blob: 46cffac7a5f1f0093ea68f4066eda03c7a9701ad [file] [log] [blame]
// 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;
}
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_allocate_pages(MAX_FDT_SIZE, 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;
}