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Commit afe9dba4 authored by Thierry Escande's avatar Thierry Escande Committed by Greg Kroah-Hartman
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firmware: google memconsole: Move specific EBDA parts 



This patch splits memconsole.c in 2 parts. One containing the
architecture-independent part and the other one containing the EBDA
specific part. This prepares the integration of coreboot support for the
memconsole.

The memconsole driver is now named as memconsole-x86-legacy.

Signed-off-by: default avatarThierry Escande <thierry.escande@collabora.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f952a401

drivers/firmware/google/Kconfig

+7 −2
Original line number Diff line number Diff line
@@ -20,8 +20,13 @@ config GOOGLE_SMI 
	  variables.



config GOOGLE_MEMCONSOLE

	tristate "Firmware Memory Console"

	depends on DMI

	tristate

	depends on GOOGLE_MEMCONSOLE_X86_LEGACY



config GOOGLE_MEMCONSOLE_X86_LEGACY

	tristate "Firmware Memory Console - X86 Legacy support"

	depends on X86 && ACPI && DMI

	select GOOGLE_MEMCONSOLE

	help

	  This option enables the kernel to search for a firmware log in

	  the EBDA on Google servers.  If found, this log is exported to

drivers/firmware/google/Makefile

+2 −1
Original line number Diff line number Diff line 


obj-$(CONFIG_GOOGLE_SMI)		+= gsmi.o

obj-$(CONFIG_GOOGLE_MEMCONSOLE)            += memconsole.o

obj-$(CONFIG_GOOGLE_MEMCONSOLE_X86_LEGACY) += memconsole-x86-legacy.o

drivers/firmware/google/memconsole-x86-legacy.c

0 → 100644
+154 −0
Original line number Diff line number Diff line 
/*

 * memconsole-x86-legacy.c

 *

 * EBDA specific parts of the memory based BIOS console.

 *

 * 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/kernel.h>

#include <linux/module.h>

#include <linux/dmi.h>

#include <linux/mm.h>

#include <asm/bios_ebda.h>

#include <asm/e820.h>

#include <linux/acpi.h>



#include "memconsole.h"



#define BIOS_MEMCONSOLE_V1_MAGIC	0xDEADBABE

#define BIOS_MEMCONSOLE_V2_MAGIC	(('M')|('C'<<8)|('O'<<16)|('N'<<24))



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 void found_v1_header(struct biosmemcon_ebda *hdr)

{

	pr_info("memconsole: BIOS console v1 EBDA structure found at %p\n",

		hdr);

	pr_info("memconsole: 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_setup(phys_to_virt(hdr->v1.buffer_addr), hdr->v1.num_chars);

}



static void found_v2_header(struct biosmemcon_ebda *hdr)

{

	pr_info("memconsole: BIOS console v2 EBDA structure found at %p\n",

		hdr);

	pr_info("memconsole: 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_setup(phys_to_virt(hdr->v2.buffer_addr + hdr->v2.start),

			 hdr->v2.end - 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 memconsole_ebda_init(void)

{

	unsigned int address;

	size_t length, cur;



	address = get_bios_ebda();

	if (!address) {

		pr_info("memconsole: 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("memconsole: BIOS console EBDA structure not found!\n");

	return false;

}



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 bool __init memconsole_find(void)

{

	if (!dmi_check_system(memconsole_dmi_table))

		return false;



	return memconsole_ebda_init();

}



static int __init memconsole_x86_init(void)

{

	if (!memconsole_find())

		return -ENODEV;



	return memconsole_sysfs_init();

}



static void __exit memconsole_x86_exit(void)

{

	memconsole_exit();

}



module_init(memconsole_x86_init);

module_exit(memconsole_x86_exit);



MODULE_AUTHOR("Google, Inc.");

MODULE_LICENSE("GPL");

drivers/firmware/google/memconsole.c

+23 −132
Original line number Diff line number Diff line 
/*

 * 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,

	return memory_read_from_buffer(buf, count, &pos, memconsole_baseaddr,

				       memconsole_length);

	iounmap(memconsole);

	return ret;

}



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)

void memconsole_setup(void *baseaddr, size_t length)

{

	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;

	memconsole_baseaddr = baseaddr;

	memconsole_length = length;

}

EXPORT_SYMBOL(memconsole_setup);



/*

 * 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)

int memconsole_sysfs_init(void)

{

	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;

}



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)

{

	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");

drivers/firmware/google/memconsole.h

0 → 100644
+43 −0
Original line number Diff line number Diff line 
/*

 * memconsole.h

 *

 * Internal headers of the memory based BIOS console.

 *

 * 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.

 */



#ifndef __FIRMWARE_GOOGLE_MEMCONSOLE_H

#define __FIRMWARE_GOOGLE_MEMCONSOLE_H



/*

 * memconsole_setup

 *

 * Initialize the memory console from raw (virtual) base

 * address and length.

 */

void memconsole_setup(void *baseaddr, size_t length);



/*

 * memconsole_sysfs_init

 *

 * Update memory console length and create binary file

 * for firmware object.

 */

int memconsole_sysfs_init(void);



/* memconsole_exit

 *

 * Unmap the console buffer.

 */

void memconsole_exit(void);



#endif /* __FIRMWARE_GOOGLE_MEMCONSOLE_H */