[PATCH 05/11] android: ram_console: split out persistent ram

John Stultz
2012-03-08T01:36:32Z

From: Colin Cross <ccross@android.com>

Split ram_console into two halves.

persistent_ram is a set of apis that handle a block of memory
that does not get erased across a reboot. It provides functions
to fill it as a single buffer or a ring buffer, and to extract
the old data after a reboot. It handles ecc on the data to
correct bit errors introduced during reboot.

ram_console is now a small wrapper around persistent_ram that
feeds console data into the ringbuffer, and exports the old
data to /proc/last_kmsg after a reboot.

[jstultz: Moved persistent_ram.h to staging dir]
CC: Greg KH <gregkh@linuxfoundation.org>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/staging/android/Kconfig | 6 +-
drivers/staging/android/Makefile | 1 +
drivers/staging/android/persistent_ram.c | 302 +++++++++++++++++++++++++++++
drivers/staging/android/persistent_ram.h | 52 +++++
drivers/staging/android/ram_console.c | 309 ++++--------------------------
5 files changed, 396 insertions(+), 274 deletions(-)
create mode 100644 drivers/staging/android/persistent_ram.c
create mode 100644 drivers/staging/android/persistent_ram.h

diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig
index 3144ddb..3f7dbc5 100644
--- a/drivers/staging/android/Kconfig
+++ b/drivers/staging/android/Kconfig
@@ -25,15 +25,19 @@ config ANDROID_LOGGER
tristate "Android log driver"
default n

+config ANDROID_PERSISTENT_RAM
+ bool
+
config ANDROID_RAM_CONSOLE
bool "Android RAM buffer console"
depends on !S390 && !UML
+ select ANDROID_PERSISTENT_RAM
default n

