diff options
Diffstat (limited to 'drivers/firmware/efi/libstub/efi-stub-helper.c')
| -rw-r--r-- | drivers/firmware/efi/libstub/efi-stub-helper.c | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c new file mode 100644 index 000000000..f07d4a67f --- /dev/null +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -0,0 +1,699 @@ +/* + * Helper functions used by the EFI stub on multiple + * architectures. This should be #included by the EFI stub + * implementation files. + * + * Copyright 2011 Intel Corporation; author Matt Fleming + * + * This file is part of the Linux kernel, and is made available + * under the terms of the GNU General Public License version 2. + * + */ + +#include <linux/efi.h> +#include <asm/efi.h> + +#include "efistub.h" + +/* + * Some firmware implementations have problems reading files in one go. + * A read chunk size of 1MB seems to work for most platforms. + * + * Unfortunately, reading files in chunks triggers *other* bugs on some + * platforms, so we provide a way to disable this workaround, which can + * be done by passing "efi=nochunk" on the EFI boot stub command line. + * + * If you experience issues with initrd images being corrupt it's worth + * trying efi=nochunk, but chunking is enabled by default because there + * are far more machines that require the workaround than those that + * break with it enabled. + */ +#define EFI_READ_CHUNK_SIZE (1024 * 1024) + +static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; + +/* + * Allow the platform to override the allocation granularity: this allows + * systems that have the capability to run with a larger page size to deal + * with the allocations for initrd and fdt more efficiently. + */ +#ifndef EFI_ALLOC_ALIGN +#define EFI_ALLOC_ALIGN EFI_PAGE_SIZE +#endif + +struct file_info { + efi_file_handle_t *handle; + u64 size; +}; + +void efi_printk(efi_system_table_t *sys_table_arg, char *str) +{ + char *s8; + + for (s8 = str; *s8; s8++) { + efi_char16_t ch[2] = { 0 }; + + ch[0] = *s8; + if (*s8 == '\n') { + efi_char16_t nl[2] = { '\r', 0 }; + efi_char16_printk(sys_table_arg, nl); + } + + efi_char16_printk(sys_table_arg, ch); + } +} + +efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg, + efi_memory_desc_t **map, + unsigned long *map_size, + unsigned long *desc_size, + u32 *desc_ver, + unsigned long *key_ptr) +{ + efi_memory_desc_t *m = NULL; + efi_status_t status; + unsigned long key; + u32 desc_version; + + *map_size = sizeof(*m) * 32; +again: + /* + * Add an additional efi_memory_desc_t because we're doing an + * allocation which may be in a new descriptor region. + */ + *map_size += sizeof(*m); + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + *map_size, (void **)&m); + if (status != EFI_SUCCESS) + goto fail; + + *desc_size = 0; + key = 0; + status = efi_call_early(get_memory_map, map_size, m, + &key, desc_size, &desc_version); + if (status == EFI_BUFFER_TOO_SMALL) { + efi_call_early(free_pool, m); + goto again; + } + + if (status != EFI_SUCCESS) + efi_call_early(free_pool, m); + + if (key_ptr && status == EFI_SUCCESS) + *key_ptr = key; + if (desc_ver && status == EFI_SUCCESS) + *desc_ver = desc_version; + +fail: + *map = m; + return status; +} + + +unsigned long get_dram_base(efi_system_table_t *sys_table_arg) +{ + efi_status_t status; + unsigned long map_size; + unsigned long membase = EFI_ERROR; + struct efi_memory_map map; + efi_memory_desc_t *md; + + status = efi_get_memory_map(sys_table_arg, (efi_memory_desc_t **)&map.map, + &map_size, &map.desc_size, NULL, NULL); + if (status != EFI_SUCCESS) + return membase; + + map.map_end = map.map + map_size; + + for_each_efi_memory_desc(&map, md) + if (md->attribute & EFI_MEMORY_WB) + if (membase > md->phys_addr) + membase = md->phys_addr; + + efi_call_early(free_pool, map.map); + + return membase; +} + +/* + * Allocate at the highest possible address that is not above 'max'. + */ +efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg, + unsigned long size, unsigned long align, + unsigned long *addr, unsigned long max) +{ + unsigned long map_size, desc_size; + efi_memory_desc_t *map; + efi_status_t status; + unsigned long nr_pages; + u64 max_addr = 0; + int