| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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 |
| */ |
| |
| #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(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(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("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("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(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) { |
| /* 'node' is an error code when negative: */ |
| status = node; |
| 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_var(fdt, node, "linux,initrd-start", initrd_image_start); |
| if (status) |
| goto fdt_set_fail; |
| |
| initrd_image_end = cpu_to_fdt64(initrd_addr + initrd_size); |
| status = fdt_setprop_var(fdt, node, "linux,initrd-end", initrd_image_end); |
| 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)efi_system_table()); |
| |
| status = fdt_setprop_var(fdt, node, "linux,uefi-system-table", fdt_val64); |
| if (status) |
| goto fdt_set_fail; |
| |
| fdt_val64 = U64_MAX; /* placeholder */ |
| |
| status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-start", fdt_val64); |
| if (status) |
| goto fdt_set_fail; |
| |
| fdt_val32 = U32_MAX; /* placeholder */ |
| |
| status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-size", fdt_val32); |
| if (status) |
| goto fdt_set_fail; |
| |
| status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32); |
| if (status) |
| goto fdt_set_fail; |
| |
| status = fdt_setprop_var(fdt, node, "linux,uefi-mmap-desc-ver", 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(sizeof(fdt_val64), |
| (u8 *)&fdt_val64); |
| if (efi_status == EFI_SUCCESS) { |
| status = fdt_setprop_var(fdt, node, "kaslr-seed", 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_var(fdt, node, "linux,uefi-mmap-start", fdt_val64); |
| if (err) |
| return EFI_LOAD_ERROR; |
| |
| fdt_val32 = cpu_to_fdt32(*map->map_size); |
| |
| err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-size", fdt_val32); |
| if (err) |
| return EFI_LOAD_ERROR; |
| |
| fdt_val32 = cpu_to_fdt32(*map->desc_size); |
| |
| err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-size", fdt_val32); |
| if (err) |
| return EFI_LOAD_ERROR; |
| |
| fdt_val32 = cpu_to_fdt32(*map->desc_ver); |
| |
| err = fdt_setprop_inplace_var(fdt, node, "linux,uefi-mmap-desc-ver", 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(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(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; |
| 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(&map); |
| if (status != EFI_SUCCESS) { |
| pr_efi_err("Unable to retrieve UEFI memory map.\n"); |
| return status; |
| } |
| |
| pr_efi("Exiting boot services and installing virtual address map...\n"); |
| |
| map.map = &memory_map; |
| status = efi_high_alloc(MAX_FDT_SIZE, EFI_FDT_ALIGN, |
| new_fdt_addr, max_addr); |
| if (status != EFI_SUCCESS) { |
| pr_efi_err("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(&map); |
| if (status != EFI_SUCCESS) |
| goto fail_free_new_fdt; |
| |
| status = update_fdt((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("Unable to construct new device tree.\n"); |
| goto fail_free_new_fdt; |
| } |
| |
| runtime_entry_count = 0; |
| 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(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 = efi_system_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("Exit boot services failed.\n"); |
| |
| fail_free_new_fdt: |
| efi_free(MAX_FDT_SIZE, *new_fdt_addr); |
| |
| fail: |
| efi_system_table()->boottime->free_pool(runtime_map); |
| |
| return EFI_LOAD_ERROR; |
| } |
| |
| void *get_fdt(unsigned long *fdt_size) |
| { |
| void *fdt; |
| |
| fdt = get_efi_config_table(DEVICE_TREE_GUID); |
| |
| if (!fdt) |
| return NULL; |
| |
| if (fdt_check_header(fdt) != 0) { |
| pr_efi_err("Invalid header detected on UEFI supplied FDT, ignoring ...\n"); |
| return NULL; |
| } |
| *fdt_size = fdt_totalsize(fdt); |
| return fdt; |
| } |