staging: android: persistent_ram: Move to fs/pstore/ram_core.c
authorAnton Vorontsov <anton.vorontsov@linaro.org>
Thu, 17 May 2012 07:15:08 +0000 (00:15 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 17 May 2012 15:50:00 +0000 (08:50 -0700)
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/android/Kconfig
drivers/staging/android/Makefile
drivers/staging/android/persistent_ram.c [deleted file]
drivers/staging/android/persistent_ram.h [deleted file]
drivers/staging/android/ram_console.c
fs/pstore/Kconfig
fs/pstore/Makefile
fs/pstore/ram_core.c [new file with mode: 0644]
include/linux/pstore_ram.h

index 775229d12569b0d0d16b9bb384b47cbfb0d428b4..63f98223760bcd9ee5272098e8e5c936ce63325b 100644 (file)
@@ -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=y
        default n
 
 config ANDROID_TIMED_OUTPUT
index b4be69f80d78210c6e9472da5e6a62eb15b2fb43..4677e7b0e07a29e660cee4c2996d197041ac2c60 100644 (file)
@@ -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 (file)
index 4b46eaa..0000000
+++ /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 (file)
index d23850c..0000000
+++ /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
index ce140ffc54eaf2d4ebc30efea0130ab06260e799..82323bb1d1a37092b2359535e326a0f8026a9037 100644 (file)
@@ -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;
index b75ee51b271438f9403ee8c2fb025e6ff0e55871..23ade2680a4a8da8e55ffb01a86c229b365bf5ee 100644 (file)
@@ -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.
index 2ab3d0d55ef6448f53429db53ed7aa343effa030..278a44e0d4e176716ebee280c0fc19dfb5042823 100644 (file)
@@ -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 (file)
index 0000000..31f8d18
--- /dev/null
@@ -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
index fa4cb02da41371943d901c6d1f70e38dc6f315c2..ffe24a52c5afb0c8844af8819f29202acbd56901 100644 (file)
@@ -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