diff options
author | Sean Paul <seanpaul@chromium.org> | 2017-05-18 09:24:30 -0400 |
---|---|---|
committer | Sean Paul <seanpaul@chromium.org> | 2017-05-18 09:24:30 -0400 |
commit | 6b7781b42dc9bc9bcd1523b6c24b876cdda0bef3 (patch) | |
tree | ee55c67e4ea30b9eb44f301ba0bde2e631a26162 /drivers/firmware/google/coreboot_table.c | |
parent | 52d9d38c183bf0e09601d875ea31bb53c05dd8cf (diff) | |
parent | e98c58e55f68f8785aebfab1f8c9a03d8de0afe1 (diff) |
Merge remote-tracking branch 'airlied/drm-next' into drm-misc-next
Picking up drm-next @ 4.12-rc1 in order to apply Michal Hocko's vmalloc patch set
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Diffstat (limited to 'drivers/firmware/google/coreboot_table.c')
-rw-r--r-- | drivers/firmware/google/coreboot_table.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c new file mode 100644 index 000000000000..0019d3ec18dd --- /dev/null +++ b/drivers/firmware/google/coreboot_table.c @@ -0,0 +1,94 @@ +/* + * coreboot_table.c + * + * Module providing coreboot table access. + * + * Copyright 2017 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License v2.0 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include "coreboot_table.h" + +struct coreboot_table_entry { + u32 tag; + u32 size; +}; + +static struct coreboot_table_header __iomem *ptr_header; + +/* + * This function parses the coreboot table for an entry that contains the base + * address of the given entry tag. The coreboot table consists of a header + * directly followed by a number of small, variable-sized entries, which each + * contain an identifying tag and their length as the first two fields. + */ +int coreboot_table_find(int tag, void *data, size_t data_size) +{ + struct coreboot_table_header header; + struct coreboot_table_entry entry; + void *ptr_entry; + int i; + + if (!ptr_header) + return -EPROBE_DEFER; + + memcpy_fromio(&header, ptr_header, sizeof(header)); + + if (strncmp(header.signature, "LBIO", sizeof(header.signature))) { + pr_warn("coreboot_table: coreboot table missing or corrupt!\n"); + return -ENODEV; + } + + ptr_entry = (void *)ptr_header + header.header_bytes; + + for (i = 0; i < header.table_entries; i++) { + memcpy_fromio(&entry, ptr_entry, sizeof(entry)); + if (entry.tag == tag) { + if (data_size < entry.size) + return -EINVAL; + + memcpy_fromio(data, ptr_entry, entry.size); + + return 0; + } + + ptr_entry += entry.size; + } + + return -ENOENT; +} +EXPORT_SYMBOL(coreboot_table_find); + +int coreboot_table_init(void __iomem *ptr) +{ + ptr_header = ptr; + + return 0; +} +EXPORT_SYMBOL(coreboot_table_init); + +int coreboot_table_exit(void) +{ + if (ptr_header) + iounmap(ptr_header); + + return 0; +} +EXPORT_SYMBOL(coreboot_table_exit); + +MODULE_AUTHOR("Google, Inc."); +MODULE_LICENSE("GPL"); |