[PATCH v3 04/14] ia64: add support for folded p4d page tables

Mike Rapoport
2020-02-27T08:45:58Z

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate, remove usage of __ARCH_USE_5LEVEL_HACK and replace
5level-fixup.h with pgtable-nop4d.h

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
arch/ia64/include/asm/pgalloc.h | 4 ++--
arch/ia64/include/asm/pgtable.h | 17 ++++++++---------
arch/ia64/mm/fault.c | 7 ++++++-
arch/ia64/mm/hugetlbpage.c | 18 ++++++++++++------
arch/ia64/mm/init.c | 28 ++++++++++++++++++++++++----
5 files changed, 52 insertions(+), 22 deletions(-)

diff --git a/arch/ia64/include/asm/pgalloc.h b/arch/ia64/include/asm/pgalloc.h
index f4c491044882..2a3050345099 100644
--- a/arch/ia64/include/asm/pgalloc.h
+++ b/arch/ia64/include/asm/pgalloc.h
@@ -36,9 +36,9 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)

#if CONFIG_PGTABLE_LEVELS = 4
static inline void
-pgd_populate(struct mm_struct *mm, pgd_t * pgd_entry, pud_t * pud)
+p4d_populate(struct mm_struct *mm, p4d_t * p4d_entry, pud_t * pud)
{
- pgd_val(*pgd_entry) = __pa(pud);
+ p4d_val(*p4d_entry) = __pa(pud);
}

static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
index d602e7c622db..c87f789bc914 100644
--- a/arch/ia64/include/asm/pgtable.h
+++ b/arch/ia64/include/asm/pgtable.h
@@ -283,12 +283,12 @@ extern unsigned long VMALLOC_END;
#define pud_page(pud) virt_to_page((pud_val(pud) + PAGE_OFFSET))

#if CONFIG_PGTABLE_LEVELS = 4
-#define pgd_none(pgd) (!pgd_val(pgd))
-#define pgd_bad(pgd) (!ia64_phys_addr_valid(pgd_val(pgd)))
-#define pgd_present(pgd) (pgd_val(pgd) != 0UL)
-#define pgd_clear(pgdp) (pgd_val(*(pgdp)) = 0UL)
-#define pgd_page_vaddr(pgd) ((unsigned long) __va(pgd_val(pgd) & _PFN_MASK))
-#define pgd_page(pgd) virt_to_page((pgd_val(pgd) + PAGE_OFFSET))
+#define p4d_none(p4d) (!p4d_val(p4d))
+#define p4d_bad(p4d) (!ia64_phys_addr_valid(p4d_val(p4d)))
+#define p4d_present(p4d) (p4d_val(p4d) != 0UL)
+#define p4d_clear(p4dp) (p4d_val(*(p4dp)) = 0UL)
+#define p4d_page_vaddr(p4d) ((unsigned long) __va(p4d_val(p4d) & _PFN_MASK))
+#define p4d_page(p4d) virt_to_page((p4d_val(p4d) + PAGE_OFFSET))
#endif

/*
@@ -388,7 +388,7 @@ pgd_offset (const struct mm_struct *mm, unsigned long address)
#if CONFIG_PGTABLE_LEVELS = 4
/* Find an entry in the second-level page table.. */
#define pud_offset(dir,addr) \
- ((pud_t *) pgd_page_vaddr(*(dir)) + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
+ ((pud_t *) p4d_page_vaddr(*(dir)) + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
#endif

/* Find an entry in the third-level page table.. */
@@ -582,10 +582,9 @@ extern struct page *zero_page_memmap_ptr;

#if CONFIG_PGTABLE_LEVELS = 3
-#define __ARCH_USE_5LEVEL_HACK
#include <asm-generic/pgtable-nopud.h>
#endif
-#include <asm-generic/5level-fixup.h>
+#include <asm-generic/pgtable-nop4d.h>
#include <asm-generic/pgtable.h>

