x86: PAT: remove follow_pfnmap_pte in favor of follow_phys

Impact: Cleanup - removes a new function in favor of a recently modified older one.

Replace follow_pfnmap_pte in pat code with follow_phys. follow_phys lso
returns protection eliminating the need of pte_pgprot call. Using follow_phys
also eliminates the need for pte_pa.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

4 files changed, 11 insertions, 70 deletions

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 579f8ceee948..2aa792bbd7e0 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -230,11 +230,6 @@ static inline unsigned long pte_pfn(pte_t pte)
         return (pte_val(pte) & PTE_PFN_MASK) >> PAGE_SHIFT;
 }
 
-static inline u64 pte_pa(pte_t pte)
-{
-        return pte_val(pte) & PTE_PFN_MASK;
-}
-
 #define pte_page(pte)   pfn_to_page(pte_pfn(pte))
 
 static inline int pmd_large(pmd_t pte)
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index d5254bae84f4..541bcc944a5b 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -685,8 +685,7 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
         int retval = 0;
         unsigned long i, j;
         u64 paddr;
-        pgprot_t prot;
-        pte_t pte;
+        unsigned long prot;
         unsigned long vma_start = vma->vm_start;
         unsigned long vma_end = vma->vm_end;
         unsigned long vma_size = vma_end - vma_start;
@@ -696,26 +695,22 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
 
         if (is_linear_pfn_mapping(vma)) {
                 /*
-                 * reserve the whole chunk starting from vm_pgoff,
-                 * But, we have to get the protection from pte.
+                 * reserve the whole chunk covered by vma. We need the
+                 * starting address and protection from pte.
                  */
-                if (follow_pfnmap_pte(vma, vma_start, &pte)) {
+                if (follow_phys(vma, vma_start, 0, &prot, &paddr)) {
                         WARN_ON_ONCE(1);
-                        return -1;
+                        return -EINVAL;
                 }
-                prot = pte_pgprot(pte);
-                paddr = (u64)vma->vm_pgoff << PAGE_SHIFT;
-                return reserve_pfn_range(paddr, vma_size, prot);
+                return reserve_pfn_range(paddr, vma_size, __pgprot(prot));
         }
 
         /* reserve entire vma page by page, using pfn and prot from pte */
         for (i = 0; i < vma_size; i += PAGE_SIZE) {
-                if (follow_pfnmap_pte(vma, vma_start + i, &pte))
+                if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
                         continue;
 
-                paddr = pte_pa(pte);
-                prot = pte_pgprot(pte);
-                retval = reserve_pfn_range(paddr, PAGE_SIZE, prot);
+                retval = reserve_pfn_range(paddr, PAGE_SIZE, __pgprot(prot));
                 if (retval)
                         goto cleanup_ret;
         }
@@ -724,10 +719,9 @@ int track_pfn_vma_copy(struct vm_area_struct *vma)
 cleanup_ret:
         /* Reserve error: Cleanup partial reservation and return error */
         for (j = 0; j < i; j += PAGE_SIZE) {
-                if (follow_pfnmap_pte(vma, vma_start + j, &pte))
+                if (follow_phys(vma, vma_start + j, 0, &prot, &paddr))
                         continue;
 
-                paddr = pte_pa(pte);
                 free_pfn_range(paddr, PAGE_SIZE);
         }
 
@@ -797,6 +791,7 @@ void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
 {
         unsigned long i;
         u64 paddr;
+        unsigned long prot;
         unsigned long vma_start = vma->vm_start;
         unsigned long vma_end = vma->vm_end;
         unsigned long vma_size = vma_end - vma_start;
@@ -821,12 +816,9 @@ void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
         } else {
                 /* free entire vma, page by page, using the pfn from pte */
                 for (i = 0; i < vma_size; i += PAGE_SIZE) {
-                        pte_t pte;
-
-                        if (follow_pfnmap_pte(vma, vma_start + i, &pte))
+                        if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
                                 continue;
 
-                        paddr = pte_pa(pte);
                         free_pfn_range(paddr, PAGE_SIZE);
                 }
         }
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2f6e2f886d4b..36f9b3fa5e15 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1239,9 +1239,6 @@ struct page *follow_page(struct vm_area_struct *, unsigned long address,
 #define FOLL_GET        0x04    /* do get_page on page */
 #define FOLL_ANON       0x08    /* give ZERO_PAGE if no pgtable */
 
-int follow_pfnmap_pte(struct vm_area_struct *vma,
-                                unsigned long address, pte_t *ret_ptep);
-
 typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr,
                         void *data);
 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
diff --git a/mm/memory.c b/mm/memory.c
index 79f28e35d4fc..6b29f39a5a3e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1168,49 +1168,6 @@ no_page_table:
         return page;
 }
 
-int follow_pfnmap_pte(struct vm_area_struct *vma, unsigned long address,
-                        pte_t *ret_ptep)
-{
-        pgd_t *pgd;
-        pud_t *pud;
-        pmd_t *pmd;
-        pte_t *ptep, pte;
-        spinlock_t *ptl;
-        struct page *page;
-        struct mm_struct *mm = vma->vm_mm;
-
-        if (!is_pfn_mapping(vma))
-                goto err;
-
-        page = NULL;
-        pgd = pgd_offset(mm, address);
-        if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
-                goto err;
-
-        pud = pud_offset(pgd, address);
-        if (pud_none(*pud) || unlikely(pud_bad(*pud)))
-                goto err;
-
-        pmd = pmd_offset(pud, address);
-        if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
-                goto err;
-
-        ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
-
-        pte = *ptep;
-        if (!pte_present(pte))
-                goto err_unlock;
-
-        *ret_ptep = pte;
-        pte_unmap_unlock(ptep, ptl);
-        return 0;
-
-err_unlock:
-        pte_unmap_unlock(ptep, ptl);
-err:
-        return -EINVAL;
-}
-
 /* Can we do the FOLL_ANON optimization? */
 static inline int use_zero_page(struct vm_area_struct *vma)
 {