From: Jeremy Fitzhardinge Date: Tue, 8 Jul 2008 22:06:53 +0000 (-0700) Subject: xen32: create initial mappings like 64-bit X-Git-Tag: v2.6.27-rc1~955^2~1^20~37 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=39dbc5bd345ebf93e066dde7f8e29467eb61b42e;p=linux-2.6-omap-h63xx.git xen32: create initial mappings like 64-bit Rearrange the pagetable initialization to share code with the 64-bit kernel. Rather than deferring anything to pagetable_setup_start, just set up an initial pagetable in swapper_pg_dir early at startup, and create an additional 8MB of physical memory mappings. This matches the native head_32.S mappings to a large degree, and allows the rest of the pagetable setup to continue without much Xen vs. native difference. Signed-off-by: Jeremy Fitzhardinge Cc: Stephen Tweedie Cc: Eduardo Habkost Cc: Mark McLoughlin Signed-off-by: Ingo Molnar --- diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index e9e3bafe48c..19c12a6c731 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -854,50 +854,6 @@ static __init void xen_set_pte_init(pte_t *ptep, pte_t pte) static __init void xen_pagetable_setup_start(pgd_t *base) { -#ifdef CONFIG_X86_32 - pgd_t *xen_pgd = (pgd_t *)xen_start_info->pt_base; - int i; - - init_mm.pgd = base; - /* - * copy top-level of Xen-supplied pagetable into place. This - * is a stand-in while we copy the pmd pages. - */ - memcpy(base, xen_pgd, PTRS_PER_PGD * sizeof(pgd_t)); - - /* - * For PAE, need to allocate new pmds, rather than - * share Xen's, since Xen doesn't like pmd's being - * shared between address spaces. - */ - for (i = 0; i < PTRS_PER_PGD; i++) { - if (pgd_val_ma(xen_pgd[i]) & _PAGE_PRESENT) { - pmd_t *pmd = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); - - memcpy(pmd, (void *)pgd_page_vaddr(xen_pgd[i]), - PAGE_SIZE); - - make_lowmem_page_readonly(pmd); - - set_pgd(&base[i], __pgd(1 + __pa(pmd))); - } else - pgd_clear(&base[i]); - } - - /* make sure zero_page is mapped RO so we can use it in pagetables */ - make_lowmem_page_readonly(empty_zero_page); - make_lowmem_page_readonly(base); - /* - * Switch to new pagetable. This is done before - * pagetable_init has done anything so that the new pages - * added to the table can be prepared properly for Xen. - */ - xen_write_cr3(__pa(base)); - - /* Unpin initial Xen pagetable */ - pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, - PFN_DOWN(__pa(xen_start_info->pt_base))); -#endif /* CONFIG_X86_32 */ } void xen_setup_shared_info(void) @@ -936,12 +892,6 @@ static __init void xen_pagetable_setup_done(pgd_t *base) pv_mmu_ops.set_pte = xen_set_pte; xen_setup_shared_info(); - -#ifdef CONFIG_X86_32 - /* Actually pin the pagetable down, but we can't set PG_pinned - yet because the page structures don't exist yet. */ - pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(base))); -#endif } static __init void xen_post_allocator_init(void) @@ -1299,14 +1249,17 @@ static void __init xen_reserve_top(void) #endif /* CONFIG_X86_32 */ } -#ifdef CONFIG_X86_64 /* * Like __va(), but returns address in the kernel mapping (which is * all we have until the physical memory mapping has been set up. */ static void *__ka(phys_addr_t paddr) { +#ifdef CONFIG_X86_64 return (void *)(paddr + __START_KERNEL_map); +#else + return __va(paddr); +#endif } /* Convert a machine address to physical address */ @@ -1326,6 +1279,7 @@ static void *m2v(phys_addr_t maddr) return __ka(m2p(maddr)); } +#ifdef CONFIG_X86_64 static void walk(pgd_t *pgd, unsigned long addr) { unsigned l4idx = pgd_index(addr); @@ -1356,13 +1310,14 @@ static void walk(pgd_t *pgd, unsigned long addr) xen_raw_printk(" l1: %016lx\n", l1.pte); xen_raw_printk(" %016lx\n", pte_val(l1)); } +#endif static void set_page_prot(void *addr, pgprot_t prot) { unsigned long pfn = __pa(addr) >> PAGE_SHIFT; pte_t pte = pfn_pte(pfn, prot); - xen_raw_printk("addr=%p pfn=%lx mfn=%lx prot=%016x pte=%016x\n", + xen_raw_printk("addr=%p pfn=%lx mfn=%lx prot=%016llx pte=%016llx\n", addr, pfn, get_phys_to_machine(pfn), pgprot_val(prot), pte.pte); @@ -1370,17 +1325,6 @@ static void set_page_prot(void *addr, pgprot_t prot) BUG(); } -static void convert_pfn_mfn(void *v) -{ - pte_t *pte = v; - int i; - - /* All levels are converted