#endif /* _ASM_IA64_PGTABLE_H */
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index c2f299fe9e04..ec994135cb74 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -29,6 +29,7 @@ static int
mapped_kernel_page_is_present (unsigned long address)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *ptep, pte;
@@ -37,7 +38,11 @@ mapped_kernel_page_is_present (unsigned long address)
if (pgd_none(*pgd) || pgd_bad(*pgd))
return 0;

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

diff --git a/arch/ia64/mm/hugetlbpage.c b/arch/ia64/mm/hugetlbpage.c
index d16e419fd712..32352a73df0c 100644
--- a/arch/ia64/mm/hugetlbpage.c
+++ b/arch/ia64/mm/hugetlbpage.c
@@ -30,12 +30,14 @@ huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz)
{
unsigned long taddr = htlbpage_to_page(addr);
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;

pgd = pgd_offset(mm, taddr);
- pud = pud_alloc(mm, pgd, taddr);
+ p4d = p4d_offset(pgd, taddr);
+ pud = pud_alloc(mm, p4d, taddr);
if (pud) {
pmd = pmd_alloc(mm, pud, taddr);
if (pmd)
@@ -49,17 +51,21 @@ huge_pte_offset (struct mm_struct *mm, unsigned long addr, unsigned long sz)
{
unsigned long taddr = htlbpage_to_page(addr);
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte = NULL;

pgd = pgd_offset(mm, taddr);
if (pgd_present(*pgd)) {
- pud = pud_offset(pgd, taddr);
- if (pud_present(*pud)) {
- pmd = pmd_offset(pud, taddr);
- if (pmd_present(*pmd))
- pte = pte_offset_map(pmd, taddr);
+ p4d = p4d_offset(pgd, addr);
+ if (p4d_present(*p4d)) {
+ pud = pud_offset(p4d, taddr);
+ if (pud_present(*pud)) {
+ pmd = pmd_offset(pud, taddr);
+ if (pmd_present(*pmd))
+ pte = pte_offset_map(pmd, taddr);
+ }
}
}

diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c
index b01d68a2d5d9..4808f58220ac 100644
--- a/arch/ia64/mm/init.c
+++ b/arch/ia64/mm/init.c
@@ -208,6 +208,7 @@ static struct page * __init
put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@@ -215,7 +216,10 @@ put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */

{
- pud = pud_alloc(&init_mm, pgd, address);
+ p4d = p4d_alloc(&init_mm, pgd, address);
+ if (!p4d)
+ goto out;
+ pud = pud_alloc(&init_mm, p4d, address);
if (!pud)
goto out;
pmd = pmd_alloc(&init_mm, pud, address);
@@ -382,6 +386,7 @@ int vmemmap_find_next_valid_pfn(int node, int i)

do {
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@@ -392,7 +397,13 @@ int vmemmap_find_next_valid_pfn(int node, int i)
continue;
}

- pud = pud_offset(pgd, end_address);
+ p4d = p4d_offset(pgd, end_address);
+ if (p4d_none(*p4d)) {
+ end_address += P4D_SIZE;
+ continue;
+ }
+
+ pud = pud_offset(p4d, end_address);
if (pud_none(*pud)) {
end_address += PUD_SIZE;
continue;
@@ -430,6 +441,7 @@ int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
struct page *map_start, *map_end;
int node;
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@@ -444,12 +456,20 @@ int __init create_mem_map_page_table(u64 start, u64 end, void *arg)
for (address = start_page; address < end_page; address += PAGE_SIZE) {
pgd = pgd_offset_k(address);
if (pgd_none(*pgd)) {
+ p4d = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
+ if (!p4d)
+ goto err_alloc;
+ pgd_populate(&init_mm, pgd, p4d);
+ }
+ p4d = p4d_offset(pgd, address);
+
+ if (p4d_none(*p4d)) {
pud = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
if (!pud)
goto err_alloc;
- pgd_populate(&init_mm, pgd, pud);
+ p4d_populate(&init_mm, p4d, pud);
}
- pud = pud_offset(pgd, address);
+ pud = pud_offset(p4d, address);

if (pud_none(*pud)) {
pmd = memblock_alloc_node(PAGE_SIZE, PAGE_SIZE, node);
--
2.24.0