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[ARM] Control v6 'global' bit via Linux PTE entries 

Unfortunately, we can't use the "user" bit in the page tables to
control whether a page table entry is "global" or "asid" specific,
since the vector page is mapped as "user" accessible but is not
process specific.

Therefore, give direct control of the ARMv6 "nG" (not global)
bit to the mm layers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2005-08-10 16:18:35 +01:00 committed by Russell King
parent 1b9749e7f1
commit 6626a7076d
3 changed files with 18 additions and 5 deletions
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17
arch/arm/mm/mm-armv.c
View File

@ -383,6 +383,7 @@ static void __init build_mem_type_table(void)
{
struct cachepolicy *cp;
unsigned int cr = get_cr();
unsigned int user_pgprot;
int cpu_arch = cpu_architecture();
int i;
@ -408,6 +409,9 @@ static void __init build_mem_type_table(void)
}
}
cp = &cache_policies[cachepolicy];
user_pgprot = cp->pte;
/*
* ARMv6 and above have extended page tables.
*/
@ -426,11 +430,18 @@ static void __init build_mem_type_table(void)
mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
/*
* Mark the device area as "shared device"
*/
mem_types[MT_DEVICE].prot_pte |= L_PTE_BUFFERABLE;
mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
}
cp = &cache_policies[cachepolicy];
/*
* User pages need to be mapped with the ASID
* (iow, non-global)
*/
user_pgprot |= L_PTE_ASID;
}
if (cpu_arch >= CPU_ARCH_ARMv5) {
mem_types[MT_LOW_VECTORS].prot_pte |= cp->pte & PTE_CACHEABLE;
@ -448,7 +459,7 @@ static void __init build_mem_type_table(void)
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
v &= (~(PTE_BUFFERABLE|PTE_CACHEABLE)) | cp->pte;
v &= (~(PTE_BUFFERABLE|PTE_CACHEABLE)) | user_pgprot;
protection_map[i] = __pgprot(v);
}

4
arch/arm/mm/proc-v6.S
View File

@ -133,7 +133,7 @@ ENTRY(cpu_v6_switch_mm)
ENTRY(cpu_v6_set_pte)
str r1, [r0], #-2048 @ linux version
bic r2, r1, #0x00000ff0
bic r2, r1, #0x000007f0
bic r2, r2, #0x00000003
orr r2, r2, #PTE_EXT_AP0 | 2
@ -142,7 +142,7 @@ ENTRY(cpu_v6_set_pte)
orreq r2, r2, #PTE_EXT_APX
tst r1, #L_PTE_USER
orrne r2, r2, #PTE_EXT_AP1 | PTE_EXT_NG
orrne r2, r2, #PTE_EXT_AP1
tstne r2, #PTE_EXT_APX
bicne r2, r2, #PTE_EXT_APX | PTE_EXT_AP0

2
include/asm-arm/pgtable.h
View File

@ -230,6 +230,8 @@ extern void __pgd_error(const char *file, int line, unsigned long val);
#define L_PTE_WRITE (1 << 5)
#define L_PTE_EXEC (1 << 6)
#define L_PTE_DIRTY (1 << 7)
#define L_PTE_SHARED (1 << 10) /* shared between CPUs (v6) */
#define L_PTE_ASID (1 << 11) /* non-global (use ASID, v6) */
#ifndef __ASSEMBLY__