Merge tag 'staging-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging tree changes from Greg Kroah-Hartman:
 "Here is the big staging tree pull request for the 3.5-rc1 merge
  window.

  Loads of changes here, and we just narrowly added more lines than we
  added:
   622 files changed, 28356 insertions(+), 26059 deletions(-)

  But, good news is that there is a number of subsystems that moved out
  of the staging tree, to their respective "real" portions of the
  kernel.

  Code that moved out was:
	- iio core code
	- mei driver
	- vme core and bridge drivers

  There was one broken network driver that moved into staging as a step
  before it is removed from the tree (pc300), and there was a few new
  drivers added to the tree:
	- new iio drivers
	- gdm72xx wimax USB driver
	- ipack subsystem and 2 drivers

  All of the movements around have acks from the various subsystem
  maintainers, and all of this has been in the linux-next tree for a
  while.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

Fixed up various trivial conflicts, along with a non-trivial one found
in -next and pointed out by Olof Johanssen: a clean - but incorrect -
merge of the arch/arm/boot/dts/at91sam9g20.dtsi file.  Fix up manually
as per Stephen Rothwell.

* tag 'staging-3.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (536 commits)
  Staging: bcm: Remove two unused variables from Adapter.h
  Staging: bcm: Removes the volatile type definition from Adapter.h
  Staging: bcm: Rename all "INT" to "int" in Adapter.h
  Staging: bcm: Fix warning: __packed vs. __attribute__((packed)) in Adapter.h
  Staging: bcm: Correctly format all comments in Adapter.h
  Staging: bcm: Fix all whitespace issues in Adapter.h
  Staging: bcm: Properly format braces in Adapter.h
  Staging: ipack/bridges/tpci200: remove unneeded casts
  Staging: ipack/bridges/tpci200: remove TPCI200_SHORTNAME constant
  Staging: ipack: remove board_name and bus_name fields from struct ipack_device
  Staging: ipack: improve the register of a bus and a device in the bus.
  staging: comedi: cleanup all the comedi_driver 'detach' functions
  staging: comedi: remove all 'default N' in Kconfig
  staging: line6/config.h: Delete unused header
  staging: gdm72xx depends on NET
  staging: gdm72xx: Set up parent link in sysfs for gdm72xx devices
  staging: drm/omap: initial dmabuf/prime import support
  staging: drm/omap: dmabuf/prime mmap support
  pstore/ram: Add ECC support
  pstore/ram: Switch to persistent_ram routines
  ...

4 files changed, 935 insertions, 0 deletions

diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index 8007ae7c0d8c..23ade2680a4a 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -11,3 +11,20 @@ config PSTORE
 	   (e.g. ACPI_APEI on X86) which will select this for you.
 	   If you don't have a platform persistent store driver,
 	   say N.
+
+config PSTORE_RAM
+	tristate "Log panic/oops to a RAM buffer"
+	depends on PSTORE
+	depends on HAS_IOMEM
+	depends on HAVE_MEMBLOCK
+	select REED_SOLOMON
+	select REED_SOLOMON_ENC8
+	select REED_SOLOMON_DEC8
+	help
+	  This enables panic and oops messages to be logged to a circular
+	  buffer in RAM where it can be read back at some later point.
+
+	  Note that for historical reasons, the module will be named
+	  "ramoops.ko".
+
+	  For more information, see Documentation/ramoops.txt.
diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile
index 760f4bce7d1d..278a44e0d4e1 100644
--- a/fs/pstore/Makefile
+++ b/fs/pstore/Makefile
@@ -5,3 +5,6 @@
 obj-y += pstore.o
 
 pstore-objs += inode.o platform.o
+
+ramoops-objs += ram.o ram_core.o
+obj-$(CONFIG_PSTORE_RAM)	+= ramoops.o
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
new file mode 100644
index 000000000000..9123cce28c1e
--- /dev/null
+++ b/fs/pstore/ram.c
@@ -0,0 +1,383 @@
+/*
+ * RAM Oops/Panic logger
+ *
+ * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
+ * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/pstore.h>
+#include <linux/time.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pstore_ram.h>
+
+#define RAMOOPS_KERNMSG_HDR "===="
+#define MIN_MEM_SIZE 4096UL
+
+static ulong record_size = MIN_MEM_SIZE;
+module_param(record_size, ulong, 0400);
+MODULE_PARM_DESC(record_size,
+		"size of each dump done on oops/panic");
+
+static ulong mem_address;
+module_param(mem_address, ulong, 0400);
+MODULE_PARM_DESC(mem_address,
+		"start of reserved RAM used to store oops/panic logs");
+
+static ulong mem_size;
+module_param(mem_size, ulong, 0400);
+MODULE_PARM_DESC(mem_size,
+		"size of reserved RAM used to store oops/panic logs");
+
+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 int ramoops_ecc;
+module_param_named(ecc, ramoops_ecc, int, 0600);
+MODULE_PARM_DESC(ramoops_ecc,
+		"set to 1 to enable ECC support");
+
+struct ramoops_context {
+	struct persistent_ram_zone **przs;
+	phys_addr_t phys_addr;
+	unsigned long size;
+	size_t record_size;
+	int dump_oops;
+	bool ecc;
+	unsigned int count;
+	unsigned int max_count;
+	unsigned int read_count;
+	struct pstore_info pstore;
+};
+
+static struct platform_device *dummy;
+static struct ramoops_platform_data *dummy_data;
+
+static int ramoops_pstore_open(struct pstore_info *psi)
+{
+	struct ramoops_context *cxt = psi->data;
+
+	cxt->read_count = 0;
+	return 0;
+}
+
+static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
+				   struct timespec *time,
+				   char **buf,
+				   struct pstore_info *psi)
+{
+	ssize_t size;
+	struct ramoops_context *cxt = psi->data;
+	struct persistent_ram_zone *prz;
+
+	if (cxt->read_count >= cxt->max_count)
+		return -EINVAL;
+
+	*id = cxt->read_count++;
+	prz = cxt->przs[*id];
+
+	/* Only supports dmesg output so far. */
+	*type = PSTORE_TYPE_DMESG;
+	/* TODO(kees): Bogus time for the moment. */
+	time->tv_sec = 0;
+	time->tv_nsec = 0;
+
+	size = persistent_ram_old_size(prz);
+	*buf = kmalloc(size, GFP_KERNEL);
+	if (*buf == NULL)
+		return -ENOMEM;
+	memcpy(*buf, persistent_ram_old(prz), size);
+
+	return size;
+}
+
+static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz)
+{
+	char *hdr;
+	struct timeval timestamp;
+	size_t len;
+
+	do_gettimeofday(&timestamp);
+	hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
+		(long)timestamp.tv_sec, (long)timestamp.tv_usec);
+	WARN_ON_ONCE(!hdr);
+	len = hdr ? strlen(hdr) : 0;
+	persistent_ram_write(prz, hdr, len);
+	kfree(hdr);
+
+	return len;
+}
+
+static int ramoops_pstore_write(enum pstore_type_id type,
+				enum kmsg_dump_reason reason,
+				u64 *id,
+				unsigned int part,
+				size_t size, struct pstore_info *psi)
+{
+	struct ramoops_context *cxt = psi->data;
+	struct persistent_ram_zone *prz = cxt->przs[cxt->count];
+	size_t hlen;
+
+	/* Currently ramoops is designed to only store dmesg dumps. */
+	if (type != PSTORE_TYPE_DMESG)
+		return -EINVAL;
+
+	/* Out of the various dmesg dump types, ramoops is currently designed
+	 * to only store crash logs, rather than storing general kernel logs.
+	 */
+	if (reason != KMSG_DUMP_OOPS &&
+	    reason != KMSG_DUMP_PANIC)
+		return -EINVAL;
+
+	/* Skip Oopes when configured to do so. */
+	if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
+		return -EINVAL;
+
+	/* Explicitly only take the first part of any new crash.
+	 * If our buffer is larger than kmsg_bytes, this can never happen,
+	 * and if our buffer is smaller than kmsg_bytes, we don't want the
+	 * report split across multiple records.
