From 1074dd44c5ba377f90e2d0d99a784f73dbea6ff7 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Wed, 4 Nov 2020 12:07:13 +0530 Subject: [PATCH] RISC-V: Use non-PGD mappings for early DTB access Currently, we use PGD mappings for early DTB mapping in early_pgd but this breaks Linux kernel on SiFive Unleashed because on SiFive Unleashed PMP checks don't work correctly for PGD mappings. To fix early DTB mappings on SiFive Unleashed, we use non-PGD mappings (i.e. PMD) for early DTB access. Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap") Signed-off-by: Anup Patel Reviewed-by: Atish Patra Tested-by: Atish Patra Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 42c14eb6bc43..8e577f14f120 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -293,6 +293,7 @@ pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; #define NUM_EARLY_PMDS (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE) #endif pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE); +pmd_t early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); static pmd_t *__init get_pmd_virt_early(phys_addr_t pa) { @@ -490,6 +491,18 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) load_pa + (va - PAGE_OFFSET), map_size, PAGE_KERNEL_EXEC); +#ifndef __PAGETABLE_PMD_FOLDED + /* Setup early PMD for DTB */ + create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA, + (uintptr_t)early_dtb_pmd, PGDIR_SIZE, PAGE_TABLE); + /* Create two consecutive PMD mappings for FDT early scan */ + pa = dtb_pa & ~(PMD_SIZE - 1); + create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA, + pa, PMD_SIZE, PAGE_KERNEL); + create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE, + pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL); + dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1)); +#else /* Create two consecutive PGD mappings for FDT early scan */ pa = dtb_pa & ~(PGDIR_SIZE - 1); create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA, @@ -497,6 +510,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE, pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL); dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1)); +#endif dtb_early_pa = dtb_pa; /*