[PATCH -V7 05/10] powerpc: Replace find_linux_pte with find_linux_pte_or_hugepte
Aneesh Kumar K.V
aneesh.kumar at linux.vnet.ibm.com
Mon Apr 29 05:51:46 EST 2013
From: "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com>
Replace find_linux_pte with find_linux_pte_or_hugepte and explicitly
document why we don't need to handle transparent hugepages at callsites.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
arch/powerpc/include/asm/pgtable-ppc64.h | 24 ------------------------
arch/powerpc/kernel/io-workarounds.c | 10 ++++++++--
arch/powerpc/kvm/book3s_hv_rm_mmu.c | 2 +-
arch/powerpc/mm/hash_utils_64.c | 8 +++++++-
arch/powerpc/mm/hugetlbpage.c | 8 ++++++--
arch/powerpc/mm/tlb_hash64.c | 7 ++++++-
arch/powerpc/platforms/pseries/eeh.c | 7 ++++++-
7 files changed, 34 insertions(+), 32 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index f0effab..97fc839 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -343,30 +343,6 @@ static inline void __ptep_set_access_flags(pte_t *ptep, pte_t entry)
void pgtable_cache_add(unsigned shift, void (*ctor)(void *));
void pgtable_cache_init(void);
-
-/*
- * find_linux_pte returns the address of a linux pte for a given
- * effective address and directory. If not found, it returns zero.
- */
-static inline pte_t *find_linux_pte(pgd_t *pgdir, unsigned long ea)
-{
- pgd_t *pg;
- pud_t *pu;
- pmd_t *pm;
- pte_t *pt = NULL;
-
- pg = pgdir + pgd_index(ea);
- if (!pgd_none(*pg)) {
- pu = pud_offset(pg, ea);
- if (!pud_none(*pu)) {
- pm = pmd_offset(pu, ea);
- if (pmd_present(*pm))
- pt = pte_offset_kernel(pm, ea);
- }
- }
- return pt;
-}
-
pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea,
unsigned *shift);
#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/kernel/io-workarounds.c b/arch/powerpc/kernel/io-workarounds.c
index 50e90b7..e5263ab 100644
--- a/arch/powerpc/kernel/io-workarounds.c
+++ b/arch/powerpc/kernel/io-workarounds.c
@@ -55,6 +55,7 @@ static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
{
+ unsigned shift;
struct iowa_bus *bus;
int token;
@@ -70,11 +71,16 @@ struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
return NULL;
- ptep = find_linux_pte(init_mm.pgd, vaddr);
+ ptep = find_linux_pte_or_hugepte(init_mm.pgd, vaddr, &shift);
if (ptep == NULL)
paddr = 0;
- else
+ else {
+ /*
+ * we don't have hugepages backing iomem
+ */
+ BUG_ON(shift);
paddr = pte_pfn(*ptep) << PAGE_SHIFT;
+ }
bus = iowa_pci_find(vaddr, paddr);
if (bus == NULL)
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 19c93ba..8c345df 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -27,7 +27,7 @@ static void *real_vmalloc_addr(void *x)
unsigned long addr = (unsigned long) x;
pte_t *p;
- p = find_linux_pte(swapper_pg_dir, addr);
+ p = find_linux_pte_or_hugepte(swapper_pg_dir, addr, NULL);
if (!p || !pte_present(*p))
return NULL;
/* assume we don't have huge pages in vmalloc space... */
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index d0eb6d4..e942ae9 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1131,6 +1131,7 @@ EXPORT_SYMBOL_GPL(hash_page);
void hash_preload(struct mm_struct *mm, unsigned long ea,
unsigned long access, unsigned long trap)
{
+ int shift;
unsigned long vsid;
pgd_t *pgdir;
pte_t *ptep;
@@ -1152,10 +1153,15 @@ void hash_preload(struct mm_struct *mm, unsigned long ea,
pgdir = mm->pgd;
if (pgdir == NULL)
return;
- ptep = find_linux_pte(pgdir, ea);
+ /*
+ * THP pages use update_mmu_cache_pmd. We don't do
+ * hash preload there. Hence can ignore THP here
+ */
+ ptep = find_linux_pte_or_hugepte(pgdir, ea, &shift);
if (!ptep)
return;
+ BUG_ON(shift);
#ifdef CONFIG_PPC_64K_PAGES
/* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on
* a 64K kernel), then we don't preload, hash_page() will take
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 081c001..1154714 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -105,6 +105,7 @@ int pgd_huge(pgd_t pgd)
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
{
+ /* Only called for HugeTLB pages, hence can ignore THP */
return find_linux_pte_or_hugepte(mm->pgd, addr, NULL);
}
@@ -673,11 +674,14 @@ follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
struct page *page;
unsigned shift;
unsigned long mask;
-
+ /*
+ * Transparent hugepages are handled by generic code. We can skip them
+ * here.
+ */
ptep = find_linux_pte_or_hugepte(mm->pgd, address, &shift);
/* Verify it is a huge page else bail. */
- if (!ptep || !shift)
+ if (!ptep || !shift || pmd_trans_huge((pmd_t)*ptep))
return ERR_PTR(-EINVAL);
mask = (1UL << shift) - 1;
diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c
index 023ec8a..56d9b85 100644
--- a/arch/powerpc/mm/tlb_hash64.c
+++ b/arch/powerpc/mm/tlb_hash64.c
@@ -189,6 +189,7 @@ void tlb_flush(struct mmu_gather *tlb)
void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
unsigned long end)
{
+ int shift;
unsigned long flags;
start = _ALIGN_DOWN(start, PAGE_SIZE);
@@ -206,11 +207,15 @@ void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
local_irq_save(flags);
arch_enter_lazy_mmu_mode();
for (; start < end; start += PAGE_SIZE) {
- pte_t *ptep = find_linux_pte(mm->pgd, start);
+ pte_t *ptep = find_linux_pte_or_hugepte(mm->pgd, start, &shift);
unsigned long pte;
if (ptep == NULL)
continue;
+ /*
+ * We won't find hugepages here, this is iomem.
+ */
+ BUG_ON(shift);
pte = pte_val(*ptep);
if (!(pte & _PAGE_HASHPTE))
continue;
diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c
index 6b73d6c..d2e76d2 100644
--- a/arch/powerpc/platforms/pseries/eeh.c
+++ b/arch/powerpc/platforms/pseries/eeh.c
@@ -258,12 +258,17 @@ void eeh_slot_error_detail(struct eeh_pe *pe, int severity)
*/
static inline unsigned long eeh_token_to_phys(unsigned long token)
{
+ int shift;
pte_t *ptep;
unsigned long pa;
- ptep = find_linux_pte(init_mm.pgd, token);
+ /*
+ * We won't find hugepages here, iomem
+ */
+ ptep = find_linux_pte_or_hugepte(init_mm.pgd, token, &shift);
if (!ptep)
return token;
+ BUG_ON(shift);
pa = pte_pfn(*ptep) << PAGE_SHIFT;
return pa | (token & (PAGE_SIZE-1));
--
1.8.1.2
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