1 files changed, 256 insertions, 181 deletions

diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c
index f8af627f0b9..97bb8f6304d 100644
--- a/drivers/mtd/mtdoops.c
+++ b/drivers/mtd/mtdoops.c
@@ -1,7 +1,7 @@
 /*
  * MTD Oops/Panic logger
  *
- * Copyright (C) 2007 Nokia Corporation. All rights reserved.
+ * Copyright © 2007 Nokia Corporation. All rights reserved.
  *
  * Author: Richard Purdie <rpurdie@openedhand.com>
  *
@@ -28,100 +28,133 @@
 #include <linux/workqueue.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
 #include <linux/mtd/mtd.h>
+#include <linux/kmsg_dump.h>
 
-#define OOPS_PAGE_SIZE 4096
+/* Maximum MTD partition size */
+#define MTDOOPS_MAX_MTD_SIZE (8 * 1024 * 1024)
+
+#define MTDOOPS_KERNMSG_MAGIC 0x5d005d00
+#define MTDOOPS_HEADER_SIZE   8
+
+static unsigned long record_size = 4096;
+module_param(record_size, ulong, 0400);
+MODULE_PARM_DESC(record_size,
+		"record size for MTD OOPS pages in bytes (default 4096)");
+
+static char mtddev[80];
+module_param_string(mtddev, mtddev, 80, 0400);
+MODULE_PARM_DESC(mtddev,
+		"name or index number of the MTD device to use");
+
+static int dump_oops = 1;
+module_param(dump_oops, int, 0600);
+MODULE_PARM_DESC(dump_oops,
+		"set to 1 to dump oopses, 0 to only dump panics (default 1)");
 
 static struct mtdoops_context {
+	struct kmsg_dumper dump;
+
 	int mtd_index;
-	struct work_struct work;
+	struct work_struct work_erase;
+	struct work_struct work_write;
 	struct mtd_info *mtd;
 	int oops_pages;
 	int nextpage;
 	int nextcount;
+	unsigned long *oops_page_used;
 
 	void *oops_buf;
-	int ready;
-	int writecount;
 } oops_cxt;
 
+static void mark_page_used(struct mtdoops_context *cxt, int page)
+{
+	set_bit(page, cxt->oops_page_used);
+}
+
+static void mark_page_unused(struct mtdoops_context *cxt, int page)
+{
+	clear_bit(page, cxt->oops_page_used);
+}
+
+static int page_is_used(struct mtdoops_context *cxt, int page)
+{
+	return test_bit(page, cxt->oops_page_used);
+}
+
 static void mtdoops_erase_callback(struct erase_info *done)
 {
 	wait_queue_head_t *wait_q = (wait_queue_head_t *)done->priv;
 	wake_up(wait_q);
 }
 
-static int mtdoops_erase_block(struct mtd_info *mtd, int offset)
+static int mtdoops_erase_block(struct mtdoops_context *cxt, int offset)
 {
+	struct mtd_info *mtd = cxt->mtd;
+	u32 start_page_offset = mtd_div_by_eb(offset, mtd) * mtd->erasesize;
+	u32 start_page = start_page_offset / record_size;
+	u32 erase_pages = mtd->erasesize / record_size;
 	struct erase_info erase;
 	DECLARE_WAITQUEUE(wait, current);
 	wait_queue_head_t wait_q;
 	int ret;
+	int page;
 
 	init_waitqueue_head(&wait_q);
 	erase.mtd = mtd;
 	erase.callback = mtdoops_erase_callback;
 	erase.addr = offset;
-	if (mtd->erasesize < OOPS_PAGE_SIZE)
-		erase.len = OOPS_PAGE_SIZE;
-	else
-		erase.len = mtd->erasesize;
+	erase.len = mtd->erasesize;
 	erase.priv = (u_long)&wait_q;
 
 	set_current_state(TASK_INTERRUPTIBLE);
 	add_wait_queue(&wait_q, &wait);
 