menuconfig ANDROID_RAM_CONSOLE_ERROR_CORRECTION
bool "Android RAM Console Enable error correction"
default n
- depends on ANDROID_RAM_CONSOLE
+ depends on ANDROID_PERSISTENT_RAM
select REED_SOLOMON
select REED_SOLOMON_ENC8
select REED_SOLOMON_DEC8
diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile
index 785f269..9b6c9ed 100644
--- a/drivers/staging/android/Makefile
+++ b/drivers/staging/android/Makefile
@@ -1,6 +1,7 @@
obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o
obj-$(CONFIG_ASHMEM) += ashmem.o
obj-$(CONFIG_ANDROID_LOGGER) += logger.o
+obj-$(CONFIG_ANDROID_PERSISTENT_RAM) += persistent_ram.o
obj-$(CONFIG_ANDROID_RAM_CONSOLE) += ram_console.o
obj-$(CONFIG_ANDROID_TIMED_OUTPUT) += timed_output.o
obj-$(CONFIG_ANDROID_TIMED_GPIO) += timed_gpio.o
diff --git a/drivers/staging/android/persistent_ram.c b/drivers/staging/android/persistent_ram.c
new file mode 100644
index 0000000..d0f4666
--- /dev/null
+++ b/drivers/staging/android/persistent_ram.c
@@ -0,0 +1,302 @@
+/*
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include "persistent_ram.h"
+
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+#include <linux/rslib.h>
+#endif
+
+struct persistent_ram_buffer {
+ uint32_t sig;
+ uint32_t start;
+ uint32_t size;
+ uint8_t data[0];
+};
+
+#define PERSISTENT_RAM_SIG (0x43474244) /* DBGC */
+
+static LIST_HEAD(zone_list);
+
+#define ECC_BLOCK_SIZE CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_DATA_SIZE
+#define ECC_SIZE CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_ECC_SIZE
+#define ECC_SYMSIZE CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE
+#define ECC_POLY CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_POLYNOMIAL
+
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+static void persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
+ uint8_t *data, size_t len, uint8_t *ecc)
+{
+ int i;
+ uint16_t par[ECC_SIZE];
+ /* Initialize the parity buffer */
+ memset(par, 0, sizeof(par));
+ encode_rs8(prz->rs_decoder, data, len, par, 0);
+ for (i = 0; i < ECC_SIZE; i++)
+ ecc[i] = par[i];
+}
+
+static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
+ void *data, size_t len, uint8_t *ecc)
+{
+ int i;
+ uint16_t par[ECC_SIZE];
+ for (i = 0; i < ECC_SIZE; i++)
+ par[i] = ecc[i];
+ return decode_rs8(prz->rs_decoder, data, par, len,
+ NULL, 0, NULL, 0, NULL);
+}
+#endif
+
+static void persistent_ram_update(struct persistent_ram_zone *prz,
+ const void *s, unsigned int count)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ uint8_t *buffer_end = buffer->data + prz->buffer_size;
+ uint8_t *block;
+ uint8_t *par;
+ int size = ECC_BLOCK_SIZE;
+#endif
+ memcpy(buffer->data + buffer->start, s, count);
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ block = buffer->data + (buffer->start & ~(ECC_BLOCK_SIZE - 1));
+ par = prz->par_buffer +
+ (buffer->start / ECC_BLOCK_SIZE) * ECC_SIZE;
+ do {
+ if (block + ECC_BLOCK_SIZE > buffer_end)
+ size = buffer_end - block;
+ persistent_ram_encode_rs8(prz, block, size, par);
+ block += ECC_BLOCK_SIZE;
+ par += ECC_SIZE;
+ } while (block < buffer->data + buffer->start + count);
+#endif
+}
+
+static void persistent_ram_update_header(struct persistent_ram_zone *prz)
+{
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ struct persistent_ram_buffer *buffer = prz->buffer;
+
+ persistent_ram_encode_rs8(prz, (uint8_t *)buffer, sizeof(*buffer),
+ prz->par_header);
+#endif
+}
+
+static void __init
