diff options
Diffstat (limited to 'arch/ia64/kernel/efi.c')
| -rw-r--r-- | arch/ia64/kernel/efi.c | 160 |
1 files changed, 111 insertions, 49 deletions
diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c index a3aa45cbcfa0..c485a3b32ba8 100644 --- a/arch/ia64/kernel/efi.c +++ b/arch/ia64/kernel/efi.c @@ -247,6 +247,32 @@ typedef struct kern_memdesc { static kern_memdesc_t *kern_memmap; +#define efi_md_size(md) (md->num_pages << EFI_PAGE_SHIFT) + +static inline u64 +kmd_end(kern_memdesc_t *kmd) +{ + return (kmd->start + (kmd->num_pages << EFI_PAGE_SHIFT)); +} + +static inline u64 +efi_md_end(efi_memory_desc_t *md) +{ + return (md->phys_addr + efi_md_size(md)); +} + +static inline int +efi_wb(efi_memory_desc_t *md) +{ + return (md->attribute & EFI_MEMORY_WB); +} + +static inline int +efi_uc(efi_memory_desc_t *md) +{ + return (md->attribute & EFI_MEMORY_UC); +} + static void walk (efi_freemem_callback_t callback, void *arg, u64 attr) { @@ -595,8 +621,8 @@ efi_get_iobase (void) return 0; } -u32 -efi_mem_type (unsigned long phys_addr) +static efi_memory_desc_t * +efi_memory_descriptor (unsigned long phys_addr) { void *efi_map_start, *efi_map_end, *p; efi_memory_desc_t *md; @@ -610,13 +636,13 @@ efi_mem_type (unsigned long phys_addr) md = p; if (phys_addr - md->phys_addr < (md->num_pages << EFI_PAGE_SHIFT)) - return md->type; + return md; } return 0; } -u64 -efi_mem_attributes (unsigned long phys_addr) +static int +efi_memmap_has_mmio (void) { void *efi_map_start, *efi_map_end, *p; efi_memory_desc_t *md; @@ -629,36 +655,98 @@ efi_mem_attributes (unsigned long phys_addr) for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) { md = p; - if (phys_addr - md->phys_addr < (md->num_pages << EFI_PAGE_SHIFT)) - return md->attribute; + if (md->type == EFI_MEMORY_MAPPED_IO) + return 1; } return 0; } + +u32 +efi_mem_type (unsigned long phys_addr) +{ + efi_memory_desc_t *md = efi_memory_descriptor(phys_addr); + + if (md) + return md->type; + return 0; +} + +u64 +efi_mem_attributes (unsigned long phys_addr) +{ + efi_memory_desc_t *md = efi_memory_descriptor(phys_addr); + + if (md) + return md->attribute; + return 0; +} EXPORT_SYMBOL(efi_mem_attributes); +/* + * Determines whether the memory at phys_addr supports the desired + * attribute (WB, UC, etc). If this returns 1, the caller can safely + * access *size bytes at phys_addr with the specified attribute. + */ +static int +efi_mem_attribute_range (unsigned long phys_addr, unsigned long *size, u64 attr) +{ + efi_memory_desc_t *md = efi_memory_descriptor(phys_addr); + unsigned long md_end; + + if (!md || (md->attribute & attr) != attr) + return 0; + + do { + md_end = efi_md_end(md); + if (phys_addr + *size <= md_end) + return 1; + + md = efi_memory_descriptor(md_end); + if (!md || (md->attribute & attr) != attr) { + *size = md_end - phys_addr; + return 1; + } + } while (md); + return 0; +} + +/* + * For /dev/mem, we only allow read & write system calls to access + * write-back memory, because read & write don't allow the user to + * control access size. + */ int valid_phys_addr_range (unsigned long phys_addr, unsigned long *size) { - void *efi_map_start, *efi_map_end, *p; - efi_memory_desc_t *md; - u64 efi_desc_size; + return efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_WB); +} - 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; +/* + * We allow mmap of anything in the EFI memory map that supports + * either write-back or uncacheable access. For uncacheable regions, + * the supported access sizes are system-dependent, and the user is + * responsible for using the correct size. + * + * Note that this doesn't currently allow access to hot-added memory, + * because that doesn't appear in the boot-time EFI memory map. + */ +int +valid_mmap_phys_addr_range (unsigned long phys_addr, unsigned long *size) +{ + if (efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_WB)) + return 1; - for (p = efi_map_start; p < efi_map_end; p += efi_desc_size) { - md = p; + if (efi_mem_attribute_range(phys_addr, size, EFI_MEMORY_UC)) + return 1; - if (phys_addr - md->phys_addr < (md->num_pages << EFI_PAGE_SHIFT)) { - if (!(md->attribute & EFI_MEMORY_WB)) - return 0; + /* + * Some firmware doesn't report MMIO regions in the EFI memory map. + * The Intel BigSur (a.k.a. HP i2000) has this problem. In this + * case, we can't use the EFI memory map to validate mmap requests. + */ + if (!efi_memmap_has_mmio()) + return 1; - if (*size > md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - phys_addr) - *size = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - phys_addr; - return 1; - } - } return 0; } @@ -707,32 +795,6 @@ efi_uart_console_only(void) return 0; } -#define efi_md_size(md) (md->num_pages << EFI_PAGE_SHIFT) - -static inline u64 -kmd_end(kern_memdesc_t *kmd) -{ - return (kmd->start + (kmd->num_pages << EFI_PAGE_SHIFT)); -} - -static inline u64 -efi_md_end(efi_memory_desc_t *md) -{ - return (md->phys_addr + efi_md_size(md)); -} - -static inline int -efi_wb(efi_memory_desc_t *md) -{ - return (md->attribute & EFI_MEMORY_WB); -} - -static inline int -efi_uc(efi_memory_desc_t *md) -{ - return (md->attribute & EFI_MEMORY_UC); -} - /* * Look for the first granule aligned memory descriptor memory * that is big enough to hold EFI memory map. Make sure this |