linux/drivers/firmware/efi/efi-stub-helper.c

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/*
* 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.
*
*/
#define EFI_READ_CHUNK_SIZE (1024 * 1024)
struct initrd {
efi_file_handle_t *handle;
u64 size;
};
static void efi_char16_printk(efi_system_table_t *sys_table_arg,
efi_char16_t *str)
{
struct efi_simple_text_output_protocol *out;
out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
efi_call_phys2(out->output_string, out, str);
}
static 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);
}
}
static efi_status_t __get_map(efi_system_table_t *sys_table_arg,
efi_memory_desc_t **map,
unsigned long *map_size,
unsigned long *desc_size)
{
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_phys3(sys_table_arg->boottime->allocate_pool,
EFI_LOADER_DATA, *map_size, (void **)&m);
if (status != EFI_SUCCESS)
goto fail;
status = efi_call_phys5(sys_table_arg->boottime->get_memory_map,
map_size, m, &key, desc_size, &desc_version);
if (status == EFI_BUFFER_TOO_SMALL) {
efi_call_phys1(sys_table_arg->boottime->free_pool, m);
goto again;
}
if (status != EFI_SUCCESS)
efi_call_phys1(sys_table_arg->boottime->free_pool, m);
fail:
*map = m;
return status;
}
/*
* Allocate at the highest possible address that is not above 'max'.
*/
static efi_status_t 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 = __get_map(sys_table_arg, &map, &map_size, &desc_size);
if (status != EFI_SUCCESS)
goto fail;
nr_pages = round_up(size, EFI_PAGE_SIZE) / 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 ((start + size) > end || (start + size) > max)
continue;
if (end - size > max)
end = max;
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_phys4(sys_table_arg->boottime->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;
}
free_pool:
efi_call_phys1(sys_table_arg->boottime->free_pool, map);
fail:
return status;
}
/*
* Allocate at the lowest possible address.
*/
static efi_status_t 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 = __get_map(sys_table_arg, &map, &map_size, &desc_size);
if (status != EFI_SUCCESS)
goto fail;
nr_pages = round_up(size, EFI_PAGE_SIZE) / 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_phys4(sys_table_arg->boottime->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;
free_pool:
efi_call_phys1(sys_table_arg->boottime->free_pool, map);
fail:
return status;
}
static void low_free(efi_system_table_t *sys_table_arg, unsigned long size,
unsigned long addr)
{
unsigned long nr_pages;
nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
efi_call_phys2(sys_table_arg->boottime->free_pages, addr, nr_pages);
}
/*
* Check the cmdline for a LILO-style initrd= arguments.
*
* We only support loading an initrd from the same filesystem as the
* kernel image.
*/
static efi_status_t handle_ramdisks(efi_system_table_t *sys_table_arg,
efi_loaded_image_t *image,
struct setup_header *hdr)
{
struct initrd *initrds;
unsigned long initrd_addr;
efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
u64 initrd_total;
efi_file_io_interface_t *io;
efi_file_handle_t *fh;
efi_status_t status;
int nr_initrds;
char *str;
int i, j, k;
initrd_addr = 0;
initrd_total = 0;
str = (char *)(unsigned long)hdr->cmd_line_ptr;
j = 0; /* See close_handles */
if (!str || !*str)
return EFI_SUCCESS;
for (nr_initrds = 0; *str; nr_initrds++) {
str = strstr(str, "initrd=");
if (!str)
break;
str += 7;
/* Skip any leading slashes */
while (*str == '/' || *str == '\\')
str++;
while (*str && *str != ' ' && *str != '\n')
str++;
}
if (!nr_initrds)
return EFI_SUCCESS;
status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
