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

Alexandre Ghiti alexandre.ghiti at canonical.com
Tue Jan 4 04:42:17 PST 2022


Hi Guo,

On Wed, Dec 29, 2021 at 4:42 AM Guo Ren <guoren at kernel.org> wrote:
>
> On Tue, Dec 7, 2021 at 11:54 AM Alexandre Ghiti
> <alexandre.ghiti at canonical.com> 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
> This is used by efi-stub.c, rv64 compat patch also need it, we reuse
> DEFAULT_MAP_WINDOW_64 macro.
>
> TASK_SIZE_MIN is also okay for me, I think it should be a separate
> patch with efi-stub midification.

IMO, TASK_SIZE_MIN is more explicit than DEFAULT_MAP_WINDOW_64. I'll
split this change in the next series.

> https://lore.kernel.org/linux-riscv/20211228143958.3409187-9-guoren@kernel.org/
>
> I've merged your patchset with compat tree and we are testing them
> together totally & carefully.
> https://github.com/c-sky/csky-linux/tree/riscv_compat_v2_sv48_v3
>
> Now, rv32_rootfs & 64_rootfs booting have been passed. But I would
> give you tested-by later after totally tested. Your patch set is very
> helpful, thx.

Thanks a lot, that will help move forward ;)

>
> ps: Could you give chance let customer choice sv48 or sv39 in dts?
>

This is already implemented in patch 13.

Thanks!

Alex

>
> >  #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);
> >  }
> >
> > 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
> > --
> > 2.32.0
> >
>
>
> --
> Best Regards
>  Guo Ren
>
> ML: https://lore.kernel.org/linux-csky/



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