staging: android: persistent_ram: Move to fs/pstore/ram_core.c

This is a first step for adding ECC support for pstore RAM backend: we
will use the persistent_ram routines, kindly provided by Google.

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

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

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5 files changed, 2 insertions, 625 deletions

diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig
index 775229d1256..63f98223760 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 b4be69f80d7..4677e7b0e07 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 4b46eaad5f5..00000000000
--- 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 d23850ce3ca..00000000000
--- 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 ce140ffc54e..82323bb1d1a 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;