EFI_LOADER_DATA,
nr_initrds * sizeof(*initrds),
&initrds);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to alloc mem for initrds\n");
goto fail;
}
str = (char *)(unsigned long)hdr->cmd_line_ptr;
for (i = 0; i < nr_initrds; i++) {
struct initrd *initrd;
efi_file_handle_t *h;
efi_file_info_t *info;
efi_char16_t filename_16[256];
unsigned long info_sz;
efi_guid_t info_guid = EFI_FILE_INFO_ID;
efi_char16_t *p;
u64 file_sz;
str = strstr(str, "initrd=");
if (!str)
break;
str += 7;
initrd = &initrds[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) {
efi_boot_services_t *boottime;
boottime = sys_table_arg->boottime;
status = efi_call_phys3(boottime->handle_protocol,
image->device_handle, &fs_proto, &io);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to handle fs_proto\n");
goto free_initrds;
}
status = efi_call_phys2(io->open_volume, io, &fh);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to open volume\n");
goto free_initrds;
}
}
status = efi_call_phys5(fh->open, fh, &h, filename_16,
EFI_FILE_MODE_READ, (u64)0);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to open initrd file: ");
efi_char16_printk(sys_table_arg, filename_16);
efi_printk(sys_table_arg, "\n");
goto close_handles;
}
initrd->handle = h;
info_sz = 0;
status = efi_call_phys4(h->get_info, h, &info_guid,
&info_sz, NULL);
if (status != EFI_BUFFER_TOO_SMALL) {
efi_printk(sys_table_arg, "Failed to get initrd info size\n");
goto close_handles;
}
grow:
status = efi_call_phys3(sys_table_arg->boottime->allocate_pool,
EFI_LOADER_DATA, info_sz, &info);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to alloc mem for initrd info\n");
goto close_handles;
}
status = efi_call_phys4(h->get_info, h, &info_guid,
&info_sz, info);
if (status == EFI_BUFFER_TOO_SMALL) {
efi_call_phys1(sys_table_arg->boottime->free_pool,
info);
goto grow;
}
file_sz = info->file_size;
efi_call_phys1(sys_table_arg->boottime->free_pool, info);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to get initrd info\n");
goto close_handles;
}
initrd->size = file_sz;
initrd_total += file_sz;
}
if (initrd_total) {
unsigned long addr;
/*
* Multiple initrd's need to be at consecutive
* addresses in memory, so allocate enough memory for
* all the initrd's.
*/
status = high_alloc(sys_table_arg, initrd_total, 0x1000,
&initrd_addr, hdr->initrd_addr_max);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to alloc highmem for initrds\n");
goto close_handles;
}
/* We've run out of free low memory. */
if (initrd_addr > hdr->initrd_addr_max) {
efi_printk(sys_table_arg, "We've run out of free low memory\n");
status = EFI_INVALID_PARAMETER;
goto free_initrd_total;
}
addr = initrd_addr;
for (j = 0; j < nr_initrds; j++) {
u64 size;
size = initrds[j].size;
while (size) {
u64 chunksize;
if (size > EFI_READ_CHUNK_SIZE)
chunksize = EFI_READ_CHUNK_SIZE;
else
chunksize = size;
status = efi_call_phys3(fh->read,
initrds[j].handle,
&chunksize, addr);
if (status != EFI_SUCCESS) {
efi_printk(sys_table_arg, "Failed to read initrd\n");
goto free_initrd_total;
}
addr += chunksize;
size -= chunksize;
}
efi_call_phys1(fh->close, initrds[j].handle);
}
}
efi_call_phys1(sys_table_arg->boottime->free_pool, initrds);
hdr->ramdisk_image = initrd_addr;
hdr->ramdisk_size = initrd_total;
return status;
free_initrd_total:
low_free(sys_table_arg, initrd_total, initrd_addr);
close_handles:
for (k = j; k < i; k++)
efi_call_phys1(fh->close, initrds[k].handle);
free_initrds:
efi_call_phys1(sys_table_arg->boottime->free_pool, initrds);
fail:
hdr->ramdisk_image = 0;
hdr->ramdisk_size = 0;
return status;
}