On a specific HW platform, pgtable_l4|[l5]_enabled won't change after
boot, and the check sits at hot code path, this characteristic makes it
suitable for optimization with static key.
_pgtable_l4|[l5]_enabled is used very early during boot, even is used
with MMU off, so the static key mechanism isn't ready. For this case,
we use another static key _pgtable_lx_ready to indicate whether we
have finalised pgtable_l4|[l5]_enabled or not, then fall back to
_pgtable_l4|[l5]_enabled_early bool.
Signed-off-by: Jisheng Zhang <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
---
arch/riscv/include/asm/pgalloc.h | 16 ++++----
arch/riscv/include/asm/pgtable-32.h | 3 ++
arch/riscv/include/asm/pgtable-64.h | 60 ++++++++++++++++++---------
arch/riscv/include/asm/pgtable.h | 5 +--
arch/riscv/kernel/cpu.c | 4 +-
arch/riscv/mm/init.c | 64 ++++++++++++++++++-----------
arch/riscv/mm/kasan_init.c | 16 ++++----
7 files changed, 103 insertions(+), 65 deletions(-)
diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index 947f23d7b6af..0280eeb4756f 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -41,7 +41,7 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
{
- if (pgtable_l4_enabled) {
+ if (pgtable_l4_enabled()) {
unsigned long pfn = virt_to_pfn(pud);
set_p4d(p4d, __p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
@@ -51,7 +51,7 @@ static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
pud_t *pud)
{
- if (pgtable_l4_enabled) {
+ if (pgtable_l4_enabled()) {
unsigned long pfn = virt_to_pfn(pud);
set_p4d_safe(p4d,
@@ -61,7 +61,7 @@ static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
{
- if (pgtable_l5_enabled) {
+ if (pgtable_l5_enabled()) {
unsigned long pfn = virt_to_pfn(p4d);
set_pgd(pgd, __pgd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
@@ -71,7 +71,7 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
p4d_t *p4d)
{
- if (pgtable_l5_enabled) {
+ if (pgtable_l5_enabled()) {
unsigned long pfn = virt_to_pfn(p4d);
set_pgd_safe(pgd,
@@ -82,7 +82,7 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
#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)
+ if (pgtable_l4_enabled())
return __pud_alloc_one(mm, addr);
return NULL;
@@ -91,7 +91,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
#define pud_free pud_free
static inline void pud_free(struct mm_struct *mm, pud_t *pud)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
__pud_free(mm, pud);
}
@@ -100,7 +100,7 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
#define p4d_alloc_one p4d_alloc_one
static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
{
- if (pgtable_l5_enabled) {
+ if (pgtable_l5_enabled()) {
gfp_t gfp = GFP_PGTABLE_USER;
if (mm == &init_mm)
@@ -120,7 +120,7 @@ static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
#define p4d_free p4d_free
static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
__p4d_free(mm, p4d);
}
diff --git a/arch/riscv/include/asm/pgtable-32.h b/arch/riscv/include/asm/pgtable-32.h
index 59ba1fbaf784..1ef52079179a 100644
--- a/arch/riscv/include/asm/pgtable-32.h
+++ b/arch/riscv/include/asm/pgtable-32.h
@@ -17,6 +17,9 @@
#define MAX_POSSIBLE_PHYSMEM_BITS 34
+#define pgtable_l5_enabled() 0
+#define pgtable_l4_enabled() 0
+
/*
* rv32 PTE format:
* | XLEN-1 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index 5c2aba5efbd0..edfff00d8ca3 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -8,18 +8,38 @@
#include <linux/bits.h>
#include <linux/const.h>
+#include <linux/jump_label.h>
#include <asm/errata_list.h>
-extern bool pgtable_l4_enabled;
-extern bool pgtable_l5_enabled;
+extern bool _pgtable_l5_enabled_early;
+extern bool _pgtable_l4_enabled_early;
+extern struct static_key_false _pgtable_l5_enabled;
+extern struct static_key_false _pgtable_l4_enabled;
+extern struct static_key_false _pgtable_lx_ready;
+
+static __always_inline bool pgtable_l5_enabled(void)
+{
+ if (static_branch_likely(&_pgtable_lx_ready))
+ return static_branch_likely(&_pgtable_l5_enabled);
+ else
+ return _pgtable_l5_enabled_early;
+}
+
+static __always_inline bool pgtable_l4_enabled(void)
+{
+ if (static_branch_likely(&_pgtable_lx_ready))
+ return static_branch_likely(&_pgtable_l4_enabled);
+ else
+ return _pgtable_l4_enabled_early;
+}
#define PGDIR_SHIFT_L3 30
#define PGDIR_SHIFT_L4 39
#define PGDIR_SHIFT_L5 48
#define PGDIR_SIZE_L3 (_AC(1, UL) << PGDIR_SHIFT_L3)
-#define PGDIR_SHIFT (pgtable_l5_enabled ? PGDIR_SHIFT_L5 : \
- (pgtable_l4_enabled ? PGDIR_SHIFT_L4 : PGDIR_SHIFT_L3))
+#define PGDIR_SHIFT (pgtable_l5_enabled() ? PGDIR_SHIFT_L5 : \
+ (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))
@@ -191,7 +211,7 @@ static inline struct page *pud_page(pud_t pud)
#define mm_p4d_folded mm_p4d_folded
static inline bool mm_p4d_folded(struct mm_struct *mm)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
return false;
return true;
@@ -200,7 +220,7 @@ static inline bool mm_p4d_folded(struct mm_struct *mm)
#define mm_pud_folded mm_pud_folded
static inline bool mm_pud_folded(struct mm_struct *mm)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
return false;
return true;
@@ -235,7 +255,7 @@ static inline unsigned long _pmd_pfn(pmd_t pmd)
static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
*p4dp = p4d;
else
set_pud((pud_t *)p4dp, (pud_t){ p4d_val(p4d) });
@@ -243,7 +263,7 @@ static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