+persistent_ram_save_old(struct persistent_ram_zone *prz)
+{
+ struct persistent_ram_buffer *buffer = prz->buffer;
+ size_t old_log_size = buffer->size;
+ char *dest;
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ uint8_t *block;
+ uint8_t *par;
+
+ block = buffer->data;
+ par = prz->par_buffer;
+ while (block < buffer->data + buffer->size) {
+ int numerr;
+ int size = ECC_BLOCK_SIZE;
+ if (block + size > buffer->data + prz->buffer_size)
+ size = buffer->data + prz->buffer_size - block;
+ numerr = persistent_ram_decode_rs8(prz, block, size, par);
+ if (numerr > 0) {
+#if 0
+ pr_info("persistent_ram: error in block %p, %d\n",
+ block, numerr);
+#endif
+ prz->corrected_bytes += numerr;
+ } else if (numerr < 0) {
+#if 0
+ pr_info("persistent_ram: uncorrectable error in block %p\n",
+ block);
+#endif
+ prz->bad_blocks++;
+ }
+ block += ECC_BLOCK_SIZE;
+ par += ECC_SIZE;
+ }
+#endif
+
+ dest = kmalloc(old_log_size, GFP_KERNEL);
+ if (dest == NULL) {
+ pr_err("persistent_ram: failed to allocate buffer\n");
+ return;
+ }
+
+ prz->old_log = dest;
+ prz->old_log_size = old_log_size;
+ memcpy(prz->old_log,
+ &buffer->data[buffer->start], buffer->size - buffer->start);
+ memcpy(prz->old_log + buffer->size - buffer->start,
+ &buffer->data[0], buffer->start);
+}
+
+int persistent_ram_write(struct persistent_ram_zone *prz,
+ const void *s, unsigned int count)
+{
+ int rem;
+ int c = count;
+ struct persistent_ram_buffer *buffer = prz->buffer;
+
+ if (c > prz->buffer_size) {
+ s += c - prz->buffer_size;
+ c = prz->buffer_size;
+ }
+ rem = prz->buffer_size - buffer->start;
+ if (rem < c) {
+ persistent_ram_update(prz, s, rem);
+ s += rem;
+ c -= rem;
+ buffer->start = 0;
+ buffer->size = prz->buffer_size;
+ }
+ persistent_ram_update(prz, s, c);
+
+ buffer->start += c;
+ if (buffer->size < prz->buffer_size)
+ buffer->size += c;
+ persistent_ram_update_header(prz);
+
+ return count;
+}
+
+ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
+ char *str, size_t len)
+{
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ ssize_t ret;
+
+ if (prz->corrected_bytes || prz->bad_blocks)
+ ret = snprintf(str, len, ""
+ "\n%d Corrected bytes, %d unrecoverable blocks\n",
+ prz->corrected_bytes, prz->bad_blocks);
+ else
+ ret = snprintf(str, len, "\nNo errors detected\n");
+
+ return ret;
+#else
+ return 0;
+#endif
+}
+
+size_t persistent_ram_old_size(struct persistent_ram_zone *prz)
+{
+ return prz->old_log_size;
+}
+
+void *persistent_ram_old(struct persistent_ram_zone *prz)
+{
+ return prz->old_log;
+}
+
+void persistent_ram_free_old(struct persistent_ram_zone *prz)
+{
+ kfree(prz->old_log);
+ prz->old_log = NULL;
+ prz->old_log_size = 0;
+}
+
+static int __init __persistent_ram_init(struct persistent_ram_zone *prz,
+ void __iomem *mem, size_t buffer_size)
+{
+ struct persistent_ram_buffer *buffer = mem;
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ int numerr;
+#endif
+
+ INIT_LIST_HEAD(&prz->node);
+
+ prz->buffer = buffer;
+ prz->buffer_size = buffer_size - sizeof(struct persistent_ram_buffer);
+
+ if (prz->buffer_size > buffer_size) {
+ pr_err("persistent_ram: buffer %p, invalid size %zu, datasize %zu\n",
+ buffer, buffer_size, prz->buffer_size);
+ return -EINVAL;
+ }
+
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ prz->buffer_size -= (DIV_ROUND_UP(prz->buffer_size,
+ ECC_BLOCK_SIZE) + 1) * ECC_SIZE;
+
+ if (prz->buffer_size > buffer_size) {
