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| author | Matt Fleming <matt.fleming@intel.com> | 2012-09-07 19:23:51 +0200 |
|---|---|---|
| committer | Matt Fleming <matt.fleming@intel.com> | 2012-10-30 11:39:19 +0100 |
| commit | 53b87cf088e2ea68d7c59619d0214cc15bb76133 (patch) | |
| tree | afa920fe2dc6e11dc023147fc6bffafcf19a2508 /arch/x86/realmode | |
| parent | efivarfs: Add documentation for the EFI variable filesystem (diff) | |
| download | linux-53b87cf088e2ea68d7c59619d0214cc15bb76133.tar.xz linux-53b87cf088e2ea68d7c59619d0214cc15bb76133.zip | |
x86, mm: Include the entire kernel memory map in trampoline_pgd
There are various pieces of code in arch/x86 that require a page table
with an identity mapping. Make trampoline_pgd a proper kernel page
table, it currently only includes the kernel text and module space
mapping.
One new feature of trampoline_pgd is that it now has mappings for the
physical I/O device addresses, which are inserted at ioremap()
time. Some broken implementations of EFI firmware require these
mappings to always be around.
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Diffstat (limited to 'arch/x86/realmode')
| -rw-r--r-- | arch/x86/realmode/init.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c index cbca565af5bd..8e6ab6137852 100644 --- a/arch/x86/realmode/init.c +++ b/arch/x86/realmode/init.c @@ -78,8 +78,21 @@ void __init setup_real_mode(void) *trampoline_cr4_features = read_cr4(); trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd); - trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE; - trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE; + + /* + * Create an identity mapping for all of physical memory. + */ + for (i = 0; i <= pgd_index(max_pfn << PAGE_SHIFT); i++) { + int index = pgd_index(PAGE_OFFSET) + i; + + trampoline_pgd[i] = (u64)pgd_val(swapper_pg_dir[index]); + } + + /* + * Copy the upper-half of the kernel pages tables. + */ + for (i = pgd_index(PAGE_OFFSET); i < PTRS_PER_PGD; i++) + trampoline_pgd[i] = (u64)pgd_val(swapper_pg_dir[i]); #endif } |