From 1bd14a66ee5200d6a24419cbd2e0a0fccd4da36f Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Wed, 7 Oct 2020 14:51:59 -0700 Subject: RISC-V: Remove any memblock representing unusable memory area RISC-V limits the physical memory size by -PAGE_OFFSET. Any memory beyond that size from DRAM start is unusable. Just remove any memblock pointing to those memory region without worrying about computing the maximum size. Signed-off-by: Atish Patra Reviewed-by: Mike Rapoport Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) (limited to 'arch/riscv/mm/init.c') diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index ea933b789a88..42c14eb6bc43 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -154,9 +154,8 @@ disable: void __init setup_bootmem(void) { - phys_addr_t mem_size = 0; - phys_addr_t total_mem = 0; - phys_addr_t mem_start, start, end = 0; + phys_addr_t mem_start = 0; + phys_addr_t start, end = 0; phys_addr_t vmlinux_end = __pa_symbol(&_end); phys_addr_t vmlinux_start = __pa_symbol(&_start); u64 i; @@ -164,21 +163,18 @@ void __init setup_bootmem(void) /* Find the memory region containing the kernel */ for_each_mem_range(i, &start, &end) { phys_addr_t size = end - start; - if (!total_mem) + if (!mem_start) mem_start = start; if (start <= vmlinux_start && vmlinux_end <= end) BUG_ON(size == 0); - total_mem = total_mem + size; } /* - * Remove memblock from the end of usable area to the - * end of region + * The maximal physical memory size is -PAGE_OFFSET. + * Make sure that any memory beyond mem_start + (-PAGE_OFFSET) is removed + * as it is unusable by kernel. */ - mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET); - if (mem_start + mem_size < end) - memblock_remove(mem_start + mem_size, - end - mem_start - mem_size); + memblock_enforce_memory_limit(mem_start - PAGE_OFFSET); /* Reserve from the start of the kernel to the end of the kernel */ memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); -- cgit v1.2.3 From 1074dd44c5ba377f90e2d0d99a784f73dbea6ff7 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Wed, 4 Nov 2020 12:07:13 +0530 Subject: 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(+) (limited to 'arch/riscv/mm/init.c') 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; /* -- cgit v1.2.3