+	 */
+	if (part != 1)
+		return -ENOSPC;
+
+	hlen = ramoops_write_kmsg_hdr(prz);
+	if (size + hlen > prz->buffer_size)
+		size = prz->buffer_size - hlen;
+	persistent_ram_write(prz, cxt->pstore.buf, size);
+
+	cxt->count = (cxt->count + 1) % cxt->max_count;
+
+	return 0;
+}
+
+static int ramoops_pstore_erase(enum pstore_type_id type, u64 id,
+				struct pstore_info *psi)
+{
+	struct ramoops_context *cxt = psi->data;
+
+	if (id >= cxt->max_count)
+		return -EINVAL;
+
+	persistent_ram_free_old(cxt->przs[id]);
+
+	return 0;
+}
+
+static struct ramoops_context oops_cxt = {
+	.pstore = {
+		.owner	= THIS_MODULE,
+		.name	= "ramoops",
+		.open	= ramoops_pstore_open,
+		.read	= ramoops_pstore_read,
+		.write	= ramoops_pstore_write,
+		.erase	= ramoops_pstore_erase,
+	},
+};
+
+static int __init ramoops_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ramoops_platform_data *pdata = pdev->dev.platform_data;
+	struct ramoops_context *cxt = &oops_cxt;
+	int err = -EINVAL;
+	int i;
+
+	/* Only a single ramoops area allowed at a time, so fail extra
+	 * probes.
+	 */
+	if (cxt->max_count)
+		goto fail_out;
+
+	if (!pdata->mem_size || !pdata->record_size) {
+		pr_err("The memory size and the record size must be "
+			"non-zero\n");
+		goto fail_out;
+	}
+
+	pdata->mem_size = rounddown_pow_of_two(pdata->mem_size);
+	pdata->record_size = rounddown_pow_of_two(pdata->record_size);
+
+	/* Check for the minimum memory size */
+	if (pdata->mem_size < MIN_MEM_SIZE &&
+			pdata->record_size < MIN_MEM_SIZE) {
+		pr_err("memory size too small, minimum is %lu\n",
+			MIN_MEM_SIZE);
+		goto fail_out;
+	}
+
+	if (pdata->mem_size < pdata->record_size) {
+		pr_err("The memory size must be larger than the "
+			"records size\n");
+		goto fail_out;
+	}
+
+	cxt->max_count = pdata->mem_size / pdata->record_size;
+	cxt->count = 0;
+	cxt->size = pdata->mem_size;
+	cxt->phys_addr = pdata->mem_address;
+	cxt->record_size = pdata->record_size;
+	cxt->dump_oops = pdata->dump_oops;
+	cxt->ecc = pdata->ecc;
+
+	cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_count, GFP_KERNEL);
+	if (!cxt->przs) {
+		err = -ENOMEM;
+		dev_err(dev, "failed to initialize a prz array\n");
+		goto fail_out;
+	}
+
+	for (i = 0; i < cxt->max_count; i++) {
+		size_t sz = cxt->record_size;
+		phys_addr_t start = cxt->phys_addr + sz * i;
+
+		cxt->przs[i] = persistent_ram_new(start, sz, cxt->ecc);
+		if (IS_ERR(cxt->przs[i])) {
+			err = PTR_ERR(cxt->przs[i]);
+			dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
+				sz, (unsigned long long)start, err);
+			goto fail_przs;
+		}
+	}
+
+	cxt->pstore.data = cxt;
+	cxt->pstore.bufsize = cxt->przs[0]->buffer_size;
+	cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
+	spin_lock_init(&cxt->pstore.buf_lock);
+	if (!cxt->pstore.buf) {
+		pr_err("cannot allocate pstore buffer\n");
+		goto fail_clear;
+	}
+
+	err = pstore_register(&cxt->pstore);
+	if (err) {
+		pr_err("registering with pstore failed\n");
+		goto fail_buf;
+	}
+
+	/*
+	 * Update the module parameter variables as well so they are visible
+	 * through /sys/module/ramoops/parameters/
+	 */
+	mem_size = pdata->mem_size;
+	mem_address = pdata->mem_address;
+	record_size = pdata->record_size;
+	dump_oops = pdata->dump_oops;
+
+	pr_info("attached 0x%lx@0x%llx (%ux0x%zx), ecc: %s\n",
+		cxt->size, (unsigned long long)cxt->phys_addr,
+		cxt->max_count, cxt->record_size,
+		ramoops_ecc ? "on" : "off");
+
+	return 0;
+
+fail_buf:
+	kfree(cxt->pstore.buf);
+fail_clear:
+	cxt->pstore.bufsize = 0;
+	cxt->max_count = 0;
+fail_przs:
+	for (i = 0; cxt->przs[i]; i++)
+		persistent_ram_free(cxt->przs[i]);
+	kfree(cxt->przs);
+fail_out:
+	return err;
+}
+
+static int __exit ramoops_remove(struct platform_device *pdev)
+{
+#if 0
+	/* TODO(kees): We cannot unload ramoops since pstore doesn't support
+	 * unregistering yet.
