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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-11-21 11:41:57 +0000 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-22 11:05:33 +0000 |
commit | 614dd0585f376a25c638abbed9c5fbd21d7baece (patch) | |
tree | 9bd2c8bb3523632901e3ddc3f9b1eba24e7671ab /arch/arm/mm/idmap.c | |
parent | 26bbf0b57a0848932f725076bcb1245ca696e8d3 (diff) | |
download | linux-stable-614dd0585f376a25c638abbed9c5fbd21d7baece.tar.gz linux-stable-614dd0585f376a25c638abbed9c5fbd21d7baece.tar.bz2 linux-stable-614dd0585f376a25c638abbed9c5fbd21d7baece.zip |
ARM: pgtable: collect up identity mapping functions
We have two places where we create identity mappings - one when we bring
secondary CPUs online, and one where we setup some mappings for soft-
reboot. Combine these two into a single implementation. Also collect
the identity mapping deletion function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/idmap.c')
-rw-r--r-- | arch/arm/mm/idmap.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c new file mode 100644 index 000000000000..034124d1272d --- /dev/null +++ b/arch/arm/mm/idmap.c @@ -0,0 +1,51 @@ +#include <linux/kernel.h> + +#include <asm/cputype.h> +#include <asm/pgalloc.h> +#include <asm/pgtable.h> + +void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end) +{ + unsigned long prot; + + prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE; + if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) + prot |= PMD_BIT4; + + for (addr &= PGDIR_MASK; addr < end;) { + pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr); + pmd[0] = __pmd(addr | prot); + addr += SECTION_SIZE; + pmd[1] = __pmd(addr | prot); + addr += SECTION_SIZE; + flush_pmd_entry(pmd); + } +} + +#ifdef CONFIG_SMP +void identity_mapping_del(pgd_t *pgd, unsigned long addr, unsigned long end) +{ + for (addr &= PGDIR_MASK; addr < end; addr += PGDIR_SIZE) { + pmd_t *pmd = pmd_offset(pgd + pgd_index(addr), addr); + pmd[0] = __pmd(0); + pmd[1] = __pmd(0); + clean_pmd_entry(pmd); + } +} +#endif + +/* + * In order to soft-boot, we need to insert a 1:1 mapping in place of + * the user-mode pages. This will then ensure that we have predictable + * results when turning the mmu off + */ +void setup_mm_for_reboot(char mode) +{ + /* + * We need to access to user-mode page tables here. For kernel threads + * we don't have any user-mode mappings so we use the context that we + * "borrowed". + */ + identity_mapping_add(current->active_mm->pgd, 0, TASK_SIZE); + local_flush_tlb_all(); +} |