From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Mon, 23 Mar 2015 16:36:54 +0100 Subject: [PATCH 2/4] arm64: fixmap: move translation tables to dedicated region In-Reply-To: <1427125016-3873-1-git-send-email-ard.biesheuvel@linaro.org> References: <1427125016-3873-1-git-send-email-ard.biesheuvel@linaro.org> Message-ID: <1427125016-3873-3-git-send-email-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This moves the fixmap translation tables to a dedicated region in the linker map. This is needed for a split kernel text from the linear mapping, to ensure that the contents of the tables rely on a single translation regime. Also make the population of the translation levels conditional, so that the kernel text can share some levels of translation if needed. Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/linkage.h | 2 ++ arch/arm64/kernel/vmlinux.lds.S | 15 ++++++++++----- arch/arm64/mm/mmu.c | 15 +++++++++------ 3 files changed, 21 insertions(+), 11 deletions(-) diff --git a/arch/arm64/include/asm/linkage.h b/arch/arm64/include/asm/linkage.h index 636c1bced7d4..dc9354de6f52 100644 --- a/arch/arm64/include/asm/linkage.h +++ b/arch/arm64/include/asm/linkage.h @@ -4,4 +4,6 @@ #define __ALIGN .align 4 #define __ALIGN_STR ".align 4" +#define __pgdir __attribute__((__section__(".pgdir"))) + #endif diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 434ef407ef0f..d3885043f0b7 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -149,11 +149,16 @@ SECTIONS BSS_SECTION(0, 0, 0) - . = ALIGN(PAGE_SIZE); - idmap_pg_dir = .; - . += IDMAP_DIR_SIZE; - swapper_pg_dir = .; - . += SWAPPER_DIR_SIZE; + .pgdir : { + . = ALIGN(PAGE_SIZE); + __pgdir_start = .; + idmap_pg_dir = .; + . += IDMAP_DIR_SIZE; + *(.pgdir) + swapper_pg_dir = .; + . += SWAPPER_DIR_SIZE; + __pgdir_stop = .; + } _end = .; diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 43496748e3d9..bb3ce41130f3 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -549,12 +549,12 @@ void vmemmap_free(unsigned long start, unsigned long end) } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ -static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss; +static pte_t bm_pte[PTRS_PER_PTE] __pgdir; #if CONFIG_ARM64_PGTABLE_LEVELS > 2 -static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss; +static pmd_t bm_pmd[PTRS_PER_PMD] __pgdir; #endif #if CONFIG_ARM64_PGTABLE_LEVELS > 3 -static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss; +static pud_t bm_pud[PTRS_PER_PUD] __pgdir; #endif static inline pud_t * fixmap_pud(unsigned long addr) @@ -592,11 +592,14 @@ void __init early_fixmap_init(void) unsigned long addr = FIXADDR_START; pgd = pgd_offset_k(addr); - pgd_populate(&init_mm, pgd, bm_pud); + if (pgd_none(*pgd)) + pgd_populate(&init_mm, pgd, bm_pud); pud = pud_offset(pgd, addr); - pud_populate(&init_mm, pud, bm_pmd); + if (pud_none(*pud)) + pud_populate(&init_mm, pud, bm_pmd); pmd = pmd_offset(pud, addr); - pmd_populate_kernel(&init_mm, pmd, bm_pte); + if (pmd_none(*pmd)) + pmd_populate_kernel(&init_mm, pmd, bm_pte); /* * The boot-ioremap range spans multiple pmds, for which -- 1.8.3.2