+	 */
+	struct ramoops_context *cxt = &oops_cxt;
+
+	iounmap(cxt->virt_addr);
+	release_mem_region(cxt->phys_addr, cxt->size);
+	cxt->max_count = 0;
+
+	/* TODO(kees): When pstore supports unregistering, call it here. */
+	kfree(cxt->pstore.buf);
+	cxt->pstore.bufsize = 0;
+
+	return 0;
+#endif
+	return -EBUSY;
+}
+
+static struct platform_driver ramoops_driver = {
+	.remove		= __exit_p(ramoops_remove),
+	.driver		= {
+		.name	= "ramoops",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init ramoops_init(void)
+{
+	int ret;
+	ret = platform_driver_probe(&ramoops_driver, ramoops_probe);
+	if (ret == -ENODEV) {
+		/*
+		 * If we didn't find a platform device, we use module parameters
+		 * building platform data on the fly.
+		 */
+		pr_info("platform device not found, using module parameters\n");
+		dummy_data = kzalloc(sizeof(struct ramoops_platform_data),
+				     GFP_KERNEL);
+		if (!dummy_data)
+			return -ENOMEM;
+		dummy_data->mem_size = mem_size;
+		dummy_data->mem_address = mem_address;
+		dummy_data->record_size = record_size;
+		dummy_data->dump_oops = dump_oops;
+		dummy_data->ecc = ramoops_ecc;
+		dummy = platform_create_bundle(&ramoops_driver, ramoops_probe,
+			NULL, 0, dummy_data,
+			sizeof(struct ramoops_platform_data));
+
+		if (IS_ERR(dummy))
+			ret = PTR_ERR(dummy);
+		else
+			ret = 0;
+	}
+
+	return ret;
+}
+
+static void __exit ramoops_exit(void)
+{
+	platform_driver_unregister(&ramoops_driver);
+	kfree(dummy_data);
+}
+
+module_init(ramoops_init);
+module_exit(ramoops_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
+MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
new file mode 100644
index 000000000000..31f8d184f3a0
--- /dev/null
+++ b/fs/pstore/ram_core.c
@@ -0,0 +1,532 @@
+/*
+ * 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/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
+#include <linux/rslib.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/pstore_ram.h>
+#include <asm/page.h>
+
+struct persistent_ram_buffer {
+	uint32_t    sig;
+	atomic_t    start;
+	atomic_t    size;
+	uint8_t     data[0];
+};
+
+#define PERSISTENT_RAM_SIG (0x43474244) /* DBGC */
+
+static __initdata LIST_HEAD(persistent_ram_list);
+
+static inline size_t buffer_size(struct persistent_ram_zone *prz)
+{
+	return atomic_read(&prz->buffer->size);
+}
+
+static inline size_t buffer_start(struct persistent_ram_zone *prz)
+{
+	return atomic_read(&prz->buffer->start);
+}
+
+/* increase and wrap the start pointer, returning the old value */
+static inline size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
+{
+	int old;
+	int new;
+
+	do {
+		old = atomic_read(&prz->buffer->start);
+		new = old + a;
+		while (unlikely(new > prz->buffer_size))
+			new -= prz->buffer_size;
+	} while (atomic_cmpxchg(&prz->buffer->start, old, new) != old);
+
+	return old;
+}
+
+/* increase the size counter until it hits the max size */
+static inline void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
+{
+	size_t old;
+	size_t new;
+
+	if (atomic_read(&prz->buffer->size) == prz->buffer_size)
+		return;
+
+	do {
+		old = atomic_read(&prz->buffer->size);
+		new = old + a;
+		if (new > prz->buffer_size)
+			new = prz->buffer_size;
+	} while (atomic_cmpxchg(&prz->buffer->size, old, new) != old);
+}
+