-	ret = mtd->erase(mtd, &erase);
+	ret = mtd_erase(mtd, &erase);
 	if (ret) {
 		set_current_state(TASK_RUNNING);
 		remove_wait_queue(&wait_q, &wait);
-		printk (KERN_WARNING "mtdoops: erase of region [0x%x, 0x%x] "
-				     "on \"%s\" failed\n",
-			erase.addr, erase.len, mtd->name);
+		printk(KERN_WARNING "mtdoops: erase of region [0x%llx, 0x%llx] on \"%s\" failed\n",
+		       (unsigned long long)erase.addr,
+		       (unsigned long long)erase.len, mtddev);
 		return ret;
 	}
 
 	schedule();  /* Wait for erase to finish. */
 	remove_wait_queue(&wait_q, &wait);
 
+	/* Mark pages as unused */
+	for (page = start_page; page < start_page + erase_pages; page++)
+		mark_page_unused(cxt, page);
+
 	return 0;
 }
 
-static int mtdoops_inc_counter(struct mtdoops_context *cxt)
+static void mtdoops_inc_counter(struct mtdoops_context *cxt)
 {
-	struct mtd_info *mtd = cxt->mtd;
-	size_t retlen;
-	u32 count;
-	int ret;
-
 	cxt->nextpage++;
-	if (cxt->nextpage > cxt->oops_pages)
+	if (cxt->nextpage >= cxt->oops_pages)
 		cxt->nextpage = 0;
 	cxt->nextcount++;
 	if (cxt->nextcount == 0xffffffff)
 		cxt->nextcount = 0;
 
-	ret = mtd->read(mtd, cxt->nextpage * OOPS_PAGE_SIZE, 4,
-			&retlen, (u_char *) &count);
-	if ((retlen != 4) || (ret < 0)) {
-		printk(KERN_ERR "mtdoops: Read failure at %d (%td of 4 read)"
-				", err %d.\n", cxt->nextpage * OOPS_PAGE_SIZE,
-				retlen, ret);
-		return 1;
+	if (page_is_used(cxt, cxt->nextpage)) {
+		schedule_work(&cxt->work_erase);
+		return;
 	}
 
-	/* See if we need to erase the next block */
-	if (count != 0xffffffff)
-		return 1;
-
-	printk(KERN_DEBUG "mtdoops: Ready %d, %d (no erase)\n",
-			cxt->nextpage, cxt->nextcount);
-	cxt->ready = 1;
-	return 0;
+	printk(KERN_DEBUG "mtdoops: ready %d, %d (no erase)\n",
+	       cxt->nextpage, cxt->nextcount);
 }
 
-static void mtdoops_prepare(struct mtdoops_context *cxt)
+/* Scheduled work - when we can't proceed without erasing a block */
+static void mtdoops_workfunc_erase(struct work_struct *work)
 {
+	struct mtdoops_context *cxt =
+			container_of(work, struct mtdoops_context, work_erase);
 	struct mtd_info *mtd = cxt->mtd;
 	int i = 0, j, ret, mod;
 
@@ -129,247 +162,289 @@ static void mtdoops_prepare(struct mtdoops_context *cxt)
 	if (!mtd)
 		return;
 
-	mod = (cxt->nextpage * OOPS_PAGE_SIZE) % mtd->erasesize;
+	mod = (cxt->nextpage * record_size) % mtd->erasesize;
 	if (mod != 0) {
-		cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / OOPS_PAGE_SIZE);
-		if (cxt->nextpage > cxt->oops_pages)
+		cxt->nextpage = cxt->nextpage + ((mtd->erasesize - mod) / record_size);
+		if (cxt->nextpage >= cxt->oops_pages)
 			cxt->nextpage = 0;
 	}
 
