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 775229d..63f9822 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=y default n

config ANDROID_TIMED_OUTPUT diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile index b4be69f..4677e7b 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

This is now straightforward: just introduce a module parameter and pass the needed value to persistent_ram_new().

Signed-off-by: Anton Vorontsov anton.vorontsov@linaro.org Acked-by: Marco Stornelli marco.stornelli@gmail.com Acked-by: Kees Cook keescook@chromium.org --- Documentation/ramoops.txt | 6 ++++++ fs/pstore/ram.c | 15 ++++++++++++--- include/linux/pstore_ram.h | 1 + 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt index 470d2c4..4ba7db2 100644 --- a/Documentation/ramoops.txt +++ b/Documentation/ramoops.txt @@ -30,6 +30,11 @@ variable while setting 0 in that variable dumps only the panics. The module uses a counter to record multiple dumps but the counter gets reset on restart (i.e. new dumps after the restart will overwrite old ones).

+Ramoops also supports software ECC protection of persistent memory regions. +This might be useful when a hardware reset was used to bring the machine back +to life (i.e. a watchdog triggered). In such cases, RAM may be somewhat +corrupt, but usually it is restorable. + 2. Setting the parameters

Setting the ramoops parameters can be done in 2 different manners: @@ -46,6 +51,7 @@ static struct ramoops_platform_data ramoops_data = { .mem_address = <...>, .record_size = <...>, .dump_oops = <...>, + .ecc = <...>, };

static struct platform_device ramoops_dev = { diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 62b13ed..9123cce 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -56,12 +56,18 @@ 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; @@ -236,6 +242,7 @@ static int __init ramoops_probe(struct platform_device *pdev) 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) { @@ -248,7 +255,7 @@ static int __init ramoops_probe(struct platform_device *pdev) size_t sz = cxt->record_size; phys_addr_t start = cxt->phys_addr + sz * i;

- cxt->przs[i] = persistent_ram_new(start, sz, 0); + 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", @@ -281,9 +288,10 @@ static int __init ramoops_probe(struct platform_device *pdev) record_size = pdata->record_size; dump_oops = pdata->dump_oops;

- pr_info("attached 0x%lx@0x%llx (%ux0x%zx)\n", + 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); + cxt->max_count, cxt->record_size, + ramoops_ecc ? "on" : "off");

return 0;

@@ -347,6 +355,7 @@ static int __init ramoops_init(void) 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)); diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index ffe24a5..7ed7fd4 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -92,6 +92,7 @@ struct ramoops_platform_data { unsigned long mem_address; unsigned long record_size; int dump_oops; + bool ecc; };

#endif