From e8dcb61f2ade040a372d66907d220dd3fdee2505 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Thu, 17 Sep 2020 15:37:12 -0700 Subject: [PATCH] RISC-V: Implement late mapping page table allocation functions Currently, page table setup is done during setup_va_final where fixmap can be used to create the temporary mappings. The physical frame is allocated from memblock_alloc_* functions. However, this won't work if page table mapping needs to be created for a different mm context (i.e. efi mm) at a later point of time. Use generic kernel page allocation function & macros for any mapping after setup_vm_final. Signed-off-by: Atish Patra Reviewed-by: Anup Patel Acked-by: Mike Rapoport Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 130 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 99 insertions(+), 31 deletions(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index b75ebe8..63acc81 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -32,6 +32,15 @@ extern char _start[]; void *dtb_early_va __initdata; uintptr_t dtb_early_pa __initdata; +struct pt_alloc_ops { + pte_t *(*get_pte_virt)(phys_addr_t pa); + phys_addr_t (*alloc_pte)(uintptr_t va); +#ifndef __PAGETABLE_PMD_FOLDED + pmd_t *(*get_pmd_virt)(phys_addr_t pa); + phys_addr_t (*alloc_pmd)(uintptr_t va); +#endif +}; + static void __init zone_sizes_init(void) { unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; @@ -203,6 +212,8 @@ void __init setup_bootmem(void) } #ifdef CONFIG_MMU +static struct pt_alloc_ops pt_ops; + unsigned long va_pa_offset; EXPORT_SYMBOL(va_pa_offset); unsigned long pfn_base; @@ -211,7 +222,6 @@ EXPORT_SYMBOL(pfn_base); pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; -static bool mmu_enabled; #define MAX_EARLY_MAPPING_SIZE SZ_128M @@ -234,27 +244,46 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) } } -static pte_t *__init get_pte_virt(phys_addr_t pa) +static inline pte_t *__init get_pte_virt_early(phys_addr_t pa) { - if (mmu_enabled) { - clear_fixmap(FIX_PTE); - return (pte_t *)set_fixmap_offset(FIX_PTE, pa); - } else { - return (pte_t *)((uintptr_t)pa); - } + return (pte_t *)((uintptr_t)pa); } -static phys_addr_t __init alloc_pte(uintptr_t va) +static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa) +{ + clear_fixmap(FIX_PTE); + return (pte_t *)set_fixmap_offset(FIX_PTE, pa); +} + +static inline pte_t *get_pte_virt_late(phys_addr_t pa) +{ + return (pte_t *) __va(pa); +} + +static inline phys_addr_t __init alloc_pte_early(uintptr_t va) { /* * We only create PMD or PGD early mappings so we * should never reach here with MMU disabled. */ - BUG_ON(!mmu_enabled); + BUG(); +} +static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va) +{ return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); } +static phys_addr_t alloc_pte_late(uintptr_t va) +{ + unsigned long vaddr; + + vaddr = __get_free_page(GFP_KERNEL); + if (!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr))) + BUG(); + return __pa(vaddr); +} + static void __init create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz, pgprot_t prot) @@ -279,28 +308,46 @@ pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; #endif pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE); -static pmd_t *__init get_pmd_virt(phys_addr_t pa) +static pmd_t *__init get_pmd_virt_early(phys_addr_t pa) { - if (mmu_enabled) { - clear_fixmap(FIX_PMD); - return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); - } else { - return (pmd_t *)((uintptr_t)pa); - } + /* Before MMU is enabled */ + return (pmd_t *)((uintptr_t)pa); } -static phys_addr_t __init alloc_pmd(uintptr_t va) +static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa) { - uintptr_t pmd_num; + clear_fixmap(FIX_PMD); + return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); +} + +static