-	while (mtd->block_isbad &&
-			mtd->block_isbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE)) {
+	while ((ret = mtd_block_isbad(mtd, cxt->nextpage * record_size)) > 0) {
 badblock:
-		printk(KERN_WARNING "mtdoops: Bad block at %08x\n",
-				cxt->nextpage * OOPS_PAGE_SIZE);
+		printk(KERN_WARNING "mtdoops: bad block at %08lx\n",
+		       cxt->nextpage * record_size);
 		i++;
-		cxt->nextpage = cxt->nextpage + (mtd->erasesize / OOPS_PAGE_SIZE);
-		if (cxt->nextpage > cxt->oops_pages)
+		cxt->nextpage = cxt->nextpage + (mtd->erasesize / record_size);
+		if (cxt->nextpage >= cxt->oops_pages)
 			cxt->nextpage = 0;
-		if (i == (cxt->oops_pages / (mtd->erasesize / OOPS_PAGE_SIZE))) {
-			printk(KERN_ERR "mtdoops: All blocks bad!\n");
+		if (i == cxt->oops_pages / (mtd->erasesize / record_size)) {
+			printk(KERN_ERR "mtdoops: all blocks bad!\n");
 			return;
 		}
 	}
 
+	if (ret < 0) {
+		printk(KERN_ERR "mtdoops: mtd_block_isbad failed, aborting\n");
+		return;
+	}
+
 	for (j = 0, ret = -1; (j < 3) && (ret < 0); j++)
-		ret = mtdoops_erase_block(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
+		ret = mtdoops_erase_block(cxt, cxt->nextpage * record_size);
 
-	if (ret < 0) {
-		if (mtd->block_markbad)
-			mtd->block_markbad(mtd, cxt->nextpage * OOPS_PAGE_SIZE);
-		goto badblock;
+	if (ret >= 0) {
+		printk(KERN_DEBUG "mtdoops: ready %d, %d\n",
+		       cxt->nextpage, cxt->nextcount);
+		return;
+	}
+
+	if (ret == -EIO) {
+		ret = mtd_block_markbad(mtd, cxt->nextpage * record_size);
+		if (ret < 0 && ret != -EOPNOTSUPP) {
+			printk(KERN_ERR "mtdoops: block_markbad failed, aborting\n");
+			return;
+		}
 	}
+	goto badblock;
+}
 
-	printk(KERN_DEBUG "mtdoops: Ready %d, %d \n", cxt->nextpage, cxt->nextcount);
+static void mtdoops_write(struct mtdoops_context *cxt, int panic)
+{
+	struct mtd_info *mtd = cxt->mtd;
+	size_t retlen;
+	u32 *hdr;
+	int ret;
+
+	/* Add mtdoops header to the buffer */
+	hdr = cxt->oops_buf;
+	hdr[0] = cxt->nextcount;
+	hdr[1] = MTDOOPS_KERNMSG_MAGIC;
 
-	cxt->ready = 1;
+	if (panic) {
+		ret = mtd_panic_write(mtd, cxt->nextpage * record_size,
+				      record_size, &retlen, cxt->oops_buf);
+		if (ret == -EOPNOTSUPP) {
+			printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n");
+			return;
+		}
+	} else
+		ret = mtd_write(mtd, cxt->nextpage * record_size,
+				record_size, &retlen, cxt->oops_buf);
+
+	if (retlen != record_size || ret < 0)
+		printk(KERN_ERR "mtdoops: write failure at %ld (%td of %ld written), error %d\n",
+		       cxt->nextpage * record_size, retlen, record_size, ret);
+	mark_page_used(cxt, cxt->nextpage);
+	memset(cxt->oops_buf, 0xff, record_size);
+
+	mtdoops_inc_counter(cxt);
 }
 
-static void mtdoops_workfunc(struct work_struct *work)
+static void mtdoops_workfunc_write(struct work_struct *work)
 {
 	struct mtdoops_context *cxt =
-			container_of(work, struct mtdoops_context, work);
+			container_of(work, struct mtdoops_context, work_write);
 
-	mtdoops_prepare(cxt);
+	mtdoops_write(cxt, 0);
 }
 
-static int find_next_position(struct mtdoops_context *cxt)
+static void find_next_position(struct mtdoops_context *cxt)
 {
 	struct mtd_info *mtd = cxt->mtd;
-	int page, maxpos = 0;
-	u32 count, maxcount = 0xffffffff;
+	int ret, page, maxpos = 0;
+	u32 count[2], maxcount = 0xffffffff;
 	size_t retlen;
 
