diff options
| -rw-r--r-- | arch/x86/xen/mmu.c | 115 |
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); } |