i; + + status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size, + NULL, NULL); + if (status != EFI_SUCCESS) + goto fail; + + /* + * Enforce minimum alignment that EFI requires when requesting + * a specific address. We are doing page-based allocations, + * so we must be aligned to a page. + */ + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; + + nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; +again: + for (i = 0; i < map_size / desc_size; i++) { + efi_memory_desc_t *desc; + unsigned long m = (unsigned long)map; + u64 start, end; + + desc = (efi_memory_desc_t *)(m + (i * desc_size)); + if (desc->type != EFI_CONVENTIONAL_MEMORY) + continue; + + if (desc->num_pages < nr_pages) + continue; + + start = desc->phys_addr; + end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT); + + if (end > max) + end = max; + + if ((start + size) > end) + continue; + + if (round_down(end - size, align) < start) + continue; + + start = round_down(end - size, align); + + /* + * Don't allocate at 0x0. It will confuse code that + * checks pointers against NULL. + */ + if (start == 0x0) + continue; + + if (start > max_addr) + max_addr = start; + } + + if (!max_addr) + status = EFI_NOT_FOUND; + else { + status = efi_call_early(allocate_pages, + EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, + nr_pages, &max_addr); + if (status != EFI_SUCCESS) { + max = max_addr; + max_addr = 0; + goto again; + } + + *addr = max_addr; + } + + efi_call_early(free_pool, map); +fail: + return status; +} + +/* + * Allocate at the lowest possible address. + */ +efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg, + unsigned long size, unsigned long align, + unsigned long *addr) +{ + unsigned long map_size, desc_size; + efi_memory_desc_t *map; + efi_status_t status; + unsigned long nr_pages; + int i; + + status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size, + NULL, NULL); + if (status != EFI_SUCCESS) + goto fail; + + /* + * Enforce minimum alignment that EFI requires when requesting + * a specific address. We are doing page-based allocations, + * so we must be aligned to a page. + */ + if (align < EFI_ALLOC_ALIGN) + align = EFI_ALLOC_ALIGN; + + nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; + for (i = 0; i < map_size / desc_size; i++) { + efi_memory_desc_t *desc; + unsigned long m = (unsigned long)map; + u64 start, end; + + desc = (efi_memory_desc_t *)(m + (i * desc_size)); + + if (desc->type != EFI_CONVENTIONAL_MEMORY) + continue; + + if (desc->num_pages < nr_pages) + continue; + + start = desc->phys_addr; + end = start + desc->num_pages * (1UL << EFI_PAGE_SHIFT); + + /* + * Don't allocate at 0x0. It will confuse code that + * checks pointers against NULL. Skip the first 8 + * bytes so we start at a nice even number. + */ + if (start == 0x0) + start += 8; + + start = round_up(start, align); + if ((start + size) > end) + continue; + + status = efi_call_early(allocate_pages, + EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, + nr_pages, &start); + if (status == EFI_SUCCESS) { + *addr = start; + break; + } + } + + if (i == map_size / desc_size) + status = EFI_NOT_FOUND; + + efi_call_early(free_pool, map); +fail: + return status; +} + +void efi_free(efi_system_table_t *sys_table_arg, unsigned long size, + unsigned long addr) +{ + unsigned long nr_pages; + + if (!size) + return; + + nr_pages = round_up(size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; + efi_call_early(free_pages, addr, nr_pages); +} + +/* + * Parse the ASCII string 'cmdline' for EFI options, denoted by the efi= + * option, e.g. efi=nochunk. + * + * It should be noted that efi= is parsed in two very different + * environments, first in the early boot environment of the EFI boot + * stub, and subsequently during the kernel boot. + */ +efi_status_t efi_parse_options(char *cmdline) +{ + char *str; + + /* + * If no EFI parameters were specified on the cmdline we've got + * nothing to do. + */ + str = strstr(cmdline, "efi="); + if (!str) + return EFI_SUCCESS; + + /* Skip ahead to first argument */ + str += strlen("efi="); + + /* + * Remember, because efi= is also used by the kernel we need to + * skip over arguments we don't understand. + */ + while (*str) { + if (!strncmp(str, "nochunk", 