[PATCH] sparc64: add support for folded p4d page tables

From: Mike Rapoport
Date: Sun Nov 24 2019 - 03:57:38 EST


From: Mike Rapoport <rppt@xxxxxxxxxxxxx>

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate and replace 5leve-fixup.h with pgtable-nop4d.h.

Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
arch/sparc/include/asm/pgalloc_64.h | 6 +++---
arch/sparc/include/asm/pgtable_64.h | 24 ++++++++++-----------
arch/sparc/kernel/signal32.c | 6 +++++-
arch/sparc/kernel/smp_64.c | 13 +++++++++++-
arch/sparc/mm/fault_64.c | 6 +++++-
arch/sparc/mm/hugetlbpage.c | 28 +++++++++++++++---------
arch/sparc/mm/init_64.c | 33 +++++++++++++++++++++++++----
7 files changed, 84 insertions(+), 32 deletions(-)

diff --git a/arch/sparc/include/asm/pgalloc_64.h b/arch/sparc/include/asm/pgalloc_64.h
index 9d3e5cc95bbb..264e76ceccf6 100644
--- a/arch/sparc/include/asm/pgalloc_64.h
+++ b/arch/sparc/include/asm/pgalloc_64.h
@@ -16,12 +16,12 @@

extern struct kmem_cache *pgtable_cache;

-static inline void __pgd_populate(pgd_t *pgd, pud_t *pud)
+static inline void __p4d_populate(p4d_t *p4d, pud_t *pud)
{
- pgd_set(pgd, pud);
+ p4d_set(p4d, pud);
}

-#define pgd_populate(MM, PGD, PUD) __pgd_populate(PGD, PUD)
+#define p4d_populate(MM, P4D, PUD) __p4d_populate(P4D, PUD)

static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 6ae8016ef4ec..34ff3b43afbb 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -13,7 +13,7 @@
* the SpitFire page tables.
*/

-#include <asm-generic/5level-fixup.h>
+#include <asm-generic/pgtable-nop4d.h>
#include <linux/compiler.h>
#include <linux/const.h>
#include <asm/types.h>
@@ -810,9 +810,9 @@ static inline int pmd_present(pmd_t pmd)

#define pud_bad(pud) (pud_val(pud) & ~PAGE_MASK)

-#define pgd_none(pgd) (!pgd_val(pgd))
+#define p4d_none(p4d) (!p4d_val(p4d))

-#define pgd_bad(pgd) (pgd_val(pgd) & ~PAGE_MASK)
+#define p4d_bad(p4d) (p4d_val(p4d) & ~PAGE_MASK)

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
@@ -859,13 +859,13 @@ static inline unsigned long pud_page_vaddr(pud_t pud)
#define pmd_clear(pmdp) (pmd_val(*(pmdp)) = 0UL)
#define pud_present(pud) (pud_val(pud) != 0U)
#define pud_clear(pudp) (pud_val(*(pudp)) = 0UL)
-#define pgd_page_vaddr(pgd) \
- ((unsigned long) __va(pgd_val(pgd)))
-#define pgd_present(pgd) (pgd_val(pgd) != 0U)
-#define pgd_clear(pgdp) (pgd_val(*(pgdp)) = 0UL)
+#define p4d_page_vaddr(p4d) \
+ ((unsigned long) __va(p4d_val(p4d)))
+#define p4d_present(p4d) (p4d_val(p4d) != 0U)
+#define p4d_clear(p4dp) (p4d_val(*(p4dp)) = 0UL)

/* only used by the stubbed out hugetlb gup code, should never be called */
-#define pgd_page(pgd) NULL
+#define p4d_page(p4d) NULL

static inline unsigned long pud_large(pud_t pud)
{
@@ -884,8 +884,8 @@ static inline unsigned long pud_pfn(pud_t pud)
/* Same in both SUN4V and SUN4U. */
#define pte_none(pte) (!pte_val(pte))

