powerpc: Replace find_linux_pte with find_linux_pte_or_hugepte

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@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index 6c9323f..e71bd25 100644 (file)
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -344,30 +344,6 @@ 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;
-}
-
 #endif /* __ASSEMBLY__ */
 
 /*

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 7c567be..af2b9ae 100644 (file)
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -260,10 +260,15 @@ static inline unsigned long eeh_token_to_phys(unsigned long token)
 {
        pte_t *ptep;
        unsigned long pa;
+       int hugepage_shift;
 
-       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, &hugepage_shift);
        if (!ptep)
                return token;
+       WARN_ON(hugepage_shift);
        pa = pte_pfn(*ptep) << PAGE_SHIFT;
 
        return pa | (token & (PAGE_SIZE-1));

diff --git a/arch/powerpc/kernel/io-workarounds.c b/arch/powerpc/kernel/io-workarounds.c
index 50e90b7..fa0b54b 100644 (file)
--- 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 hugepage_shift;
        struct iowa_bus *bus;
        int token;
 
@@ -70,11 +71,17 @@ 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,
+                                                &hugepage_shift);
                if (ptep == NULL)
                        paddr = 0;
-               else
+               else {
+                       /*
+                        * we don't have hugepages backing iomem
+                        */
+                       WARN_ON(hugepage_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 6dcbb49..dcf892d 100644 (file)
--- 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 2f47080..e8434ca 100644 (file)
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -1145,6 +1145,7 @@ EXPORT_SYMBOL_GPL(hash_page);
 void hash_preload(struct mm_struct *mm, unsigned long ea,
                  unsigned long access, unsigned long trap)
 {
+       int hugepage_shift;
        unsigned long vsid;
        pgd_t *pgdir;
        pte_t *ptep;
@@ -1166,10 +1167,15 @@ 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, &hugepage_shift);
        if (!ptep)
                return;
 
+       WARN_ON(hugepage_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 4928204..8add580 100644 (file)
--- 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 hugetlbfs 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 48bf63e..313c85c 100644 (file)
--- 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 hugepage_shift;
        unsigned long flags;
 
        start = _ALIGN_DOWN(start, PAGE_SIZE);
@@ -206,7 +207,8 @@ 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,
+                                                       &hugepage_shift);
                unsigned long pte;
 
                if (ptep == NULL)
@@ -214,7 +216,10 @@ void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
                pte = pte_val(*ptep);
                if (!(pte & _PAGE_HASHPTE))
                        continue;
-               hpte_need_flush(mm, start, ptep, pte, 0);
+               if (unlikely(hugepage_shift && pmd_trans_huge(*(pmd_t *)pte)))
+                       hpte_do_hugepage_flush(mm, start, (pmd_t *)pte);
+               else
+                       hpte_need_flush(mm, start, ptep, pte, 0);
        }
        arch_leave_lazy_mmu_mode();
        local_irq_restore(flags);