aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--arch/x86/xen/mmu.c115
1 files changed, 75 insertions, 40 deletions
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index eb31ed291b9..046c1f23dd6 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -44,6 +44,7 @@
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
+#include <asm/fixmap.h>
#include <asm/mmu_context.h>
#include <asm/paravirt.h>
#include <asm/linkage.h>
@@ -491,77 +492,103 @@ void xen_set_pgd(pgd_t *ptr, pgd_t val)
#endif /* PAGETABLE_LEVELS == 4 */
/*
- (Yet another) pagetable walker. This one is intended for pinning a
- pagetable. This means that it walks a pagetable and calls the
- callback function on each page it finds making up the page table,
- at every level. It walks the entire pagetable, but it only bothers
- pinning pte pages which are below pte_limit. In the normal case
- this will be TASK_SIZE, but at boot we need to pin up to
- FIXADDR_TOP. But the important bit is that we don't pin beyond
- there, because then we start getting into Xen's ptes.
-*/
-static int pgd_walk(pgd_t *pgd_base, int (*func)(struct page *, enum pt_level),
+ * (Yet another) pagetable walker. This one is intended for pinning a
+ * pagetable. This means that it walks a pagetable and calls the
+ * callback function on each page it finds making up the page table,
+ * at every level. It walks the entire pagetable, but it only bothers
+ * pinning pte pages which are below limit. In the normal case this
+ * will be STACK_TOP_MAX, but at boot we need to pin up to
+ * FIXADDR_TOP.
+ *
+ * For 32-bit the important bit is that we don't pin beyond there,
+ * because then we start getting into Xen's ptes.
+ *
+ * For 64-bit, we must skip the Xen hole in the middle of the address
+ * space, just after the big x86-64 virtual hole.
+ */
+static int pgd_walk(pgd_t *pgd, int (*func)(struct page *, enum pt_level),
unsigned long limit)
{
- pgd_t *pgd = pgd_base;
int flush = 0;
- unsigned long addr = 0;
- unsigned long pgd_next;
+ unsigned hole_low, hole_high;
+ unsigned pgdidx_limit, pudidx_limit, pmdidx_limit;
+ unsigned pgdidx, pudidx, pmdidx;
- BUG_ON(limit > FIXADDR_TOP);
+ /* The limit is the last byte to be touched */
+ limit--;
+ BUG_ON(limit >= FIXADDR_TOP);
if (xen_feature(XENFEAT_auto_translated_physmap))
return 0;
- for (; addr != FIXADDR_TOP; pgd++, addr = pgd_next) {
+ /*
+ * 64-bit has a great big hole in the middle of the address
+ * space, which contains the Xen mappings. On 32-bit these
+ * will end up making a zero-sized hole and so is a no-op.
+ */
+ hole_low = pgd_index(STACK_TOP_MAX + PGDIR_SIZE - 1);
+ hole_high = pgd_index(PAGE_OFFSET);
+
+ pgdidx_limit = pgd_index(limit);
+#if PTRS_PER_PUD > 1
+ pudidx_limit = pud_index(limit);
+#else
+ pudidx_limit = 0;
+#endif
+#if PTRS_PER_PMD > 1
+ pmdidx_limit = pmd_index(limit);
+#else
+ pmdidx_limit = 0;
+#endif
+
+ flush |= (*func)(virt_to_page(pgd), PT_PGD);
+
+ for (pgdidx = 0; pgdidx <= pgdidx_limit; pgdidx++) {
pud_t *pud;
- unsigned long pud_limit, pud_next;
- pgd_next = pud_limit = pgd_addr_end(addr, FIXADDR_TOP);
+ if (pgdidx >= hole_low && pgdidx < hole_high)
+ continue;
- if (!pgd_val(*pgd))
+ if (!pgd_val(pgd[pgdidx]))
continue;
- pud = pud_offset(pgd, 0);
+ pud = pud_offset(&pgd[pgdidx], 0);
if (PTRS_PER_PUD > 1) /* not folded */
flush |= (*func)(virt_to_page(pud), PT_PUD);
- for (; addr != pud_limit; pud++, addr = pud_next) {
+ for (pudidx = 0; pudidx < PTRS_PER_PUD; pudidx++) {
pmd_t *pmd;
- unsigned long pmd_limit;
- pud_next = pud_addr_end(addr, pud_limit);
-
- if (pud_next < limit)
- pmd_limit = pud_next;
- else
- pmd_limit = limit;
+ if (pgdidx == pgdidx_limit &&
+ pudidx > pudidx_limit)
+ goto out;
- if (pud_none(*pud))
+ if (pud_none(pud[pudidx]))
continue;
- pmd = pmd_offset(pud, 0);
+ pmd = pmd_offset(&pud[pudidx], 0);
if (PTRS_PER_PMD > 1) /* not folded */
flush |= (*func)(virt_to_page(pmd), PT_PMD);
- for (; addr != pmd_limit; pmd++) {
- addr += (PAGE_SIZE * PTRS_PER_PTE);
- if ((pmd_limit-1) < (addr-1)) {
- addr = pmd_limit;
- break;
- }
+ for (pmdidx = 0; pmdidx < PTRS_PER_PMD; pmdidx++) {
+ struct page *pte;
+
+ if (pgdidx == pgdidx_limit &&
+ pudidx == pudidx_limit &&
+ pmdidx > pmdidx_limit)
+ goto out;
- if (pmd_none(*pmd))
+ if (pmd_none(pmd[pmdidx]))
continue;
- flush |= (*func)(pmd_page(*pmd), PT_PTE);
+ pte = pmd_page(pmd[pmdidx]);
+ flush |= (*func)(pte, PT_PTE);
}
}
}
-
- flush |= (*func)(virt_to_page(pgd_base), PT_PGD);
+out:
return flush;
}
@@ -650,6 +677,11 @@ void xen_pgd_pin(pgd_t *pgd)
xen_mc_batch();
}
+#ifdef CONFIG_X86_PAE
+ /* Need to make sure unshared kernel PMD is pinnable */
+ pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
+#endif
+
xen_do_pin(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(pgd)));
xen_mc_issue(0);
}
@@ -731,6 +763,10 @@ static void xen_pgd_unpin(pgd_t *pgd)
xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
+#ifdef CONFIG_X86_PAE
+ /* Need to make sure unshared kernel PMD is unpinned */
+ pin_page(virt_to_page(pgd_page(pgd[pgd_index(TASK_SIZE)])), PT_PMD);
+#endif
pgd_walk(pgd, unpin_page, TASK_SIZE);
xen_mc_issue(0);
@@ -750,7 +786,6 @@ void xen_mm_unpin_all(void)
list_for_each_entry(page, &pgd_list, lru) {
if (PageSavePinned(page)) {
BUG_ON(!PagePinned(page));
- printk("unpinning pinned %p\n", page_address(page));
xen_pgd_unpin((pgd_t *)page_address(page));
ClearPageSavePinned(page);
}