From 840125a97abc7e676d839adc2743e8f703a156b3 Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Mon, 6 Dec 2021 11:46:47 +0100 Subject: [PATCH] riscv: Introduce functions to switch pt_ops This simply gathers the different pt_ops initialization in functions where a comment was added to explain why the page table operations must be changed along the boot process. Signed-off-by: Alexandre Ghiti Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 74 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 51 insertions(+), 23 deletions(-) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index f5d0052..424d777 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -581,6 +581,52 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa) dtb_early_pa = dtb_pa; } +/* + * MMU is not enabled, the page tables are allocated directly using + * early_pmd/pud/p4d and the address returned is the physical one. + */ +void pt_ops_set_early(void) +{ + 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 +} + +/* + * MMU is enabled but page table setup is not complete yet. + * fixmap page table alloc functions must be used as a means to temporarily + * map the allocated physical pages since the linear mapping does not exist yet. + * + * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va, + * but it will be used as described above. + */ +void pt_ops_set_fixmap(void) +{ + pt_ops.alloc_pte = kernel_mapping_pa_to_va((uintptr_t)alloc_pte_fixmap); + pt_ops.get_pte_virt = kernel_mapping_pa_to_va((uintptr_t)get_pte_virt_fixmap); +#ifndef __PAGETABLE_PMD_FOLDED + pt_ops.alloc_pmd = kernel_mapping_pa_to_va((uintptr_t)alloc_pmd_fixmap); + pt_ops.get_pmd_virt = kernel_mapping_pa_to_va((uintptr_t)get_pmd_virt_fixmap); +#endif +} + +/* + * MMU is enabled and page table setup is complete, so from now, we can use + * generic page allocation functions to setup page table. + */ +void pt_ops_set_late(void) +{ + 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 +} + asmlinkage void __init setup_vm(uintptr_t dtb_pa) { pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd; @@ -625,12 +671,8 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); #endif - 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 + pt_ops_set_early(); + /* Setup early PGD for fixmap */ create_pgd_mapping(early_pg_dir, FIXADDR_START, (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); @@ -694,6 +736,8 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); } #endif + + pt_ops_set_fixmap(); } static void __init setup_vm_final(void) @@ -702,16 +746,6 @@ static void __init setup_vm_final(void) phys_addr_t pa, start, end; u64 i; - /** - * 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), @@ -753,13 +787,7 @@ static void __init setup_vm_final(void) 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 + pt_ops_set_late(); } #else asmlinkage void __init setup_vm(uintptr_t dtb_pa) -- 2.7.4