static inline int p4d_none(p4d_t p4d)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
return (p4d_val(p4d) == 0);
return 0;
@@ -251,7 +271,7 @@ static inline int p4d_none(p4d_t p4d)
static inline int p4d_present(p4d_t p4d)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
return (p4d_val(p4d) & _PAGE_PRESENT);
return 1;
@@ -259,7 +279,7 @@ static inline int p4d_present(p4d_t p4d)
static inline int p4d_bad(p4d_t p4d)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
return !p4d_present(p4d);
return 0;
@@ -267,7 +287,7 @@ static inline int p4d_bad(p4d_t p4d)
static inline void p4d_clear(p4d_t *p4d)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
set_p4d(p4d, __p4d(0));
}
@@ -283,7 +303,7 @@ static inline unsigned long _p4d_pfn(p4d_t p4d)
static inline pud_t *p4d_pgtable(p4d_t p4d)
{
- if (pgtable_l4_enabled)
+ 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) });
@@ -300,7 +320,7 @@ static inline struct page *p4d_page(p4d_t p4d)
#define pud_offset pud_offset
static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
{
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
return p4d_pgtable(*p4d) + pud_index(address);
return (pud_t *)p4d;
@@ -308,7 +328,7 @@ static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
*pgdp = pgd;
else
set_p4d((p4d_t *)pgdp, (p4d_t){ pgd_val(pgd) });
@@ -316,7 +336,7 @@ static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
static inline int pgd_none(pgd_t pgd)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
return (pgd_val(pgd) == 0);
return 0;
@@ -324,7 +344,7 @@ static inline int pgd_none(pgd_t pgd)
static inline int pgd_present(pgd_t pgd)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
return (pgd_val(pgd) & _PAGE_PRESENT);
return 1;
@@ -332,7 +352,7 @@ static inline int pgd_present(pgd_t pgd)
static inline int pgd_bad(pgd_t pgd)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
return !pgd_present(pgd);
return 0;
@@ -340,13 +360,13 @@ static inline int pgd_bad(pgd_t pgd)
static inline void pgd_clear(pgd_t *pgd)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
set_pgd(pgd, __pgd(0));
}
static inline p4d_t *pgd_pgtable(pgd_t pgd)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
return (p4d_t *)pfn_to_virt(pgd_val(pgd) >> _PAGE_PFN_SHIFT);
return (p4d_t *)p4d_pgtable((p4d_t) { pgd_val(pgd) });
@@ -364,7 +384,7 @@ static inline struct page *pgd_page(pgd_t pgd)
#define p4d_offset p4d_offset
static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
{
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
return pgd_pgtable(*pgd) + p4d_index(address);
return (p4d_t *)pgd;
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 1d1be9d9419c..3eaa01d880b9 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -63,8 +63,8 @@
* position vmemmap directly below the VMALLOC region.
*/
#ifdef CONFIG_64BIT
-#define VA_BITS (pgtable_l5_enabled ? \
- 57 : (pgtable_l4_enabled ? 48 : 39))
+#define VA_BITS (pgtable_l5_enabled() ? \
+ 57 : (pgtable_l4_enabled() ? 48 : 39))
#else
#define VA_BITS 32
#endif
@@ -834,7 +834,6 @@ extern uintptr_t _dtb_early_pa;
#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/cpu.c b/arch/riscv/kernel/cpu.c
index fba9e9f46a8c..9b3697a97e41 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -143,9 +143,9 @@ static void print_mmu(struct seq_file *f)
#if defined(CONFIG_32BIT)
strncpy(sv_type, "sv32", 5);
#elif defined(CONFIG_64BIT)
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
strncpy(sv_type, "sv57", 5);
- else if (pgtable_l4_enabled)
+ else if (pgtable_l4_enabled())
strncpy(sv_type, "sv48", 5);
else
strncpy(sv_type, "sv39", 5);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index d466ec670e1f..11708cdb7094 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -44,10 +44,16 @@ u64 satp_mode __ro_after_init = SATP_MODE_32;
#endif
EXPORT_SYMBOL(satp_mode);
-bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
-bool pgtable_l5_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
-EXPORT_SYMBOL(pgtable_l4_enabled);
-EXPORT_SYMBOL(pgtable_l5_enabled);
+DEFINE_STATIC_KEY_FALSE(_pgtable_l4_enabled);
+DEFINE_STATIC_KEY_FALSE(_pgtable_l5_enabled);
+DEFINE_STATIC_KEY_FALSE(_pgtable_lx_ready);
+EXPORT_SYMBOL(_pgtable_l4_enabled);
+EXPORT_SYMBOL(_pgtable_l5_enabled);
+EXPORT_SYMBOL(_pgtable_lx_ready);
+bool _pgtable_l4_enabled_early = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
+bool _pgtable_l5_enabled_early = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
+EXPORT_SYMBOL(_pgtable_l4_enabled_early);
+EXPORT_SYMBOL(_pgtable_l5_enabled_early);
phys_addr_t phys_ram_base __ro_after_init;
EXPORT_SYMBOL(phys_ram_base);
@@ -585,26 +591,26 @@ static void __init create_p4d_mapping(p4d_t *p4dp,
}
#define pgd_next_t p4d_t
-#define alloc_pgd_next(__va) (pgtable_l5_enabled ? \
- pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ? \
+#define alloc_pgd_next(__va) (pgtable_l5_enabled() ? \
+ pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled() ? \
pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
-#define get_pgd_next_virt(__pa) (pgtable_l5_enabled ? \
- pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ? \
+#define get_pgd_next_virt(__pa) (pgtable_l5_enabled() ? \
+ pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled() ? \
pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
- (pgtable_l5_enabled ? \
+ (pgtable_l5_enabled() ? \