7)) { + str += strlen("nochunk"); + __chunk_size = -1UL; + } + + /* Group words together, delimited by "," */ + while (*str && *str != ',') + str++; + + if (*str == ',') + str++; + } + + return EFI_SUCCESS; +} + +/* + * Check the cmdline for a LILO-style file= arguments. + * + * We only support loading a file from the same filesystem as + * the kernel image. + */ +efi_status_t handle_cmdline_files(efi_system_table_t *sys_table_arg, + efi_loaded_image_t *image, + char *cmd_line, char *option_string, + unsigned long max_addr, + unsigned long *load_addr, + unsigned long *load_size) +{ + struct file_info *files; + unsigned long file_addr; + u64 file_size_total; + efi_file_handle_t *fh = NULL; + efi_status_t status; + int nr_files; + char *str; + int i, j, k; + + file_addr = 0; + file_size_total = 0; + + str = cmd_line; + + j = 0; /* See close_handles */ + + if (!load_addr || !load_size) + return EFI_INVALID_PARAMETER; + + *load_addr = 0; + *load_size = 0; + + if (!str || !*str) + return EFI_SUCCESS; + + for (nr_files = 0; *str; nr_files++) { + str = strstr(str, option_string); + if (!str) + break; + + str += strlen(option_string); + + /* Skip any leading slashes */ + while (*str == '/' || *str == '\\') + str++; + + while (*str && *str != ' ' && *str != '\n') + str++; + } + + if (!nr_files) + return EFI_SUCCESS; + + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + nr_files * sizeof(*files), (void **)&files); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to alloc mem for file handle list\n"); + goto fail; + } + + str = cmd_line; + for (i = 0; i < nr_files; i++) { + struct file_info *file; + efi_char16_t filename_16[256]; + efi_char16_t *p; + + str = strstr(str, option_string); + if (!str) + break; + + str += strlen(option_string); + + file = &files[i]; + p = filename_16; + + /* Skip any leading slashes */ + while (*str == '/' || *str == '\\') + str++; + + while (*str && *str != ' ' && *str != '\n') { + if ((u8 *)p >= (u8 *)filename_16 + sizeof(filename_16)) + break; + + if (*str == '/') { + *p++ = '\\'; + str++; + } else { + *p++ = *str++; + } + } + + *p = '\0'; + + /* Only open the volume once. */ + if (!i) { + status = efi_open_volume(sys_table_arg, image, + (void **)&fh); + if (status != EFI_SUCCESS) + goto free_files; + } + + status = efi_file_size(sys_table_arg, fh, filename_16, + (void **)&file->handle, &file->size); + if (status != EFI_SUCCESS) + goto close_handles; + + file_size_total += file->size; + } + + if (file_size_total) { + unsigned long addr; + + /* + * Multiple files need to be at consecutive addresses in memory, + * so allocate enough memory for all the files. This is used + * for loading multiple files. + */ + status = efi_high_alloc(sys_table_arg, file_size_total, 0x1000, + &file_addr, max_addr); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to alloc highmem for files\n"); + goto close_handles; + } + + /* We've run out of free low memory. */ + if (file_addr > max_addr) { + pr_efi_err(sys_table_arg, "We've run out of free low memory\n"); + status = EFI_INVALID_PARAMETER; + goto free_file_total; + } + + addr = file_addr; + for (j = 0; j < nr_files; j++) { + unsigned long size; + + size = files[j].size; + while (size) { + unsigned long chunksize; + if (size > __chunk_size) + chunksize = __chunk_size; + else + chunksize = size; + + status = efi_file_read(files[j].handle, + &chunksize, + (void *)addr); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to read file\n"); + goto free_file_total; + } + addr += chunksize; + size -= chunksize; + } + + efi_file_close(files[j].handle); + } + + } + + efi_call_early(free_pool, files); + + *load_addr = file_addr; + *load_size = file_size_total; + + return status; + +free_file_total: + efi_free(sys_table_arg, file_size_total, file_addr); + +close_handles: + for (k = j; k < i; k++) + efi_file_close(files[k].handle); +free_files: + efi_call_early(free_pool, files); +fail: + *load_addr = 0; + *load_size = 0; + + return status; +} +/* + * Relocate a kernel image, either compressed or uncompressed. + * In the ARM64 case, all kernel images are currently + * uncompressed, and as such when we relocate it we need to + * allocate additional space for the BSS