diff options
Diffstat (limited to 'drivers/firmware/google/memconsole.c')
| -rw-r--r-- | drivers/firmware/google/memconsole.c | 155 |
1 files changed, 23 insertions, 132 deletions
diff --git a/drivers/firmware/google/memconsole.c b/drivers/firmware/google/memconsole.c index 2f569aaed4c7..94e200ddb4fa 100644 --- a/drivers/firmware/google/memconsole.c +++ b/drivers/firmware/google/memconsole.c @@ -1,66 +1,36 @@ /* * memconsole.c * - * Infrastructure for importing the BIOS memory based console - * into the kernel log ringbuffer. + * Architecture-independent parts of the memory based BIOS console. * - * Copyright 2010 Google Inc. All rights reserved. + * 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/ctype.h> #include <linux/init.h> -#include <linux/kernel.h> -#include <linux/string.h> #include <linux/sysfs.h> #include <linux/kobject.h> #include <linux/module.h> -#include <linux/dmi.h> -#include <linux/io.h> -#include <asm/bios_ebda.h> -#define BIOS_MEMCONSOLE_V1_MAGIC 0xDEADBABE -#define BIOS_MEMCONSOLE_V2_MAGIC (('M')|('C'<<8)|('O'<<16)|('N'<<24)) +#include "memconsole.h" -struct biosmemcon_ebda { - u32 signature; - union { - struct { - u8 enabled; - u32 buffer_addr; - u16 start; - u16 end; - u16 num_chars; - u8 wrapped; - } __packed v1; - struct { - u32 buffer_addr; - /* Misdocumented as number of pages! */ - u16 num_bytes; - u16 start; - u16 end; - } __packed v2; - }; -} __packed; - -static u32 memconsole_baseaddr; +static char *memconsole_baseaddr; static size_t memconsole_length; static ssize_t memconsole_read(struct file *filp, struct kobject *kobp, struct bin_attribute *bin_attr, char *buf, loff_t pos, size_t count) { - char *memconsole; - ssize_t ret; - - memconsole = ioremap_cache(memconsole_baseaddr, memconsole_length); - if (!memconsole) { - pr_err("memconsole: ioremap_cache failed\n"); - return -ENOMEM; - } - ret = memory_read_from_buffer(buf, count, &pos, memconsole, - memconsole_length); - iounmap(memconsole); - return ret; + return memory_read_from_buffer(buf, count, &pos, memconsole_baseaddr, + memconsole_length); } static struct bin_attribute memconsole_bin_attr = { @@ -68,104 +38,25 @@ static struct bin_attribute memconsole_bin_attr = { .read = memconsole_read, }; - -static void __init found_v1_header(struct biosmemcon_ebda *hdr) -{ - pr_info("BIOS console v1 EBDA structure found at %p\n", hdr); - pr_info("BIOS console buffer at 0x%.8x, " - "start = %d, end = %d, num = %d\n", - hdr->v1.buffer_addr, hdr->v1.start, - hdr->v1.end, hdr->v1.num_chars); - - memconsole_length = hdr->v1.num_chars; - memconsole_baseaddr = hdr->v1.buffer_addr; -} - -static void __init found_v2_header(struct biosmemcon_ebda *hdr) -{ - pr_info("BIOS console v2 EBDA structure found at %p\n", hdr); - pr_info("BIOS console buffer at 0x%.8x, " - "start = %d, end = %d, num_bytes = %d\n", - hdr->v2.buffer_addr, hdr->v2.start, - hdr->v2.end, hdr->v2.num_bytes); - - memconsole_length = hdr->v2.end - hdr->v2.start; - memconsole_baseaddr = hdr->v2.buffer_addr + hdr->v2.start; -} - -/* - * Search through the EBDA for the BIOS Memory Console, and - * set the global variables to point to it. Return true if found. - */ -static bool __init found_memconsole(void) +void memconsole_setup(void *baseaddr, size_t length) { - unsigned int address; - size_t length, cur; - - address = get_bios_ebda(); - if (!address) { - pr_info("BIOS EBDA non-existent.\n"); - return false; - } - - /* EBDA length is byte 0 of EBDA (in KB) */ - length = *(u8 *)phys_to_virt(address); - length <<= 10; /* convert to bytes */ - - /* - * Search through EBDA for BIOS memory console structure - * note: signature is not necessarily dword-aligned - */ - for (cur = 0; cur < length; cur++) { - struct biosmemcon_ebda *hdr = phys_to_virt(address + cur); - - /* memconsole v1 */ - if (hdr->signature == BIOS_MEMCONSOLE_V1_MAGIC) { - found_v1_header(hdr); - return true; - } - - /* memconsole v2 */ - if (hdr->signature == BIOS_MEMCONSOLE_V2_MAGIC) { - found_v2_header(hdr); - return true; - } - } - - pr_info("BIOS console EBDA structure not found!\n"); - return false; + memconsole_baseaddr = baseaddr; + memconsole_length = length; } +EXPORT_SYMBOL(memconsole_setup); -static struct dmi_system_id memconsole_dmi_table[] __initdata = { - { - .ident = "Google Board", - .matches = { - DMI_MATCH(DMI_BOARD_VENDOR, "Google, Inc."), - }, - }, - {} -}; -MODULE_DEVICE_TABLE(dmi, memconsole_dmi_table); - -static int __init memconsole_init(void) +int memconsole_sysfs_init(void) { - if (!dmi_check_system(memconsole_dmi_table)) - return -ENODEV; - - if (!found_memconsole()) - return -ENODEV; - memconsole_bin_attr.size = memconsole_length; return sysfs_create_bin_file(firmware_kobj, &memconsole_bin_attr); } +EXPORT_SYMBOL(memconsole_sysfs_init); -static void __exit memconsole_exit(void) +void memconsole_exit(void) { sysfs_remove_bin_file(firmware_kobj, &memconsole_bin_attr); } - -module_init(memconsole_init); -module_exit(memconsole_exit); +EXPORT_SYMBOL(memconsole_exit); MODULE_AUTHOR("Google, Inc."); MODULE_LICENSE("GPL"); |