create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
- (pgtable_l4_enabled ? \
+ (pgtable_l4_enabled() ? \
create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) : \
create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
-#define fixmap_pgd_next (pgtable_l5_enabled ? \
- (uintptr_t)fixmap_p4d : (pgtable_l4_enabled ? \
+#define fixmap_pgd_next (pgtable_l5_enabled() ? \
+ (uintptr_t)fixmap_p4d : (pgtable_l4_enabled() ? \
(uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
-#define trampoline_pgd_next (pgtable_l5_enabled ? \
- (uintptr_t)trampoline_p4d : (pgtable_l4_enabled ? \
+#define trampoline_pgd_next (pgtable_l5_enabled() ? \
+ (uintptr_t)trampoline_p4d : (pgtable_l4_enabled() ? \
(uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
-#define early_dtb_pgd_next (pgtable_l5_enabled ? \
- (uintptr_t)early_dtb_p4d : (pgtable_l4_enabled ? \
+#define early_dtb_pgd_next (pgtable_l5_enabled() ? \
+ (uintptr_t)early_dtb_p4d : (pgtable_l4_enabled() ? \
(uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd))
#else
#define pgd_next_t pte_t
@@ -710,14 +716,14 @@ static __init pgprot_t pgprot_from_va(uintptr_t va)
#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
static void __init disable_pgtable_l5(void)
{
- pgtable_l5_enabled = false;
+ _pgtable_l5_enabled_early = false;
kernel_map.page_offset = PAGE_OFFSET_L4;
satp_mode = SATP_MODE_48;
}
static void __init disable_pgtable_l4(void)
{
- pgtable_l4_enabled = false;
+ _pgtable_l4_enabled_early = false;
kernel_map.page_offset = PAGE_OFFSET_L3;
satp_mode = SATP_MODE_39;
}
@@ -846,11 +852,11 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
PGDIR_SIZE,
IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
(uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
- if (pgtable_l4_enabled)
+ if (pgtable_l4_enabled())
create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
(uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
@@ -992,11 +998,11 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
#ifndef __PAGETABLE_PMD_FOLDED
/* Setup fixmap P4D and PUD */
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
create_p4d_mapping(fixmap_p4d, FIXADDR_START,
(uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
/* Setup fixmap PUD and PMD */
- if (pgtable_l4_enabled)
+ 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,
@@ -1004,10 +1010,10 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
/* Setup trampoline PGD and PMD */
create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
- if (pgtable_l5_enabled)
+ if (pgtable_l5_enabled())
create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
(uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
- if (pgtable_l4_enabled)
+ 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
@@ -1196,6 +1202,15 @@ static void __init reserve_crashkernel(void)
crashk_res.end = crash_base + crash_size - 1;
}
+static void __init riscv_finalise_pgtable_lx(void)
+{
+ if (_pgtable_l5_enabled_early)
+ static_branch_enable(&_pgtable_l5_enabled);
+ if (_pgtable_l4_enabled_early)
+ static_branch_enable(&_pgtable_l4_enabled);
+ static_branch_enable(&_pgtable_lx_ready);
+}
+
void __init paging_init(void)
{
setup_bootmem();
@@ -1207,6 +1222,7 @@ void __init misc_mem_init(void)
early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
arch_numa_init();
sparse_init();
+ riscv_finalise_pgtable_lx();
zone_sizes_init();
reserve_crashkernel();
memblock_dump_all();
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index a22e418dbd82..356044498e8a 100644
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -209,15 +209,15 @@ static void __init kasan_populate_p4d(pgd_t *pgd,
set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_p4d)), PAGE_TABLE));
}
-#define kasan_early_shadow_pgd_next (pgtable_l5_enabled ? \
+#define kasan_early_shadow_pgd_next (pgtable_l5_enabled() ? \
(uintptr_t)kasan_early_shadow_p4d : \
- (pgtable_l4_enabled ? \
+ (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_l5_enabled ? \
+ (pgtable_l5_enabled() ? \
kasan_populate_p4d(pgdp, vaddr, next, early) : \
- (pgtable_l4_enabled ? \
+ (pgtable_l4_enabled() ? \
kasan_populate_pud(pgdp, vaddr, next, early) : \
kasan_populate_pmd((pud_t *)pgdp, vaddr, next)))
@@ -274,7 +274,7 @@ asmlinkage void __init kasan_early_init(void)
(__pa((uintptr_t)kasan_early_shadow_pte)),
PAGE_TABLE));
- if (pgtable_l4_enabled) {
+ if (pgtable_l4_enabled()) {
for (i = 0; i < PTRS_PER_PUD; ++i)
set_pud(kasan_early_shadow_pud + i,
pfn_pud(PFN_DOWN
@@ -282,7 +282,7 @@ asmlinkage void __init kasan_early_init(void)
PAGE_TABLE));
}
- if (pgtable_l5_enabled) {
+ if (pgtable_l5_enabled()) {
for (i = 0; i < PTRS_PER_P4D; ++i)
set_p4d(kasan_early_shadow_p4d + i,
pfn_p4d(PFN_DOWN
@@ -393,9 +393,9 @@ static void __init kasan_shallow_populate_p4d(pgd_t *pgdp,
}
#define kasan_shallow_populate_pgd_next(pgdp, vaddr, next) \
- (pgtable_l5_enabled ? \
+ (pgtable_l5_enabled() ? \
kasan_shallow_populate_p4d(pgdp, vaddr, next) : \
- (pgtable_l4_enabled ? \
+ (pgtable_l4_enabled() ? \
kasan_shallow_populate_pud(pgdp, vaddr, next) : \
kasan_shallow_populate_pmd(pgdp, vaddr, next)))
--
2.34.1
On Fri, 15 Jul 2022 at 15:59, Jisheng Zhang <[email protected]> wrote:
> On a specific HW platform, pgtable_l4|[l5]_enabled won't change after
> boot, and the check sits at hot code path, this characteristic makes it
> suitable for optimization with static key.
