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>
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 @@
# 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 @@
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 @@
/* 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;
}
/*