Messages in this thread Patch in this message | | | From | guoren@kernel ... | Subject | [RFC PATCH V4 1/6] riscv: pgtable: Add custom protection_map init | Date | Sat, 11 Sep 2021 17:21:34 +0800 |
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From: Guo Ren <guoren@linux.alibaba.com>
Some RISC-V CPU vendors have defined their own PTE attributes to solve non-coherent DMA bus problems. That makes _P/SXXX definitions contain global variables which could be initialized at the early boot stage before setup_vm. The patch prevents compile errors.
This patch is similar to 316d097c4cd4 (x86/pti: Filter at vma->vm_page_prot population) which give a choice for arch custom implementation.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Atish Patra <atish.patra@wdc.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> --- arch/riscv/Kconfig | 4 ++++ arch/riscv/mm/init.c | 22 ++++++++++++++++++++++ mm/mmap.c | 4 ++++ 3 files changed, 30 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 4f7b70ae7c31..3ab3730bee92 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -25,6 +25,7 @@ config RISCV select ARCH_HAS_GIGANTIC_PAGE select ARCH_HAS_KCOV select ARCH_HAS_MMIOWB + select ARCH_HAS_PROTECTION_MAP_INIT select ARCH_HAS_PTE_SPECIAL select ARCH_HAS_SET_DIRECT_MAP if MMU select ARCH_HAS_SET_MEMORY if MMU @@ -201,6 +202,9 @@ config GENERIC_HWEIGHT config FIX_EARLYCON_MEM def_bool MMU +config ARCH_HAS_PROTECTION_MAP_INIT + def_bool y + config PGTABLE_LEVELS int default 3 if 64BIT diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 7cb4f391d106..975c7322d6c4 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -550,6 +550,26 @@ static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size, } #endif +static void __init setup_protection_map(void) +{ + protection_map[0] = __P000; + protection_map[1] = __P001; + protection_map[2] = __P010; + protection_map[3] = __P011; + protection_map[4] = __P100; + protection_map[5] = __P101; + protection_map[6] = __P110; + protection_map[7] = __P111; + protection_map[8] = __S000; + protection_map[9] = __S001; + protection_map[10] = __S010; + protection_map[11] = __S011; + protection_map[12] = __S100; + protection_map[13] = __S101; + protection_map[14] = __S110; + protection_map[15] = __S111; +} + asmlinkage void __init setup_vm(uintptr_t dtb_pa) { uintptr_t __maybe_unused pa; @@ -558,6 +578,8 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) pmd_t fix_bmap_spmd, fix_bmap_epmd; #endif + setup_protection_map(); + kernel_map.virt_addr = KERNEL_LINK_ADDR; #ifdef CONFIG_XIP_KERNEL diff --git a/mm/mmap.c b/mm/mmap.c index 181a113b545d..6d74537122ad 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -100,10 +100,14 @@ static void unmap_region(struct mm_struct *mm, * w: (no) no * x: (yes) yes */ +#ifdef CONFIG_ARCH_HAS_PROTECTION_MAP_INIT +pgprot_t protection_map[16] __ro_after_init; +#else pgprot_t protection_map[16] __ro_after_init = { __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111, __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111 }; +#endif #ifndef CONFIG_ARCH_HAS_FILTER_PGPROT static inline pgprot_t arch_filter_pgprot(pgprot_t prot) -- 2.25.1
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