>
> _pgtable_l4|[l5]_enabled is used very early during boot, even is used
> with MMU off, so the static key mechanism isn't ready. For this case,
> we use another static key _pgtable_lx_ready to indicate whether we
> have finalised pgtable_l4|[l5]_enabled or not, then fall back to
> _pgtable_l4|[l5]_enabled_early bool.
>
> Signed-off-by: Jisheng Zhang <[email protected]>
> Reviewed-by: Anup Patel <[email protected]>
> ---
> arch/riscv/include/asm/pgalloc.h | 16 ++++----
> arch/riscv/include/asm/pgtable-32.h | 3 ++
> arch/riscv/include/asm/pgtable-64.h | 60 ++++++++++++++++++---------
> arch/riscv/include/asm/pgtable.h | 5 +--
> arch/riscv/kernel/cpu.c | 4 +-
> arch/riscv/mm/init.c | 64 ++++++++++++++++++-----------
> arch/riscv/mm/kasan_init.c | 16 ++++----
> 7 files changed, 103 insertions(+), 65 deletions(-)
>
> diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
> index 947f23d7b6af..0280eeb4756f 100644
> --- a/arch/riscv/include/asm/pgalloc.h
> +++ b/arch/riscv/include/asm/pgalloc.h
> @@ -41,7 +41,7 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
>
> static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
> {
> - if (pgtable_l4_enabled) {
> + if (pgtable_l4_enabled()) {
> unsigned long pfn = virt_to_pfn(pud);
>
> set_p4d(p4d, __p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
> @@ -51,7 +51,7 @@ static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
> static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
> pud_t *pud)
> {
> - if (pgtable_l4_enabled) {
> + if (pgtable_l4_enabled()) {
> unsigned long pfn = virt_to_pfn(pud);
>
> set_p4d_safe(p4d,
> @@ -61,7 +61,7 @@ static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
>
> static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
> {
> - if (pgtable_l5_enabled) {
> + if (pgtable_l5_enabled()) {
> unsigned long pfn = virt_to_pfn(p4d);
>
> set_pgd(pgd, __pgd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
> @@ -71,7 +71,7 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
> static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
> p4d_t *p4d)
> {
> - if (pgtable_l5_enabled) {
> + if (pgtable_l5_enabled()) {
> unsigned long pfn = virt_to_pfn(p4d);
>
> set_pgd_safe(pgd,
> @@ -82,7 +82,7 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
> #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)
> + if (pgtable_l4_enabled())
> return __pud_alloc_one(mm, addr);
>
> return NULL;
> @@ -91,7 +91,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
> #define pud_free pud_free
> static inline void pud_free(struct mm_struct *mm, pud_t *pud)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> __pud_free(mm, pud);
> }
>
> @@ -100,7 +100,7 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
> #define p4d_alloc_one p4d_alloc_one
> static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
> {
> - if (pgtable_l5_enabled) {
> + if (pgtable_l5_enabled()) {
> gfp_t gfp = GFP_PGTABLE_USER;
>
> if (mm == &init_mm)
> @@ -120,7 +120,7 @@ static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
> #define p4d_free p4d_free
> static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> __p4d_free(mm, p4d);
> }
>
> diff --git a/arch/riscv/include/asm/pgtable-32.h b/arch/riscv/include/asm/pgtable-32.h
> index 59ba1fbaf784..1ef52079179a 100644
> --- a/arch/riscv/include/asm/pgtable-32.h
> +++ b/arch/riscv/include/asm/pgtable-32.h
> @@ -17,6 +17,9 @@
>
> #define MAX_POSSIBLE_PHYSMEM_BITS 34
>
> +#define pgtable_l5_enabled() 0
> +#define pgtable_l4_enabled() 0
> +
> /*
> * rv32 PTE format:
> * | XLEN-1 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
> diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
> index 5c2aba5efbd0..edfff00d8ca3 100644
> --- a/arch/riscv/include/asm/pgtable-64.h
> +++ b/arch/riscv/include/asm/pgtable-64.h
> @@ -8,18 +8,38 @@
>
> #include <linux/bits.h>
> #include <linux/const.h>
> +#include <linux/jump_label.h>
> #include <asm/errata_list.h>
>
> -extern bool pgtable_l4_enabled;
> -extern bool pgtable_l5_enabled;
> +extern bool _pgtable_l5_enabled_early;
> +extern bool _pgtable_l4_enabled_early;
> +extern struct static_key_false _pgtable_l5_enabled;
> +extern struct static_key_false _pgtable_l4_enabled;
> +extern struct static_key_false _pgtable_lx_ready;
It amounts to the same, but I wonder if we ought to use the
DECLARE_STATIC_KEY_FALSE macro here.
