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| author | Jeremy Fitzhardinge <jeremy@goop.org> | 2008-07-01 23:46:36 (GMT) |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-07-08 11:16:29 (GMT) |
| commit | ef5e94af16c0c82452e1ea5d387e1203dd2198d6 (patch) | |
| tree | 7d80d1bba8a0c58e91995ead6f8b2cd6eddd314e /arch/x86/mm | |
| parent | 8490638cf0fb3975f7636c5268f27d5daf4eaaa5 (diff) | |
| download | linux-ef5e94af16c0c82452e1ea5d387e1203dd2198d6.tar.xz | |
x86_32: remove __PAGE_KERNEL(_EXEC)
From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Older x86-32 processors do not support global mappings (PGD), so must
only use it if the processor supports it.
The _PAGE_KERNEL* flags always have _PAGE_KERNEL set, since logically
we always want it set.
This is OK even on processors which do not support PGD, since all
_PAGE flags are masked with __supported_pte_mask before being turned
into a real in-pagetable pte. On 32-bit systems, __supported_pte_mask
is initialized to not contain _PAGE_GLOBAL, and it is then added if
the CPU is found to support it.
The x86-32 code used to use __PAGE_KERNEL/__PAGE_KERNEL_EXEC for this
purpose, but they're now redundant and can be removed.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/init_32.c | 10 |
1 files changed, 2 insertions, 8 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 8efe872..b5a0fd5 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -383,11 +383,6 @@ static void __init set_highmem_pages_init(void) # define set_highmem_pages_init() do { } while (0) #endif /* CONFIG_HIGHMEM */ -pteval_t __PAGE_KERNEL = _PAGE_KERNEL; -EXPORT_SYMBOL(__PAGE_KERNEL); - -pteval_t __PAGE_KERNEL_EXEC = _PAGE_KERNEL_EXEC; - void __init native_pagetable_setup_start(pgd_t *base) { unsigned long pfn, va; @@ -509,7 +504,7 @@ void zap_low_mappings(void) int nx_enabled; -pteval_t __supported_pte_mask __read_mostly = ~_PAGE_NX; +pteval_t __supported_pte_mask __read_mostly = ~(_PAGE_NX | _PAGE_GLOBAL); EXPORT_SYMBOL_GPL(__supported_pte_mask); #ifdef CONFIG_X86_PAE @@ -796,8 +791,7 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, /* Enable PGE if available */ if (cpu_has_pge) { set_in_cr4(X86_CR4_PGE); - __PAGE_KERNEL |= _PAGE_GLOBAL; - __PAGE_KERNEL_EXEC |= _PAGE_GLOBAL; + __supported_pte_mask |= _PAGE_GLOBAL; } /* |