From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Mon, 4 Jan 2016 17:56:44 +0000 Subject: [PATCHv2 11/18] arm64: mm: avoid redundant __pa(__va(x)) In-Reply-To: <1451930211-22460-1-git-send-email-mark.rutland@arm.com> References: <1451930211-22460-1-git-send-email-mark.rutland@arm.com> Message-ID: <1451930211-22460-12-git-send-email-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org When we "upgrade" to a section mapping, we free any table we made redundant by giving it back to memblock. To get the PA, we acquire the physical address and convert this to a VA, then subsequently convert this back to a PA. This works currently, but will not work if the tables are not accessed via linear map VAs (e.g. is we use fixmap slots). This patch uses {pmd,pud}_page_paddr to acquire the PA. This avoids the __pa(__va()) round trip, saving some work and avoiding reliance on the linear mapping. Signed-off-by: Mark Rutland Cc: Ard Biesheuvel Cc: Catalin Marinas Cc: Jeremy Linton Cc: Laura Abbott Cc: Will Deacon --- arch/arm64/mm/mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index c3ea9df..8879aed 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -171,7 +171,7 @@ static void alloc_init_pmd(struct mm_struct *mm, pud_t *pud, if (!pmd_none(old_pmd)) { flush_tlb_all(); if (pmd_table(old_pmd)) { - phys_addr_t table = __pa(pte_offset_map(&old_pmd, 0)); + phys_addr_t table = pmd_page_paddr(old_pmd); if (!WARN_ON_ONCE(slab_is_available())) memblock_free(table, PAGE_SIZE); } @@ -232,7 +232,7 @@ static void alloc_init_pud(struct mm_struct *mm, pgd_t *pgd, if (!pud_none(old_pud)) { flush_tlb_all(); if (pud_table(old_pud)) { - phys_addr_t table = __pa(pmd_offset(&old_pud, 0)); + phys_addr_t table = pud_page_paddr(old_pud); if (!WARN_ON_ONCE(slab_is_available())) memblock_free(table, PAGE_SIZE); } -- 1.9.1