> +static __always_inline bool pgtable_l5_enabled(void)
> +{
> + if (static_branch_likely(&_pgtable_lx_ready))
> + return static_branch_likely(&_pgtable_l5_enabled);
> + else
> + return _pgtable_l5_enabled_early;
> +}
> +
> +static __always_inline bool pgtable_l4_enabled(void)
> +{
> + if (static_branch_likely(&_pgtable_lx_ready))
> + return static_branch_likely(&_pgtable_l4_enabled);
> + else
> + return _pgtable_l4_enabled_early;
> +}
>
> #define PGDIR_SHIFT_L3 30
> #define PGDIR_SHIFT_L4 39
> #define PGDIR_SHIFT_L5 48
> #define PGDIR_SIZE_L3 (_AC(1, UL) << PGDIR_SHIFT_L3)
>
> -#define PGDIR_SHIFT (pgtable_l5_enabled ? PGDIR_SHIFT_L5 : \
> - (pgtable_l4_enabled ? PGDIR_SHIFT_L4 : PGDIR_SHIFT_L3))
> +#define PGDIR_SHIFT (pgtable_l5_enabled() ? PGDIR_SHIFT_L5 : \
> + (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))
> @@ -191,7 +211,7 @@ static inline struct page *pud_page(pud_t pud)
> #define mm_p4d_folded mm_p4d_folded
> static inline bool mm_p4d_folded(struct mm_struct *mm)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> return false;
>
> return true;
> @@ -200,7 +220,7 @@ static inline bool mm_p4d_folded(struct mm_struct *mm)
> #define mm_pud_folded mm_pud_folded
> static inline bool mm_pud_folded(struct mm_struct *mm)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> return false;
>
> return true;
> @@ -235,7 +255,7 @@ static inline unsigned long _pmd_pfn(pmd_t pmd)
>
> static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> *p4dp = p4d;
> else
> set_pud((pud_t *)p4dp, (pud_t){ p4d_val(p4d) });
> @@ -243,7 +263,7 @@ static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
>
> static inline int p4d_none(p4d_t p4d)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> return (p4d_val(p4d) == 0);
>
> return 0;
> @@ -251,7 +271,7 @@ static inline int p4d_none(p4d_t p4d)
>
> static inline int p4d_present(p4d_t p4d)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> return (p4d_val(p4d) & _PAGE_PRESENT);
>
> return 1;
> @@ -259,7 +279,7 @@ static inline int p4d_present(p4d_t p4d)
>
> static inline int p4d_bad(p4d_t p4d)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> return !p4d_present(p4d);
>
> return 0;
> @@ -267,7 +287,7 @@ static inline int p4d_bad(p4d_t p4d)
>
> static inline void p4d_clear(p4d_t *p4d)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> set_p4d(p4d, __p4d(0));
> }
>
> @@ -283,7 +303,7 @@ static inline unsigned long _p4d_pfn(p4d_t p4d)
>
> static inline pud_t *p4d_pgtable(p4d_t p4d)
> {
> - if (pgtable_l4_enabled)
> + 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) });
> @@ -300,7 +320,7 @@ static inline struct page *p4d_page(p4d_t p4d)
> #define pud_offset pud_offset
> static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
> {
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> return p4d_pgtable(*p4d) + pud_index(address);
>
> return (pud_t *)p4d;
> @@ -308,7 +328,7 @@ static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
>
> static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> *pgdp = pgd;
> else
> set_p4d((p4d_t *)pgdp, (p4d_t){ pgd_val(pgd) });
> @@ -316,7 +336,7 @@ static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
>
> static inline int pgd_none(pgd_t pgd)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> return (pgd_val(pgd) == 0);
>
> return 0;
> @@ -324,7 +344,7 @@ static inline int pgd_none(pgd_t pgd)
>
> static inline int pgd_present(pgd_t pgd)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> return (pgd_val(pgd) & _PAGE_PRESENT);
>
> return 1;
> @@ -332,7 +352,7 @@ static inline int pgd_present(pgd_t pgd)
>
> static inline int pgd_bad(pgd_t pgd)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> return !pgd_present(pgd);
>
> return 0;
> @@ -340,13 +360,13 @@ static inline int pgd_bad(pgd_t pgd)
>
> static inline void pgd_clear(pgd_t *pgd)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> set_pgd(pgd, __pgd(0));
> }
>
> static inline p4d_t *pgd_pgtable(pgd_t pgd)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> return (p4d_t *)pfn_to_virt(pgd_val(pgd) >> _PAGE_PFN_SHIFT);
>
> return (p4d_t *)p4d_pgtable((p4d_t) { pgd_val(pgd) });
> @@ -364,7 +384,7 @@ static inline struct page *pgd_page(pgd_t pgd)
> #define p4d_offset p4d_offset
> static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
> {
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> return pgd_pgtable(*pgd) + p4d_index(address);
>
> return (p4d_t *)pgd;
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 1d1be9d9419c..3eaa01d880b9 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -63,8 +63,8 @@
> * position vmemmap directly below the VMALLOC region.