segment. Any low + * memory that this function should avoid needs to be + * unavailable in the EFI memory map, as if the preferred + * address is not available the lowest available address will + * be used. + */ +efi_status_t efi_relocate_kernel(efi_system_table_t *sys_table_arg, + unsigned long *image_addr, + unsigned long image_size, + unsigned long alloc_size, + unsigned long preferred_addr, + unsigned long alignment) +{ + unsigned long cur_image_addr; + unsigned long new_addr = 0; + efi_status_t status; + unsigned long nr_pages; + efi_physical_addr_t efi_addr = preferred_addr; + + if (!image_addr || !image_size || !alloc_size) + return EFI_INVALID_PARAMETER; + if (alloc_size < image_size) + return EFI_INVALID_PARAMETER; + + cur_image_addr = *image_addr; + + /* + * The EFI firmware loader could have placed the kernel image + * anywhere in memory, but the kernel has restrictions on the + * max physical address it can run at. Some architectures + * also have a prefered address, so first try to relocate + * to the preferred address. If that fails, allocate as low + * as possible while respecting the required alignment. + */ + nr_pages = round_up(alloc_size, EFI_ALLOC_ALIGN) / EFI_PAGE_SIZE; + status = efi_call_early(allocate_pages, + EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, + nr_pages, &efi_addr); + new_addr = efi_addr; + /* + * If preferred address allocation failed allocate as low as + * possible. + */ + if (status != EFI_SUCCESS) { + status = efi_low_alloc(sys_table_arg, alloc_size, alignment, + &new_addr); + } + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table_arg, "Failed to allocate usable memory for kernel.\n"); + return status; + } + + /* + * We know source/dest won't overlap since both memory ranges + * have been allocated by UEFI, so we can safely use memcpy. + */ + memcpy((void *)new_addr, (void *)cur_image_addr, image_size); + + /* Return the new address of the relocated image. */ + *image_addr = new_addr; + + return status; +} + +/* + * Get the number of UTF-8 bytes corresponding to an UTF-16 character. + * This overestimates for surrogates, but that is okay. + */ +static int efi_utf8_bytes(u16 c) +{ + return 1 + (c >= 0x80) + (c >= 0x800); +} + +/* + * Convert an UTF-16 string, not necessarily null terminated, to UTF-8. + */ +static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n) +{ + unsigned int c; + + while (n--) { + c = *src++; + if (n && c >= 0xd800 && c <= 0xdbff && + *src >= 0xdc00 && *src <= 0xdfff) { + c = 0x10000 + ((c & 0x3ff) << 10) + (*src & 0x3ff); + src++; + n--; + } + if (c >= 0xd800 && c <= 0xdfff) + c = 0xfffd; /* Unmatched surrogate */ + if (c < 0x80) { + *dst++ = c; + continue; + } + if (c < 0x800) { + *dst++ = 0xc0 + (c >> 6); + goto t1; + } + if (c < 0x10000) { + *dst++ = 0xe0 + (c >> 12); + goto t2; + } + *dst++ = 0xf0 + (c >> 18); + *dst++ = 0x80 + ((c >> 12) & 0x3f); + t2: + *dst++ = 0x80 + ((c >> 6) & 0x3f); + t1: + *dst++ = 0x80 + (c & 0x3f); + } + + return dst; +} + +/* + * Convert the unicode UEFI command line to ASCII to pass to kernel. + * Size of memory allocated return in *cmd_line_len. + * Returns NULL on error. + */ +char *efi_convert_cmdline(efi_system_table_t *sys_table_arg, + efi_loaded_image_t *image, + int *cmd_line_len) +{ + const u16 *s2; + u8 *s1 = NULL; + unsigned long cmdline_addr = 0; + int load_options_chars = image->load_options_size / 2; /* UTF-16 */ + const u16 *options = image->load_options; + int options_bytes = 0; /* UTF-8 bytes */ + int options_chars = 0; /* UTF-16 chars */ + efi_status_t status; + u16 zero = 0; + + if (options) { + s2 = options; + while (*s2 && *s2 != '\n' + && options_chars < load_options_chars) { + options_bytes += efi_utf8_bytes(*s2++); + options_chars++; + } + } + + if (!options_chars) { + /* No command line options, so return empty string*/ + options = &zero; + } + + options_bytes++; /* NUL termination */ + + status = efi_low_alloc(sys_table_arg, options_bytes, 0, &cmdline_addr); + if (status != EFI_SUCCESS) + return NULL; + + s1 = (u8 *)cmdline_addr; + s2 = (const u16 *)options; + + s1 = efi_utf16_to_utf8(s1, s2, options_chars); + *s1 = '\0'; + + *cmd_line_len = options_bytes; + return (char *)cmdline_addr; +} |