From 9ed2b4616d4e846ece2a04cb5007ce1d1bd9e3f3 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Fri, 18 Nov 2022 11:01:02 +0530 Subject: [PATCH] arm64/mm: Drop redundant BUG_ON(!pgtable_alloc) __create_pgd_mapping_locked() expects a page allocator used while mapping a virtual range. This page allocator function propagates down the call chain, while building intermediate levels in the page table. Passed page allocator is a necessary ingredient required to build the page table but its presence can be asserted just once in the very beginning rather than in all the down stream functions. This consolidates BUG_ON(!pgtable_alloc) checks just in a single place i.e __create_pgd_mapping_locked(). Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Andrew Morton Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20221118053102.500216-1-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/mm/mmu.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index d386033a074c..73a12b3abf82 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -207,7 +207,6 @@ static void alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr, if (flags & NO_EXEC_MAPPINGS) pmdval |= PMD_TABLE_PXN; - BUG_ON(!pgtable_alloc); pte_phys = pgtable_alloc(PAGE_SHIFT); __pmd_populate(pmdp, pte_phys, pmdval); pmd = READ_ONCE(*pmdp); @@ -285,7 +284,6 @@ static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr, if (flags & NO_EXEC_MAPPINGS) pudval |= PUD_TABLE_PXN; - BUG_ON(!pgtable_alloc); pmd_phys = pgtable_alloc(PMD_SHIFT); __pud_populate(pudp, pmd_phys, pudval); pud = READ_ONCE(*pudp); @@ -324,7 +322,6 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end, if (flags & NO_EXEC_MAPPINGS) p4dval |= P4D_TABLE_PXN; - BUG_ON(!pgtable_alloc); pud_phys = pgtable_alloc(PUD_SHIFT); __p4d_populate(p4dp, pud_phys, p4dval); p4d = READ_ONCE(*p4dp); @@ -383,6 +380,7 @@ static void __create_pgd_mapping_locked(pgd_t *pgdir, phys_addr_t phys, phys &= PAGE_MASK; addr = virt & PAGE_MASK; end = PAGE_ALIGN(virt + size); + BUG_ON(!pgtable_alloc); do { next = pgd_addr_end(addr, end);