> */
> #ifdef CONFIG_64BIT
> -#define VA_BITS (pgtable_l5_enabled ? \
> - 57 : (pgtable_l4_enabled ? 48 : 39))
> +#define VA_BITS (pgtable_l5_enabled() ? \
> + 57 : (pgtable_l4_enabled() ? 48 : 39))
> #else
> #define VA_BITS 32
> #endif
> @@ -834,7 +834,6 @@ extern uintptr_t _dtb_early_pa;
> #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/cpu.c b/arch/riscv/kernel/cpu.c
> index fba9e9f46a8c..9b3697a97e41 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -143,9 +143,9 @@ static void print_mmu(struct seq_file *f)
> #if defined(CONFIG_32BIT)
> strncpy(sv_type, "sv32", 5);
> #elif defined(CONFIG_64BIT)
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> strncpy(sv_type, "sv57", 5);
> - else if (pgtable_l4_enabled)
> + else if (pgtable_l4_enabled())
> strncpy(sv_type, "sv48", 5);
> else
> strncpy(sv_type, "sv39", 5);
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index d466ec670e1f..11708cdb7094 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -44,10 +44,16 @@ u64 satp_mode __ro_after_init = SATP_MODE_32;
> #endif
> EXPORT_SYMBOL(satp_mode);
>
> -bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
> -bool pgtable_l5_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
> -EXPORT_SYMBOL(pgtable_l4_enabled);
> -EXPORT_SYMBOL(pgtable_l5_enabled);
> +DEFINE_STATIC_KEY_FALSE(_pgtable_l4_enabled);
> +DEFINE_STATIC_KEY_FALSE(_pgtable_l5_enabled);
> +DEFINE_STATIC_KEY_FALSE(_pgtable_lx_ready);
> +EXPORT_SYMBOL(_pgtable_l4_enabled);
> +EXPORT_SYMBOL(_pgtable_l5_enabled);
> +EXPORT_SYMBOL(_pgtable_lx_ready);
> +bool _pgtable_l4_enabled_early = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
> +bool _pgtable_l5_enabled_early = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL);
> +EXPORT_SYMBOL(_pgtable_l4_enabled_early);
> +EXPORT_SYMBOL(_pgtable_l5_enabled_early);
>
> phys_addr_t phys_ram_base __ro_after_init;
> EXPORT_SYMBOL(phys_ram_base);
> @@ -585,26 +591,26 @@ static void __init create_p4d_mapping(p4d_t *p4dp,
> }
>
> #define pgd_next_t p4d_t
> -#define alloc_pgd_next(__va) (pgtable_l5_enabled ? \
> - pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ? \
> +#define alloc_pgd_next(__va) (pgtable_l5_enabled() ? \
> + pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled() ? \
> pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va)))
> -#define get_pgd_next_virt(__pa) (pgtable_l5_enabled ? \
> - pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ? \
> +#define get_pgd_next_virt(__pa) (pgtable_l5_enabled() ? \
> + pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled() ? \
> pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa)))
> #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \
> - (pgtable_l5_enabled ? \
> + (pgtable_l5_enabled() ? \
> create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \
> - (pgtable_l4_enabled ? \
> + (pgtable_l4_enabled() ? \
> create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) : \
> create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot)))
> -#define fixmap_pgd_next (pgtable_l5_enabled ? \
> - (uintptr_t)fixmap_p4d : (pgtable_l4_enabled ? \
> +#define fixmap_pgd_next (pgtable_l5_enabled() ? \
> + (uintptr_t)fixmap_p4d : (pgtable_l4_enabled() ? \
> (uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd))
> -#define trampoline_pgd_next (pgtable_l5_enabled ? \
> - (uintptr_t)trampoline_p4d : (pgtable_l4_enabled ? \
> +#define trampoline_pgd_next (pgtable_l5_enabled() ? \
> + (uintptr_t)trampoline_p4d : (pgtable_l4_enabled() ? \
> (uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd))
> -#define early_dtb_pgd_next (pgtable_l5_enabled ? \
> - (uintptr_t)early_dtb_p4d : (pgtable_l4_enabled ? \
> +#define early_dtb_pgd_next (pgtable_l5_enabled() ? \
> + (uintptr_t)early_dtb_p4d : (pgtable_l4_enabled() ? \
> (uintptr_t)early_dtb_pud : (uintptr_t)early_dtb_pmd))
> #else
> #define pgd_next_t pte_t
> @@ -710,14 +716,14 @@ static __init pgprot_t pgprot_from_va(uintptr_t va)
> #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
> static void __init disable_pgtable_l5(void)
> {
> - pgtable_l5_enabled = false;
> + _pgtable_l5_enabled_early = false;
> kernel_map.page_offset = PAGE_OFFSET_L4;
> satp_mode = SATP_MODE_48;
> }
>
> static void __init disable_pgtable_l4(void)
> {
> - pgtable_l4_enabled = false;
> + _pgtable_l4_enabled_early = false;
> kernel_map.page_offset = PAGE_OFFSET_L3;
> satp_mode = SATP_MODE_39;
> }