+ pr_err("persistent_ram: buffer %p, invalid size %zu, non-ecc datasize %zu\n",
+ buffer, buffer_size, prz->buffer_size);
+ return -EINVAL;
+ }
+
+ prz->par_buffer = buffer->data + prz->buffer_size;
+ prz->par_header = prz->par_buffer +
+ DIV_ROUND_UP(prz->buffer_size, ECC_BLOCK_SIZE) * ECC_SIZE;
+
+
+ /* first consecutive root is 0
+ * primitive element to generate roots = 1
+ */
+ prz->rs_decoder = init_rs(ECC_SYMSIZE, ECC_POLY, 0, 1, ECC_SIZE);
+ if (prz->rs_decoder == NULL) {
+ pr_info("persistent_ram: init_rs failed\n");
+ return -EINVAL;
+ }
+
+ prz->corrected_bytes = 0;
+ prz->bad_blocks = 0;
+
+ numerr = persistent_ram_decode_rs8(prz, buffer, sizeof(*buffer),
+ prz->par_header);
+ if (numerr > 0) {
+ pr_info("persistent_ram: error in header, %d\n", numerr);
+ prz->corrected_bytes += numerr;
+ } else if (numerr < 0) {
+ pr_info("persistent_ram: uncorrectable error in header\n");
+ prz->bad_blocks++;
+ }
+#endif
+
+ if (buffer->sig == PERSISTENT_RAM_SIG) {
+ if (buffer->size > prz->buffer_size
+ || buffer->start > buffer->size)
+ pr_info("persistent_ram: found existing invalid buffer, size %d, start %d\n",
+ buffer->size, buffer->start);
+ else {
+ pr_info("persistent_ram: found existing buffer, size %d, start %d\n",
+ buffer->size, buffer->start);
+ persistent_ram_save_old(prz);
+ }
+ } else {
+ pr_info("persistent_ram: no valid data in buffer (sig = 0x%08x)\n",
+ buffer->sig);
+ }
+
+ buffer->sig = PERSISTENT_RAM_SIG;
+ buffer->start = 0;
+ buffer->size = 0;
+
+ list_add_tail(&prz->node, &zone_list);
+
+ return 0;
+}
+
+int __init persistent_ram_init_ringbuffer(struct persistent_ram_zone *prz,
+ void __iomem *mem, size_t buffer_size)
+{
+ return __persistent_ram_init(prz, mem, buffer_size);
+}
diff --git a/drivers/staging/android/persistent_ram.h b/drivers/staging/android/persistent_ram.h
new file mode 100644
index 0000000..f73fb08
--- /dev/null
+++ b/drivers/staging/android/persistent_ram.h
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2011 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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 __LINUX_PERSISTENT_RAM_H__
+#define __LINUX_PERSISTENT_RAM_H__
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+struct persistent_ram_buffer;
+
+struct persistent_ram_zone {
+ struct list_head node;
+ struct persistent_ram_buffer *buffer;
+ size_t buffer_size;
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ char *par_buffer;
+ char *par_header;
+ struct rs_control *rs_decoder;
+ int corrected_bytes;
+ int bad_blocks;
+#endif
+ char *old_log;
+ size_t old_log_size;
+ size_t old_log_footer_size;
+ bool early;
+};
+
+int persistent_ram_init_ringbuffer(struct persistent_ram_zone *prz,
+ void __iomem *buffer, size_t buffer_size);
+
+int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
+ unsigned int count);
+
+size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
+void *persistent_ram_old(struct persistent_ram_zone *prz);
+void persistent_ram_free_old(struct persistent_ram_zone *prz);
+ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
+ char *str, size_t len);
+
+#endif
diff --git a/drivers/staging/android/ram_console.c b/drivers/staging/android/ram_console.c
index 73215e2..689c3dc 100644
--- a/drivers/staging/android/ram_console.c
+++ b/drivers/staging/android/ram_console.c
@@ -21,121 +21,18 @@
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/io.h>
+#include "persistent_ram.h"
#include "ram_console.h"

