X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fxen%2Fmmu.c;h=a44d56e38bd1725ce891627249cb9cbf314a546d;hb=d6182fbf04164016cb6540db02eef3d6bdc967c3;hp=a8f023271819ba2157341622433472146227002f;hpb=ce803e705f1cbdd2703e83061622089b5b4a5417;p=linux-2.6-omap-h63xx.git diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index a8f02327181..a44d56e38bd 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -44,6 +44,7 @@ #include #include +#include #include #include #include @@ -57,6 +58,13 @@ #include "multicalls.h" #include "mmu.h" +/* + * Just beyond the highest usermode address. STACK_TOP_MAX has a + * redzone above it, so round it up to a PGD boundary. + */ +#define USER_LIMIT ((STACK_TOP_MAX + PGDIR_SIZE - 1) & PGDIR_MASK) + + #define P2M_ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(unsigned long)) #define TOP_ENTRIES (MAX_DOMAIN_PAGES / P2M_ENTRIES_PER_PAGE) @@ -282,35 +290,7 @@ void xen_set_pmd(pmd_t *ptr, pmd_t val) */ void set_pte_mfn(unsigned long vaddr, unsigned long mfn, pgprot_t flags) { - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - - pgd = swapper_pg_dir + pgd_index(vaddr); - if (pgd_none(*pgd)) { - BUG(); - return; - } - pud = pud_offset(pgd, vaddr); - if (pud_none(*pud)) { - BUG(); - return; - } - pmd = pmd_offset(pud, vaddr); - if (pmd_none(*pmd)) { - BUG(); - return; - } - pte = pte_offset_kernel(pmd, vaddr); - /* stored as-is, to permit clearing entries */ - xen_set_pte(pte, mfn_pte(mfn, flags)); - - /* - * It's enough to flush this one mapping. - * (PGE mappings get flushed as well) - */ - __flush_tlb_one(vaddr); + set_pte_vaddr(vaddr, mfn_pte(mfn, flags)); } void xen_set_pte_at(struct mm_struct *mm, unsigned long addr, @@ -488,17 +468,45 @@ pud_t xen_make_pud(pudval_t pud) return native_make_pud(pud); } -void xen_set_pgd_hyper(pgd_t *ptr, pgd_t val) +pgd_t *xen_get_user_pgd(pgd_t *pgd) { - struct mmu_update u; + pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK); + unsigned offset = pgd - pgd_page; + pgd_t *user_ptr = NULL; - preempt_disable(); + if (offset < pgd_index(USER_LIMIT)) { + struct page *page = virt_to_page(pgd_page); + user_ptr = (pgd_t *)page->private; + if (user_ptr) + user_ptr += offset; + } - xen_mc_batch(); + return user_ptr; +} + +static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val) +{ + struct mmu_update u; u.ptr = virt_to_machine(ptr).maddr; u.val = pgd_val_ma(val); extend_mmu_update(&u); +} + +/* + * Raw hypercall-based set_pgd, intended for in early boot before + * there's a page structure. This implies: + * 1. The only existing pagetable is the kernel's + * 2. It is always pinned + * 3. It has no user pagetable attached to it + */ +void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val) +{ + preempt_disable(); + + xen_mc_batch(); + + __xen_set_pgd_hyper(ptr, val); xen_mc_issue(PARAVIRT_LAZY_MMU); @@ -507,89 +515,129 @@ void xen_set_pgd_hyper(pgd_t *ptr, pgd_t val) void xen_set_pgd(pgd_t *ptr, pgd_t val) { + pgd_t *user_ptr = xen_get_user_pgd(ptr); + /* If page is not pinned, we can just update the entry directly */ if (!page_pinned(ptr)) { *ptr = val; + if (user_ptr) { + WARN_ON(page_pinned(user_ptr)); + *user_ptr = val; + } return; } - xen_set_pgd_hyper(ptr, val); + /* If it's pinned, then we can at least batch the kernel and + user updates together. */ + xen_mc_batch(); + + __xen_set_pgd_hyper(ptr, val); + if (user_ptr) + __xen_set_pgd_hyper(user_ptr, val); + + xen_mc_issue(PARAVIRT_LAZY_MMU); } #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(USER_LIMIT); + 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; } @@ -671,14 +719,31 @@ void xen_pgd_pin(pgd_t *pgd) { xen_mc_batch(); - if (pgd_walk(pgd, pin_page, TASK_SIZE)) { + if (pgd_walk(pgd, pin_page, USER_LIMIT)) { /* re-enable interrupts for kmap_flush_unused */ xen_mc_issue(0); kmap_flush_unused(); xen_mc_batch(); } +#ifdef CONFIG_X86_64 + { + pgd_t *user_pgd = xen_get_user_pgd(pgd); + + xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(pgd))); + + if (user_pgd) { + pin_page(virt_to_page(user_pgd), PT_PGD); + xen_do_pin(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa(user_pgd))); + } + } +#else /* CONFIG_X86_32 */ +#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))); +#endif /* CONFIG_X86_64 */ xen_mc_issue(0); } @@ -759,7 +824,23 @@ static void xen_pgd_unpin(pgd_t *pgd) xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd))); - pgd_walk(pgd, unpin_page, TASK_SIZE); +#ifdef CONFIG_X86_64 + { + pgd_t *user_pgd = xen_get_user_pgd(pgd); + + if (user_pgd) { + xen_do_pin(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(user_pgd))); + unpin_page(virt_to_page(user_pgd), PT_PGD); + } + } +#endif + +#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, USER_LIMIT); xen_mc_issue(0); } @@ -778,7 +859,6 @@ 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); }