> @@ -846,11 +852,11 @@ static void __init create_fdt_early_page_table(pgd_t *pgdir, uintptr_t dtb_pa)
> PGDIR_SIZE,
> IS_ENABLED(CONFIG_64BIT) ? PAGE_TABLE : PAGE_KERNEL);
>
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> create_p4d_mapping(early_dtb_p4d, DTB_EARLY_BASE_VA,
> (uintptr_t)early_dtb_pud, P4D_SIZE, PAGE_TABLE);
>
> - if (pgtable_l4_enabled)
> + if (pgtable_l4_enabled())
> create_pud_mapping(early_dtb_pud, DTB_EARLY_BASE_VA,
> (uintptr_t)early_dtb_pmd, PUD_SIZE, PAGE_TABLE);
>
> @@ -992,11 +998,11 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
>
> #ifndef __PAGETABLE_PMD_FOLDED
> /* Setup fixmap P4D and PUD */
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> create_p4d_mapping(fixmap_p4d, FIXADDR_START,
> (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE);
> /* Setup fixmap PUD and PMD */
> - if (pgtable_l4_enabled)
> + 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,
> @@ -1004,10 +1010,10 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
> /* Setup trampoline PGD and PMD */
> create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
> trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE);
> - if (pgtable_l5_enabled)
> + if (pgtable_l5_enabled())
> create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr,
> (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE);
> - if (pgtable_l4_enabled)
> + 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
> @@ -1196,6 +1202,15 @@ static void __init reserve_crashkernel(void)
> crashk_res.end = crash_base + crash_size - 1;
> }
>
> +static void __init riscv_finalise_pgtable_lx(void)
> +{
> + if (_pgtable_l5_enabled_early)
> + static_branch_enable(&_pgtable_l5_enabled);
> + if (_pgtable_l4_enabled_early)
> + static_branch_enable(&_pgtable_l4_enabled);
> + static_branch_enable(&_pgtable_lx_ready);
> +}
> +
> void __init paging_init(void)
> {
> setup_bootmem();
> @@ -1207,6 +1222,7 @@ void __init misc_mem_init(void)
> early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
> arch_numa_init();
> sparse_init();
> + riscv_finalise_pgtable_lx();
> zone_sizes_init();
> reserve_crashkernel();
> memblock_dump_all();
> diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
> index a22e418dbd82..356044498e8a 100644
> --- a/arch/riscv/mm/kasan_init.c
> +++ b/arch/riscv/mm/kasan_init.c
> @@ -209,15 +209,15 @@ static void __init kasan_populate_p4d(pgd_t *pgd,
> set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_p4d)), PAGE_TABLE));
> }
>
> -#define kasan_early_shadow_pgd_next (pgtable_l5_enabled ? \
> +#define kasan_early_shadow_pgd_next (pgtable_l5_enabled() ? \
> (uintptr_t)kasan_early_shadow_p4d : \
> - (pgtable_l4_enabled ? \
> + (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_l5_enabled ? \
> + (pgtable_l5_enabled() ? \
> kasan_populate_p4d(pgdp, vaddr, next, early) : \
> - (pgtable_l4_enabled ? \
> + (pgtable_l4_enabled() ? \
> kasan_populate_pud(pgdp, vaddr, next, early) : \
> kasan_populate_pmd((pud_t *)pgdp, vaddr, next)))
>
> @@ -274,7 +274,7 @@ asmlinkage void __init kasan_early_init(void)
> (__pa((uintptr_t)kasan_early_shadow_pte)),
> PAGE_TABLE));
>
> - if (pgtable_l4_enabled) {
> + if (pgtable_l4_enabled()) {
> for (i = 0; i < PTRS_PER_PUD; ++i)
> set_pud(kasan_early_shadow_pud + i,
> pfn_pud(PFN_DOWN
> @@ -282,7 +282,7 @@ asmlinkage void __init kasan_early_init(void)
> PAGE_TABLE));
> }
>
> - if (pgtable_l5_enabled) {
> + if (pgtable_l5_enabled()) {
> for (i = 0; i < PTRS_PER_P4D; ++i)
> set_p4d(kasan_early_shadow_p4d + i,
> pfn_p4d(PFN_DOWN
> @@ -393,9 +393,9 @@ static void __init kasan_shallow_populate_p4d(pgd_t *pgdp,
> }
>
> #define kasan_shallow_populate_pgd_next(pgdp, vaddr, next) \
> - (pgtable_l5_enabled ? \
> + (pgtable_l5_enabled() ? \
> kasan_shallow_populate_p4d(pgdp, vaddr, next) : \
> - (pgtable_l4_enabled ? \
> + (pgtable_l4_enabled() ? \
> kasan_shallow_populate_pud(pgdp, vaddr, next) : \
> kasan_shallow_populate_pmd(pgdp, vaddr, next)))
>
> --
> 2.34.1
>
>
> _______________________________________________
> linux-riscv mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-riscv
On Fri, Jul 15, 2022 at 05:04:38PM +0200, Emil Renner Berthing wrote:
> On Fri, 15 Jul 2022 at 15:59, Jisheng Zhang <[email protected]> wrote:
> > On a specific HW platform, pgtable_l4|[l5]_enabled won't change after
> > boot, and the check sits at hot code path, this characteristic makes it
> > suitable for optimization with static key.
