diff options
Diffstat (limited to 'drivers/firmware/efi/libstub/fdt.c')
| -rw-r--r-- | drivers/firmware/efi/libstub/fdt.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c new file mode 100644 index 000000000000..c846a9608cbd --- /dev/null +++ b/drivers/firmware/efi/libstub/fdt.c @@ -0,0 +1,287 @@ +/* + * 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> + +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, + efi_memory_desc_t *memory_map, + unsigned long map_size, unsigned long desc_size, + u32 desc_ver) +{ + int node, prev, 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) + goto fdt_set_fail; + + /* + * Delete any memory nodes present. We must delete nodes which + * early_init_dt_scan_memory may try to use. + */ + prev = 0; + for (;;) { + const char *type; + int len; + + node = fdt_next_node(fdt, prev, NULL); + if (node < 0) + break; + + type = fdt_getprop(fdt, node, "device_type", &len); + if (type && strncmp(type, "memory", len) == 0) { + fdt_del_node(fdt, node); + continue; + } + + prev = node; + } + + /* + * 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 = cpu_to_fdt64((u64)(unsigned long)memory_map); + status = fdt_setprop(fdt, node, "linux,uefi-mmap-start", + &fdt_val64, sizeof(fdt_val64)); + if (status) + goto fdt_set_fail; + + fdt_val32 = cpu_to_fdt32(map_size); + status = fdt_setprop(fdt, node, "linux,uefi-mmap-size", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + fdt_val32 = cpu_to_fdt32(desc_size); + status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-size", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + fdt_val32 = cpu_to_fdt32(desc_ver); + status = fdt_setprop(fdt, node, "linux,uefi-mmap-desc-ver", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + + /* + * Add kernel version banner so stub/kernel match can be + * verified. + */ + status = fdt_setprop_string(fdt, node, "linux,uefi-stub-kern-ver", + linux_banner); + if (status) + goto fdt_set_fail; + + return EFI_SUCCESS; + +fdt_set_fail: + if (status == -FDT_ERR_NOSPACE) + return EFI_BUFFER_TOO_SMALL; + + return EFI_LOAD_ERROR; +} + +#ifndef EFI_FDT_ALIGN +#define EFI_FDT_ALIGN EFI_PAGE_SIZE +#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; + u32 desc_ver; + unsigned long mmap_key; + efi_memory_desc_t *memory_map; + unsigned long new_fdt_size; + efi_status_t status; + + /* + * Estimate size of new FDT, and allocate memory for it. We + * will allocate a bigger buffer if this ends up being too + * small, so a rough guess is OK here. + */ + new_fdt_size = fdt_size + EFI_PAGE_SIZE; + while (1) { + status = efi_high_alloc(sys_table, new_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, &memory_map, &map_size, + &desc_size, &desc_ver, &mmap_key); + if (status != EFI_SUCCESS) + goto fail_free_new_fdt; + + status = update_fdt(sys_table, + (void *)fdt_addr, fdt_size, + (void *)*new_fdt_addr, new_fdt_size, + cmdline_ptr, initrd_addr, initrd_size, + memory_map, map_size, desc_size, desc_ver); + + /* Succeeding the first time is the expected case. */ + if (status == EFI_SUCCESS) + break; + + if (status == EFI_BUFFER_TOO_SMALL) { + /* + * We need to allocate more space for the new + * device tree, so free existing buffer that is + * too small. Also free memory map, as we will need + * to get new one that reflects the free/alloc we do + * on the device tree buffer. + */ + efi_free(sys_table, new_fdt_size, *new_fdt_addr); + sys_table->boottime->free_pool(memory_map); + new_fdt_size += EFI_PAGE_SIZE; + } else { + pr_efi_err(sys_table, "Unable to constuct new device tree.\n"); + goto fail_free_mmap; + } + } + + /* Now we are ready to exit_boot_services.*/ + status = sys_table->boottime->exit_boot_services(handle, mmap_key); + + + if (status == EFI_SUCCESS) + return status; + + pr_efi_err(sys_table, "Exit boot services failed.\n"); + +fail_free_mmap: + sys_table->boottime->free_pool(memory_map); + +fail_free_new_fdt: + efi_free(sys_table, new_fdt_size, *new_fdt_addr); + +fail: + return EFI_LOAD_ERROR; +} + +void *get_fdt(efi_system_table_t *sys_table) +{ + 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; + break; + } + + return fdt; +} |