Messages in this thread Patch in this message | | | Date | Thu, 9 Dec 2021 12:32:26 +0800 | Subject | Re: [PATCH v3 07/13] riscv: Implement sv48 support | From | 潘庆霖 <> |
| |
Hi Alex,
On 2021/12/6 19:05, Alexandre ghiti wrote: > On 12/6/21 11:46, Alexandre Ghiti wrote: >> By adding a new 4th level of page table, give the possibility to 64bit >> kernel to address 2^48 bytes of virtual address: in practice, that offers >> 128TB of virtual address space to userspace and allows up to 64TB of >> physical memory. >> >> If the underlying hardware does not support sv48, we will automatically >> fallback to a standard 3-level page table by folding the new PUD level into >> PGDIR level. In order to detect HW capabilities at runtime, we >> use SATP feature that ignores writes with an unsupported mode. >> >> Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com> >> --- >> arch/riscv/Kconfig | 4 +- >> arch/riscv/include/asm/csr.h | 3 +- >> arch/riscv/include/asm/fixmap.h | 1 + >> arch/riscv/include/asm/kasan.h | 6 +- >> arch/riscv/include/asm/page.h | 14 ++ >> arch/riscv/include/asm/pgalloc.h | 40 +++++ >> arch/riscv/include/asm/pgtable-64.h | 108 +++++++++++- >> arch/riscv/include/asm/pgtable.h | 24 ++- >> arch/riscv/kernel/head.S | 3 +- >> arch/riscv/mm/context.c | 4 +- >> arch/riscv/mm/init.c | 212 +++++++++++++++++++++--- >> arch/riscv/mm/kasan_init.c | 137 ++++++++++++++- >> drivers/firmware/efi/libstub/efi-stub.c | 2 + >> 13 files changed, 514 insertions(+), 44 deletions(-) >> >> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> index ac6c0cd9bc29..d28fe0148e13 100644 >> --- a/arch/riscv/Kconfig >> +++ b/arch/riscv/Kconfig >> @@ -150,7 +150,7 @@ config PAGE_OFFSET >> hex >> default 0xC0000000 if 32BIT >> default 0x80000000 if 64BIT && !MMU >> - default 0xffffffd800000000 if 64BIT >> + default 0xffffaf8000000000 if 64BIT >> config KASAN_SHADOW_OFFSET >> hex >> @@ -201,7 +201,7 @@ config FIX_EARLYCON_MEM >> config PGTABLE_LEVELS >> int >> - default 3 if 64BIT >> + default 4 if 64BIT >> default 2 >> config LOCKDEP_SUPPORT >> diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h >> index 87ac65696871..3fdb971c7896 100644 >> --- a/arch/riscv/include/asm/csr.h >> +++ b/arch/riscv/include/asm/csr.h >> @@ -40,14 +40,13 @@ >> #ifndef CONFIG_64BIT >> #define SATP_PPN _AC(0x003FFFFF, UL) >> #define SATP_MODE_32 _AC(0x80000000, UL) >> -#define SATP_MODE SATP_MODE_32 >> #define SATP_ASID_BITS 9 >> #define SATP_ASID_SHIFT 22 >> #define SATP_ASID_MASK _AC(0x1FF, UL) >> #else >> #define SATP_PPN _AC(0x00000FFFFFFFFFFF, UL) >> #define SATP_MODE_39 _AC(0x8000000000000000, UL) >> -#define SATP_MODE SATP_MODE_39 >> +#define SATP_MODE_48 _AC(0x9000000000000000, UL) >> #define SATP_ASID_BITS 16 >> #define SATP_ASID_SHIFT 44 >> #define SATP_ASID_MASK _AC(0xFFFF, UL) >> diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h >> index 54cbf07fb4e9..58a718573ad6 100644 >> --- a/arch/riscv/include/asm/fixmap.h >> +++ b/arch/riscv/include/asm/fixmap.h >> @@ -24,6 +24,7 @@ enum fixed_addresses { >> FIX_HOLE, >> FIX_PTE, >> FIX_PMD, >> + FIX_PUD, >> FIX_TEXT_POKE1, >> FIX_TEXT_POKE0, >> FIX_EARLYCON_MEM_BASE, >> diff --git a/arch/riscv/include/asm/kasan.h b/arch/riscv/include/asm/kasan.h >> index 743e6ff57996..0b85e363e778 100644 >> --- a/arch/riscv/include/asm/kasan.h >> +++ b/arch/riscv/include/asm/kasan.h >> @@ -28,7 +28,11 @@ >> #define KASAN_SHADOW_SCALE_SHIFT 3 >> #define KASAN_SHADOW_SIZE (UL(1) << ((VA_BITS - 1) - KASAN_SHADOW_SCALE_SHIFT)) >> -#define KASAN_SHADOW_START (KASAN_SHADOW_END - KASAN_SHADOW_SIZE) >> +/* >> + * Depending on the size of the virtual address space, the region may not be >> + * aligned on PGDIR_SIZE, so force its alignment to ease its population. >> + */ >> +#define KASAN_SHADOW_START ((KASAN_SHADOW_END - KASAN_SHADOW_SIZE) & PGDIR_MASK) >> #define KASAN_SHADOW_END MODULES_LOWEST_VADDR >> #define KASAN_SHADOW_OFFSET _AC(CONFIG_KASAN_SHADOW_OFFSET, UL) >> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h >> index e03559f9b35e..d089fe46f7d8 100644 >> --- a/arch/riscv/include/asm/page.h >> +++ b/arch/riscv/include/asm/page.h >> @@ -31,7 +31,20 @@ >> * When not using MMU this corresponds to the first free page