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| author | Kees Cook <keescook@chromium.org> | 2014-04-04 23:27:49 +0200 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2014-10-16 23:38:52 +0200 |
| commit | 99b4ac9afce4129323b5b4c7002a942a9489914c (patch) | |
| tree | e3e5a3a562883eac4999f72e940fa5261c518b46 /arch | |
| parent | ARM: expand fixmap region to 3MB (diff) | |
| download | linux-99b4ac9afce4129323b5b4c7002a942a9489914c.tar.xz linux-99b4ac9afce4129323b5b4c7002a942a9489914c.zip | |
arm: fixmap: implement __set_fixmap()
This is used from set_fixmap() and clear_fixmap() via asm-generic/fixmap.h.
Also makes sure that the fixmap allocation fits into the expected range.
Based on patch by Rabin Vincent.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Rabin Vincent <rabin@rab.in>
Acked-by: Nicolas Pitre <nico@linaro.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/fixmap.h | 2 | ||||
| -rw-r--r-- | arch/arm/mm/mmu.c | 24 |
2 files changed, 26 insertions, 0 deletions
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index d984ca69ce19..714606f70425 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -14,6 +14,8 @@ enum fixed_addresses { __end_of_fixed_addresses }; +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); + #include <asm-generic/fixmap.h> #endif diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 7fa0966cd15f..bdf5c94f7c36 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -22,6 +22,7 @@ #include <asm/cputype.h> #include <asm/sections.h> #include <asm/cachetype.h> +#include <asm/fixmap.h> #include <asm/sections.h> #include <asm/setup.h> #include <asm/smp_plat.h> @@ -393,6 +394,29 @@ SET_MEMORY_FN(x, pte_set_x) SET_MEMORY_FN(nx, pte_set_nx) /* + * To avoid TLB flush broadcasts, this uses local_flush_tlb_kernel_range(). + * As a result, this can only be called with preemption disabled, as under + * stop_machine(). + */ +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) +{ + unsigned long vaddr = __fix_to_virt(idx); + pte_t *pte = pte_offset_kernel(pmd_off_k(vaddr), vaddr); + + /* Make sure fixmap region does not exceed available allocation. */ + BUILD_BUG_ON(FIXADDR_START + (__end_of_fixed_addresses * PAGE_SIZE) > + FIXADDR_END); + BUG_ON(idx >= __end_of_fixed_addresses); + + if (pgprot_val(prot)) + set_pte_at(NULL, vaddr, pte, + pfn_pte(phys >> PAGE_SHIFT, prot)); + else + pte_clear(NULL, vaddr, pte); + local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); +} + +/* * Adjust the PMD section entries according to the CPU in use. */ static void __init build_mem_type_table(void) |