--- /dev/null
+/* drivers/android/ram_console.c
+ *
+ * Copyright (C) 2007-2008 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/console.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/proc_fs.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
+#include <asm/io.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 */
+
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
+static char __initdata
+ ram_console_old_log_init_buffer[CONFIG_ANDROID_RAM_CONSOLE_EARLY_SIZE];
+#endif
+static char *ram_console_old_log;
+static size_t ram_console_old_log_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();
+}
+
+static struct console ram_console = {
+ .name = "ram",
+ .write = ram_console_write,
+ .flags = CON_PRINTBUFFER | CON_ENABLED,
+ .index = -1,
+};
+
+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;
+ char strbuf[80];
+ int strbuf_len;
+
+ 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;
+ }
+ if (ram_console_corrected_bytes || ram_console_bad_blocks)
+ strbuf_len = snprintf(strbuf, sizeof(strbuf),
+ "\n%d Corrected bytes, %d unrecoverable blocks\n",
+ ram_console_corrected_bytes, ram_console_bad_blocks);
+ else
+ strbuf_len = snprintf(strbuf, sizeof(strbuf),
+ "\nNo errors detected\n");
+ if (strbuf_len >= sizeof(strbuf))
+ strbuf_len = sizeof(strbuf) - 1;
+ old_log_size += strbuf_len;
+#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);
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ memcpy(ram_console_old_log + old_log_size - strbuf_len,
+ strbuf, strbuf_len);
+#endif
+}
+
+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);
+
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION
+ ram_console_buffer_size -= (DIV_ROUND_UP(ram_console_buffer_size,
+ ECC_BLOCK_SIZE) + 1) * ECC_SIZE;
+ 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);
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_ENABLE_VERBOSE
+ console_verbose();
+#endif
+ return 0;
+}
+
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
+static int __init ram_console_early_init(void)
+{
+ return ram_console_init((struct ram_console_buffer *)
+ CONFIG_ANDROID_RAM_CONSOLE_EARLY_ADDR,
+ CONFIG_ANDROID_RAM_CONSOLE_EARLY_SIZE,
+ ram_console_old_log_init_buffer);
+}
+#else
+static int ram_console_driver_probe(struct platform_device *pdev)
+{
+ struct resource *res = pdev->resource;
+ size_t start;
+ size_t buffer_size;
+ void *buffer;
+
+ if (res == NULL || pdev->num_resources != 1 ||
+ !(res->flags & IORESOURCE_MEM)) {
+ printk(KERN_ERR "ram_console: invalid resource, %p %d flags "
+ "%lx\n", res, pdev->num_resources, res ? res->flags : 0);
+ return -ENXIO;
+ }
+ buffer_size = res->end - res->start + 1;
+ start = res->start;
+ printk(KERN_INFO "ram_console: got buffer at %x, size %x\n",
+ start, buffer_size);
+ buffer = ioremap(res->start, buffer_size);
+ if (buffer == NULL) {
+ printk(KERN_ERR "ram_console: failed to map memory\n");
+ return -ENOMEM;
+ }
+
+ return ram_console_init(buffer, buffer_size, NULL/* allocate */);
+}
+
+static struct platform_driver ram_console_driver = {
+ .probe = ram_console_driver_probe,
+ .driver = {
+ .name = "ram_console",
+ },
+};
+
+static int __init ram_console_module_init(void)
+{
+ int err;
+ err = platform_driver_register(&ram_console_driver);
+ return err;
+}
+#endif
+
+static ssize_t ram_console_read_old(struct file *file, char __user *buf,
+ size_t len, loff_t *offset)
+{
+ loff_t pos = *offset;
+ ssize_t count;
+
+ if (pos >= ram_console_old_log_size)
+ return 0;
+
+ count = min(len, (size_t)(ram_console_old_log_size - pos));
+ if (copy_to_user(buf, ram_console_old_log + pos, count))
+ return -EFAULT;
+
+ *offset += count;
+ return count;
+}
+
+static struct file_operations ram_console_file_ops = {
+ .owner = THIS_MODULE,
+ .read = ram_console_read_old,
+};
+
+static int __init ram_console_late_init(void)
+{
+ struct proc_dir_entry *entry;
+
+ if (ram_console_old_log == NULL)
+ return 0;
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
+ ram_console_old_log = kmalloc(ram_console_old_log_size, GFP_KERNEL);
+ if (ram_console_old_log == NULL) {
+ printk(KERN_ERR
+ "ram_console: failed to allocate buffer for old log\n");
+ ram_console_old_log_size = 0;
+ return 0;
+ }
+ memcpy(ram_console_old_log,
+ ram_console_old_log_init_buffer, ram_console_old_log_size);
+#endif
+ 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;
+ return 0;
+ }
+
+ entry->proc_fops = &ram_console_file_ops;
+ entry->size = ram_console_old_log_size;
+ return 0;
+}
+
+#ifdef CONFIG_ANDROID_RAM_CONSOLE_EARLY_INIT
+console_initcall(ram_console_early_init);
+#else
+module_init(ram_console_module_init);
+#endif
+late_initcall(ram_console_late_init);
+
projects / deliverable / linux.git / commitdiff
