Messages in this thread Patch in this message |  | | From | Paul Jackson <> | Date | Sun, 15 Jun 2008 23:30:01 -0700 | Subject | [PATCH 4/8] x86 boot: allow overlapping ebda and efi memmap memory ranges |
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From: Paul Jackson <pj@sgi.com>
In order to support EFI firmware which places the EFI memmap within the EBDA (Extended BIOS Data Area), allow for the possibility that we might try to reserve_early() the "EFI memmap" area twice, once as part of the larger EBDA area and once by itself. Since the reserve_early() mechanism does not allow such double reservations, detect and avoid the "EFI memmap" reserve_early() call if it would overlap the EBDA area.
Signed-off-by: Paul Jackson <pj@sgi.com>
--- arch/x86/kernel/efi.c | 3 ++- arch/x86/kernel/head.c | 12 +++++++++++- include/asm-x86/bios_ebda.h | 1 + include/asm-x86/e820.h | 1 + 4 files changed, 15 insertions(+), 2 deletions(-)
--- linux.orig/arch/x86/kernel/efi.c 2008-06-13 00:51:17.350774123 -0700 +++ linux/arch/x86/kernel/efi.c 2008-06-13 00:53:10.053599898 -0700 @@ -253,7 +253,8 @@ void __init efi_reserve_early(void) boot_params.efi_info.efi_memdesc_size; memmap.desc_version = boot_params.efi_info.efi_memdesc_version; memmap.desc_size = boot_params.efi_info.efi_memdesc_size; - reserve_early(pmap, pmap + memmap.nr_map * memmap.desc_size, + if (!range_in_ebda_area(pmap, pmap + memmap.nr_map * memmap.desc_size)) + reserve_early(pmap, pmap + memmap.nr_map * memmap.desc_size, "EFI memmap"); } --- linux.orig/arch/x86/kernel/head.c 2008-06-13 00:51:17.350774123 -0700 +++ linux/arch/x86/kernel/head.c 2008-06-13 00:52:45.208095174 -0700 @@ -6,6 +6,9 @@ #define BIOS_LOWMEM_KILOBYTES 0x413 +static unsigned int __initdata ebda_start; +static unsigned int __initdata ebda_end; + /* * The BIOS places the EBDA/XBDA at the top of conventional * memory, and usually decreases the reported amount of @@ -51,7 +54,14 @@ void __init reserve_ebda_region(void) lowmem = 0x9f000; /* reserve all memory between lowmem and the 1MB mark */ - reserve_early(lowmem, 0x100000, "BIOS reserved"); + ebda_start = lowmem; + ebda_end = 0x100000; + reserve_early(ebda_start, ebda_end, "BIOS reserved"); +} + +int __init range_in_ebda_area(u64 start, u64 end) +{ + return start >= ebda_start && end <= ebda_end; } void __init reserve_setup_data(void) --- linux.orig/include/asm-x86/bios_ebda.h 2008-06-13 00:51:17.350774123 -0700 +++ linux/include/asm-x86/bios_ebda.h 2008-06-13 00:51:31.819650439 -0700 @@ -15,5 +15,6 @@ static inline unsigned int get_bios_ebda } void reserve_ebda_region(void); +int range_in_ebda_area(u64 start, u64 end); #endif /* _MACH_BIOS_EBDA_H */ --- linux.orig/include/asm-x86/e820.h 2008-06-13 00:51:17.354774365 -0700 +++ linux/include/asm-x86/e820.h 2008-06-13 00:51:31.831651166 -0700 @@ -84,6 +84,7 @@ extern unsigned long end_user_pfn; extern u64 find_e820_area(u64 start, u64 end, u64 size, u64 align); extern u64 find_e820_area_size(u64 start, u64 *sizep, u64 align); extern void reserve_early(u64 start, u64 end, char *name); +extern int range_in_ebda_area(u64 start, u64 end); extern void free_early(u64 start, u64 end); extern void early_res_to_bootmem(u64 start, u64 end); extern int page_is_reserved_early(unsigned long pagenr); -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson <pj@sgi.com> 1.650.933.1373
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