 	for (page = 0; page < cxt->oops_pages; page++) {
-		mtd->read(mtd, page * OOPS_PAGE_SIZE, 4, &retlen, (u_char *) &count);
-		if (count == 0xffffffff)
+		if (mtd_block_isbad(mtd, page * record_size))
+			continue;
+		/* Assume the page is used */
+		mark_page_used(cxt, page);
+		ret = mtd_read(mtd, page * record_size, MTDOOPS_HEADER_SIZE,
+			       &retlen, (u_char *)&count[0]);
+		if (retlen != MTDOOPS_HEADER_SIZE ||
+				(ret < 0 && !mtd_is_bitflip(ret))) {
+			printk(KERN_ERR "mtdoops: read failure at %ld (%td of %d read), err %d\n",
+			       page * record_size, retlen,
+			       MTDOOPS_HEADER_SIZE, ret);
+			continue;
+		}
+
+		if (count[0] == 0xffffffff && count[1] == 0xffffffff)
+			mark_page_unused(cxt, page);
+		if (count[0] == 0xffffffff || count[1] != MTDOOPS_KERNMSG_MAGIC)
 			continue;
 		if (maxcount == 0xffffffff) {
-			maxcount = count;
+			maxcount = count[0];
 			maxpos = page;
-		} else if ((count < 0x40000000) && (maxcount > 0xc0000000)) {
-			maxcount = count;
+		} else if (count[0] < 0x40000000 && maxcount > 0xc0000000) {
+			maxcount = count[0];
 			maxpos = page;
-		} else if ((count > maxcount) && (count < 0xc0000000)) {
-			maxcount = count;
+		} else if (count[0] > maxcount && count[0] < 0xc0000000) {
+			maxcount = count[0];
 			maxpos = page;
-		} else if ((count > maxcount) && (count > 0xc0000000)
-					&& (maxcount > 0x80000000)) {
-			maxcount = count;
+		} else if (count[0] > maxcount && count[0] > 0xc0000000
+					&& maxcount > 0x80000000) {
+			maxcount = count[0];
 			maxpos = page;
 		}
 	}
 	if (maxcount == 0xffffffff) {
-		cxt->nextpage = 0;
-		cxt->nextcount = 1;
-		cxt->ready = 1;
-		printk(KERN_DEBUG "mtdoops: Ready %d, %d (first init)\n",
-				cxt->nextpage, cxt->nextcount);
-		return 0;
+		cxt->nextpage = cxt->oops_pages - 1;
+		cxt->nextcount = 0;
+	}
+	else {
+		cxt->nextpage = maxpos;
+		cxt->nextcount = maxcount;
 	}
 
-	cxt->nextpage = maxpos;
-	cxt->nextcount = maxcount;
-
-	return mtdoops_inc_counter(cxt);
+	mtdoops_inc_counter(cxt);
 }
 
-
-static void mtdoops_notify_add(struct mtd_info *mtd)
+static void mtdoops_do_dump(struct kmsg_dumper *dumper,
+			    enum kmsg_dump_reason reason)
 {
-	struct mtdoops_context *cxt = &oops_cxt;
-	int ret;
+	struct mtdoops_context *cxt = container_of(dumper,
+			struct mtdoops_context, dump);
 
-	if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)
+	/* Only dump oopses if dump_oops is set */
+	if (reason == KMSG_DUMP_OOPS && !dump_oops)
 		return;
 
-	if (mtd->size < (mtd->erasesize * 2)) {
-		printk(KERN_ERR "MTD partition %d not big enough for mtdoops\n",
-				mtd->index);
-		return;
-	}
+	kmsg_dump_get_buffer(dumper, true, cxt->oops_buf + MTDOOPS_HEADER_SIZE,
+			     record_size - MTDOOPS_HEADER_SIZE, NULL);
 
-	cxt->mtd = mtd;
-	cxt->oops_pages = mtd->size / OOPS_PAGE_SIZE;
-
-	ret = find_next_position(cxt);
-	if (ret == 1)
-		mtdoops_prepare(cxt);
+	/* Panics must be written immediately */
+	if (reason != KMSG_DUMP_OOPS)
+		mtdoops_write(cxt, 1);
 
-	printk(KERN_DEBUG "mtdoops: Attached to MTD device %d\n", mtd->index);
+	/* For other cases, schedule work to write it "nicely" */
+	schedule_work(&cxt->work_write);
 }
 