in >> * physical memory (aligned on a page boundary). >> */ >> +#ifdef CONFIG_64BIT >> +#ifdef CONFIG_MMU >> +#define PAGE_OFFSET kernel_map.page_offset >> +#else >> +#define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) >> +#endif >> +/* >> + * By default, CONFIG_PAGE_OFFSET value corresponds to SV48 address space so >> + * define the PAGE_OFFSET value for SV39. >> + */ >> +#define PAGE_OFFSET_L3 _AC(0xffffffd800000000, UL) >> +#else >> #define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL) >> +#endif /* CONFIG_64BIT */ >> /* >> * Half of the kernel address space (half of the entries of the page global >> @@ -90,6 +103,7 @@ extern unsigned long riscv_pfn_base; >> #endif /* CONFIG_MMU */ >> struct kernel_mapping { >> + unsigned long page_offset; >> unsigned long virt_addr; >> uintptr_t phys_addr; >> uintptr_t size; >> diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h >> index 0af6933a7100..11823004b87a 100644 >> --- a/arch/riscv/include/asm/pgalloc.h >> +++ b/arch/riscv/include/asm/pgalloc.h >> @@ -11,6 +11,8 @@ >> #include <asm/tlb.h> >> #ifdef CONFIG_MMU >> +#define __HAVE_ARCH_PUD_ALLOC_ONE >> +#define __HAVE_ARCH_PUD_FREE >> #include <asm-generic/pgalloc.h> >> static inline void pmd_populate_kernel(struct mm_struct *mm, >> @@ -36,6 +38,44 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) >> set_pud(pud, __pud((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE)); >> } >> + >> +static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud) >> +{ >> + if (pgtable_l4_enabled) { >> + unsigned long pfn = virt_to_pfn(pud); >> + >> + set_p4d(p4d, __p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE)); >> + } >> +} >> + >> +static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d, >> + pud_t *pud) >> +{ >> + if (pgtable_l4_enabled) { >> + unsigned long pfn = virt_to_pfn(pud); >> + >> + set_p4d_safe(p4d, >> + __p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE)); >> + } >> +} >> + >> +#define pud_alloc_one pud_alloc_one >> +static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr) >> +{ >> + if (pgtable_l4_enabled) >> + return __pud_alloc_one(mm, addr); >> + >> + return NULL; >> +} >> + >> +#define pud_free pud_free >> +static inline void pud_free(struct mm_struct *mm, pud_t *pud) >> +{ >> + if (pgtable_l4_enabled) >> + __pud_free(mm, pud); >> +} >> + >> +#define __pud_free_tlb(tlb, pud, addr) pud_free((tlb)->mm, pud) >> #endif /* __PAGETABLE_PMD_FOLDED */ >> static inline pgd_t *pgd_alloc(struct mm_struct *mm) >> diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h >> index 228261aa9628..bbbdd66e5e2f 100644 >> --- a/arch/riscv/include/asm/pgtable-64.h >> +++ b/arch/riscv/include/asm/pgtable-64.h >> @@ -8,16 +8,36 @@ >> #include <linux/const.h> >> -#define PGDIR_SHIFT 30 >> +extern bool pgtable_l4_enabled; >> + >> +#define PGDIR_SHIFT_L3 30 >> +#define PGDIR_SHIFT_L4 39 >> +#define PGDIR_SIZE_L3 (_AC(1, UL) << PGDIR_SHIFT_L3) >> + >> +#define PGDIR_SHIFT (pgtable_l4_enabled ? PGDIR_SHIFT_L4 : PGDIR_SHIFT_L3) >> /* Size of region mapped by a page global directory */ >> #define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT) >> #define PGDIR_MASK (~(PGDIR_SIZE - 1)) >> +/* pud is folded into pgd in case of 3-level page table */ >> +#define PUD_SHIFT 30 >> +#define PUD_SIZE (_AC(1, UL) << PUD_SHIFT) >> +#define PUD_MASK (~(PUD_SIZE - 1)) >> + >> #define PMD_SHIFT 21 >> /* Size of region mapped by a page middle directory */ >> #define PMD_SIZE (_AC(1, UL) << PMD_SHIFT) >> #define PMD_MASK (~(PMD_SIZE - 1)) >> +/* Page Upper Directory entry */ >> +typedef struct { >> + unsigned long pud; >> +} pud_t; >> + >> +#define pud_val(x) ((x).pud) >> +#define __pud(x) ((pud_t) { (x) }) >> +#define PTRS_PER_PUD (PAGE_SIZE / sizeof(pud_t)) >> + >> /* Page Middle Directory entry */ >> typedef struct { >> unsigned long pmd; >> @@ -59,6 +79,16 @@ static inline void pud_clear(pud_t *pudp) >> set_pud(pudp, __pud(0)); >> } >> +static inline pud_t pfn_pud(unsigned long pfn, pgprot_t prot) >> +{ >> + return __pud((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); >> +} >> + >> +static inline unsigned long _pud_pfn(pud_t pud) >> +{ >> + return pud_val(pud) >> _PAGE_PFN_SHIFT; >> +} >> + >> static