Commit e2a71476 authored Jun 16, 2009 by Cliff Wickman Committed by H. Peter Anvin Jun 16, 2009

x86: correct the conversion of EFI memory types



This patch causes all the EFI_RESERVED_TYPE memory reservations to be recorded
in the e820 table as type E820_RESERVED.

(This patch replaces one called 'x86: vendor reserved memory type'.
 This version has been discussed a bit with Peter and Yinghai but not given
 a final opinion.)

Without this patch EFI_RESERVED_TYPE memory reservations may be
marked usable in the e820 table. There may be a collision between
kernel use and some reserver's use of this memory.

(An example use of this functionality is the UV system, which
 will access extremely large areas of memory with a memory engine
 that allows a user to address beyond the processor's range.  Such
 areas are reserved in the EFI table by the BIOS.
 Some loaders have a restricted number of entries possible in the e820 table,
 hence the need to record the reservations in the unrestricted EFI table.)

The call to do_add_efi_memmap() is only made if "add_efi_memmap" is specified
on the kernel command line.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

parent 95ee14e4

arch/x86/kernel/efi.c

+28 −3

Original line number	Diff line number	Diff line
		@@ -240,10 +240,35 @@ static void __init do_add_efi_memmap(void)
		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
		int e820_type;

		switch (md->type) {
		case EFI_LOADER_CODE:
		case EFI_LOADER_DATA:
		case EFI_BOOT_SERVICES_CODE:
		case EFI_BOOT_SERVICES_DATA:
		case EFI_CONVENTIONAL_MEMORY:
		if (md->attribute & EFI_MEMORY_WB)
		e820_type = E820_RAM;
		else
		e820_type = E820_RESERVED;
		break;
		case EFI_ACPI_RECLAIM_MEMORY:
		e820_type = E820_ACPI;
		break;
		case EFI_ACPI_MEMORY_NVS:
		e820_type = E820_NVS;
		break;
		case EFI_UNUSABLE_MEMORY:
		e820_type = E820_UNUSABLE;
		break;
		default:
		/*
		* EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
		* EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
		* EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
		*/
		e820_type = E820_RESERVED;
		break;
		}
		e820_add_region(start, size, e820_type);
		}
		sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);

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