diff options
Diffstat (limited to 'drivers/firmware/efi/libstub/fdt.c')
| -rw-r--r-- | drivers/firmware/efi/libstub/fdt.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c new file mode 100644 index 000000000..dba296a44 --- /dev/null +++ b/drivers/firmware/efi/libstub/fdt.c @@ -0,0 +1,394 @@ +/* + * FDT related Helper functions used by the EFI stub on multiple + * architectures. This should be #included by the EFI stub + * implementation files. + * + * Copyright 2013 Linaro Limited; author Roy Franz + * + * 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 <linux/libfdt.h> +#include <asm/efi.h> + +#include "efistub.h" + +#define EFI_DT_ADDR_CELLS_DEFAULT 2 +#define EFI_DT_SIZE_CELLS_DEFAULT 2 + +static void fdt_update_cell_size(efi_system_table_t *sys_table, void *fdt) +{ + int offset; + + offset = fdt_path_offset(fdt, "/"); + /* Set the #address-cells and #size-cells values for an empty tree */ + + fdt_setprop_u32(fdt, offset, "#address-cells", + EFI_DT_ADDR_CELLS_DEFAULT); + + fdt_setprop_u32(fdt, offset, "#size-cells", EFI_DT_SIZE_CELLS_DEFAULT); +} + +static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, + unsigned long orig_fdt_size, + void *fdt, int new_fdt_size, char *cmdline_ptr, + u64 initrd_addr, u64 initrd_size) +{ + int node, num_rsv; + int status; + u32 fdt_val32; + u64 fdt_val64; + + /* Do some checks on provided FDT, if it exists*/ + if (orig_fdt) { + if (fdt_check_header(orig_fdt)) { + pr_efi_err(sys_table, "Device Tree header not valid!\n"); + return EFI_LOAD_ERROR; + } + /* + * We don't get the size of the FDT if we get if from a + * configuration table. + */ + if (orig_fdt_size && fdt_totalsize(orig_fdt) > orig_fdt_size) { + pr_efi_err(sys_table, "Truncated device tree! foo!\n"); + return EFI_LOAD_ERROR; + } + } + + if (orig_fdt) { + status = fdt_open_into(orig_fdt, fdt, new_fdt_size); + } else { + status = fdt_create_empty_tree(fdt, new_fdt_size); + if (status == 0) { + /* + * Any failure from the following function is non + * critical + */ + fdt_update_cell_size(sys_table, fdt); + } + } + + if (status != 0) + goto fdt_set_fail; + + /* + * Delete all memory reserve map entries. When booting via UEFI, + * kernel will use the UEFI memory map to find reserved regions. + */ + num_rsv = fdt_num_mem_rsv(fdt); + while (num_rsv-- > 0) + fdt_del_mem_rsv(fdt, num_rsv); + + node = fdt_subnode_offset(fdt, 0, "chosen"); + if (node < 0) { + node = fdt_add_subnode(fdt, 0, "chosen"); + if (node < 0) { + status = node; /* node is error code when negative */ + goto fdt_set_fail; + } + } + + if ((cmdline_ptr != NULL) && (strlen(cmdline_ptr) > 0)) { + status = fdt_setprop(fdt, node, "bootargs", cmdline_ptr, + strlen(cmdline_ptr) + 1); + if (status) + goto fdt_set_fail; + } + + /* Set initrd address/end in device tree, if present */ + if (initrd_size != 0) { + u64 initrd_image_end; + u64 initrd_image_start = cpu_to_fdt64(initrd_addr); + + status = fdt_setprop(fdt, node, "linux,initrd-start", + &initrd_image_start, sizeof(u64)); + if (status) + goto fdt_set_fail; + initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size); + status = fdt_setprop(fdt, node, "linux,initrd-end", + &initrd_image_end, sizeof(u64)); + if (status) + goto fdt_set_fail; + } + + /* Add FDT entries for EFI runtime services in chosen node. */ + node = fdt_subnode_offset(fdt, 0, "chosen"); + fdt_val64 = cpu_to_fdt64((u64)(unsigned long)sys_table); + status = fdt_setprop(fdt, node, "linux,uefi-system-table", + &fdt_val64, sizeof(fdt_val64)); + if (status) + goto