the same way, so just treat them - as ptes. */ - for(i = 0; i < PTRS_PER_PTE; i++) - pte[i] = xen_make_pte(pte[i].pte); -} - /* * Identity map, in addition to plain kernel map. This needs to be * large enough to allocate page table pages to allocate the rest. @@ -1388,7 +1332,7 @@ static void convert_pfn_mfn(void *v) */ static pte_t level1_ident_pgt[PTRS_PER_PTE * 4] __page_aligned_bss; -static __init void xen_map_identity_early(unsigned long max_pfn) +static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) { unsigned pmdidx, pteidx; unsigned ident_pte; @@ -1399,11 +1343,9 @@ static __init void xen_map_identity_early(unsigned long max_pfn) for(pmdidx = 0; pmdidx < PTRS_PER_PMD && pfn < max_pfn; pmdidx++) { pte_t *pte_page; - BUG_ON(level2_ident_pgt[pmdidx].pmd != level2_kernel_pgt[pmdidx].pmd); - /* Reuse or allocate a page of ptes */ - if (pmd_present(level2_ident_pgt[pmdidx])) - pte_page = m2v(level2_ident_pgt[pmdidx].pmd); + if (pmd_present(pmd[pmdidx])) + pte_page = m2v(pmd[pmdidx].pmd); else { /* Check for free pte pages */ if (ident_pte == ARRAY_SIZE(level1_ident_pgt)) @@ -1412,9 +1354,7 @@ static __init void xen_map_identity_early(unsigned long max_pfn) pte_page = &level1_ident_pgt[ident_pte]; ident_pte += PTRS_PER_PTE; - /* Install new l1 in l2(s) */ - level2_ident_pgt[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE); - level2_kernel_pgt[pmdidx] = level2_ident_pgt[pmdidx]; + pmd[pmdidx] = __pmd(__pa(pte_page) | _PAGE_TABLE); } /* Install mappings */ @@ -1434,6 +1374,20 @@ static __init void xen_map_identity_early(unsigned long max_pfn) for(pteidx = 0; pteidx < ident_pte; pteidx += PTRS_PER_PTE) set_page_prot(&level1_ident_pgt[pteidx], PAGE_KERNEL_RO); + + set_page_prot(pmd, PAGE_KERNEL_RO); +} + +#ifdef CONFIG_X86_64 +static void convert_pfn_mfn(void *v) +{ + pte_t *pte = v; + int i; + + /* All levels are converted the same way, so just treat them + as ptes. */ + for(i = 0; i < PTRS_PER_PTE; i++) + pte[i] = xen_make_pte(pte[i].pte); } /* @@ -1471,18 +1425,18 @@ static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pf memcpy(level2_fixmap_pgt, l2, sizeof(pmd_t) * PTRS_PER_PMD); /* Set up identity map */ - xen_map_identity_early(max_pfn); + xen_map_identity_early(level2_ident_pgt, max_pfn); /* Make pagetable pieces RO */ set_page_prot(init_level4_pgt, PAGE_KERNEL_RO); set_page_prot(level3_ident_pgt, PAGE_KERNEL_RO); set_page_prot(level3_kernel_pgt, PAGE_KERNEL_RO); - set_page_prot(level2_ident_pgt, PAGE_KERNEL_RO); set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO); set_page_prot(level2_fixmap_pgt, PAGE_KERNEL_RO); /* Pin down new L4 */ - pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE, PFN_DOWN(__pa_symbol(init_level4_pgt))); + pin_pagetable_pfn(MMUEXT_PIN_L4_TABLE, + PFN_DOWN(__pa_symbol(init_level4_pgt))); /* Unpin Xen-provided one */ pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd))); @@ -1498,17 +1452,37 @@ static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pf return pgd; } -#else +#else /* !CONFIG_X86_64 */ +static pmd_t level2_kernel_pgt[PTRS_PER_PMD] __page_aligned_bss; + static __init pgd_t *xen_setup_kernel_pagetable(pgd_t *pgd, unsigned long max_pfn) { + pmd_t *kernel_pmd; + init_pg_tables_start = __pa(pgd); init_pg_tables_end = __pa(pgd) + xen_start_info->nr_pt_frames*PAGE_SIZE; max_pfn_mapped = PFN_DOWN(init_pg_tables_end + 512*1024); - x86_write_percpu(xen_cr3, __pa(pgd)); - x86_write_percpu(xen_current_cr3, __pa(pgd)); + kernel_pmd = m2v(pgd[KERNEL_PGD_BOUNDARY].pgd); + memcpy(level2_kernel_pgt, kernel_pmd, sizeof(pmd_t) * PTRS_PER_PMD); - return pgd; + xen_map_identity_early(level2_kernel_pgt, max_pfn); + + memcpy(swapper_pg_dir, pgd, sizeof(pgd_t) * PTRS_PER_PGD); + set_pgd(&swapper_pg_dir[KERNEL_PGD_BOUNDARY], + __pgd(__pa(level2_kernel_pgt) | _PAGE_PRESENT)); + + set_page_prot(level2_kernel_pgt, PAGE_KERNEL_RO); + set_page_prot(swapper_pg_dir, PAGE_KERNEL_RO); + set_page_prot(empty_zero_page, PAGE_KERNEL_RO); + + pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd))); + + xen_write_cr3(__pa(swapper_pg_dir)); + + pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE, PFN_DOWN(__pa(swapper_pg_dir))); + + return swapper_pg_dir; } #endif /* CONFIG_X86_64 */