> >
> > _pgtable_l4|[l5]_enabled is used very early during boot, even is used
> > with MMU off, so the static key mechanism isn't ready. For this case,
> > we use another static key _pgtable_lx_ready to indicate whether we
> > have finalised pgtable_l4|[l5]_enabled or not, then fall back to
> > _pgtable_l4|[l5]_enabled_early bool.
> >
> > Signed-off-by: Jisheng Zhang <[email protected]>
> > Reviewed-by: Anup Patel <[email protected]>
> > ---
> > arch/riscv/include/asm/pgalloc.h | 16 ++++----
> > arch/riscv/include/asm/pgtable-32.h | 3 ++
> > arch/riscv/include/asm/pgtable-64.h | 60 ++++++++++++++++++---------
> > arch/riscv/include/asm/pgtable.h | 5 +--
> > arch/riscv/kernel/cpu.c | 4 +-
> > arch/riscv/mm/init.c | 64 ++++++++++++++++++-----------
> > arch/riscv/mm/kasan_init.c | 16 ++++----
> > 7 files changed, 103 insertions(+), 65 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
> > index 947f23d7b6af..0280eeb4756f 100644
> > --- a/arch/riscv/include/asm/pgalloc.h
> > +++ b/arch/riscv/include/asm/pgalloc.h
> > @@ -41,7 +41,7 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
> >
> > static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
> > {
> > - if (pgtable_l4_enabled) {
> > + if (pgtable_l4_enabled()) {
> > unsigned long pfn = virt_to_pfn(pud);
> >
> > set_p4d(p4d, __p4d((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
> > @@ -51,7 +51,7 @@ static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
> > static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
> > pud_t *pud)
> > {
> > - if (pgtable_l4_enabled) {
> > + if (pgtable_l4_enabled()) {
> > unsigned long pfn = virt_to_pfn(pud);
> >
> > set_p4d_safe(p4d,
> > @@ -61,7 +61,7 @@ static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d,
> >
> > static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
> > {
> > - if (pgtable_l5_enabled) {
> > + if (pgtable_l5_enabled()) {
> > unsigned long pfn = virt_to_pfn(p4d);
> >
> > set_pgd(pgd, __pgd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
> > @@ -71,7 +71,7 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
> > static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
> > p4d_t *p4d)
> > {
> > - if (pgtable_l5_enabled) {
> > + if (pgtable_l5_enabled()) {
> > unsigned long pfn = virt_to_pfn(p4d);
> >
> > set_pgd_safe(pgd,
> > @@ -82,7 +82,7 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
> > #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)
> > + if (pgtable_l4_enabled())
> > return __pud_alloc_one(mm, addr);
> >
> > return NULL;
> > @@ -91,7 +91,7 @@ static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
> > #define pud_free pud_free
> > static inline void pud_free(struct mm_struct *mm, pud_t *pud)
> > {
> > - if (pgtable_l4_enabled)
> > + if (pgtable_l4_enabled())
> > __pud_free(mm, pud);
> > }
> >
> > @@ -100,7 +100,7 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
> > #define p4d_alloc_one p4d_alloc_one
> > static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
> > {
> > - if (pgtable_l5_enabled) {
> > + if (pgtable_l5_enabled()) {
> > gfp_t gfp = GFP_PGTABLE_USER;
> >
> > if (mm == &init_mm)
> > @@ -120,7 +120,7 @@ static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)
> > #define p4d_free p4d_free
> > static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
> > {
> > - if (pgtable_l5_enabled)
> > + if (pgtable_l5_enabled())
> > __p4d_free(mm, p4d);
> > }
> >
> > diff --git a/arch/riscv/include/asm/pgtable-32.h b/arch/riscv/include/asm/pgtable-32.h
> > index 59ba1fbaf784..1ef52079179a 100644
> > --- a/arch/riscv/include/asm/pgtable-32.h
> > +++ b/arch/riscv/include/asm/pgtable-32.h
> > @@ -17,6 +17,9 @@
> >
> > #define MAX_POSSIBLE_PHYSMEM_BITS 34
> >
> > +#define pgtable_l5_enabled() 0
> > +#define pgtable_l4_enabled() 0
> > +
> > /*
> > * rv32 PTE format:
> > * | XLEN-1 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
> > diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
> > index 5c2aba5efbd0..edfff00d8ca3 100644
> > --- a/arch/riscv/include/asm/pgtable-64.h
> > +++ b/arch/riscv/include/asm/pgtable-64.h
> > @@ -8,18 +8,38 @@
> >
> > #include <linux/bits.h>
> > #include <linux/const.h>
> > +#include <linux/jump_label.h>
> > #include <asm/errata_list.h>
> >
> > -extern bool pgtable_l4_enabled;
> > -extern bool pgtable_l5_enabled;
> > +extern bool _pgtable_l5_enabled_early;
> > +extern bool _pgtable_l4_enabled_early;
> > +extern struct static_key_false _pgtable_l5_enabled;
> > +extern struct static_key_false _pgtable_l4_enabled;
> > +extern struct static_key_false _pgtable_lx_ready;
>
> It amounts to the same, but I wonder if we ought to use the
> DECLARE_STATIC_KEY_FALSE macro here.
Thanks for the hint, will send out a newer version soon. Before
that, I will wait a bit for other review feedbacks.
Thanks