[PATCH v4 02/14] arm: add support for folded p4d page tables

From: Mike Rapoport
Date: Tue Apr 14 2020 - 11:36:28 EST

From: Mike Rapoport <rppt@xxxxxxxxxxxxx>

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate, and remove __ARCH_USE_5LEVEL_HACK.

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
arch/arm/include/asm/pgtable.h | 1 -
arch/arm/lib/uaccess_with_memcpy.c | 7 +++++-
arch/arm/mach-sa1100/assabet.c | 2 +-
arch/arm/mm/dump.c | 29 +++++++++++++++++-----
arch/arm/mm/fault-armv.c | 7 +++++-
arch/arm/mm/fault.c | 22 ++++++++++------
arch/arm/mm/idmap.c | 3 ++-
arch/arm/mm/init.c | 2 +-
arch/arm/mm/ioremap.c | 12 ++++++---
arch/arm/mm/mm.h | 2 +-
arch/arm/mm/mmu.c | 35 +++++++++++++++++++++-----
arch/arm/mm/pgd.c | 40 ++++++++++++++++++++++++------
12 files changed, 125 insertions(+), 37 deletions(-)

diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index befc8fcec98f..fba20607c53c 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -17,7 +17,6 @@

#else

-#define __ARCH_USE_5LEVEL_HACK
#include <asm-generic/pgtable-nopud.h>
#include <asm/memory.h>
#include <asm/pgtable-hwdef.h>
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index c9450982a155..d72b14c96670 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -24,6 +24,7 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
{
unsigned long addr = (unsigned long)_addr;
pgd_t *pgd;
+ p4d_t *p4d;
pmd_t *pmd;
pte_t *pte;
pud_t *pud;
@@ -33,7 +34,11 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
if (unlikely(pgd_none(*pgd) || pgd_bad(*pgd)))
return 0;

- pud = pud_offset(pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ if (unlikely(p4d_none(*p4d) || p4d_bad(*p4d)))
+ return 0;
+
+ pud = pud_offset(p4d, addr);
if (unlikely(pud_none(*pud) || pud_bad(*pud)))
return 0;

diff --git a/arch/arm/mach-sa1100/assabet.c b/arch/arm/mach-sa1100/assabet.c
index d96a101e5504..0631a7b02678 100644
--- a/arch/arm/mach-sa1100/assabet.c
+++ b/arch/arm/mach-sa1100/assabet.c
@@ -633,7 +633,7 @@ static void __init map_sa1100_gpio_regs( void )
int prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_DOMAIN(DOMAIN_IO);
pmd_t *pmd;

- pmd = pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
+ pmd = pmd_offset(pud_offset(p4d_offset(pgd_offset_k(virt), virt), virt), virt);
*pmd = __pmd(phys | prot);
flush_pmd_entry(pmd);
}
diff --git a/arch/arm/mm/dump.c b/arch/arm/mm/dump.c
index 7d6291f23251..677549d6854c 100644
--- a/arch/arm/mm/dump.c
+++ b/arch/arm/mm/dump.c
@@ -207,6 +207,7 @@ struct pg_level {
static struct pg_level pg_level[] = {
{
}, { /* pgd */
+ }, { /* p4d */
}, { /* pud */
}, { /* pmd */
.bits = section_bits,
@@ -308,7 +309,7 @@ static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start,

for (i = 0; i < PTRS_PER_PTE; i++, pte++) {
addr = start + i * PAGE_SIZE;
- note_page(st, addr, 4, pte_val(*pte), domain);
+ note_page(st, addr, 5, pte_val(*pte), domain);
}
}

@@ -350,14 +351,14 @@ static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
addr += SECTION_SIZE;
pmd++;
domain = get_domain_name(pmd);
- note_page(st, addr, 3, pmd_val(*pmd), domain);
+ note_page(st, addr, 4, pmd_val(*pmd), domain);
}
}
}

-static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
+static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start)
{
- pud_t *pud = pud_offset(pgd, 0);
+ pud_t *pud = pud_offset(p4d, 0);
unsigned long addr;
unsigned i;

