From e7cd190385d17790cc3eb3821b1094b00aacf325 Mon Sep 17 00:00:00 2001 From: AKASHI Takahiro Date: Mon, 22 Aug 2016 15:55:24 +0900 Subject: [PATCH] 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 Tested-by: James Morse Reviewed-by: James Morse Signed-off-by: AKASHI Takahiro Signed-off-by: Will Deacon --- arch/arm64/include/asm/acpi.h | 8 ++++++-- 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 +#include #include #include @@ -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); -- 2.20.1