[LINUX] x86/64: Sync pagetable management with i386 Xen code.

PUDs,PMDs,PTEs are all marked as ForeignPage so that they can be
grabbed from tlb_remove_page() at the appropriate time and freed in a
special way.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff --git a/linux-2.6-xen-sparse/arch/x86_64/mm/pageattr-xen.c b/linux-2.6-xen-sparse/arch/x86_64/mm/pageattr-xen.c
index 3641bfb805ebaf955417010c5696c2084c9b7818..d717708de9dc2ce79d1d3f3eea30778e0e38362a 100644 (file)
--- a/linux-2.6-xen-sparse/arch/x86_64/mm/pageattr-xen.c
+++ b/linux-2.6-xen-sparse/arch/x86_64/mm/pageattr-xen.c
@@ -164,6 +164,18 @@ void _arch_exit_mmap(struct mm_struct *mm)
         mm_unpin(mm);
 }
 
+struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
+{
+       struct page *pte;
+
+       pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
+       if (pte) {
+               SetPageForeign(pte, pte_free);
+               set_page_count(pte, 1);
+       }
+       return pte;
+}
+
 void pte_free(struct page *pte)
 {
        unsigned long va = (unsigned long)__va(page_to_pfn(pte)<<PAGE_SHIFT);
@@ -171,6 +183,10 @@ void pte_free(struct page *pte)
        if (!pte_write(*virt_to_ptep(va)))
                BUG_ON(HYPERVISOR_update_va_mapping(
                        va, pfn_pte(page_to_pfn(pte), PAGE_KERNEL), 0));
+
+       ClearPageForeign(pte);
+       set_page_count(pte, 1);
+
        __free_page(pte);
 }
 #endif /* CONFIG_XEN */

diff --git a/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/pgalloc.h b/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/pgalloc.h
index 6a7f8de3ffc67aa45664b7b4c64e859d6d8cfc10..dd7308b028afd382bfea51e651360ea6a5caf246 100644 (file)
--- a/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/pgalloc.h
+++ b/linux-2.6-xen-sparse/include/asm-x86_64/mach-xen/asm/pgalloc.h
@@ -64,50 +64,43 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
        }
 }
 
-static inline void pmd_free(pmd_t *pmd)
+extern struct page *pte_alloc_one(struct mm_struct *mm, unsigned long addr);
+extern void pte_free(struct page *pte);
+
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-       pte_t *ptep = virt_to_ptep(pmd);
+       struct page *pg;
 
-       if (!pte_write(*ptep)) {
-               BUG_ON(HYPERVISOR_update_va_mapping(
-                       (unsigned long)pmd,
-                       pfn_pte(virt_to_phys(pmd)>>PAGE_SHIFT, PAGE_KERNEL),
-                       0));
-       }
-       free_page((unsigned long)pmd);
+       pg = pte_alloc_one(mm, addr);
+       return pg ? page_address(pg) : NULL;
 }
 
-static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
+static inline void pmd_free(pmd_t *pmd)
 {
-        pmd_t *pmd = (pmd_t *) get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
-        return pmd;
+       BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
+       pte_free(virt_to_page(pmd));
 }
 
 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-        pud_t *pud = (pud_t *) get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
-        return pud;
+       struct page *pg;
+
+       pg = pte_alloc_one(mm, addr);
+       return pg ? page_address(pg) : NULL;
 }
 
 static inline void pud_free(pud_t *pud)
 {
-       pte_t *ptep = virt_to_ptep(pud);
-
-       if (!pte_write(*ptep)) {
-               BUG_ON(HYPERVISOR_update_va_mapping(
-                       (unsigned long)pud,
-                       pfn_pte(virt_to_phys(pud)>>PAGE_SHIFT, PAGE_KERNEL),
-                       0));
-       }
-       free_page((unsigned long)pud);
+       BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
+       pte_free(virt_to_page(pud));
 }
 
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-        /*
-         * We allocate two contiguous pages for kernel and user.
-         */
-        unsigned boundary;
+       /*
+        * We allocate two contiguous pages for kernel and user.
+        */
+       unsigned boundary;
        pgd_t *pgd = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_REPEAT, 1);
 
        if (!pgd)
@@ -124,11 +117,11 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
               (PTRS_PER_PGD - boundary) * sizeof(pgd_t));
 
        memset(__user_pgd(pgd), 0, PAGE_SIZE); /* clean up user pgd */
-        /*
-         * Set level3_user_pgt for vsyscall area
-         */
+       /*
+        * Set level3_user_pgt for vsyscall area
+        */
        set_pgd(__user_pgd(pgd) + pgd_index(VSYSCALL_START), 
-                mk_kernel_pgd(__pa_symbol(level3_user_pgt)));
+               mk_kernel_pgd(__pa_symbol(level3_user_pgt)));
        return pgd;
 }
 
@@ -160,39 +153,25 @@ static inline void pgd_free(pgd_t *pgd)
 
 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
 {
-        pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
-        if (pte)
+       pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
+       if (pte)
                make_page_readonly(pte, XENFEAT_writable_page_tables);
 
        return pte;
 }
 
-static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
-{
-       struct page *pte;
-
-       pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
-       return pte;
-}
-
 /* Should really implement gc for free page table pages. This could be
    done with a reference count in struct page. */
 
 static inline void pte_free_kernel(pte_t *pte)
 {
        BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
-        make_page_writable(pte, XENFEAT_writable_page_tables);
+       make_page_writable(pte, XENFEAT_writable_page_tables);
        free_page((unsigned long)pte); 
 }
 
-extern void pte_free(struct page *pte);
-
-//#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte)) 
-//#define __pmd_free_tlb(tlb,x)   tlb_remove_page((tlb),virt_to_page(x))
-//#define __pud_free_tlb(tlb,x)   tlb_remove_page((tlb),virt_to_page(x))
-
-#define __pte_free_tlb(tlb,x)   pte_free((x))
-#define __pmd_free_tlb(tlb,x)   pmd_free((x))
-#define __pud_free_tlb(tlb,x)   pud_free((x))
+#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte))
+#define __pmd_free_tlb(tlb,x)   tlb_remove_page((tlb),virt_to_page(x))
+#define __pud_free_tlb(tlb,x)   tlb_remove_page((tlb),virt_to_page(x))
 
 #endif /* _X86_64_PGALLOC_H */