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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 16:34:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 16:34:21 -0700
commitfb09bafda67041b74a668dc9d77735e36bd33d3b (patch)
tree2dd32b65062a95045468fdcab366ecdb8e4fcac6 /fs
parent94b5aff4c6f72fee6b0f49d49e4fa8b204e8ded9 (diff)
parentc3c6cc91b0ae7b3d598488ad0b593bafba4a0817 (diff)
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 ...
Diffstat (limited to 'fs')
-rw-r--r--fs/pstore/Kconfig17
-rw-r--r--fs/pstore/Makefile3
-rw-r--r--fs/pstore/ram.c383
-rw-r--r--fs/pstore/ram_core.c532
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