-static void mtdoops_notify_remove(struct mtd_info *mtd)
+static void mtdoops_notify_add(struct mtd_info *mtd)
 {
 	struct mtdoops_context *cxt = &oops_cxt;
+	u64 mtdoops_pages = div_u64(mtd->size, record_size);
+	int err;
 
-	if ((mtd->index != cxt->mtd_index) || cxt->mtd_index < 0)
-		return;
+	if (!strcmp(mtd->name, mtddev))
+		cxt->mtd_index = mtd->index;
 
-	cxt->mtd = NULL;
-	flush_scheduled_work();
-}
-
-static void mtdoops_console_sync(void)
-{
-	struct mtdoops_context *cxt = &oops_cxt;
-	struct mtd_info *mtd = cxt->mtd;
-	size_t retlen;
-	int ret;
-
-	if (!cxt->ready || !mtd)
+	if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
 		return;
 
-	if (cxt->writecount == 0)
+	if (mtd->size < mtd->erasesize * 2) {
+		printk(KERN_ERR "mtdoops: MTD partition %d not big enough for mtdoops\n",
+		       mtd->index);
 		return;
-
-	if (cxt->writecount < OOPS_PAGE_SIZE)
-		memset(cxt->oops_buf + cxt->writecount, 0xff,
-					OOPS_PAGE_SIZE - cxt->writecount);
-
-	ret = mtd->write(mtd, cxt->nextpage * OOPS_PAGE_SIZE,
-					OOPS_PAGE_SIZE, &retlen, cxt->oops_buf);
-	cxt->ready = 0;
-	cxt->writecount = 0;
-
-	if ((retlen != OOPS_PAGE_SIZE) || (ret < 0))
-		printk(KERN_ERR "mtdoops: Write failure at %d (%td of %d written), err %d.\n",
-			cxt->nextpage * OOPS_PAGE_SIZE, retlen,	OOPS_PAGE_SIZE, ret);
-
-	ret = mtdoops_inc_counter(cxt);
-	if (ret == 1)
-		schedule_work(&cxt->work);
-}
-
-static void
-mtdoops_console_write(struct console *co, const char *s, unsigned int count)
-{
-	struct mtdoops_context *cxt = co->data;
-	struct mtd_info *mtd = cxt->mtd;
-	int i;
-
-	if (!oops_in_progress) {
-		mtdoops_console_sync();
+	}
+	if (mtd->erasesize < record_size) {
+		printk(KERN_ERR "mtdoops: eraseblock size of MTD partition %d too small\n",
+		       mtd->index);
 		return;
 	}
-
-	if (!cxt->ready || !mtd)
+	if (mtd->size > MTDOOPS_MAX_MTD_SIZE) {
+		printk(KERN_ERR "mtdoops: mtd%d is too large (limit is %d MiB)\n",
+		       mtd->index, MTDOOPS_MAX_MTD_SIZE / 1024 / 1024);
 		return;
-
-	if (cxt->writecount == 0) {
-		u32 *stamp = cxt->oops_buf;
-		*stamp = cxt->nextcount;
-		cxt->writecount = 4;
 	}
 
-	if ((count + cxt->writecount) > OOPS_PAGE_SIZE)
-		count = OOPS_PAGE_SIZE - cxt->writecount;
+	/* oops_page_used is a bit field */
+	cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages,
+			BITS_PER_LONG) * sizeof(unsigned long));
+	if (!cxt->oops_page_used) {
+		printk(KERN_ERR "mtdoops: could not allocate page array\n");
+		return;
+	}
 
-	for (i = 0; i < count; i++, s++)
-		*((char *)(cxt->oops_buf) + cxt->writecount + i) = *s;
+	cxt->dump.max_reason = KMSG_DUMP_OOPS;
+	cxt->dump.dump = mtdoops_do_dump;
+	err = kmsg_dump_register(&cxt->dump);
+	if (err) {
+		printk(KERN_ERR "mtdoops: registering kmsg dumper failed, error %d\n", err);
+		vfree(cxt->oops_page_used);
+		cxt->oops_page_used = NULL;
+		return;
+	}
 
