Messages in this thread |  | | Date | Sun, 15 Jun 2008 23:54:38 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH 4/8] x86 boot: allow overlapping ebda and efi memmap memory ranges |
| |
On Sun, Jun 15, 2008 at 11:30 PM, Paul Jackson <pj@sgi.com> wrote: > 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);
how about patial overlapping?
YH
|  |