@@ -366,7 +367,23 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
if (!pud_none(*pud)) {
walk_pmd(st, pud, addr);
} else {
- note_page(st, addr, 2, pud_val(*pud), NULL);
+ note_page(st, addr, 3, pud_val(*pud), NULL);
+ }
+ }
+}
+
+static void walk_p4d(struct pg_state *st, pgd_t *pgd, unsigned long start)
+{
+ p4d_t *p4d = p4d_offset(pgd, 0);
+ unsigned long addr;
+ unsigned i;
+
+ for (i = 0; i < PTRS_PER_P4D; i++, p4d++) {
+ addr = start + i * P4D_SIZE;
+ if (!p4d_none(*p4d)) {
+ walk_pud(st, p4d, addr);
+ } else {
+ note_page(st, addr, 2, p4d_val(*p4d), NULL);
}
}
}
@@ -381,7 +398,7 @@ static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
for (i = 0; i < PTRS_PER_PGD; i++, pgd++) {
addr = start + i * PGDIR_SIZE;
if (!pgd_none(*pgd)) {
- walk_pud(st, pgd, addr);
+ walk_p4d(st, pgd, addr);
} else {
note_page(st, addr, 1, pgd_val(*pgd), NULL);
}
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index ae857f41f68d..489aaafa6ebd 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -91,6 +91,7 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
{
spinlock_t *ptl;
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@@ -100,7 +101,11 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
if (pgd_none_or_clear_bad(pgd))
return 0;

- pud = pud_offset(pgd, address);
+ p4d = p4d_offset(pgd, address);
+ if (p4d_none_or_clear_bad(p4d))
+ return 0;
+
+ pud = pud_offset(p4d, address);
if (pud_none_or_clear_bad(pud))
return 0;

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 2dd5c41cbb8d..ff230e9affc4 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -43,19 +43,21 @@ void show_pte(const char *lvl, struct mm_struct *mm, unsigned long addr)
printk("%s[%08lx] *pgd=%08llx", lvl, addr, (long long)pgd_val(*pgd));

do {
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;

- if (pgd_none(*pgd))
+ p4d = p4d_offset(pgd, addr);
+ if (p4d_none(*p4d))
break;

- if (pgd_bad(*pgd)) {
+ if (p4d_bad(*p4d)) {
pr_cont("(bad)");
break;
}

- pud = pud_offset(pgd, addr);
+ pud = pud_offset(p4d, addr);
if (PTRS_PER_PUD != 1)
pr_cont(", *pud=%08llx", (long long)pud_val(*pud));

@@ -405,6 +407,7 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
{
unsigned int index;
pgd_t *pgd, *pgd_k;
+ p4d_t *p4d, *p4d_k;
pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;

@@ -419,13 +422,16 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
pgd = cpu_get_pgd() + index;
pgd_k = init_mm.pgd + index;

- if (pgd_none(*pgd_k))
+ p4d = p4d_offset(pgd, addr);
+ p4d_k = p4d_offset(pgd_k, addr);
+
+ if (p4d_none(*p4d_k))
goto bad_area;
- if (!pgd_present(*pgd))
- set_pgd(pgd, *pgd_k);
+ if (!p4d_present(*p4d))
+ set_p4d(p4d, *p4d_k);

- pud = pud_offset(pgd, addr);
- pud_k = pud_offset(pgd_k, addr);
+ pud = pud_offset(p4d, addr);
+ pud_k = pud_offset(p4d_k, addr);

if (pud_none(*pud_k))
goto bad_area;
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index a033f6134a64..cd54411ef1b8 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -68,7 +68,8 @@ static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
unsigned long prot)
{
- pud_t *pud = pud_offset(pgd, addr);
+ p4d_t *p4d = p4d_offset(pgd, addr);
+ pud_t *pud = pud_offset(p4d, addr);
unsigned long next;

do {
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 054be44d1cdb..963b5284d284 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -571,7 +571,7 @@ static inline void section_update(unsigned long addr, pmdval_t mask,
{
pmd_t *pmd;

- pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
+ pmd = pmd_off_k(addr);

#ifdef CONFIG_ARM_LPAE
pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 72286f9a4d30..75529d76d28c 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -142,12 +142,14 @@ static void unmap_area_sections(unsigned long virt, unsigned long size)
{
unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1));
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmdp;

flush_cache_vunmap(addr, end);
pgd = pgd_offset_k(addr);
- pud = pud_offset(pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ pud = pud_offset(p4d, addr);
pmdp = pmd_offset(pud, addr);
do {
pmd_t pmd = *pmdp;
@@ -190,6 +192,7 @@ remap_area_sections(unsigned long virt, unsigned long pfn,
{
unsigned long addr = virt, end = virt + size;
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;