inline pmd_t *pud_pgtable(pud_t pud) >> { >> return (pmd_t *)pfn_to_virt(pud_val(pud) >> _PAGE_PFN_SHIFT); >> @@ -69,6 +99,17 @@ static inline struct page *pud_page(pud_t pud) >> return pfn_to_page(pud_val(pud) >> _PAGE_PFN_SHIFT); >> } >> +#define mm_pud_folded mm_pud_folded >> +static inline bool mm_pud_folded(struct mm_struct *mm) >> +{ >> + if (pgtable_l4_enabled) >> + return false; >> + >> + return true; >> +} >> + >> +#define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1)) >> + >> static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot) >> { >> return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); >> @@ -84,4 +125,69 @@ static inline unsigned long _pmd_pfn(pmd_t pmd) >> #define pmd_ERROR(e) \ >> pr_err("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e)) >> +#define pud_ERROR(e) \ >> + pr_err("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e)) >> + >> +static inline void set_p4d(p4d_t *p4dp, p4d_t p4d) >> +{ >> + if (pgtable_l4_enabled) >> + *p4dp = p4d; >> + else >> + set_pud((pud_t *)p4dp, (pud_t){ p4d_val(p4d) }); >> +} >> + >> +static inline int p4d_none(p4d_t p4d) >> +{ >> + if (pgtable_l4_enabled) >> + return (p4d_val(p4d) == 0); >> + >> + return 0; >> +} >> + >> +static inline int p4d_present(p4d_t p4d) >> +{ >> + if (pgtable_l4_enabled) >> + return (p4d_val(p4d) & _PAGE_PRESENT); >> + >> + return 1; >> +} >> + >> +static inline int p4d_bad(p4d_t p4d) >> +{ >> + if (pgtable_l4_enabled) >> + return !p4d_present(p4d); >> + >> + return 0; >> +} >> + >> +static inline void p4d_clear(p4d_t *p4d) >> +{ >> + if (pgtable_l4_enabled) >> + set_p4d(p4d, __p4d(0)); >> +} >> + >> +static inline pud_t *p4d_pgtable(p4d_t p4d) >> +{ >> + if (pgtable_l4_enabled) >> + return (pud_t *)pfn_to_virt(p4d_val(p4d) >> _PAGE_PFN_SHIFT); >> + >> + return (pud_t *)pud_pgtable((pud_t) { p4d_val(p4d) }); >> +} >> + >> +static inline struct page *p4d_page(p4d_t p4d) >> +{ >> + return pfn_to_page(p4d_val(p4d) >> _PAGE_PFN_SHIFT); >> +} >> + >> +#define pud_index(addr) (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)) >> + >> +#define pud_offset pud_offset >> +static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address) >> +{ >> + if (pgtable_l4_enabled) >> + return p4d_pgtable(*p4d) + pud_index(address); >> + >> + return (pud_t *)p4d; >> +} >> + >> #endif /* _ASM_RISCV_PGTABLE_64_H */ >> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h >> index e1a52e22ad7e..e1c74ef4ead2 100644 >> --- a/arch/riscv/include/asm/pgtable.h >> +++ b/arch/riscv/include/asm/pgtable.h >> @@ -51,7 +51,7 @@ >> * position vmemmap directly below the VMALLOC region. >> */ >> #ifdef CONFIG_64BIT >> -#define VA_BITS 39 >> +#define VA_BITS (pgtable_l4_enabled ? 48 : 39) >> #else >> #define VA_BITS 32 >> #endif >> @@ -90,8 +90,7 @@ >> #ifndef __ASSEMBLY__ >> -/* Page Upper Directory not used in RISC-V */ >> -#include <asm-generic/pgtable-nopud.h> >> +#include <asm-generic/pgtable-nop4d.h> >> #include <asm/page.h> >> #include <asm/tlbflush.h> >> #include <linux/mm_types.h> >> @@ -113,6 +112,17 @@ >> #define XIP_FIXUP(addr) (addr) >> #endif /* CONFIG_XIP_KERNEL */ >> +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); >> + pud_t *(*get_pud_virt)(phys_addr_t pa); >> + phys_addr_t (*alloc_pud)(uintptr_t va); >> +#endif >> +}; >> + >> #ifdef CONFIG_MMU >> /* Number of entries in the page global directory */ >> #define PTRS_PER_PGD (PAGE_SIZE / sizeof(pgd_t)) >> @@ -669,9 +679,11 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, >> * Note that PGDIR_SIZE must evenly divide TASK_SIZE. >> */ >> #ifdef CONFIG_64BIT >> -#define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2) >> +#define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2) >> +#define TASK_SIZE_MIN (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2) >> #else >> -#define TASK_SIZE FIXADDR_START >> +#define TASK_SIZE FIXADDR_START >> +#define TASK_SIZE_MIN TASK_SIZE >> #endif >> #else /* CONFIG_MMU */ >> @@ -697,6 +709,8 @@ extern uintptr_t _dtb_early_pa; >> #define dtb_early_va _dtb_early_va >> #define dtb_early_pa _dtb_early_pa >> #endif /* CONFIG_XIP_KERNEL */ >> +extern u64 satp_mode; >> +extern bool pgtable_l4_enabled; >> void