Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 581 insertions, 0 deletions

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
new file mode 100644
index 000000000..3c777ec80
--- /dev/null
+++ b/fs/pstore/ram_core.c
@@ -0,0 +1,581 @@
+/*
+ * 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.
+ *
+ */
+
+#define pr_fmt(fmt) "persistent_ram: " fmt
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/memblock.h>
+#include <linux/pstore_ram.h>
+#include <linux/rslib.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/vmalloc.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 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 size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
+{
+	int old;
+	int new;
+	unsigned long flags = 0;
+
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_lock_irqsave(&prz->buffer_lock, flags);
+
+	old = atomic_read(&prz->buffer->start);
+	new = old + a;
+	while (unlikely(new >= prz->buffer_size))
+		new -= prz->buffer_size;
+	atomic_set(&prz->buffer->start, new);
+
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
+
+	return old;
+}
+
+/* increase the size counter until it hits the max size */
+static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
+{
+	size_t old;
+	size_t new;
+	unsigned long flags = 0;
+
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_lock_irqsave(&prz->buffer_lock, flags);
+
+	old = atomic_read(&prz->buffer->size);
+	if (old == prz->buffer_size)
+		goto exit;
+
+	new = old + a;
+	if (new > prz->buffer_size)
+		new = prz->buffer_size;
+	atomic_set(&prz->buffer->size, new);
+
+exit:
+	if (!(prz->flags & PRZ_FLAG_NO_LOCK))
+		raw_spin_unlock_irqrestore(&prz->buffer_lock, flags);
+}
+
+static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
+	uint8_t *data, size_t len, uint8_t *ecc)
+{
+	int i;
+
+	/* Initialize the parity buffer */
+	memset(prz->ecc_info.par, 0,
+	       prz->ecc_info.ecc_size * sizeof(prz->ecc_info.par[0]));
+	encode_rs8(prz->rs_decoder, data, len, prz->ecc_info.par, 0);
+	for (i = 0; i < prz->ecc_info.ecc_size; i++)
+		ecc[i] = prz->ecc_info.par[i];
+}
+
+static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
+	void *data, size_t len, uint8_t *ecc)
+{
+	int i;
+
+	for (i = 0; i < prz->ecc_info.ecc_size; i++)
+		prz->ecc_info.par[i] = ecc[i];
+	return decode_rs8(prz->rs_decoder, data, prz->ecc_info.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_info.block_size;
+	int ecc_size = prz->ecc_info.ecc_size;
+	int size = ecc_block_size;
+
+	if (!ecc_size)
+		return;
+
+	block = buffer->data + (start & ~(ecc_block_size - 1));
+	par = prz->par_buffer + (start / ecc_block_size) * 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_info.ecc_size)
+		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_info.ecc_size)
+		return;
+
+	block = buffer->data;
+	par = prz->par_buffer;
+	while (block < buffer->data + buffer_size(prz)) {
+		int numerr;
+		int size = prz->ecc_info.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("error in block %p, %d\n", block, numerr);
+			prz->corrected_bytes += numerr;
+		} else if (numerr < 0) {
+			pr_devel("uncorrectable error in block %p\n", block);
+			prz->bad_blocks++;
+		}
+		block += prz->ecc_info.block_size;
+		par += prz->ecc_info.ecc_size;
+	}
+}
+
+static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
+				   struct persistent_ram_ecc_info *ecc_info)
+{
+	int numerr;
+	struct persistent_ram_buffer *buffer = prz->buffer;
+	int ecc_blocks;
+	size_t ecc_total;
+
+	if (!ecc_info || !ecc_info->ecc_size)
+		return 0;
+
+	prz->ecc_info.block_size = ecc_info->block_size ?: 128;
+	prz->ecc_info.ecc_size = ecc_info->ecc_size ?: 16;
+	prz->ecc_info.symsize = ecc_info->symsize ?: 8;
+	prz->ecc_info.poly = ecc_info->poly ?: 0x11d;
