diff options
-rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 8 | ||||
-rw-r--r-- | arch/x86/mm/pageattr.c | 40 |
2 files changed, 44 insertions, 4 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 106b7d0e2dae..d6ff0bbdb394 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -564,8 +564,12 @@ extern pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, unsigned int *level); extern pmd_t *lookup_pmd_address(unsigned long address); extern phys_addr_t slow_virt_to_phys(void *__address); -extern int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, - unsigned numpages, unsigned long page_flags); +extern int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, + unsigned long address, + unsigned numpages, + unsigned long page_flags); +extern int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address, + unsigned long numpages); #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_PGTABLE_DEFS_H */ diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index db7a10082238..bac35001d896 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -2338,8 +2338,8 @@ bool kernel_page_present(struct page *page) #endif /* CONFIG_DEBUG_PAGEALLOC */ -int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, - unsigned numpages, unsigned long page_flags) +int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, + unsigned numpages, unsigned long page_flags) { int retval = -EINVAL; @@ -2353,6 +2353,8 @@ int kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, .flags = 0, }; + WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); + if (!(__supported_pte_mask & _PAGE_NX)) goto out; @@ -2375,6 +2377,40 @@ out: } /* + * __flush_tlb_all() flushes mappings only on current CPU and hence this + * function shouldn't be used in an SMP environment. Presently, it's used only + * during boot (way before smp_init()) by EFI subsystem and hence is ok. + */ +int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address, + unsigned long numpages) +{ + int retval; + + /* + * The typical sequence for unmapping is to find a pte through + * lookup_address_in_pgd() (ideally, it should never return NULL because + * the address is already mapped) and change it's protections. As pfn is + * the *target* of a mapping, it's not useful while unmapping. + */ + struct cpa_data cpa = { + .vaddr = &address, + .pfn = 0, + .pgd = pgd, + .numpages = numpages, + .mask_set = __pgprot(0), + .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), + .flags = 0, + }; + + WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); + + retval = __change_page_attr_set_clr(&cpa, 0); + __flush_tlb_all(); + + return retval; +} + +/* * The testcases use internal knowledge of the implementation that shouldn't * be exposed to the rest of the kernel. Include these directly here. */ |