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>

1 files changed, 28 insertions, 3 deletions

diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c
index 1736acc4d7aa..96f7ac0bbf01 100644
--- a/arch/x86/kernel/efi.c
+++ b/arch/x86/kernel/efi.c
@@ -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;
 
-                if (md->attribute & EFI_MEMORY_WB)
-                        e820_type = E820_RAM;
-                else
+                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);