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2016-08-25 19:00:31 +0200 |
| commit | e7cd190385d17790cc3eb3821b1094b00aacf325 (patch) | |
| tree | e37c2a1592816f77a65078fb260aff10b07c7c40 | |
| parent | arm64: hibernate: Support DEBUG_PAGEALLOC (diff) | |
| download | linux-e7cd190385d17790cc3eb3821b1094b00aacf325.tar.xz linux-e7cd190385d17790cc3eb3821b1094b00aacf325.zip | |
arm64: mark reserved memblock regions explicitly in iomem
Kdump(kexec-tools) parses /proc/iomem to identify all the memory regions
on the system. Since the current kernel names "nomap" regions, like UEFI
runtime services code/data, as "System RAM," kexec-tools sets up elf core
header to include them in a crash dump file (/proc/vmcore).
Then crash dump kernel parses UEFI memory map again, re-marks those regions
as "nomap" and does not create a memory mapping for them unlike the other
areas of System RAM. In this case, copying /proc/vmcore through
copy_oldmem_page() on crash dump kernel will end up with a kernel abort,
as reported in [1].
This patch names all the "nomap" regions explicitly as "reserved" so that
we can exclude them from a crash dump file. acpi_os_ioremap() must also
be modified because those regions have WB attributes [2].
Apart from kdump, this change also matches x86's use of acpi (and
/proc/iomem).
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/448186.html
[2] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/450089.html
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
| -rw-r--r-- | arch/arm64/include/asm/acpi.h | 8 | ||||
| -rw-r--r-- | arch/arm64/kernel/setup.c | 9 |
2 files changed, 13 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 5420cb0fcb3e..e517088d635f 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -12,7 +12,7 @@ #ifndef _ASM_ACPI_H #define _ASM_ACPI_H -#include <linux/mm.h> +#include <linux/memblock.h> #include <linux/psci.h> #include <asm/cputype.h> @@ -32,7 +32,11 @@ static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) { - if (!page_is_ram(phys >> PAGE_SHIFT)) + /* + * EFI's reserve_regions() call adds memory with the WB attribute + * to memblock via early_init_dt_add_memory_arch(). + */ + if (!memblock_is_memory(phys)) return ioremap(phys, size); return ioremap_cache(phys, size); diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 536dce22fe76..514b4e3ba029 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -206,10 +206,15 @@ static void __init request_standard_resources(void) for_each_memblock(memory, region) { res = alloc_bootmem_low(sizeof(*res)); - res->name = "System RAM"; + if (memblock_is_nomap(region)) { + res->name = "reserved"; + res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; + } else { + res->name = "System RAM"; + res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; + } res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1; - res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; request_resource(&iomem_resource, res); |