-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
-#include <linux/rslib.h>
-#endif
-
-struct ram_console_buffer {
- uint32_t sig;
- uint32_t start;
- uint32_t size;
- uint8_t data[0];
-};
-
-#define RAM_CONSOLE_SIG (0x43474244) /* DBGC */
-
-static char *ram_console_old_log;
-static size_t ram_console_old_log_size;
+static struct persistent_ram_zone ram_console_zone;
static const char *bootinfo;
static size_t bootinfo_size;

-static struct ram_console_buffer *ram_console_buffer;
-static size_t ram_console_buffer_size;
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
-static char *ram_console_par_buffer;
-static struct rs_control *ram_console_rs_decoder;
-static int ram_console_corrected_bytes;
-static int ram_console_bad_blocks;
-#define ECC_BLOCK_SIZE CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_DATA_SIZE
-#define ECC_SIZE CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_ECC_SIZE
-#define ECC_SYMSIZE CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_SYMBOL_SIZE
-#define ECC_POLY CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION_POLYNOMIAL
-#endif
-
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
-static void ram_console_encode_rs8(uint8_t *data, size_t len, uint8_t *ecc)
-{
- int i;
- uint16_t par[ECC_SIZE];
- /* Initialize the parity buffer */
- memset(par, 0, sizeof(par));
- encode_rs8(ram_console_rs_decoder, data, len, par, 0);
- for (i = 0; i < ECC_SIZE; i++)
- ecc[i] = par[i];
-}
-
-static int ram_console_decode_rs8(void *data, size_t len, uint8_t *ecc)
-{
- int i;
- uint16_t par[ECC_SIZE];
- for (i = 0; i < ECC_SIZE; i++)
- par[i] = ecc[i];
- return decode_rs8(ram_console_rs_decoder, data, par, len,
- NULL, 0, NULL, 0, NULL);
-}
-#endif
-
-static void ram_console_update(const char *s, unsigned int count)
-{
- struct ram_console_buffer *buffer = ram_console_buffer;
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
- uint8_t *buffer_end = buffer->data + ram_console_buffer_size;
- uint8_t *block;
- uint8_t *par;
- int size = ECC_BLOCK_SIZE;
-#endif
- memcpy(buffer->data + buffer->start, s, count);
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
- block = buffer->data + (buffer->start & ~(ECC_BLOCK_SIZE - 1));
- par = ram_console_par_buffer +
- (buffer->start / ECC_BLOCK_SIZE) * ECC_SIZE;
- do {
- if (block + ECC_BLOCK_SIZE > buffer_end)
- size = buffer_end - block;
- ram_console_encode_rs8(block, size, par);
- block += ECC_BLOCK_SIZE;
- par += ECC_SIZE;
- } while (block < buffer->data + buffer->start + count);
-#endif
-}
-
-static void ram_console_update_header(void)
-{
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
- struct ram_console_buffer *buffer = ram_console_buffer;
- uint8_t *par;
- par = ram_console_par_buffer +
- DIV_ROUND_UP(ram_console_buffer_size, ECC_BLOCK_SIZE) * ECC_SIZE;
- ram_console_encode_rs8((uint8_t *)buffer, sizeof(*buffer), par);
-#endif
-}
-
static void
ram_console_write(struct console *console, const char *s, unsigned int count)
{
- int rem;
- struct ram_console_buffer *buffer = ram_console_buffer;
-
- if (count > ram_console_buffer_size) {
- s += count - ram_console_buffer_size;
- count = ram_console_buffer_size;
- }
- rem = ram_console_buffer_size - buffer->start;
- if (rem < count) {
- ram_console_update(s, rem);
- s += rem;
- count -= rem;
- buffer->start = 0;
- buffer->size = ram_console_buffer_size;
- }
- ram_console_update(s, count);
-
- buffer->start += count;
- if (buffer->size < ram_console_buffer_size)
- buffer->size += count;
- ram_console_update_header();
+ struct persistent_ram_zone *prz = console->data;
+ persistent_ram_write(prz, s, count);
}

