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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