+static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
+	uint8_t *data, size_t len, uint8_t *ecc)
+{
+	int i;
+	uint16_t par[prz->ecc_size];
+
+	/* Initialize the parity buffer */
+	memset(par, 0, sizeof(par));
+	encode_rs8(prz->rs_decoder, data, len, par, 0);
+	for (i = 0; i < prz->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[prz->ecc_size];
+
+	for (i = 0; i < prz->ecc_size; i++)
+		par[i] = ecc[i];
+	return decode_rs8(prz->rs_decoder, data, par, len,
+				NULL, 0, NULL, 0, NULL);
+}
+
+static void notrace persistent_ram_update_ecc(struct persistent_ram_zone *prz,
+	unsigned int start, unsigned int count)
+{
+	struct persistent_ram_buffer *buffer = prz->buffer;
+	uint8_t *buffer_end = buffer->data + prz->buffer_size;
+	uint8_t *block;
+	uint8_t *par;
+	int ecc_block_size = prz->ecc_block_size;
+	int ecc_size = prz->ecc_size;
+	int size = prz->ecc_block_size;
+
+	if (!prz->ecc)
+		return;
+
+	block = buffer->data + (start & ~(ecc_block_size - 1));
+	par = prz->par_buffer + (start / ecc_block_size) * prz->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 + start + count);
+}
+
+static void persistent_ram_update_header_ecc(struct persistent_ram_zone *prz)
+{
+	struct persistent_ram_buffer *buffer = prz->buffer;
+
+	if (!prz->ecc)
+		return;
+
+	persistent_ram_encode_rs8(prz, (uint8_t *)buffer, sizeof(*buffer),
+				  prz->par_header);
+}
+
+static void persistent_ram_ecc_old(struct persistent_ram_zone *prz)
+{
+	struct persistent_ram_buffer *buffer = prz->buffer;
+	uint8_t *block;
+	uint8_t *par;
+
+	if (!prz->ecc)
+		return;
+
+	block = buffer->data;
+	par = prz->par_buffer;
+	while (block < buffer->data + buffer_size(prz)) {
+		int numerr;
+		int size = prz->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) {
+			pr_devel("persistent_ram: error in block %p, %d\n",
+			       block, numerr);
+			prz->corrected_bytes += numerr;
+		} else if (numerr < 0) {
+			pr_devel("persistent_ram: uncorrectable error in block %p\n",
+				block);
+			prz->bad_blocks++;
+		}
+		block += prz->ecc_block_size;
+		par += prz->ecc_size;
+	}
+}
+
+static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
+	size_t buffer_size)
+{
+	int numerr;
+	struct persistent_ram_buffer *buffer = prz->buffer;
+	int ecc_blocks;
+
+	if (!prz->ecc)
+		return 0;
+
+	prz->ecc_block_size = 128;
+	prz->ecc_size = 16;
+	prz->ecc_symsize = 8;
+	prz->ecc_poly = 0x11d;
+
+	ecc_blocks = DIV_ROUND_UP(prz->buffer_size, prz->ecc_block_size);
+	prz->buffer_size -= (ecc_blocks + 1) * prz->ecc_size;
+
+	if (prz->buffer_size > buffer_size) {
+		pr_err("persistent_ram: invalid size %zu, non-ecc datasize %zu\n",
+		       buffer_size, prz->buffer_size);
+		return -EINVAL;
+	}
+
+	prz->par_buffer = buffer->data + prz->buffer_size;
+	prz->par_header = prz->par_buffer + ecc_blocks * prz->ecc_size;
+
+	/*
+	 * first consecutive root is 0
+	 * primitive element to generate roots = 1
+	 */
+	prz->rs_decoder = init_rs(prz->ecc_symsize, prz->ecc_poly, 0, 1,
+				  prz->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++;
+	}
+
+	return 0;
+}
+
+ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
+	char *str, size_t len)
+{
+	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;
+}
+
+static void notrace persistent_ram_update(struct persistent_ram_zone *prz,