+
+	ecc_blocks = DIV_ROUND_UP(prz->buffer_size - prz->ecc_info.ecc_size,
+				  prz->ecc_info.block_size +
+				  prz->ecc_info.ecc_size);
+	ecc_total = (ecc_blocks + 1) * prz->ecc_info.ecc_size;
+	if (ecc_total >= prz->buffer_size) {
+		pr_err("%s: invalid ecc_size %u (total %zu, buffer size %zu)\n",
+		       __func__, prz->ecc_info.ecc_size,
+		       ecc_total, prz->buffer_size);
+		return -EINVAL;
+	}
+
+	prz->buffer_size -= ecc_total;
+	prz->par_buffer = buffer->data + prz->buffer_size;
+	prz->par_header = prz->par_buffer +
+			  ecc_blocks * prz->ecc_info.ecc_size;
+
+	/*
+	 * first consecutive root is 0
+	 * primitive element to generate roots = 1
+	 */
+	prz->rs_decoder = init_rs(prz->ecc_info.symsize, prz->ecc_info.poly,
+				  0, 1, prz->ecc_info.ecc_size);
+	if (prz->rs_decoder == NULL) {
+		pr_info("init_rs failed\n");
+		return -EINVAL;
+	}
+
+	/* allocate workspace instead of using stack VLA */
+	prz->ecc_info.par = kmalloc_array(prz->ecc_info.ecc_size,
+					  sizeof(*prz->ecc_info.par),
+					  GFP_KERNEL);
+	if (!prz->ecc_info.par) {
+		pr_err("cannot allocate ECC parity workspace\n");
+		return -ENOMEM;
+	}
+
+	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("error in header, %d\n", numerr);
+		prz->corrected_bytes += numerr;
+	} else if (numerr < 0) {
+		pr_info("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->ecc_info.ecc_size)
+		return 0;
+
+	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_toio(buffer->data + start, s, count);
+	persistent_ram_update_ecc(prz, start, count);
+}
+
+static int notrace persistent_ram_update_user(struct persistent_ram_zone *prz,
+	const void __user *s, unsigned int start, unsigned int count)
+{
+	struct persistent_ram_buffer *buffer = prz->buffer;
+	int ret = unlikely(__copy_from_user(buffer->data + start, s, count)) ?
+		-EFAULT : 0;
+	persistent_ram_update_ecc(prz, start, count);
+	return ret;
+}
+
+void 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);
+
+	if (!size)
+		return;
+
+	if (!prz->old_log) {
+		persistent_ram_ecc_old(prz);
+		prz->old_log = kmalloc(size, GFP_KERNEL);
+	}
+	if (!prz->old_log) {
+		pr_err("failed to allocate buffer\n");
+		return;
+	}
+
+	prz->old_log_size = size;
+	memcpy_fromio(prz->old_log, &buffer->data[start], size - start);
+	memcpy_fromio(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;
+}
+
+int notrace persistent_ram_write_user(struct persistent_ram_zone *prz,
+	const void __user *s, unsigned int count)
+{
+	int rem, ret = 0, c = count;
+	size_t start;
+
+	if (unlikely(!access_ok(VERIFY_READ, s, count)))
+		return -EFAULT;
+	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)) {
+		ret = persistent_ram_update_user(prz, s, start, rem);
+		s += rem;
+		c -= rem;
+		start = 0;
+	}
+	if (likely(!ret))
+		ret = persistent_ram_update_user(prz, s, start, c);
+
+	persistent_ram_update_header_ecc(prz);
+
+	return unlikely(ret) ? ret : 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;
+}
+
+void persistent_ram_zap(struct persistent_ram_zone *prz)
+{
+	atomic_set(&prz->buffer->start, 0);
+	atomic_set(&prz->buffer->size, 0);
+	persistent_ram_update_header_ecc(prz);
+}
+
+static void *persistent_ram_vmap(phys_addr_t start, size_t size,
+		unsigned int memtype)
+{
+	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);
+
+	if (memtype)
+		prot = pgprot_noncached(PAGE_KERNEL);
+	else
+		prot = pgprot_writecombine(PAGE_KERNEL);
+
+	pages = kmalloc_array(page_count, sizeof(struct page *), 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);
+
+	/*
+	 * Since vmap() uses page granularity, we must add the offset
+	 * into the page here, to get the byte granularity address
+	 * into the mapping to represent the actual "start" location.
