diff options
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/x86_init.h | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/x86_init.c | 4 | ||||
| -rw-r--r-- | arch/x86/mm/init.c | 24 | ||||
| -rw-r--r-- | arch/x86/xen/mmu.c | 15 |
5 files changed, 54 insertions, 2 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 7db7723d1f32..d56187c6b838 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -299,6 +299,7 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, /* Install a pte for a particular vaddr in kernel space. */ void set_pte_vaddr(unsigned long vaddr, pte_t pte); +extern void native_pagetable_reserve(u64 start, u64 end); #ifdef CONFIG_X86_32 extern void native_pagetable_setup_start(pgd_t *base); extern void native_pagetable_setup_done(pgd_t *base); diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h index 643ebf2e2ad8..d3d859035af9 100644 --- a/arch/x86/include/asm/x86_init.h +++ b/arch/x86/include/asm/x86_init.h @@ -68,6 +68,17 @@ struct x86_init_oem { }; /** + * struct x86_init_mapping - platform specific initial kernel pagetable setup + * @pagetable_reserve: reserve a range of addresses for kernel pagetable usage + * + * For more details on the purpose of this hook, look in + * init_memory_mapping and the commit that added it. + */ +struct x86_init_mapping { + void (*pagetable_reserve)(u64 start, u64 end); +}; + +/** * struct x86_init_paging - platform specific paging functions * @pagetable_setup_start: platform specific pre paging_init() call * @pagetable_setup_done: platform specific post paging_init() call @@ -123,6 +134,7 @@ struct x86_init_ops { struct x86_init_mpparse mpparse; struct x86_init_irqs irqs; struct x86_init_oem oem; + struct x86_init_mapping mapping; struct x86_init_paging paging; struct x86_init_timers timers; struct x86_init_iommu iommu; diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index c11514e9128b..75ef4b18e9b7 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -61,6 +61,10 @@ struct x86_init_ops x86_init __initdata = { .banner = default_banner, }, + .mapping = { + .pagetable_reserve = native_pagetable_reserve, + }, + .paging = { .pagetable_setup_start = native_pagetable_setup_start, .pagetable_setup_done = native_pagetable_setup_done, diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 286d289b039b..722a4c372ce3 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -81,6 +81,11 @@ static void __init find_early_table_space(unsigned long end, int use_pse, end, pgt_buf_start << PAGE_SHIFT, pgt_buf_top << PAGE_SHIFT); } +void native_pagetable_reserve(u64 start, u64 end) +{ + memblock_x86_reserve_range(start, end, "PGTABLE"); +} + struct map_range { unsigned long start; unsigned long end; @@ -272,9 +277,24 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, __flush_tlb_all(); + /* + * Reserve the kernel pagetable pages we used (pgt_buf_start - + * pgt_buf_end) and free the other ones (pgt_buf_end - pgt_buf_top) + * so that they can be reused for other purposes. + * + * On native it just means calling memblock_x86_reserve_range, on Xen it + * also means marking RW the pagetable pages that we allocated before + * but that haven't been used. + * + * In fact on xen we mark RO the whole range pgt_buf_start - + * pgt_buf_top, because we have to make sure that when + * init_memory_mapping reaches the pagetable pages area, it maps + * RO all the pagetable pages, including the ones that are beyond + * pgt_buf_end at that time. + */ if (!after_bootmem && pgt_buf_end > pgt_buf_start) - memblock_x86_reserve_range(pgt_buf_start << PAGE_SHIFT, - pgt_buf_end << PAGE_SHIFT, "PGTABLE"); + x86_init.mapping.pagetable_reserve(PFN_PHYS(pgt_buf_start), + PFN_PHYS(pgt_buf_end)); if (!after_bootmem) early_memtest(start, end); diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index cf4ef61e425b..0684f3c74d53 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -1275,6 +1275,20 @@ static __init void xen_pagetable_setup_start(pgd_t *base) { } +static __init void xen_mapping_pagetable_reserve(u64 start, u64 end) +{ + /* reserve the range used */ + native_pagetable_reserve(start, end); + + /* set as RW the rest */ + printk(KERN_DEBUG "xen: setting RW the range %llx - %llx\n", end, + PFN_PHYS(pgt_buf_top)); + while (end < PFN_PHYS(pgt_buf_top)) { + make_lowmem_page_readwrite(__va(end)); + end += PAGE_SIZE; + } +} + static void xen_post_allocator_init(void); static __init void xen_pagetable_setup_done(pgd_t *base) @@ -2105,6 +2119,7 @@ static const struct pv_mmu_ops xen_mmu_ops __initdata = { void __init xen_init_mmu_ops(void) { + x86_init.mapping.pagetable_reserve = xen_mapping_pagetable_reserve; x86_init.paging.pagetable_setup_start = xen_pagetable_setup_start; x86_init.paging.pagetable_setup_done = xen_pagetable_setup_done; pv_mmu_ops = xen_mmu_ops; |