paging_init(void); >> void misc_mem_init(void); >> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S >> index 52c5ff9804c5..c3c0ed559770 100644 >> --- a/arch/riscv/kernel/head.S >> +++ b/arch/riscv/kernel/head.S >> @@ -95,7 +95,8 @@ relocate: >> /* Compute satp for kernel page tables, but don't load it yet */ >> srl a2, a0, PAGE_SHIFT >> - li a1, SATP_MODE >> + la a1, satp_mode >> + REG_L a1, 0(a1) >> or a2, a2, a1 >> /* >> diff --git a/arch/riscv/mm/context.c b/arch/riscv/mm/context.c >> index ee3459cb6750..a7246872bd30 100644 >> --- a/arch/riscv/mm/context.c >> +++ b/arch/riscv/mm/context.c >> @@ -192,7 +192,7 @@ static void set_mm_asid(struct mm_struct *mm, unsigned int cpu) >> switch_mm_fast: >> csr_write(CSR_SATP, virt_to_pfn(mm->pgd) | >> ((cntx & asid_mask) << SATP_ASID_SHIFT) | >> - SATP_MODE); >> + satp_mode); >> if (need_flush_tlb) >> local_flush_tlb_all(); >> @@ -201,7 +201,7 @@ static void set_mm_asid(struct mm_struct *mm, unsigned int cpu) >> static void set_mm_noasid(struct mm_struct *mm) >> { >> /* Switch the page table and blindly nuke entire local TLB */ >> - csr_write(CSR_SATP, virt_to_pfn(mm->pgd) | SATP_MODE); >> + csr_write(CSR_SATP, virt_to_pfn(mm->pgd) | satp_mode); >> local_flush_tlb_all(); >> } >> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c >> index 1552226fb6bd..6a19a1b1caf8 100644 >> --- a/arch/riscv/mm/init.c >> +++ b/arch/riscv/mm/init.c >> @@ -37,6 +37,17 @@ EXPORT_SYMBOL(kernel_map); >> #define kernel_map (*(struct kernel_mapping *)XIP_FIXUP(&kernel_map)) >> #endif >> +#ifdef CONFIG_64BIT >> +u64 satp_mode = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_48 : SATP_MODE_39; >> +#else >> +u64 satp_mode = SATP_MODE_32; >> +#endif >> +EXPORT_SYMBOL(satp_mode); >> + >> +bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL) ? >> + true : false; >> +EXPORT_SYMBOL(pgtable_l4_enabled); >> + >> phys_addr_t phys_ram_base __ro_after_init; >> EXPORT_SYMBOL(phys_ram_base); >> @@ -53,15 +64,6 @@ 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 phys_addr_t dma32_phys_limit __initdata; >> static void __init zone_sizes_init(void) >> @@ -222,7 +224,7 @@ static void __init setup_bootmem(void) >> } >> #ifdef CONFIG_MMU >> -static struct pt_alloc_ops _pt_ops __initdata; >> +struct pt_alloc_ops _pt_ops __initdata; >> #ifdef CONFIG_XIP_KERNEL >> #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&_pt_ops)) >> @@ -238,6 +240,7 @@ pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; >> static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; >> pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); >> +static pud_t __maybe_unused early_dtb_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE); >> static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); >> #ifdef CONFIG_XIP_KERNEL >> @@ -326,6 +329,16 @@ static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); >> #define early_pmd ((pmd_t *)XIP_FIXUP(early_pmd)) >> #endif /* CONFIG_XIP_KERNEL */ >> +static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss; >> +static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss; >> +static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE); >> + >> +#ifdef CONFIG_XIP_KERNEL >> +#define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud)) >> +#define fixmap_pud ((pud_t *)XIP_FIXUP(fixmap_pud)) >> +#define early_pud ((pud_t *)XIP_FIXUP(early_pud)) >> +#endif /* CONFIG_XIP_KERNEL */ >> + >> static pmd_t *__init get_pmd_virt_early(phys_addr_t pa) >> { >> /* Before MMU is enabled */ >> @@ -345,7 +358,7 @@ static pmd_t *__init get_pmd_virt_late(phys_addr_t pa) >> static phys_addr_t __init alloc_pmd_early(uintptr_t va) >> { >> - BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT); >> + BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT); >> return (uintptr_t)early_pmd; >> } >> @@ -391,21 +404,97 @@ static void __init create_pmd_mapping(pmd_t *pmdp, >> create_pte_mapping(ptep, va, pa, sz, prot); >> } >> -#define pgd_next_t pmd_t >> -#define alloc_pgd_next(__va) pt_ops.alloc_pmd(__va) >> -#define get_pgd_next_virt(__pa) pt_ops.get_pmd_virt(__pa) >> +static pud_t *__init get_pud_virt_early(phys_addr_t pa) >> +{ >> + return (pud_t *)((uintptr_t)pa); >> +} >> + >> +static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa) >> +{ >> + clear_fixmap(FIX_PUD); >> + return (pud_t *)set_fixmap_offset(FIX_PUD, pa); >> +} >> + >> +static pud_t *__init get_pud_virt_late(phys_addr_t pa) >> +{ >> + return (pud_t *)__va(pa); >> +} >> + >> +static phys_addr_t __init alloc_pud_early(uintptr_t va) >> +{ >> + /* Only one PUD is available for early mapping */ >> + BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT); >> + >> + return (uintptr_t)early_pud; >> +} >> + >> +static phys_addr_t __init alloc_pud_fixmap(uintptr_t va) >> +{ >> + return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); >> +} >> + >> +static phys_addr_t alloc_pud_late(uintptr_t va) >> +{ >> + unsigned long vaddr; >> + >> + vaddr = __get_free_page(GFP_KERNEL); >> + BUG_ON(!vaddr); >> + return __pa(vaddr); >> +} >> + >> +static void __init create_pud_mapping(pud_t *pudp, >> + uintptr_t va, phys_addr_t pa, >> + phys_addr_t sz, pgprot_t prot) >> +{ >> + pmd_t *nextp; >> + phys_addr_t next_phys; >> + uintptr_t pud_index = pud_index(va); >> + >> + if (sz == PUD_SIZE) { >> + if (pud_val(pudp[pud_index]) == 0) >> + pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot); >> + return; >> + } >> + >> + if (pud_val(pudp[pud_index]) == 0) { >> + next_phys = pt_ops.alloc_pmd(va); >> + pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE); >> + nextp = pt_ops.get_pmd_virt(next_phys); >> + memset(nextp, 0, PAGE_SIZE); >> + } else { >> + next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index])); >> + nextp = pt_ops.get_pmd_virt(next_phys); >> + } >> + >> + create_pmd_mapping(nextp, va, pa, sz, prot); >> +} >> + >> +#define pgd_next_t pud_t >> +#define alloc_pgd_next(__va) (pgtable_l4_enabled ? \ >> + pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)) >> +#define get_pgd_next_virt(__pa) (pgtable_l4_enabled ? \ >> + pt_ops.get_pud_virt(__pa) : (pgd_next_t *)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 >> + (pgtable_l4_enabled ? \ >> + create_pud_mapping(__nextp, __va, __pa, __sz, __prot) : \ >> + create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)) >> +#define fixmap_pgd_next (pgtable_l4_enabled ? \ >> + (uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd) >> +#define trampoline_pgd_next (pgtable_l4_enabled ? \ >> + (uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd) >> +#define early_dtb_pgd_next (pgtable_l4_enabled ? \ >> + (uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd) >> #else >> #define pgd_next_t pte_t >> #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 >> +#define fixmap_pgd_next ((uintptr_t)fixmap_pte) >> +#define early_dtb_pgd_next ((uintptr_t)early_dtb_pmd) >> +#define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) >> #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) >> -#endif >> +#endif /* __PAGETABLE_PMD_FOLDED */ >> void __init create_pgd_mapping(pgd_t *pgdp, >> uintptr_t va, phys_addr_t pa, >> @@ -493,6 +582,57 @@ static __init pgprot_t pgprot_from_va(uintptr_t va) >> } >> #endif /* CONFIG_STRICT_KERNEL_RWX */ >> +#ifdef CONFIG_64BIT >> +static void __init disable_pgtable_l4(void) >> +{ >> + pgtable_l4_enabled = false; >> + kernel_map.page_offset = PAGE_OFFSET_L3; >> + satp_mode = SATP_MODE_39; >> +} >> + >> +/* >> + * There is a simple way to determine if 4-level is supported by the >> + * underlying hardware: establish 1:1 mapping in 4-level page table mode >> + * then read SATP to see if the configuration was taken into account >> + * meaning sv48 is supported. >> + */ >> +static __init void set_satp_mode(void) >> +{ >> + u64 identity_satp, hw_satp; >> + uintptr_t set_satp_mode_pmd; >> + >> + set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK; >> + create_pgd_mapping(early_pg_dir, >> + set_satp_mode_pmd, (uintptr_t)early_pud, >> + PGDIR_SIZE, PAGE_TABLE); >> + create_pud_mapping(early_pud, >> + set_satp_mode_pmd, (uintptr_t)early_pmd, >> + PUD_SIZE, PAGE_TABLE); >> + /* Handle the case where set_satp_mode straddles 2 PMDs */ >> + create_pmd_mapping(early_pmd, >> + set_satp_mode_pmd, set_satp_mode_pmd, >> + PMD_SIZE, PAGE_KERNEL_EXEC); >> + create_pmd_mapping(early_pmd, >> + set_satp_mode_pmd + PMD_SIZE, >> + set_satp_mode_pmd + PMD_SIZE, >> + PMD_SIZE, PAGE_KERNEL_EXEC); >> + >> + identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode; >> + >> + local_flush_tlb_all(); >> + csr_write(CSR_SATP, identity_satp); >> + hw_satp = csr_swap(CSR_SATP, 0ULL); >> + local_flush_tlb_all(); >> + >> + if (hw_satp != identity_satp) >> + disable_pgtable_l4(); >> + >> + memset(early_pg_dir, 0, PAGE_SIZE); >> + memset(early_pud, 0, PAGE_SIZE); >> + memset(early_pmd, 0, PAGE_SIZE); >> +} >> +#endif >> + >> /* >> * setup_vm() is called from head.S with MMU-off. >> * >> @@ -557,10 +697,15 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa) >> uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1); >> create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA, >> - IS_ENABLED(CONFIG_64BIT) ? (uintptr_t)early_dtb_pmd : pa, >> + IS_ENABLED(CONFIG_64BIT) ? early_dtb_pgd_next : pa, >> PGDIR_SIZE, >> IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL); >> + if (pgtable_l4_enabled) { >> + create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA, >> + (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE); >> + } >> + >> if (IS_ENABLED(CONFIG_64BIT)) { >> create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA, >> pa, PMD_SIZE, PAGE_KERNEL); >> @@ -593,6 +738,8 @@ void pt_ops_set_early(void) >> #ifndef __PAGETABLE_PMD_FOLDED >> pt_ops.alloc_pmd = alloc_pmd_early; >> pt_ops.get_pmd_virt = get_pmd_virt_early; >> + pt_ops.alloc_pud = alloc_pud_early; >> + pt_ops.get_pud_virt = get_pud_virt_early; >> #endif >> } >> @@ -611,6 +758,8 @@ void pt_ops_set_fixmap(void) >> #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); >> + pt_ops.alloc_pud = kernel_mapping_pa_to_va((uintptr_t)alloc_pud_fixmap); >> + pt_ops.get_pud_virt = kernel_mapping_pa_to_va((uintptr_t)get_pud_virt_fixmap); >> #endif >> } >> @@ -625,6 +774,8 @@ void pt_ops_set_late(void) >> #ifndef __PAGETABLE_PMD_FOLDED >> pt_ops.alloc_pmd = alloc_pmd_late; >> pt_ops.get_pmd_virt = get_pmd_virt_late; >> + pt_ops.alloc_pud = alloc_pud_late; >> + pt_ops.get_pud_virt = get_pud_virt_late; >> #endif >> } >> @@ -633,6 +784,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >> pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd; >> kernel_map.virt_addr = KERNEL_LINK_ADDR; >> + kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL); >> #ifdef CONFIG_XIP_KERNEL >> kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR; >> @@ -647,6 +799,11 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >> kernel_map.phys_addr = (uintptr_t)(&_start); >> kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr; >> #endif >> + >> +#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) >> + set_satp_mode(); >> +#endif >> + >> kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr; >> kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr; >> @@ -676,15 +833,21 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >> /* Setup early PGD for fixmap */ >> create_pgd_mapping(early_pg_dir, FIXADDR_START, >> - (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); >> + fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); >> #ifndef __PAGETABLE_PMD_FOLDED >> - /* Setup fixmap PMD */ >> + /* Setup fixmap PUD and PMD */ >> + if (pgtable_l4_enabled) >> + create_pud_mapping(fixmap_pud, FIXADDR_START, >> + (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE); >> create_pmd_mapping(fixmap_pmd, FIXADDR_START, >> (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); >> /* Setup trampoline PGD and PMD */ >> create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr, >> - (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE); >> + trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE); >> + if (pgtable_l4_enabled) >> + create_pud_mapping(trampoline_pud, kernel_map.virt_addr, >> + (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE); >> #ifdef CONFIG_XIP_KERNEL >> create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr, >> kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC); >> @@ -712,7 +875,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) >> * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap >> * range can not span multiple pmds. >> */ >> - BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) >> + BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) >> != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); >> #ifndef __PAGETABLE_PMD_FOLDED >> @@ -783,9 +946,10 @@ static void __init setup_vm_final(void) >> /* Clear fixmap PTE and PMD mappings */ >> clear_fixmap(FIX_PTE); >> clear_fixmap(FIX_PMD); >> + clear_fixmap(FIX_PUD); >> /* Move to swapper page table */ >> - csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE); >> + csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode); >> local_flush_tlb_all(); >> pt_ops_set_late(); >> diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c >> index 1434a0225140..993f50571a3b 100644 >> --- a/arch/riscv/mm/kasan_init.c >> +++ b/arch/riscv/mm/kasan_init.c >> @@ -11,7 +11,29 @@ >> #include <asm/fixmap.h> >> #include <asm/pgalloc.h> >> +/* >> + * Kasan shadow region must lie at a fixed address across sv39, sv48 and sv57 >> + * which is right before the kernel. >> + * >> + * For sv39, the region is aligned on PGDIR_SIZE so we only need to populate >> + * the page global directory with kasan_early_shadow_pmd. >> + * >> + * For sv48 and sv57, the region is not aligned on PGDIR_SIZE so the mapping >> + * must be divided as follows: >> + * - the first PGD entry, although incomplete, is populated with >> + * kasan_early_shadow_pud/p4d >> + * - the PGD entries in the middle are populated with kasan_early_shadow_pud/p4d >> + * - the last PGD entry is shared with the kernel mapping so populated at the >> + * lower levels pud/p4d >> + * >> + * In addition, when shallow populating a kasan region (for example vmalloc), >> + * this region may also not be aligned on PGDIR size, so we must go down to the >> + * pud level too. >> + */ >> + >> extern pgd_t early_pg_dir[PTRS_PER_PGD]; >> +extern struct pt_alloc_ops _pt_ops __initdata; >> +#define pt_ops _pt_ops >> static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end) >> { >> @@ -35,15 +57,19 @@ static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned >> set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(base_pte)), PAGE_TABLE)); >> } >> -static void __init kasan_populate_pmd(pgd_t *pgd, unsigned long vaddr, unsigned long end) >> +static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned long end) >> { >> phys_addr_t phys_addr; >> pmd_t *pmdp, *base_pmd; >> unsigned long next; >> - base_pmd = (pmd_t *)pgd_page_vaddr(*pgd); >> - if (base_pmd == lm_alias(kasan_early_shadow_pmd)) >> + if (pud_none(*pud)) { >> base_pmd = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE); >> + } else { >> + base_pmd = (pmd_t *)pud_pgtable(*pud); >> + if (base_pmd == lm_alias(kasan_early_shadow_pmd)) >> + base_pmd = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE); >> + } >> pmdp = base_pmd + pmd_index(vaddr); >> @@ -67,9 +93,72 @@ static void __init kasan_populate_pmd(pgd_t *pgd, unsigned long vaddr, unsigned >> * it entirely, memblock could allocate a page at a physical address >> * where KASAN is not populated yet and then we'd get a page fault. >> */ >> - set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE)); >> + set_pud(pud, pfn_pud(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE)); >> +} >> + >> +static void __init kasan_populate_pud(pgd_t *pgd, >> + unsigned long vaddr, unsigned long end, >> + bool early) >> +{ >> + phys_addr_t phys_addr; >> + pud_t *pudp, *base_pud; >> + unsigned long next; >> + >> + if (early) { >> + /* >> + * We can't use pgd_page_vaddr here as it would return a linear >> + * mapping address but it is not mapped yet, but when populating >> + * early_pg_dir, we need the physical address and when populating >> + * swapper_pg_dir, we need the kernel virtual address so use >> + * pt_ops facility. >> + */ >> + base_pud = pt_ops.get_pud_virt(pfn_to_phys(_pgd_pfn(*pgd))); >> + } else { >> + base_pud = (pud_t *)pgd_page_vaddr(*pgd); >> + if (base_pud == lm_alias(kasan_early_shadow_pud)) >> + base_pud = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE); >> + } >> + >> + pudp = base_pud + pud_index(vaddr); >> + >> + do { >> + next = pud_addr_end(vaddr, end); >> + >> + if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) { >> + if (early) { >> + phys_addr = __pa(((uintptr_t)kasan_early_shadow_pmd)); >> + set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE)); >> + continue; >> + } else { >> + phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE); >> + if (phys_addr) { >> + set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL)); >> + continue; >> + } >> + } >> + } >> + >> + kasan_populate_pmd(pudp, vaddr, next); >> + } while (pudp++, vaddr = next, vaddr != end); >> + >> + /* >> + * Wait for the whole PGD to be populated before setting the PGD in >> + * the page table, otherwise, if we did set the PGD before populating >> + * it entirely, memblock could allocate a page at a physical address >> + * where KASAN is not populated yet and then we'd get a page fault. >> + */ >> + if (!early) >> + set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pud)), PAGE_TABLE)); >> } >> +#define kasan_early_shadow_pgd_next (pgtable_l4_enabled ? \ >> + (uintptr_t)kasan_early_shadow_pud : \ >> + (uintptr_t)kasan_early_shadow_pmd) >> +#define kasan_populate_pgd_next(pgdp, vaddr, next, early) \ >> + (pgtable_l4_enabled ? \ >> + kasan_populate_pud(pgdp, vaddr, next, early) : \ >> + kasan_populate_pmd((pud_t *)pgdp, vaddr, next)) >> + >> static void __init kasan_populate_pgd(pgd_t *pgdp, >> unsigned long vaddr, unsigned long end, >> bool early) >> @@ -102,7 +191,7 @@ static void __init kasan_populate_pgd(pgd_t *pgdp, >> } >> } >> - kasan_populate_pmd(pgdp, vaddr, next); >> + kasan_populate_pgd_next(pgdp, vaddr, next, early); >> } while (pgdp++, vaddr = next, vaddr != end); >> } >> @@ -157,18 +246,54 @@ static void __init kasan_populate(void *start, void *end) >> memset(start, KASAN_SHADOW_INIT, end - start); >> } >> +static void __init kasan_shallow_populate_pud(pgd_t *pgdp, >> + unsigned long vaddr, unsigned long end, >> + bool kasan_populate) >> +{ >> + unsigned long next; >> + pud_t *pudp, *base_pud; >> + pmd_t *base_pmd; >> + bool is_kasan_pmd; >> + >> + base_pud = (pud_t *)pgd_page_vaddr(*pgdp); >> + pudp = base_pud + pud_index(vaddr); >> + >> + if (kasan_populate) >> + memcpy(base_pud, (void *)kasan_early_shadow_pgd_next, >> + sizeof(pud_t) * PTRS_PER_PUD); >> + >> + do { >> + next = pud_addr_end(vaddr, end); >> + is_kasan_pmd = (pud_pgtable(*pudp) == lm_alias(kasan_early_shadow_pmd)); >> + >> + if (is_kasan_pmd) { >> + base_pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> + set_pud(pudp, pfn_pud(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE)); >> + } >> + } while (pudp++, vaddr = next, vaddr != end); >> +} >> + >> static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end) >> { >> unsigned long next; >> void *p; >> pgd_t *pgd_k = pgd_offset_k(vaddr); >> + bool is_kasan_pgd_next; >> do { >> next = pgd_addr_end(vaddr, end); >> - if (pgd_page_vaddr(*pgd_k) == (unsigned long)lm_alias(kasan_early_shadow_pmd)) { >> + is_kasan_pgd_next = (pgd_page_vaddr(*pgd_k) == >> + (unsigned long)lm_alias(kasan_early_shadow_pgd_next)); >> + >> + if (is_kasan_pgd_next) { >> p = memblock_alloc(PAGE_SIZE, PAGE_SIZE); >> set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE)); >> } >> + >> + if (IS_ALIGNED(vaddr, PGDIR_SIZE) && (next - vaddr) >= PGDIR_SIZE) >> + continue; >> + >> + kasan_shallow_populate_pud(pgd_k, vaddr, next, is_kasan_pgd_next); >> } while (pgd_k++, vaddr = next, vaddr != end); >> }
> > @Qinglin: I can deal with sv57 kasan population if needs be as it is a bit tricky and I think it would save you quite some time :)
Thanks so much for you suggestion! And I want to give it a try firstly as I am now making new Sv57 patchset :) I will ask for your help when I meet any trouble, and thanks again!
Yours, Qinglin
> > >> diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c >> index 26e69788f27a..b3db5d91ed38 100644 >> --- a/drivers/firmware/efi/libstub/efi-stub.c >> +++ b/drivers/firmware/efi/libstub/efi-stub.c >> @@ -40,6 +40,8 @@ >> #ifdef CONFIG_ARM64 >> # define EFI_RT_VIRTUAL_LIMIT DEFAULT_MAP_WINDOW_64 >> +#elif defined(CONFIG_RISCV) >> +# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_MIN >> #else >> # define EFI_RT_VIRTUAL_LIMIT TASK_SIZE >> #endif
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