-#define pgd_set(pgdp, pudp) \
- (pgd_val(*(pgdp)) = (__pa((unsigned long) (pudp))))
+#define p4d_set(p4dp, pudp) \
+ (p4d_val(*(p4dp)) = (__pa((unsigned long) (pudp))))

/* to find an entry in a page-table-directory. */
#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
@@ -896,8 +896,8 @@ static inline unsigned long pud_pfn(pud_t pud)

/* Find an entry in the third-level page table.. */
#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
-#define pud_offset(pgdp, address) \
- ((pud_t *) pgd_page_vaddr(*(pgdp)) + pud_index(address))
+#define pud_offset(p4dp, address) \
+ ((pud_t *) p4d_page_vaddr(*(p4dp)) + pud_index(address))

/* Find an entry in the second-level page table.. */
#define pmd_offset(pudp, address) \
diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index a237810aa9f4..2a734ecd0a40 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c
@@ -299,6 +299,7 @@ static void flush_signal_insns(unsigned long address)
unsigned long pstate, paddr;
pte_t *ptep, pte;
pgd_t *pgdp;
+ p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;

@@ -318,7 +319,10 @@ static void flush_signal_insns(unsigned long address)
pgdp = pgd_offset(current->mm, address);
if (pgd_none(*pgdp))
goto out_irqs_on;
- pudp = pud_offset(pgdp, address);
+ p4dp = p4d_offset(pgdp, address);
+ if (p4d_none(*p4dp))
+ goto out_irqs_on;
+ pudp = pud_offset(p4dp, address);
if (pud_none(*pudp))
goto out_irqs_on;
pmdp = pmd_offset(pudp, address);
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index a8275fea4b70..eb9455798338 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1621,6 +1621,7 @@ static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
static void __init pcpu_populate_pte(unsigned long addr)
{
pgd_t *pgd = pgd_offset_k(addr);
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;

@@ -1633,7 +1634,17 @@ static void __init pcpu_populate_pte(unsigned long addr)
pgd_populate(&init_mm, pgd, new);
}

- pud = pud_offset(pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ if (p4d_none(*p4d)) {
+ pud_t *new;
+
+ new = memblock_alloc_from(PAGE_SIZE, PAGE_SIZE, PAGE_SIZE);
+ if (!new)
+ goto err_alloc;
+ p4d_populate(&init_mm, p4d, new);
+ }
+
+ pud = pud_offset(p4d, addr);
if (pud_none(*pud)) {
pmd_t *new;

diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index 2371fb6b97e4..8b7ddbd14b65 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -80,6 +80,7 @@ static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
static unsigned int get_user_insn(unsigned long tpc)
{
pgd_t *pgdp = pgd_offset(current->mm, tpc);
+ p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep, pte;
@@ -88,7 +89,10 @@ static unsigned int get_user_insn(unsigned long tpc)

if (pgd_none(*pgdp) || unlikely(pgd_bad(*pgdp)))
goto out;
- pudp = pud_offset(pgdp, tpc);
+ p4dp = p4d_offset(pgdp, tpc);
+ if (p4d_none(*p4dp) || unlikely(p4d_bad(*p4dp)))
+ goto out;
+ pudp = pud_offset(p4dp, tpc);
if (pud_none(*pudp) || unlikely(pud_bad(*pudp)))
goto out;

diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index f78793a06bbd..7b9fa861b67c 100644
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -277,11 +277,13 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;

pgd = pgd_offset(mm, addr);
- pud = pud_alloc(mm, pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ pud = pud_alloc(mm, p4d, addr);
if (!pud)
return NULL;
if (sz >= PUD_SIZE)
@@ -298,13 +300,17 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;

pgd = pgd_offset(mm, addr);
if (pgd_none(*pgd))
return NULL;
- pud = pud_offset(pgd, addr);
+ p4d = p4d_offset(pgd, addr);
+ if (p4d_none(*p4d))
+ return NULL;
+ pud = pud_offset(p4d, addr);
if (pud_none(*pud))
return NULL;
if (is_hugetlb_pud(*pud))
@@ -449,7 +455,7 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
mm_dec_nr_pmds(tlb->mm);
}

