[PATCH V5 1/3] powerpc/mm: Add missing pmd accessors
Aneesh Kumar K.V
aneesh.kumar at linux.vnet.ibm.com
Thu Nov 6 03:27:39 AEDT 2014
This patch add documentation and missing accessors.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/pgtable-ppc64-4k.h | 16 ++++++++-
arch/powerpc/include/asm/pgtable-ppc64-64k.h | 3 ++
arch/powerpc/include/asm/pgtable-ppc64.h | 51 +++++++++++++++++++++-------
arch/powerpc/mm/hugetlbpage.c | 3 ++
arch/powerpc/mm/pgtable_64.c | 22 ++++++++++--
5 files changed, 78 insertions(+), 17 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc64-4k.h b/arch/powerpc/include/asm/pgtable-ppc64-4k.h
index 7b935683f268..132ee1d482c2 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64-4k.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64-4k.h
@@ -57,7 +57,21 @@
#define pgd_present(pgd) (pgd_val(pgd) != 0)
#define pgd_clear(pgdp) (pgd_val(*(pgdp)) = 0)
#define pgd_page_vaddr(pgd) (pgd_val(pgd) & ~PGD_MASKED_BITS)
-#define pgd_page(pgd) virt_to_page(pgd_page_vaddr(pgd))
+
+#ifndef __ASSEMBLY__
+
+static inline pte_t pgd_pte(pgd_t pgd)
+{
+ return __pte(pgd_val(pgd));
+}
+
+static inline pgd_t pte_pgd(pte_t pte)
+{
+ return __pgd(pte_val(pte));
+}
+extern struct page *pgd_page(pgd_t pgd);
+
+#endif /* !__ASSEMBLY__ */
#define pud_offset(pgdp, addr) \
(((pud_t *) pgd_page_vaddr(*(pgdp))) + \
diff --git a/arch/powerpc/include/asm/pgtable-ppc64-64k.h b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
index a56b82fb0609..1de35bbd02a6 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64-64k.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
@@ -38,4 +38,7 @@
/* Bits to mask out from a PGD/PUD to get to the PMD page */
#define PUD_MASKED_BITS 0x1ff
+#define pgd_pte(pgd) (pud_pte(((pud_t){ pgd })))
+#define pte_pgd(pte) ((pgd_t)pte_pud(pte))
+
#endif /* _ASM_POWERPC_PGTABLE_PPC64_64K_H */
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index ae153c40ab7c..d12092420560 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -152,7 +152,7 @@
#define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_bad(pmd) (!is_kernel_addr(pmd_val(pmd)) \
|| (pmd_val(pmd) & PMD_BAD_BITS))
-#define pmd_present(pmd) (pmd_val(pmd) != 0)
+#define pmd_present(pmd) (!pmd_none(pmd))
#define pmd_clear(pmdp) (pmd_val(*(pmdp)) = 0)
#define pmd_page_vaddr(pmd) (pmd_val(pmd) & ~PMD_MASKED_BITS)
extern struct page *pmd_page(pmd_t pmd);
@@ -164,9 +164,21 @@ extern struct page *pmd_page(pmd_t pmd);
#define pud_present(pud) (pud_val(pud) != 0)
#define pud_clear(pudp) (pud_val(*(pudp)) = 0)
#define pud_page_vaddr(pud) (pud_val(pud) & ~PUD_MASKED_BITS)
-#define pud_page(pud) virt_to_page(pud_page_vaddr(pud))
+extern struct page *pud_page(pud_t pud);
+
+static inline pte_t pud_pte(pud_t pud)
+{
+ return __pte(pud_val(pud));
+}
+
+static inline pud_t pte_pud(pte_t pte)
+{
+ return __pud(pte_val(pte));
+}
+#define pud_write(pud) pte_write(pud_pte(pud))
#define pgd_set(pgdp, pudp) ({pgd_val(*(pgdp)) = (unsigned long)(pudp);})
+#define pgd_write(pgd) pte_write(pgd_pte(pgd))
/*
* Find an entry in a page-table-directory. We combine the address region
@@ -422,7 +434,22 @@ extern void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd);
extern void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd);
-
+/*
+ *
+ * For core kernel code by design pmd_trans_huge is never run on any hugetlbfs
+ * page. The hugetlbfs page table walking and mangling paths are totally
+ * separated form the core VM paths and they're differentiated by
+ * VM_HUGETLB being set on vm_flags well before any pmd_trans_huge could run.
