From: Joerg Roedel <[email protected]>

Track at which levels in the page-table entries were modified by
vmap/vunmap. After the page-table has been modified, use that
information do decide whether the new arch_sync_kernel_mappings()
needs to be called.

Signed-off-by: Joerg Roedel <[email protected]>
---
 include/linux/vmalloc.h | 11 ++++++
 mm/vmalloc.c            | 88 ++++++++++++++++++++++++++++++-----------
 2 files changed, 75 insertions(+), 24 deletions(-)

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index a95d3cc74d79..eb364000cb03 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -144,6 +144,17 @@ extern int remap_vmalloc_range(struct vm_area_struct *vma, 
void *addr,
 void vmalloc_sync_mappings(void);
 void vmalloc_sync_unmappings(void);
 
+/*
+ * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED 
values
+ * and let generic vmalloc and ioremap code know when 
arch_sync_kernel_mappings()
+ * needs to be called.
+ */
+#ifndef ARCH_PAGE_TABLE_SYNC_MASK
+#define ARCH_PAGE_TABLE_SYNC_MASK 0
+#endif
+
+void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
+
 /*
  *     Lowlevel-APIs (not for driver use!)
  */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 9a8227afa073..184f5a556cf7 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -69,7 +69,8 @@ static void free_work(struct work_struct *w)
 
 /*** Page table manipulation functions ***/
 
-static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
+static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+                            pgtbl_mod_mask *mask)
 {
        pte_t *pte;
 
@@ -78,73 +79,104 @@ static void vunmap_pte_range(pmd_t *pmd, unsigned long 
addr, unsigned long end)
                pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
                WARN_ON(!pte_none(ptent) && !pte_present(ptent));
        } while (pte++, addr += PAGE_SIZE, addr != end);
+       *mask |= PGTBL_PTE_MODIFIED;
 }
 
-static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
+static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
+                            pgtbl_mod_mask *mask)
 {
        pmd_t *pmd;
        unsigned long next;
+       int cleared;
 
        pmd = pmd_offset(pud, addr);
        do {
                next = pmd_addr_end(addr, end);
-               if (pmd_clear_huge(pmd))
+
+               cleared = pmd_clear_huge(pmd);
+               if (cleared || pmd_bad(*pmd))
+                       *mask |= PGTBL_PMD_MODIFIED;
+
+               if (cleared)
                        continue;
                if (pmd_none_or_clear_bad(pmd))
                        continue;
-               vunmap_pte_range(pmd, addr, next);
+               vunmap_pte_range(pmd, addr, next, mask);
        } while (pmd++, addr = next, addr != end);
 }
 
-static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end)
+static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
+                            pgtbl_mod_mask *mask)
 {
        pud_t *pud;
        unsigned long next;
+       int cleared;
 
        pud = pud_offset(p4d, addr);
        do {
                next = pud_addr_end(addr, end);
-               if (pud_clear_huge(pud))
+
+               cleared = pud_clear_huge(pud);
+               if (cleared || pud_bad(*pud))
+                       *mask |= PGTBL_PUD_MODIFIED;
+
+               if (cleared)
                        continue;
                if (pud_none_or_clear_bad(pud))
                        continue;
-               vunmap_pmd_range(pud, addr, next);
+               vunmap_pmd_range(pud, addr, next, mask);
        } while (pud++, addr = next, addr != end);
 }
 
-static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end)
+static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
+                            pgtbl_mod_mask *mask)
 {
        p4d_t *p4d;
        unsigned long next;
+       int cleared;
 
        p4d = p4d_offset(pgd, addr);
        do {
                next = p4d_addr_end(addr, end);
-               if (p4d_clear_huge(p4d))
+
+               cleared = p4d_clear_huge(p4d);
+               if (cleared || p4d_bad(*p4d))
+                       *mask |= PGTBL_P4D_MODIFIED;
+
+               if (cleared)
                        continue;
                if (p4d_none_or_clear_bad(p4d))
                        continue;
-               vunmap_pud_range(p4d, addr, next);
+               vunmap_pud_range(p4d, addr, next, mask);
        } while (p4d++, addr = next, addr != end);
 }
 
