*
*/
+#define pr_fmt(fmt) "persistent_ram: " fmt
+
#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/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 <linux/pstore_ram.h>
#include <asm/page.h>
struct persistent_ram_buffer {
return atomic_read(&prz->buffer->start);
}
+static DEFINE_RAW_SPINLOCK(buffer_lock);
+
/* 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)
+static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a)
{
int old;
int new;
+ unsigned long flags;
- 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);
+ raw_spin_lock_irqsave(&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);
+
+ raw_spin_unlock_irqrestore(&buffer_lock, flags);
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)
+static void buffer_size_add(struct persistent_ram_zone *prz, size_t a)
{
size_t old;
size_t new;
+ unsigned long flags;
- if (atomic_read(&prz->buffer->size) == prz->buffer_size)
- return;
+ raw_spin_lock_irqsave(&buffer_lock, flags);
- 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);
+ 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:
+ raw_spin_unlock_irqrestore(&buffer_lock, flags);
}
static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
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);
+ pr_devel("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);
+ pr_devel("uncorrectable error in block %p\n", block);
prz->bad_blocks++;
}
block += prz->ecc_info.block_size;
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("persistent_ram: init_rs failed\n");
+ pr_info("init_rs failed\n");
return -EINVAL;
}
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);
+ pr_info("error in header, %d\n", numerr);
prz->corrected_bytes += numerr;
} else if (numerr < 0) {
- pr_info("persistent_ram: uncorrectable error in header\n");
+ pr_info("uncorrectable error in header\n");
prz->bad_blocks++;
}
const void *s, unsigned int start, unsigned int count)
{
struct persistent_ram_buffer *buffer = prz->buffer;
- memcpy(buffer->data + start, s, count);
+ 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;
prz->old_log = kmalloc(size, GFP_KERNEL);
}
if (!prz->old_log) {
- pr_err("persistent_ram: failed to allocate buffer\n");
+ pr_err("failed to allocate buffer\n");
return;
}
prz->old_log_size = size;
- memcpy(prz->old_log, &buffer->data[start], size - start);
- memcpy(prz->old_log + size - start, &buffer->data[0], start);
+ 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,
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;
persistent_ram_update_header_ecc(prz);
}
-static void *persistent_ram_vmap(phys_addr_t start, size_t size)
+static void *persistent_ram_vmap(phys_addr_t start, size_t size,
+ unsigned int memtype)
{
struct page **pages;
phys_addr_t page_start;
page_start = start - offset_in_page(start);
page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE);
- prot = pgprot_noncached(PAGE_KERNEL);
+ if (memtype)
+ prot = pgprot_noncached(PAGE_KERNEL);
+ else
+ prot = pgprot_writecombine(PAGE_KERNEL);
- pages = kmalloc(sizeof(struct page *) * page_count, GFP_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);
+ pr_err("%s: Failed to allocate array for %u pages\n",
+ __func__, page_count);
return NULL;
}
return vaddr;
}
-static void *persistent_ram_iomap(phys_addr_t start, size_t size)
+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;
}
- return ioremap(start, size);
+ if (memtype)
+ va = ioremap(start, size);
+ else
+ va = ioremap_wc(start, size);
+
+ return va;
}
static int persistent_ram_buffer_map(phys_addr_t start, phys_addr_t size,
- struct persistent_ram_zone *prz)
+ 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);
+ prz->vaddr = persistent_ram_vmap(start, size, memtype);
else
- prz->vaddr = persistent_ram_iomap(start, size);
+ 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__,
if (prz->buffer->sig == 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));
+ pr_info("found existing invalid buffer, size %zu, start %zu\n",
+ buffer_size(prz), buffer_start(prz));
else {
- pr_debug("persistent_ram: found existing buffer,"
- " size %zu, start %zu\n",
- buffer_size(prz), buffer_start(prz));
+ 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("persistent_ram: no valid data in buffer"
- " (sig = 0x%08x)\n", prz->buffer->sig);
+ pr_debug("no valid data in buffer (sig = 0x%08x)\n",
+ prz->buffer->sig);
}
prz->buffer->sig = sig;
}
struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
- u32 sig, struct persistent_ram_ecc_info *ecc_info)
+ u32 sig, struct persistent_ram_ecc_info *ecc_info,
+ unsigned int memtype)
{
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");
+ pr_err("failed to allocate persistent ram zone\n");
goto err;
}
- ret = persistent_ram_buffer_map(start, size, prz);
+ ret = persistent_ram_buffer_map(start, size, prz, memtype);
if (ret)
goto err;