diff options
Diffstat (limited to 'drivers/staging/android/persistent_ram.c')
-rw-r--r-- | drivers/staging/android/persistent_ram.c | 473 |
1 files changed, 0 insertions, 473 deletions
diff --git a/drivers/staging/android/persistent_ram.c b/drivers/staging/android/persistent_ram.c deleted file mode 100644 index 8d8c1e3..0000000 --- a/drivers/staging/android/persistent_ram.c +++ /dev/null @@ -1,473 +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 "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); -} - -/* increase the size counter, retuning an error if it hits the max size */ -static inline ssize_t buffer_size_add_clamp(struct persistent_ram_zone *prz, - size_t a) -{ - size_t old; - size_t new; - - do { - old = atomic_read(&prz->buffer->size); - new = old + a; - if (new > prz->buffer_size) - return -ENOMEM; - } while (atomic_cmpxchg(&prz->buffer->size, old, new) != old); - - return 0; -} - -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_clamp(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 int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size, - struct persistent_ram_zone *prz) -{ - struct page **pages; - phys_addr_t page_start; - unsigned int page_count; - pgprot_t prot; - unsigned int i; - - 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 -ENOMEM; - } - - for (i = 0; i < page_count; i++) { - phys_addr_t addr = page_start + i * PAGE_SIZE; - pages[i] = pfn_to_page(addr >> PAGE_SHIFT); - } - prz->vaddr = vmap(pages, page_count, VM_MAP, prot); - kfree(pages); - if (!prz->vaddr) { - pr_err("%s: Failed to map %u pages\n", __func__, page_count); - 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_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; - } - - INIT_LIST_HEAD(&prz->node); - - ret = persistent_ram_buffer_init(dev_name(dev), prz); - if (ret) { - pr_err("persistent_ram: failed to initialize buffer\n"); - goto err; - } - - prz->ecc = ecc; - ret = persistent_ram_init_ecc(prz, prz->buffer_size); - if (ret) - goto err; - - 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 %ld, start %ld\n", - buffer_size(prz), buffer_start(prz)); - else { - pr_info("persistent_ram: found existing buffer," - " size %ld, start %ld\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 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; -} |