[PATCH 2/5] firmware: google memconsole: Move specific EBDA parts

From: Thierry Escande
Date: Thu Mar 23 2017 - 17:06:13 EST

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: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
---
drivers/firmware/google/Kconfig | 9 +-
drivers/firmware/google/Makefile | 3 +-
drivers/firmware/google/memconsole-x86-legacy.c | 154 +++++++++++++++++++++++
drivers/firmware/google/memconsole.c | 155 ++++--------------------
drivers/firmware/google/memconsole.h | 43 +++++++
5 files changed, 229 insertions(+), 135 deletions(-)
create mode 100644 drivers/firmware/google/memconsole-x86-legacy.c
create mode 100644 drivers/firmware/google/memconsole.h

diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig
index 475bd01..27a0658 100644
--- a/drivers/firmware/google/Kconfig
+++ b/drivers/firmware/google/Kconfig
@@ -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
diff --git a/drivers/firmware/google/Makefile b/drivers/firmware/google/Makefile
index 54a294e..10683ef 100644
--- a/drivers/firmware/google/Makefile
+++ b/drivers/firmware/google/Makefile
@@ -1,3 +1,4 @@

obj-$(CONFIG_GOOGLE_SMI) += gsmi.o
-obj-$(CONFIG_GOOGLE_MEMCONSOLE) += memconsole.o
+obj-$(CONFIG_GOOGLE_MEMCONSOLE) += memconsole.o
+obj-$(CONFIG_GOOGLE_MEMCONSOLE_X86_LEGACY) += memconsole-x86-legacy.o
diff --git a/drivers/firmware/google/memconsole-x86-legacy.c b/drivers/firmware/google/memconsole-x86-legacy.c
new file mode 100644
index 0000000..529078c
--- /dev/null
+++ b/drivers/firmware/google/memconsole-x86-legacy.c
@@ -0,0 +1,154 @@
+/*
+ * 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");
diff --git a/drivers/firmware/google/memconsole.c b/drivers/firmware/google/memconsole.c
index 2f569aa..94e200d 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");
diff --git a/drivers/firmware/google/memconsole.h b/drivers/firmware/google/memconsole.h
new file mode 100644
index 0000000..190fc03
--- /dev/null
+++ b/drivers/firmware/google/memconsole.h
@@ -0,0 +1,43 @@
+/*
+ * 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 */
--
2.7.4