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Subject[PATCH 4/6] persistent_ram: Move to fs/pstore/ram_core.c
This is a first step for adding ECC support for pstore RAM backend: we
will use the persistent_ram routines, kindly provided by Google.

Basically, persistent_ram is a set of helper routines to deal with the
[optionally] ECC-protected persistent ram regions.

A bit of Makefile, Kconfig and header files adjustments were needed
because of the move.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
---
drivers/staging/android/Kconfig | 10 +-
drivers/staging/android/Makefile | 1 -
drivers/staging/android/persistent_ram.c | 532 ------------------------------
drivers/staging/android/persistent_ram.h | 82 -----
drivers/staging/android/ram_console.c | 2 +-
fs/pstore/Kconfig | 7 +-
fs/pstore/Makefile | 2 +-
fs/pstore/ram_core.c | 532 ++++++++++++++++++++++++++++++
include/linux/pstore_ram.h | 80 +++++
9 files changed, 620 insertions(+), 628 deletions(-)
delete mode 100644 drivers/staging/android/persistent_ram.c
delete mode 100644 drivers/staging/android/persistent_ram.h
create mode 100644 fs/pstore/ram_core.c
diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig
index 42f0133..4bfcceb 100644
--- a/drivers/staging/android/Kconfig
+++ b/drivers/staging/android/Kconfig
@@ -25,17 +25,9 @@ config ANDROID_LOGGER
tristate "Android log driver"
default n

-config ANDROID_PERSISTENT_RAM
- bool
- depends on HAVE_MEMBLOCK
- select REED_SOLOMON
- select REED_SOLOMON_ENC8
- select REED_SOLOMON_DEC8
-
config ANDROID_RAM_CONSOLE
bool "Android RAM buffer console"
- depends on !S390 && !UML && HAVE_MEMBLOCK
- select ANDROID_PERSISTENT_RAM
+ depends on !S390 && !UML && HAVE_MEMBLOCK && PSTORE_RAM
default n

config ANDROID_TIMED_OUTPUT
diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile
index 2de5c10..98711e2 100644
--- a/drivers/staging/android/Makefile
+++ b/drivers/staging/android/Makefile
@@ -1,7 +1,6 @@
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
deleted file mode 100644
index 4b46eaa..0000000
--- a/drivers/staging/android/persistent_ram.c
+++ /dev/null
@@ -1,532 +0,0 @@
-/*
- * 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 <asm/page.h>
-#include "persistent_ram.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
diff --git a/drivers/staging/android/persistent_ram.h b/drivers/staging/android/persistent_ram.h
deleted file mode 100644
index d23850c..0000000
--- a/drivers/staging/android/persistent_ram.h
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * 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/device.h>
-#include <linux/kernel.h>
-#include <linux/list.h>
-#include <linux/types.h>
-#include <linux/init.h>
-
-struct persistent_ram_buffer;
-
-struct persistent_ram_descriptor {
- const char *name;
- phys_addr_t size;
-};
-
-struct persistent_ram {
- phys_addr_t start;
- phys_addr_t size;
-
- int num_descs;
- struct persistent_ram_descriptor *descs;
-
- struct list_head node;
-};
-
-struct persistent_ram_zone {
- phys_addr_t paddr;
- size_t size;
- void *vaddr;
- struct persistent_ram_buffer *buffer;
- size_t buffer_size;
-
- /* ECC correction */
- bool ecc;
- char *par_buffer;
- char *par_header;
- struct rs_control *rs_decoder;
- int corrected_bytes;
- int bad_blocks;
- int ecc_block_size;
- int ecc_size;
- int ecc_symsize;
- int ecc_poly;
-
- char *old_log;
- size_t old_log_size;
-};
-
-int persistent_ram_early_init(struct persistent_ram *ram);
-
-struct persistent_ram_zone * __init persistent_ram_new(phys_addr_t start,
- size_t size,
- bool ecc);
-void persistent_ram_free(struct persistent_ram_zone *prz);
-struct persistent_ram_zone *persistent_ram_init_ringbuffer(struct device *dev,
- bool ecc);
-
-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 ce140ff..82323bb 100644
--- a/drivers/staging/android/ram_console.c
+++ b/drivers/staging/android/ram_console.c
@@ -21,7 +21,7 @@
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/io.h>
-#include "persistent_ram.h"
+#include <linux/pstore_ram.h>
#include "ram_console.h"

static struct persistent_ram_zone *ram_console_zone;
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig
index b75ee51..23ade26 100644
--- a/fs/pstore/Kconfig
+++ b/fs/pstore/Kconfig
@@ -14,9 +14,12 @@ config PSTORE

config PSTORE_RAM
tristate "Log panic/oops to a RAM buffer"
- depends on HAS_IOMEM
depends on PSTORE
- default n
+ 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.
diff --git a/fs/pstore/Makefile b/fs/pstore/Makefile
index 2ab3d0d..278a44e 100644
--- a/fs/pstore/Makefile
+++ b/fs/pstore/Makefile
@@ -6,5 +6,5 @@ obj-y += pstore.o

pstore-objs += inode.o platform.o

-ramoops-objs += ram.o
+ramoops-objs += ram.o ram_core.o
obj-$(CONFIG_PSTORE_RAM) += ramoops.o
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
new file mode 100644
index 0000000..31f8d18
--- /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
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index fa4cb02..ffe24a5 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -1,6 +1,86 @@
+/*
+ * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
+ * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
+ * 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_PSTORE_RAM_H__
#define __LINUX_PSTORE_RAM_H__

+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/types.h>
+#include <linux/init.h>
+
+struct persistent_ram_buffer;
+
+struct persistent_ram_descriptor {
+ const char *name;
+ phys_addr_t size;
+};
+
+struct persistent_ram {
+ phys_addr_t start;
+ phys_addr_t size;
+
+ int num_descs;
+ struct persistent_ram_descriptor *descs;
+
+ struct list_head node;
+};
+
+struct persistent_ram_zone {
+ phys_addr_t paddr;
+ size_t size;
+ void *vaddr;
+ struct persistent_ram_buffer *buffer;
+ size_t buffer_size;
+
+ /* ECC correction */
+ bool ecc;
+ char *par_buffer;
+ char *par_header;
+ struct rs_control *rs_decoder;
+ int corrected_bytes;
+ int bad_blocks;
+ int ecc_block_size;
+ int ecc_size;
+ int ecc_symsize;
+ int ecc_poly;
+
+ char *old_log;
+ size_t old_log_size;
+};
+
+int persistent_ram_early_init(struct persistent_ram *ram);
+
+struct persistent_ram_zone * __init persistent_ram_new(phys_addr_t start,
+ size_t size,
+ bool ecc);
+void persistent_ram_free(struct persistent_ram_zone *prz);
+struct persistent_ram_zone *persistent_ram_init_ringbuffer(struct device *dev,
+ bool ecc);
+
+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);
+
/*
* Ramoops platform data
* @mem_size memory size for ramoops
--
1.7.9.2


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