+	const void *s, unsigned int start, unsigned int count)
+{
+	struct persistent_ram_buffer *buffer = prz->buffer;
+	memcpy(buffer->data + start, s, count);
+	persistent_ram_update_ecc(prz, start, count);
+}
+
+static void __init
+persistent_ram_save_old(struct persistent_ram_zone *prz)
+{
+	struct persistent_ram_buffer *buffer = prz->buffer;
+	size_t size = buffer_size(prz);
+	size_t start = buffer_start(prz);
+	char *dest;
+
+	persistent_ram_ecc_old(prz);
+
+	dest = kmalloc(size, GFP_KERNEL);
+	if (dest == NULL) {
+		pr_err("persistent_ram: failed to allocate buffer\n");
+		return;
+	}
+
+	prz->old_log = dest;
+	prz->old_log_size = size;
+	memcpy(prz->old_log, &buffer->data[start], size - start);
+	memcpy(prz->old_log + size - start, &buffer->data[0], start);
+}
+
+int notrace persistent_ram_write(struct persistent_ram_zone *prz,
+	const void *s, unsigned int count)
+{
+	int rem;
+	int c = count;
+	size_t start;
+
+	if (unlikely(c > prz->buffer_size)) {
+		s += c - prz->buffer_size;
+		c = prz->buffer_size;
+	}
+
+	buffer_size_add(prz, c);
+
+	start = buffer_start_add(prz, c);
+
+	rem = prz->buffer_size - start;
+	if (unlikely(rem < c)) {
+		persistent_ram_update(prz, s, start, rem);
+		s += rem;
+		c -= rem;
+		start = 0;
+	}
+	persistent_ram_update(prz, s, start, c);
+
+	persistent_ram_update_header_ecc(prz);
+
+	return count;
+}
+
+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 void *persistent_ram_vmap(phys_addr_t start, size_t size)
+{
+	struct page **pages;
+	phys_addr_t page_start;
+	unsigned int page_count;
+	pgprot_t prot;
+	unsigned int i;
+	void *vaddr;
+
+	page_start = start - offset_in_page(start);
+	page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
+
+	prot = pgprot_noncached(PAGE_KERNEL);
+
+	pages = kmalloc(sizeof(struct page *) * page_count, GFP_KERNEL);
+	if (!pages) {
+		pr_err("%s: Failed to allocate array for %u pages\n", __func__,
+			page_count);
+		return NULL;
+	}
+
+	for (i = 0; i < page_count; i++) {
+		phys_addr_t addr = page_start + i * PAGE_SIZE;
+		pages[i] = pfn_to_page(addr >> PAGE_SHIFT);
+	}
+	vaddr = vmap(pages, page_count, VM_MAP, prot);
+	kfree(pages);
+
+	return vaddr;
+}
+
+static void *persistent_ram_iomap(phys_addr_t start, size_t size)
+{
+	if (!request_mem_region(start, size, "persistent_ram")) {
+		pr_err("request mem region (0x%llx@0x%llx) failed\n",
+			(unsigned long long)size, (unsigned long long)start);
+		return NULL;
+	}
+
+	return ioremap(start, size);
+}
+
+static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
+		struct persistent_ram_zone *prz)
+{
+	prz->paddr = start;
+	prz->size = size;
+
+	if (pfn_valid(start >> PAGE_SHIFT))
+		prz->vaddr = persistent_ram_vmap(start, size);
+	else
+		prz->vaddr = persistent_ram_iomap(start, size);
+
+	if (!prz->vaddr) {
+		pr_err("%s: Failed to map 0x%llx pages at 0x%llx\n", __func__,
+			(unsigned long long)size, (unsigned long long)start);
+		return -ENOMEM;
+	}
+
+	prz->buffer = prz->vaddr + offset_in_page(start);
+	prz->buffer_size = size - sizeof(struct persistent_ram_buffer);
+
+	return 0;
+}
+
+static int __init persistent_ram_post_init(struct persistent_ram_zone *prz, bool ecc)
+{
+	int ret;
+
+	prz->ecc = ecc;
+
+	ret = persistent_ram_init_ecc(prz, prz->buffer_size);
+	if (ret)
+		return ret;
+
+	if (prz->buffer->sig == PERSISTENT_RAM_SIG) {
