diff options
Diffstat (limited to 'arch/ia64/kernel/efi.c')
| -rw-r--r-- | arch/ia64/kernel/efi.c | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c index f45f91d38ca..78d29b79947 100644 --- a/arch/ia64/kernel/efi.c +++ b/arch/ia64/kernel/efi.c @@ -660,6 +660,29 @@ efi_memory_descriptor (unsigned long phys_addr) return NULL; } +static int +efi_memmap_intersects (unsigned long phys_addr, unsigned long size) +{ + void *efi_map_start, *efi_map_end, *p; + efi_memory_desc_t *md; + u64 efi_desc_size; + unsigned long end; + + efi_map_start = __va(ia64_boot_param->efi_memmap); + efi_map_end = efi_map_start + ia64_boot_param->efi_memmap_size; + efi_desc_size = ia64_boot_param->efi_memdesc_size; + + end = phys_addr + size; + + for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) { + md = p; + + if (md->phys_addr < end && efi_md_end(md) > phys_addr) + return 1; + } + return 0; +} + u32 efi_mem_type (unsigned long phys_addr) { @@ -766,11 +789,28 @@ valid_phys_addr_range (unsigned long phys_addr, unsigned long size) int valid_mmap_phys_addr_range (unsigned long pfn, unsigned long size) { + unsigned long phys_addr = pfn << PAGE_SHIFT; + u64 attr; + + attr = efi_mem_attribute(phys_addr, size); + /* - * MMIO regions are often missing from the EFI memory map. - * We must allow mmap of them for programs like X, so we - * currently can't do any useful validation. + * /dev/mem mmap uses normal user pages, so we don't need the entire + * granule, but the entire region we're mapping must support the same + * attribute. */ + if (attr & EFI_MEMORY_WB || attr & EFI_MEMORY_UC) + return 1; + + /* + * Intel firmware doesn't tell us about all the MMIO regions, so + * in general we have to allow mmap requests. But if EFI *does* + * tell us about anything inside this region, we should deny it. + * The user can always map a smaller region to avoid the overlap. + */ + if (efi_memmap_intersects(phys_addr, size)) + return 0; + return 1; } |