pmd_t *get_pmd_virt_late(phys_addr_t pa) +{ + return (pmd_t *) __va(pa); +} - if (mmu_enabled) - return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); +static phys_addr_t __init alloc_pmd_early(uintptr_t va) +{ + uintptr_t pmd_num; pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT; BUG_ON(pmd_num >= NUM_EARLY_PMDS); return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD]; } +static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va) +{ + return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); +} + +static phys_addr_t alloc_pmd_late(uintptr_t va) +{ + unsigned long vaddr; + + vaddr = __get_free_page(GFP_KERNEL); + BUG_ON(!vaddr); + return __pa(vaddr); +} + static void __init create_pmd_mapping(pmd_t *pmdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, pgprot_t prot) @@ -316,28 +363,28 @@ static void __init create_pmd_mapping(pmd_t *pmdp, } if (pmd_none(pmdp[pmd_idx])) { - pte_phys = alloc_pte(va); + pte_phys = pt_ops.alloc_pte(va); pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE); - ptep = get_pte_virt(pte_phys); + ptep = pt_ops.get_pte_virt(pte_phys); memset(ptep, 0, PAGE_SIZE); } else { pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx])); - ptep = get_pte_virt(pte_phys); + ptep = pt_ops.get_pte_virt(pte_phys); } create_pte_mapping(ptep, va, pa, sz, prot); } #define pgd_next_t pmd_t -#define alloc_pgd_next(__va) alloc_pmd(__va) -#define get_pgd_next_virt(__pa) get_pmd_virt(__pa) +#define alloc_pgd_next(__va) pt_ops.alloc_pmd(__va) +#define get_pgd_next_virt(__pa) pt_ops.get_pmd_virt(__pa) #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ create_pmd_mapping(__nextp, __va, __pa, __sz, __prot) #define fixmap_pgd_next fixmap_pmd #else #define pgd_next_t pte_t -#define alloc_pgd_next(__va) alloc_pte(__va) -#define get_pgd_next_virt(__pa) get_pte_virt(__pa) +#define alloc_pgd_next(__va) pt_ops.alloc_pte(__va) +#define get_pgd_next_virt(__pa) pt_ops.get_pte_virt(__pa) #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ create_pte_mapping(__nextp, __va, __pa, __sz, __prot) #define fixmap_pgd_next fixmap_pte @@ -421,6 +468,12 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) BUG_ON((load_pa % map_size) != 0); BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE); + pt_ops.alloc_pte = alloc_pte_early; + pt_ops.get_pte_virt = get_pte_virt_early; +#ifndef __PAGETABLE_PMD_FOLDED + pt_ops.alloc_pmd = alloc_pmd_early; + pt_ops.get_pmd_virt = get_pmd_virt_early; +#endif /* Setup early PGD for fixmap */ create_pgd_mapping(early_pg_dir, FIXADDR_START, (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); @@ -497,9 +550,16 @@ static void __init setup_vm_final(void) phys_addr_t pa, start, end; struct memblock_region *reg; - /* Set mmu_enabled flag */ - mmu_enabled = true; - + /** + * MMU is enabled at this point. But page table setup is not complete yet. + * fixmap page table alloc functions should be used at this point + */ + pt_ops.alloc_pte = alloc_pte_fixmap; + pt_ops.get_pte_virt = get_pte_virt_fixmap; +#ifndef __PAGETABLE_PMD_FOLDED + pt_ops.alloc_pmd = alloc_pmd_fixmap; + pt_ops.get_pmd_virt = get_pmd_virt_fixmap; +#endif /* Setup swapper PGD for fixmap */ create_pgd_mapping(swapper_pg_dir, FIXADDR_START, __pa_symbol(fixmap_pgd_next), @@ -533,6 +593,14 @@ static void __init setup_vm_final(void) /* Move to swapper page table */ csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE); local_flush_tlb_all(); + + /* generic page allocation functions must be used to setup page table */ + pt_ops.alloc_pte = alloc_pte_late; + pt_ops.get_pte_virt = get_pte_virt_late; +#ifndef __PAGETABLE_PMD_FOLDED + pt_ops.alloc_pmd = alloc_pmd_late; + pt_ops.get_pmd_virt = get_pmd_virt_late; +#endif } #else asmlinkage void __init setup_vm(uintptr_t dtb_pa) -- 2.7.4