@@ -200,7 +203,8 @@ remap_area_sections(unsigned long virt, unsigned long pfn,
unmap_area_sections(virt, size);

pgd = pgd_offset_k(addr);
- pud = pud_offset(pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ pud = pud_offset(p4d, addr);
pmd = pmd_offset(pud, addr);
do {
pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
@@ -222,6 +226,7 @@ remap_area_supersections(unsigned long virt, unsigned long pfn,
{
unsigned long addr = virt, end = virt + size;
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;

@@ -232,7 +237,8 @@ remap_area_supersections(unsigned long virt, unsigned long pfn,
unmap_area_sections(virt, size);

pgd = pgd_offset_k(virt);
- pud = pud_offset(pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ pud = pud_offset(p4d, addr);
pmd = pmd_offset(pud, addr);
do {
unsigned long super_pmd_val, i;
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 88c121ac14b3..4f1f72b75890 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -38,7 +38,7 @@ static inline pte_t get_top_pte(unsigned long va)

static inline pmd_t *pmd_off_k(unsigned long virt)
{
- return pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);
+ return pmd_offset(pud_offset(p4d_offset(pgd_offset_k(virt), virt), virt), virt);
}

struct mem_type {
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index ec8d0008bfa1..c425288f1a86 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -357,7 +357,8 @@ static pte_t *pte_offset_late_fixmap(pmd_t *dir, unsigned long addr)
static inline pmd_t * __init fixmap_pmd(unsigned long addr)
{
pgd_t *pgd = pgd_offset_k(addr);
- pud_t *pud = pud_offset(pgd, addr);
+ p4d_t *p4d = p4d_offset(pgd, addr);
+ pud_t *pud = pud_offset(p4d, addr);
pmd_t *pmd = pmd_offset(pud, addr);

return pmd;
@@ -801,12 +802,12 @@ static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
} while (pmd++, addr = next, addr != end);
}

-static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
+static void __init alloc_init_pud(p4d_t *p4d, unsigned long addr,
unsigned long end, phys_addr_t phys,
const struct mem_type *type,
void *(*alloc)(unsigned long sz), bool ng)
{
- pud_t *pud = pud_offset(pgd, addr);
+ pud_t *pud = pud_offset(p4d, addr);
unsigned long next;

do {
@@ -816,6 +817,21 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
} while (pud++, addr = next, addr != end);
}

+static void __init alloc_init_p4d(pgd_t *pgd, unsigned long addr,
+ unsigned long end, phys_addr_t phys,
+ const struct mem_type *type,
+ void *(*alloc)(unsigned long sz), bool ng)
+{
+ p4d_t *p4d = p4d_offset(pgd, addr);
+ unsigned long next;
+
+ do {
+ next = p4d_addr_end(addr, end);
+ alloc_init_pud(p4d, addr, next, phys, type, alloc, ng);
+ phys += next - addr;
+ } while (p4d++, addr = next, addr != end);
+}
+
#ifndef CONFIG_ARM_LPAE
static void __init create_36bit_mapping(struct mm_struct *mm,
struct map_desc *md,
@@ -863,7 +879,8 @@ static void __init create_36bit_mapping(struct mm_struct *mm,
pgd = pgd_offset(mm, addr);
end = addr + length;
do {
- pud_t *pud = pud_offset(pgd, addr);
+ p4d_t *p4d = p4d_offset(pgd, addr);
+ pud_t *pud = pud_offset(p4d, addr);
pmd_t *pmd = pmd_offset(pud, addr);
int i;

@@ -914,7 +931,7 @@ static void __init __create_mapping(struct mm_struct *mm, struct map_desc *md,
do {
unsigned long next = pgd_addr_end(addr, end);