-static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
+static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
@@ -458,7 +464,7 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
unsigned long start;

start = addr;
- pud = pud_offset(pgd, addr);
+ pud = pud_offset(p4d, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
@@ -481,8 +487,8 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
if (end - 1 > ceiling - 1)
return;

- pud = pud_offset(pgd, start);
- pgd_clear(pgd);
+ pud = pud_offset(p4d, start);
+ p4d_clear(p4d);
pud_free_tlb(tlb, pud, start);
mm_dec_nr_puds(tlb->mm);
}
@@ -492,6 +498,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long floor, unsigned long ceiling)
{
pgd_t *pgd;
+ p4d_t *p4d;
unsigned long next;

addr &= PMD_MASK;
@@ -511,10 +518,11 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
return;

pgd = pgd_offset(tlb->mm, addr);
+ p4d = p4d_offset(pgd, addr);
do {
- next = pgd_addr_end(addr, end);
- if (pgd_none_or_clear_bad(pgd))
+ next = p4d_addr_end(addr, end);
+ if (p4d_none_or_clear_bad(p4d))
continue;
- hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
- } while (pgd++, addr = next, addr != end);
+ hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
+ } while (p4d++, addr = next, addr != end);
}
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index e6d91819da92..1cf0d666dea3 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -530,7 +530,8 @@ void __kprobes flush_icache_range(unsigned long start, unsigned long end)
paddr = kaddr & mask;
else {
pgd_t *pgdp = pgd_offset_k(kaddr);
- pud_t *pudp = pud_offset(pgdp, kaddr);
+ p4d_t *p4dp = p4d_offset(pgdp, kaddr);
+ pud_t *pudp = pud_offset(p4dp, kaddr);
pmd_t *pmdp = pmd_offset(pudp, kaddr);
pte_t *ptep = pte_offset_kernel(pmdp, kaddr);

@@ -1653,6 +1654,7 @@ static unsigned long max_phys_bits = 40;
bool kern_addr_valid(unsigned long addr)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@@ -1674,7 +1676,11 @@ bool kern_addr_valid(unsigned long addr)
if (pgd_none(*pgd))
return 0;

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

@@ -1800,6 +1806,7 @@ static unsigned long __ref kernel_map_range(unsigned long pstart,
while (vstart < vend) {
unsigned long this_end, paddr = __pa(vstart);
pgd_t *pgd = pgd_offset_k(vstart);
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@@ -1814,7 +1821,20 @@ static unsigned long __ref kernel_map_range(unsigned long pstart,
alloc_bytes += PAGE_SIZE;
pgd_populate(&init_mm, pgd, new);
}
- pud = pud_offset(pgd, vstart);
+
+ p4d = p4d_offset(pgd, vstart);
+ if (p4d_none(*p4d)) {
+ pud_t *new;
+
+ new = memblock_alloc_from(PAGE_SIZE, PAGE_SIZE,
+ PAGE_SIZE);
+ if (!new)
+ goto err_alloc;
+ alloc_bytes += PAGE_SIZE;
+ p4d_populate(&init_mm, p4d, new);
+ }
+
+ pud = pud_offset(p4d, vstart);
if (pud_none(*pud)) {
pmd_t *new;

@@ -2612,13 +2632,18 @@ int __meminit vmemmap_populate(unsigned long vstart, unsigned long vend,
for (; vstart < vend; vstart += PMD_SIZE) {
pgd_t *pgd = vmemmap_pgd_populate(vstart, node);
unsigned long pte;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;

if (!pgd)
return -ENOMEM;

- pud = vmemmap_pud_populate(pgd, vstart, node);
+ p4d = vmemmap_p4d_populate(pgd, vstart, node);
+ if (!p4d)
+ return -ENOMEM;
+
+ pud = vmemmap_pud_populate(p4d, vstart, node);
if (!pud)
return -ENOMEM;

--
2.24.0