+	 */
+	return vaddr + offset_in_page(start);
+}
+
+static void *persistent_ram_iomap(phys_addr_t start, size_t size,
+		unsigned int memtype)
+{
+	void *va;
+
+	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;
+	}
+
+	if (memtype)
+		va = ioremap(start, size);
+	else
+		va = ioremap_wc(start, size);
+
+	/*
+	 * Since request_mem_region() and ioremap() are byte-granularity
+	 * there is no need handle anything special like we do when the
+	 * vmap() case in persistent_ram_vmap() above.
+	 */
+	return va;
+}
+
+static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
+		struct persistent_ram_zone *prz, int memtype)
+{
+	prz->paddr = start;
+	prz->size = size;
+
+	if (pfn_valid(start >> PAGE_SHIFT))
+		prz->vaddr = persistent_ram_vmap(start, size, memtype);
+	else
+		prz->vaddr = persistent_ram_iomap(start, size, memtype);
+
+	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;
+	prz->buffer_size = size - sizeof(struct persistent_ram_buffer);
+
+	return 0;
+}
+
+static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
+				    struct persistent_ram_ecc_info *ecc_info)
+{
+	int ret;
+
+	ret = persistent_ram_init_ecc(prz, ecc_info);
+	if (ret)
+		return ret;
+
+	sig ^= PERSISTENT_RAM_SIG;
+
+	if (prz->buffer->sig == sig) {
+		if (buffer_size(prz) == 0) {
+			pr_debug("found existing empty buffer\n");
+			return 0;
+		}
+
+		if (buffer_size(prz) > prz->buffer_size ||
+		    buffer_start(prz) > buffer_size(prz))
+			pr_info("found existing invalid buffer, size %zu, start %zu\n",
+				buffer_size(prz), buffer_start(prz));
+		else {
+			pr_debug("found existing buffer, size %zu, start %zu\n",
+				 buffer_size(prz), buffer_start(prz));
+			persistent_ram_save_old(prz);
+			return 0;
+		}
+	} else {
+		pr_debug("no valid data in buffer (sig = 0x%08x)\n",
+			 prz->buffer->sig);
+	}
+
+	/* Rewind missing or invalid memory area. */
+	prz->buffer->sig = sig;
+	persistent_ram_zap(prz);
+
+	return 0;
+}
+
+void persistent_ram_free(struct persistent_ram_zone *prz)
+{
+	if (!prz)
+		return;
+
+	if (prz->vaddr) {
+		if (pfn_valid(prz->paddr >> PAGE_SHIFT)) {
+			/* We must vunmap() at page-granularity. */
+			vunmap(prz->vaddr - offset_in_page(prz->paddr));
+		} else {
+			iounmap(prz->vaddr);
+			release_mem_region(prz->paddr, prz->size);
+		}
+		prz->vaddr = NULL;
+	}
+	if (prz->rs_decoder) {
+		free_rs(prz->rs_decoder);
+		prz->rs_decoder = NULL;
+	}
+	kfree(prz->ecc_info.par);
+	prz->ecc_info.par = NULL;
+
+	persistent_ram_free_old(prz);
+	kfree(prz);
+}
+
+struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
+			u32 sig, struct persistent_ram_ecc_info *ecc_info,
+			unsigned int memtype, u32 flags)
+{
+	struct persistent_ram_zone *prz;
+	int ret = -ENOMEM;
+
+	prz = kzalloc(sizeof(struct persistent_ram_zone), GFP_KERNEL);
+	if (!prz) {
+		pr_err("failed to allocate persistent ram zone\n");
+		goto err;
+	}
+
+	/* Initialize general buffer state. */
+	raw_spin_lock_init(&prz->buffer_lock);
+	prz->flags = flags;
+
+	ret = persistent_ram_buffer_map(start, size, prz, memtype);
+	if (ret)
+		goto err;
+
+	ret = persistent_ram_post_init(prz, sig, ecc_info);
+	if (ret)
+		goto err;
+
+	return prz;
+err:
+	persistent_ram_free(prz);
+	return ERR_PTR(ret);
+}