static struct console ram_console = {
@@ -153,159 +50,6 @@ void ram_console_enable_console(int enabled)
ram_console.flags &= ~CON_ENABLED;
}

-static void __init
-ram_console_save_old(struct ram_console_buffer *buffer, char *dest)
-{
- size_t old_log_size = buffer->size;
-
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
- uint8_t *block;
- uint8_t *par;
-
- block = buffer->data;
- par = ram_console_par_buffer;
- while (block < buffer->data + buffer->size) {
- int numerr;
- int size = ECC_BLOCK_SIZE;
- if (block + size > buffer->data + ram_console_buffer_size)
- size = buffer->data + ram_console_buffer_size - block;
- numerr = ram_console_decode_rs8(block, size, par);
- if (numerr > 0) {
-#if 0
- printk(KERN_INFO "ram_console: error in block %p, %d\n",
- block, numerr);
-#endif
- ram_console_corrected_bytes += numerr;
- } else if (numerr < 0) {
-#if 0
- printk(KERN_INFO "ram_console: uncorrectable error in "
- "block %p\n", block);
-#endif
- ram_console_bad_blocks++;
- }
- block += ECC_BLOCK_SIZE;
- par += ECC_SIZE;
- }
-#endif
-
- if (dest == NULL) {
- dest = kmalloc(old_log_size, GFP_KERNEL);
- if (dest == NULL) {
- printk(KERN_ERR
- "ram_console: failed to allocate buffer\n");
- return;
- }
- }
-
- ram_console_old_log = dest;
- ram_console_old_log_size = old_log_size;
- memcpy(ram_console_old_log,
- &buffer->data[buffer->start], buffer->size - buffer->start);
- memcpy(ram_console_old_log + buffer->size - buffer->start,
- &buffer->data[0], buffer->start);
-}
-
-static int __init ram_console_init(struct ram_console_buffer *buffer,
- size_t buffer_size, char *old_buf)
-{
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
- int numerr;
- uint8_t *par;
-#endif
- ram_console_buffer = buffer;
- ram_console_buffer_size =
- buffer_size - sizeof(struct ram_console_buffer);
-
- if (ram_console_buffer_size > buffer_size) {
- pr_err("ram_console: buffer %p, invalid size %zu, "
- "datasize %zu\n", buffer, buffer_size,
- ram_console_buffer_size);
- return 0;
- }
-
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
- ram_console_buffer_size -= (DIV_ROUND_UP(ram_console_buffer_size,
- ECC_BLOCK_SIZE) + 1) * ECC_SIZE;
-
- if (ram_console_buffer_size > buffer_size) {
- pr_err("ram_console: buffer %p, invalid size %zu, "
- "non-ecc datasize %zu\n",
- buffer, buffer_size, ram_console_buffer_size);
- return 0;
- }
-
- ram_console_par_buffer = buffer->data + ram_console_buffer_size;
-
-
- /* first consecutive root is 0
- * primitive element to generate roots = 1
- */
- ram_console_rs_decoder = init_rs(ECC_SYMSIZE, ECC_POLY, 0, 1, ECC_SIZE);
- if (ram_console_rs_decoder == NULL) {
- printk(KERN_INFO "ram_console: init_rs failed\n");
- return 0;
- }
-
- ram_console_corrected_bytes = 0;
- ram_console_bad_blocks = 0;
-
- par = ram_console_par_buffer +
- DIV_ROUND_UP(ram_console_buffer_size, ECC_BLOCK_SIZE) * ECC_SIZE;
-
- numerr = ram_console_decode_rs8(buffer, sizeof(*buffer), par);
- if (numerr > 0) {
- printk(KERN_INFO "ram_console: error in header, %d\n", numerr);
- ram_console_corrected_bytes += numerr;
- } else if (numerr < 0) {
- printk(KERN_INFO
- "ram_console: uncorrectable error in header\n");
- ram_console_bad_blocks++;
- }
-#endif
-
- if (buffer->sig == RAM_CONSOLE_SIG) {
- if (buffer->size > ram_console_buffer_size
- || buffer->start > buffer->size)
- printk(KERN_INFO "ram_console: found existing invalid "
- "buffer, size %d, start %d\n",
- buffer->size, buffer->start);
- else {
- printk(KERN_INFO "ram_console: found existing buffer, "
- "size %d, start %d\n",
- buffer->size, buffer->start);
- ram_console_save_old(buffer, old_buf);
- }
- } else {
- printk(KERN_INFO "ram_console: no valid data in buffer "
- "(sig = 0x%08x)\n", buffer->sig);
- }
-
- buffer->sig = RAM_CONSOLE_SIG;
- buffer->start = 0;
- buffer->size = 0;
-
- register_console(&ram_console);
- return 0;
-}
-
-static ssize_t ram_console_ecc_string(char *str, size_t len)
-{
-#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
- ssize_t ret;
-
- if (ram_console_corrected_bytes || ram_console_bad_blocks)
- ret = snprintf(str, len, ""
- "\n%d Corrected bytes, %d unrecoverable blocks\n",
- ram_console_corrected_bytes, ram_console_bad_blocks);
- else
- ret = snprintf(str, len, "\nNo errors detected\n");
-
- return ret;
-#else
- return 0;
-#endif
-}
-
static int ram_console_driver_probe(struct platform_device *pdev)
{
struct resource *res = pdev->resource;
@@ -313,6 +57,7 @@ static int ram_console_driver_probe(struct platform_device *pdev)
size_t buffer_size;
void *buffer;
struct ram_console_platform_data *pdata = pdev->dev.platform_data;
+ int ret;