+ *
+ * pmd_trans_huge() is defined as false at build time if
+ * CONFIG_TRANSPARENT_HUGEPAGE=n to optimize away code blocks at build
+ * time in such case.
+ *
+ * For ppc64 we need to differntiate from explicit hugepages from THP, because
+ * for THP we also track the subpage details at the pmd level. We don't do
+ * that for explicit huge pages.
+ *
+ */
static inline int pmd_trans_huge(pmd_t pmd)
{
/*
@@ -431,16 +458,6 @@ static inline int pmd_trans_huge(pmd_t pmd)
return (pmd_val(pmd) & 0x3) && (pmd_val(pmd) & _PAGE_THP_HUGE);
}
-static inline int pmd_large(pmd_t pmd)
-{
- /*
- * leaf pte for huge page, bottom two bits != 00
- */
- if (pmd_trans_huge(pmd))
- return pmd_val(pmd) & _PAGE_PRESENT;
- return 0;
-}
-
static inline int pmd_trans_splitting(pmd_t pmd)
{
if (pmd_trans_huge(pmd))
@@ -451,6 +468,14 @@ static inline int pmd_trans_splitting(pmd_t pmd)
extern int has_transparent_hugepage(void);
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+static inline int pmd_large(pmd_t pmd)
+{
+ /*
+ * leaf pte for huge page, bottom two bits != 00
+ */
+ return ((pmd_val(pmd) & 0x3) != 0x0);
+}
+
static inline pte_t pmd_pte(pmd_t pmd)
{
return __pte(pmd_val(pmd));
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 7e70ae968e5f..2e35b9a82929 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -62,6 +62,9 @@ static unsigned nr_gpages;
/*
* We have PGD_INDEX_SIZ = 12 and PTE_INDEX_SIZE = 8, so that we can have
* 16GB hugepage pte in PGD and 16MB hugepage pte at PMD;
+ *
+ * Defined in such a way that we can optimize away code block at build time
+ * if CONFIG_HUGETLB_PAGE=n.
*/
int pmd_huge(pmd_t pmd)
{
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index c8d709ab489d..e40ca0e3f2bf 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -36,6 +36,7 @@
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
+#include <linux/hugetlb.h>
#include <asm/pgalloc.h>
#include <asm/page.h>
@@ -352,16 +353,31 @@ EXPORT_SYMBOL(iounmap);
EXPORT_SYMBOL(__iounmap);
EXPORT_SYMBOL(__iounmap_at);
+#ifndef __PAGETABLE_PUD_FOLDED
+/* 4 level page table */
+struct page *pgd_page(pgd_t pgd)
+{
+ if (pgd_huge(pgd))
+ return pte_page(pgd_pte(pgd));
+ return virt_to_page(pgd_page_vaddr(pgd));
+}
+#endif
+
+struct page *pud_page(pud_t pud)
+{
+ if (pud_huge(pud))
+ return pte_page(pud_pte(pud));
+ return virt_to_page(pud_page_vaddr(pud));
+}
+
/*
* For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
* For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
*/
struct page *pmd_page(pmd_t pmd)
{
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- if (pmd_trans_huge(pmd))
+ if (pmd_trans_huge(pmd) || pmd_huge(pmd))
return pfn_to_page(pmd_pfn(pmd));
-#endif
return virt_to_page(pmd_page_vaddr(pmd));
}
--
2.1.0
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