-	cxt->writecount = cxt->writecount + count;
+	cxt->mtd = mtd;
+	cxt->oops_pages = (int)mtd->size / record_size;
+	find_next_position(cxt);
+	printk(KERN_INFO "mtdoops: Attached to MTD device %d\n", mtd->index);
 }
 
-static int __init mtdoops_console_setup(struct console *co, char *options)
+static void mtdoops_notify_remove(struct mtd_info *mtd)
 {
-	struct mtdoops_context *cxt = co->data;
+	struct mtdoops_context *cxt = &oops_cxt;
 
-	if (cxt->mtd_index != -1)
-		return -EBUSY;
-	if (co->index == -1)
-		return -EINVAL;
+	if (mtd->index != cxt->mtd_index || cxt->mtd_index < 0)
+		return;
 
-	cxt->mtd_index = co->index;
-	return 0;
+	if (kmsg_dump_unregister(&cxt->dump) < 0)
+		printk(KERN_WARNING "mtdoops: could not unregister kmsg_dumper\n");
+
+	cxt->mtd = NULL;
+	flush_work(&cxt->work_erase);
+	flush_work(&cxt->work_write);
 }
 
+
 static struct mtd_notifier mtdoops_notifier = {
 	.add	= mtdoops_notify_add,
 	.remove	= mtdoops_notify_remove,
 };
 
-static struct console mtdoops_console = {
-	.name		= "ttyMTD",
-	.write		= mtdoops_console_write,
-	.setup		= mtdoops_console_setup,
-	.unblank	= mtdoops_console_sync,
-	.flags		= CON_PRINTBUFFER,
-	.index		= -1,
-	.data		= &oops_cxt,
-};
-
-static int __init mtdoops_console_init(void)
+static int __init mtdoops_init(void)
 {
 	struct mtdoops_context *cxt = &oops_cxt;
+	int mtd_index;
+	char *endp;
+
+	if (strlen(mtddev) == 0) {
+		printk(KERN_ERR "mtdoops: mtd device (mtddev=name/number) must be supplied\n");
+		return -EINVAL;
+	}
+	if ((record_size & 4095) != 0) {
+		printk(KERN_ERR "mtdoops: record_size must be a multiple of 4096\n");
+		return -EINVAL;
+	}
+	if (record_size < 4096) {
+		printk(KERN_ERR "mtdoops: record_size must be over 4096 bytes\n");
+		return -EINVAL;
+	}
 
+	/* Setup the MTD device to use */
 	cxt->mtd_index = -1;
-	cxt->oops_buf = vmalloc(OOPS_PAGE_SIZE);
+	mtd_index = simple_strtoul(mtddev, &endp, 0);
+	if (*endp == '\0')
+		cxt->mtd_index = mtd_index;
 
+	cxt->oops_buf = vmalloc(record_size);
 	if (!cxt->oops_buf) {
-		printk(KERN_ERR "Failed to allocate oops buffer workspace\n");
+		printk(KERN_ERR "mtdoops: failed to allocate buffer workspace\n");
 		return -ENOMEM;
 	}
+	memset(cxt->oops_buf, 0xff, record_size);
 
-	INIT_WORK(&cxt->work, mtdoops_workfunc);
+	INIT_WORK(&cxt->work_erase, mtdoops_workfunc_erase);
+	INIT_WORK(&cxt->work_write, mtdoops_workfunc_write);
 
-	register_console(&mtdoops_console);
 	register_mtd_user(&mtdoops_notifier);
 	return 0;
 }
 
-static void __exit mtdoops_console_exit(void)
+static void __exit mtdoops_exit(void)
 {
 	struct mtdoops_context *cxt = &oops_cxt;
 
 	unregister_mtd_user(&mtdoops_notifier);
-	unregister_console(&mtdoops_console);
 	vfree(cxt->oops_buf);
+	vfree(cxt->oops_page_used);
 }
 
 
-subsys_initcall(mtdoops_console_init);
-module_exit(mtdoops_console_exit);
+module_init(mtdoops_init);
+module_exit(mtdoops_exit);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");