[PATCH v3 07/13] riscv: Implement sv48 support

潘庆霖 panqinglin2020 at iscas.ac.cn
Wed Dec 8 20:32:26 PST 2021


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 at 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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