[PATCH v2 2/5] arm64: mmu: move TLB maintenance from callers to create_mapping_late()
From: mark.rutland@arm.com (Mark Rutland)
Date: 2017-02-14 15:54:36
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kvmarm
On Sat, Feb 11, 2017 at 08:23:03PM +0000, Ard Biesheuvel wrote:
In preparation of changing the way we invoke create_mapping_late() (which is currently invoked twice from the same function), move the TLB flushing it performs from the caller into create_mapping_late() itself, and change it to a TLB maintenance by VA rather than a full flush, which is more appropriate here.
It's not immediately clear what's meant by "changing the way we invoke create_mapping_late()" here. It's probably worth explicitly mentioning that we need to add another caller of create_mapping_late(), and this saves us adding (overly strong) TLB maintenance to all callers.
quoted hunk ↗ jump to hunk
Signed-off-by: Ard Biesheuvel <redacted> --- arch/arm64/mm/mmu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 2131521ddc24..9e0ec1a8cd3b 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c@@ -356,6 +356,9 @@ static void create_mapping_late(phys_addr_t phys, unsigned long virt, __create_pgd_mapping(init_mm.pgd, phys, virt, size, prot, NULL, debug_pagealloc_enabled()); + + /* flush the TLBs after updating live kernel mappings */ + flush_tlb_kernel_range(virt, virt + size); }
It feels a little odd to have the maintenance here given we still call this *create*_mapping_late. Given the only users of this are changing permissions, perhaps we should rename this to change_mapping_prot(), or something like that? Otherwise, this looks fine to me, and boots fine. Either way: Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Thanks, Mark.
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static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end)@@ -438,9 +441,6 @@ void mark_rodata_ro(void) create_mapping_late(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, section_size, PAGE_KERNEL_RO); - /* flush the TLBs after updating live kernel mappings */ - flush_tlb_all(); - debug_checkwx(); }-- 2.7.4