fdt_set_fail; + + fdt_val64 = U64_MAX; /* placeholder */ + status = fdt_setprop(fdt, node, "linux,uefi-mmap-start", + &fdt_val64, sizeof(fdt_val64)); + if (status) + goto fdt_set_fail; + + fdt_val32 = U32_MAX; /* placeholder */ + status = fdt_setprop(fdt, node, "linux,uefi-mmap-size", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { + efi_status_t efi_status; + + efi_status = efi_get_random_bytes(sys_table, sizeof(fdt_val64), + (u8 *)&fdt_val64); + if (efi_status == EFI_SUCCESS) { + status = fdt_setprop(fdt, node, "kaslr-seed", + &fdt_val64, sizeof(fdt_val64)); + if (status) + goto fdt_set_fail; + } else if (efi_status != EFI_NOT_FOUND) { + return efi_status; + } + } + + /* shrink the FDT back to its minimum size */ + fdt_pack(fdt); + + return EFI_SUCCESS; + +fdt_set_fail: + if (status == -FDT_ERR_NOSPACE) + return EFI_BUFFER_TOO_SMALL; + + return EFI_LOAD_ERROR; +} + +static efi_status_t update_fdt_memmap(void *fdt, struct efi_boot_memmap *map) +{ + int node = fdt_path_offset(fdt, "/chosen"); + u64 fdt_val64; + u32 fdt_val32; + int err; + + if (node < 0) + return EFI_LOAD_ERROR; + + fdt_val64 = cpu_to_fdt64((unsigned long)*map->map); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-start", + &fdt_val64, sizeof(fdt_val64)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->map_size); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-size", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->desc_size); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-size", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + fdt_val32 = cpu_to_fdt32(*map->desc_ver); + err = fdt_setprop_inplace(fdt, node, "linux,uefi-mmap-desc-ver", + &fdt_val32, sizeof(fdt_val32)); + if (err) + return EFI_LOAD_ERROR; + + return EFI_SUCCESS; +} + +#ifndef EFI_FDT_ALIGN +#define EFI_FDT_ALIGN EFI_PAGE_SIZE +#endif + +struct exit_boot_struct { + efi_memory_desc_t *runtime_map; + int *runtime_entry_count; + void *new_fdt_addr; +}; + +static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg, + struct efi_boot_memmap *map, + void *priv) +{ + struct exit_boot_struct *p = priv; + /* + * Update the memory map with virtual addresses. The function will also + * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME + * entries so that we can pass it straight to SetVirtualAddressMap() + */ + efi_get_virtmap(*map->map, *map->map_size, *map->desc_size, + p->runtime_map, p->runtime_entry_count); + + return update_fdt_memmap(p->new_fdt_addr, map); +} + +#ifndef MAX_FDT_SIZE +#define MAX_FDT_SIZE SZ_2M +#endif + +/* + * Allocate memory for a new FDT, then add EFI, commandline, and + * initrd related fields to the FDT. This routine increases the + * FDT allocation size until the allocated memory is large + * enough. EFI allocations are in EFI_PAGE_SIZE granules, + * which are fixed at 4K bytes, so in most cases the first + * allocation should succeed. + * EFI boot services are exited at the end of this function. + * There must be no allocations between the get_memory_map() + * call and the exit_boot_services() call, so the exiting of + * boot services is very tightly tied to the creation of the FDT + * with the final memory map in it. + */ + +efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, + void *handle, + unsigned long *new_fdt_addr, + unsigned long max_addr, + u64 initrd_addr, u64 initrd_size, + char *cmdline_ptr, + unsigned long fdt_addr, + unsigned long fdt_size) +{ + unsigned long map_size, desc_size, buff_size; + u32 desc_ver; + unsigned long mmap_key; + efi_memory_desc_t *memory_map, *runtime_map; + efi_status_t status; + int runtime_entry_count = 0; + struct efi_boot_memmap map; + struct exit_boot_struct priv; + + map.map = &runtime_map; + map.map_size = &map_size; + map.desc_size = &desc_size; + map.desc_ver = &desc_ver; + map.key_ptr = &mmap_key; + map.buff_size = &buff_size; + + /* + * Get a copy of the current memory map that we will use to prepare + * the input for SetVirtualAddressMap(). We don't have to worry about + * subsequent allocations adding entries, since they could not affect + * the number of EFI_MEMORY_RUNTIME regions. + */ + status = efi_get_memory_map(sys_table, &map); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to retrieve UEFI memory map.\n"); + return status; + } + + pr_efi(sys_table, + "Exiting boot services and installing virtual address map...\n"); + + map.map = &memory_map; + status = efi_high_alloc(sys_table, MAX_FDT_SIZE, EFI_FDT_ALIGN, + new_fdt_addr, max_addr); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, + "Unable to allocate memory for new device tree.\n"); + goto fail; + } + + /* + * Now that we have done our final memory allocation (and free) + * we can get the memory map key needed for exit_boot_services(). + */ + status = efi_get_memory_map(sys_table, &map); + if (status != EFI_SUCCESS) + goto fail_free_new_fdt; + + status = update_fdt(sys_table, (void *)fdt_addr, fdt_size, + (void *)*new_fdt_addr, MAX_FDT_SIZE, cmdline_ptr, + initrd_addr, initrd_size); + + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to construct new device tree.\n"); + goto fail_free_new_fdt; + } + + priv.runtime_map = runtime_map; + priv.runtime_entry_count = &runtime_entry_count; + priv.new_fdt_addr = (void *)*new_fdt_addr; + status = efi_exit_boot_services(sys_table, handle, &map, &priv, + exit_boot_func); + + if (status == EFI_SUCCESS) { + efi_set_virtual_address_map_t *svam; + + if (novamap()) + return EFI_SUCCESS; + + /* Install the new virtual address map */ + svam = sys_table->runtime->set_virtual_address_map; + status = svam(runtime_entry_count * desc_size, desc_size, + desc_ver, runtime_map); + + /* + * We are beyond the point of no return here, so if the call to + * SetVirtualAddressMap() failed, we need to signal that to the + * incoming kernel but proceed normally otherwise. + */ + if (status != EFI_SUCCESS) { + int l; + + /* + * Set the virtual address field of all + * EFI_MEMORY_RUNTIME entries to 0. This will signal + * the incoming kernel that no virtual translation has + * been installed. + */ + for (l = 0; l < map_size; l += desc_size) { + efi_memory_desc_t *p = (void *)memory_map + l; + + if (p->attribute & EFI_MEMORY_RUNTIME) + p->virt_addr = 0; + } + } + return EFI_SUCCESS; + } + + pr_efi_err(sys_table, "Exit boot services failed.\n"); + +fail_free_new_fdt: + efi_free(sys_table, MAX_FDT_SIZE, *new_fdt_addr); + +fail: + sys_table->boottime->free_pool(runtime_map); + return EFI_LOAD_ERROR; +} + +void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size) +{ + efi_guid_t fdt_guid = DEVICE_TREE_GUID; + efi_config_table_t *tables; + void *fdt; + int i; + + tables = (efi_config_table_t *) sys_table->tables; + fdt = NULL; + + for (i = 0; i < sys_table->nr_tables; i++) + if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) { + fdt = (void *) tables[i].table; + if (fdt_check_header(fdt) != 0) { + pr_efi_err(sys_table, "Invalid header detected on UEFI supplied FDT, ignoring ...\n"); + return NULL; + } + *fdt_size = fdt_totalsize(fdt); + break; + } + + return fdt; +} |