+		if (buffer_size(prz) > prz->buffer_size ||
+		    buffer_start(prz) > buffer_size(prz))
+			pr_info("persistent_ram: found existing invalid buffer,"
+				" size %zu, start %zu\n",
+			       buffer_size(prz), buffer_start(prz));
+		else {
+			pr_info("persistent_ram: found existing buffer,"
+				" size %zu, start %zu\n",
+			       buffer_size(prz), buffer_start(prz));
+			persistent_ram_save_old(prz);
+		}
+	} else {
+		pr_info("persistent_ram: no valid data in buffer"
+			" (sig = 0x%08x)\n", prz->buffer->sig);
+	}
+
+	prz->buffer->sig = PERSISTENT_RAM_SIG;
+	atomic_set(&prz->buffer->start, 0);
+	atomic_set(&prz->buffer->size, 0);
+
+	return 0;
+}
+
+void persistent_ram_free(struct persistent_ram_zone *prz)
+{
+	if (pfn_valid(prz->paddr >> PAGE_SHIFT)) {
+		vunmap(prz->vaddr);
+	} else {
+		iounmap(prz->vaddr);
+		release_mem_region(prz->paddr, prz->size);
+	}
+	persistent_ram_free_old(prz);
+	kfree(prz);
+}
+
+struct persistent_ram_zone * __init persistent_ram_new(phys_addr_t start,
+						       size_t size,
+						       bool ecc)
+{
+	struct persistent_ram_zone *prz;
+	int ret = -ENOMEM;
+
+	prz = kzalloc(sizeof(struct persistent_ram_zone), GFP_KERNEL);
+	if (!prz) {
+		pr_err("persistent_ram: failed to allocate persistent ram zone\n");
+		goto err;
+	}
+
+	ret = persistent_ram_buffer_map(start, size, prz);
+	if (ret)
+		goto err;
+
+	persistent_ram_post_init(prz, ecc);
+	persistent_ram_update_header_ecc(prz);
+
+	return prz;
+err:
+	kfree(prz);
+	return ERR_PTR(ret);
+}
+
+#ifndef MODULE
+static int __init persistent_ram_buffer_init(const char *name,
+		struct persistent_ram_zone *prz)
+{
+	int i;
+	struct persistent_ram *ram;
+	struct persistent_ram_descriptor *desc;
+	phys_addr_t start;
+
+	list_for_each_entry(ram, &persistent_ram_list, node) {
+		start = ram->start;
+		for (i = 0; i < ram->num_descs; i++) {
+			desc = &ram->descs[i];
+			if (!strcmp(desc->name, name))
+				return persistent_ram_buffer_map(start,
+						desc->size, prz);
+			start += desc->size;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static  __init
+struct persistent_ram_zone *__persistent_ram_init(struct device *dev, bool ecc)
+{
+	struct persistent_ram_zone *prz;
+	int ret = -ENOMEM;
+
+	prz = kzalloc(sizeof(struct persistent_ram_zone), GFP_KERNEL);
+	if (!prz) {
+		pr_err("persistent_ram: failed to allocate persistent ram zone\n");
+		goto err;
+	}
+
+	ret = persistent_ram_buffer_init(dev_name(dev), prz);
+	if (ret) {
+		pr_err("persistent_ram: failed to initialize buffer\n");
+		goto err;
+	}
+
+	persistent_ram_post_init(prz, ecc);
+
+	return prz;
+err:
+	kfree(prz);
+	return ERR_PTR(ret);
+}
+
+struct persistent_ram_zone * __init
+persistent_ram_init_ringbuffer(struct device *dev, bool ecc)
+{
+	return __persistent_ram_init(dev, ecc);
+}
+
+int __init persistent_ram_early_init(struct persistent_ram *ram)
+{
+	int ret;
+
+	ret = memblock_reserve(ram->start, ram->size);
+	if (ret) {
+		pr_err("Failed to reserve persistent memory from %08lx-%08lx\n",
+			(long)ram->start, (long)(ram->start + ram->size - 1));
+		return ret;
+	}
+
+	list_add_tail(&ram->node, &persistent_ram_list);
+
+	pr_info("Initialized persistent memory from %08lx-%08lx\n",
+		(long)ram->start, (long)(ram->start + ram->size - 1));
+
+	return 0;
+}
+#endif