-static void vunmap_page_range(unsigned long addr, unsigned long end)
+static void vunmap_page_range(unsigned long start, unsigned long end)
 {
        pgd_t *pgd;
+       unsigned long addr = start;
        unsigned long next;
+       pgtbl_mod_mask mask = 0;
 
        BUG_ON(addr >= end);
+       start = addr;
        pgd = pgd_offset_k(addr);
        do {
                next = pgd_addr_end(addr, end);
+               if (pgd_bad(*pgd))
+                       mask |= PGTBL_PGD_MODIFIED;
                if (pgd_none_or_clear_bad(pgd))
                        continue;
-               vunmap_p4d_range(pgd, addr, next);
+               vunmap_p4d_range(pgd, addr, next, &mask);
        } while (pgd++, addr = next, addr != end);
+
+       if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
+               arch_sync_kernel_mappings(start, end);
 }
 
 static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
-               unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+               unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+               pgtbl_mod_mask *mask)
 {
        pte_t *pte;
 
@@ -153,7 +185,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
         * callers keep track of where we're up to.
         */
 
-       pte = pte_alloc_kernel(pmd, addr);
+       pte = pte_alloc_kernel_track(pmd, addr, mask);
        if (!pte)
                return -ENOMEM;
        do {
@@ -166,55 +198,59 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
                set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
                (*nr)++;
        } while (pte++, addr += PAGE_SIZE, addr != end);
+       *mask |= PGTBL_PTE_MODIFIED;
        return 0;
 }
 
 static int vmap_pmd_range(pud_t *pud, unsigned long addr,
-               unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+               unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+               pgtbl_mod_mask *mask)
 {
        pmd_t *pmd;
        unsigned long next;
 
-       pmd = pmd_alloc(&init_mm, pud, addr);
+       pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
        if (!pmd)
                return -ENOMEM;
        do {
                next = pmd_addr_end(addr, end);
-               if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
+               if (vmap_pte_range(pmd, addr, next, prot, pages, nr, mask))
                        return -ENOMEM;
        } while (pmd++, addr = next, addr != end);
        return 0;
 }
 
 static int vmap_pud_range(p4d_t *p4d, unsigned long addr,
-               unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+               unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+               pgtbl_mod_mask *mask)
 {
        pud_t *pud;
        unsigned long next;
 
-       pud = pud_alloc(&init_mm, p4d, addr);
+       pud = pud_alloc_track(&init_mm, p4d, addr, mask);
        if (!pud)
                return -ENOMEM;
        do {
                next = pud_addr_end(addr, end);
-               if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
+               if (vmap_pmd_range(pud, addr, next, prot, pages, nr, mask))
                        return -ENOMEM;
        } while (pud++, addr = next, addr != end);
        return 0;
 }
 
 static int vmap_p4d_range(pgd_t *pgd, unsigned long addr,
-               unsigned long end, pgprot_t prot, struct page **pages, int *nr)
+               unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+               pgtbl_mod_mask *mask)
 {
        p4d_t *p4d;
        unsigned long next;
 
-       p4d = p4d_alloc(&init_mm, pgd, addr);
+       p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
        if (!p4d)
                return -ENOMEM;
        do {
                next = p4d_addr_end(addr, end);
-               if (vmap_pud_range(p4d, addr, next, prot, pages, nr))
+               if (vmap_pud_range(p4d, addr, next, prot, pages, nr, mask))
                        return -ENOMEM;
        } while (p4d++, addr = next, addr != end);
        return 0;
@@ -234,16 +270,20 @@ static int vmap_page_range_noflush(unsigned long start, 
unsigned long end,
        unsigned long addr = start;
        int err = 0;
        int nr = 0;
+       pgtbl_mod_mask mask = 0;
 
        BUG_ON(addr >= end);
        pgd = pgd_offset_k(addr);
        do {
                next = pgd_addr_end(addr, end);
-               err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr);
+               err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
                if (err)
                        return err;
        } while (pgd++, addr = next, addr != end);
 
+       if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
+               arch_sync_kernel_mappings(start, end);
+
        return nr;
 }
 
-- 
2.17.1

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