if (res == NULL || pdev->num_resources != 1 ||
!(res->flags & IORESOURCE_MEM)) {
@@ -330,13 +75,25 @@ static int ram_console_driver_probe(struct platform_device *pdev)
return -ENOMEM;
}

+ ret = persistent_ram_init_ringbuffer(&ram_console_zone, buffer,
+ buffer_size);
+ if (ret)
+ goto err;
+
if (pdata) {
bootinfo = kstrdup(pdata->bootinfo, GFP_KERNEL);
if (bootinfo)
bootinfo_size = strlen(bootinfo);
}

- return ram_console_init(buffer, buffer_size, NULL/* allocate */);
+ ram_console.data = &ram_console_zone;
+
+ register_console(&ram_console);
+ return 0;
+
+err:
+ iounmap(buffer);
+ return ret;
}

static struct platform_driver ram_console_driver = {
@@ -358,25 +115,28 @@ static ssize_t ram_console_read_old(struct file *file, char __user *buf,
{
loff_t pos = *offset;
ssize_t count;
+ struct persistent_ram_zone *prz = &ram_console_zone;
+ size_t old_log_size = persistent_ram_old_size(prz);
+ const char *old_log = persistent_ram_old(prz);
char *str;
int ret;

/* Main last_kmsg log */
- if (pos < ram_console_old_log_size) {
- count = min(len, (size_t)(ram_console_old_log_size - pos));
- if (copy_to_user(buf, ram_console_old_log + pos, count))
+ if (pos < old_log_size) {
+ count = min(len, (size_t)(old_log_size - pos));
+ if (copy_to_user(buf, old_log + pos, count))
return -EFAULT;
goto out;
}

/* ECC correction notice */
- pos -= ram_console_old_log_size;
- count = ram_console_ecc_string(NULL, 0);
+ pos -= old_log_size;
+ count = persistent_ram_ecc_string(prz, NULL, 0);
if (pos < count) {
str = kmalloc(count, GFP_KERNEL);
if (!str)
return -ENOMEM;
- ram_console_ecc_string(str, count + 1);
+ persistent_ram_ecc_string(prz, str, count + 1);
count = min(len, (size_t)(count - pos));
ret = copy_to_user(buf, str + pos, count);
kfree(str);
@@ -410,22 +170,25 @@ static const struct file_operations ram_console_file_ops = {
static int __init ram_console_late_init(void)
{
struct proc_dir_entry *entry;
+ struct persistent_ram_zone *prz = &ram_console_zone;

- if (ram_console_old_log == NULL)
+ if (persistent_ram_old_size(prz) == 0)
return 0;
+
entry = create_proc_entry("last_kmsg", S_IFREG | S_IRUGO, NULL);
if (!entry) {
printk(KERN_ERR "ram_console: failed to create proc entry\n");
- kfree(ram_console_old_log);
- ram_console_old_log = NULL;
+ persistent_ram_free_old(prz);
return 0;
}

entry->proc_fops = &ram_console_file_ops;
- entry->size = ram_console_old_log_size;
+ entry->size = persistent_ram_old_size(prz) +
+ persistent_ram_ecc_string(prz, NULL, 0) +
+ bootinfo_size;
+
return 0;
}

-postcore_initcall(ram_console_module_init);
late_initcall(ram_console_late_init);
-
+postcore_initcall(ram_console_module_init);
--
1.7.3.2.146.gca209