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path: root/drivers/firmware/google/memconsole.c
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Diffstat (limited to 'drivers/firmware/google/memconsole.c')
-rw-r--r--drivers/firmware/google/memconsole.c155
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");