- alloc_init_pud(pgd, addr, next, phys, type, alloc, ng);
+ alloc_init_p4d(pgd, addr, next, phys, type, alloc, ng);

phys += next - addr;
addr = next;
@@ -950,7 +967,13 @@ void __init create_mapping_late(struct mm_struct *mm, struct map_desc *md,
bool ng)
{
#ifdef CONFIG_ARM_LPAE
- pud_t *pud = pud_alloc(mm, pgd_offset(mm, md->virtual), md->virtual);
+ p4d_t *p4d;
+ pud_t *pud;
+
+ p4d = p4d_alloc(mm, pgd_offset(mm, md->virtual), md->virtual);
+ if (!WARN_ON(!p4d))
+ return;
+ pud = pud_alloc(mm, p4d, md->virtual);
if (WARN_ON(!pud))
return;
pmd_alloc(mm, pud, 0);
diff --git a/arch/arm/mm/pgd.c b/arch/arm/mm/pgd.c
index 478bd2c6aa50..c5e1b27046a8 100644
--- a/arch/arm/mm/pgd.c
+++ b/arch/arm/mm/pgd.c
@@ -30,6 +30,7 @@
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *new_pgd, *init_pgd;
+ p4d_t *new_p4d, *init_p4d;
pud_t *new_pud, *init_pud;
pmd_t *new_pmd, *init_pmd;
pte_t *new_pte, *init_pte;
@@ -53,8 +54,12 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
/*
* Allocate PMD table for modules and pkmap mappings.
*/
- new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
+ new_p4d = p4d_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
MODULES_VADDR);
+ if (!new_p4d)
+ goto no_p4d;
+
+ new_pud = pud_alloc(mm, new_p4d, MODULES_VADDR);
if (!new_pud)
goto no_pud;

@@ -69,7 +74,11 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
* contains the machine vectors. The vectors are always high
* with LPAE.
*/
- new_pud = pud_alloc(mm, new_pgd, 0);
+ new_p4d = p4d_alloc(mm, new_pgd, 0);
+ if (!new_p4d)
+ goto no_p4d;
+
+ new_pud = pud_alloc(mm, new_p4d, 0);
if (!new_pud)
goto no_pud;

@@ -91,7 +100,8 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
pmd_val(*new_pmd) |= PMD_DOMAIN(DOMAIN_VECTORS);
#endif

- init_pud = pud_offset(init_pgd, 0);
+ init_p4d = p4d_offset(init_pgd, 0);
+ init_pud = pud_offset(init_p4d, 0);
init_pmd = pmd_offset(init_pud, 0);
init_pte = pte_offset_map(init_pmd, 0);
set_pte_ext(new_pte + 0, init_pte[0], 0);
@@ -108,6 +118,8 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
no_pmd:
pud_free(mm, new_pud);
no_pud:
+ p4d_free(mm, new_p4d);
+no_p4d:
__pgd_free(new_pgd);
no_pgd:
return NULL;
@@ -116,6 +128,7 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pgtable_t pte;
@@ -127,7 +140,11 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
if (pgd_none_or_clear_bad(pgd))
goto no_pgd;

- pud = pud_offset(pgd, 0);
+ p4d = p4d_offset(pgd, 0);
+ if (p4d_none_or_clear_bad(p4d))
+ goto no_p4d;
+
+ pud = pud_offset(p4d, 0);
if (pud_none_or_clear_bad(pud))
goto no_pud;

@@ -144,8 +161,11 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
pmd_free(mm, pmd);
mm_dec_nr_pmds(mm);
no_pud:
- pgd_clear(pgd);
+ p4d_clear(p4d);
pud_free(mm, pud);
+no_p4d:
+ pgd_clear(pgd);
+ p4d_free(mm, p4d);
no_pgd:
#ifdef CONFIG_ARM_LPAE
/*
@@ -156,15 +176,21 @@ void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
continue;
if (pgd_val(*pgd) & L_PGD_SWAPPER)
continue;
- pud = pud_offset(pgd, 0);
+ p4d = p4d_offset(pgd, 0);
+ if (p4d_none_or_clear_bad(p4d))
+ continue;
+ pud = pud_offset(p4d, 0);
if (pud_none_or_clear_bad(pud))
continue;
pmd = pmd_offset(pud, 0);
pud_clear(pud);
pmd_free(mm, pmd);
mm_dec_nr_pmds(mm);
- pgd_clear(pgd);
+ p4d_clear(p4d);
pud_free(mm, pud);
+ mm_dec_nr_puds(mm);
+ pgd_clear(pgd);
+ p4d_free(mm, p4d);
}
#endif
__pgd_free(pgd_base);
--
2.25.1