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-rw-r--r--drivers/mtd/spi-nor/core.c337
-rw-r--r--include/linux/mtd/spi-nor.h13
2 files changed, 334 insertions, 16 deletions
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 75ec7a3d0b43..9e6a0730cdb8 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -589,6 +589,65 @@ int spi_nor_sr_ready(struct spi_nor *nor)
}
/**
+ * spi_nor_use_parallel_locking() - Checks if RWW locking scheme shall be used
+ * @nor: pointer to 'struct spi_nor'.
+ *
+ * Return: true if parallel locking is enabled, false otherwise.
+ */
+static bool spi_nor_use_parallel_locking(struct spi_nor *nor)
+{
+ return nor->flags & SNOR_F_RWW;
+}
+
+/* Locking helpers for status read operations */
+static int spi_nor_rww_start_rdst(struct spi_nor *nor)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+ int ret = -EAGAIN;
+
+ mutex_lock(&nor->lock);
+
+ if (rww->ongoing_io || rww->ongoing_rd)
+ goto busy;
+
+ rww->ongoing_io = true;
+ rww->ongoing_rd = true;
+ ret = 0;
+
+busy:
+ mutex_unlock(&nor->lock);
+ return ret;
+}
+
+static void spi_nor_rww_end_rdst(struct spi_nor *nor)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+
+ mutex_lock(&nor->lock);
+
+ rww->ongoing_io = false;
+ rww->ongoing_rd = false;
+
+ mutex_unlock(&nor->lock);
+}
+
+static int spi_nor_lock_rdst(struct spi_nor *nor)
+{
+ if (spi_nor_use_parallel_locking(nor))
+ return spi_nor_rww_start_rdst(nor);
+
+ return 0;
+}
+
+static void spi_nor_unlock_rdst(struct spi_nor *nor)
+{
+ if (spi_nor_use_parallel_locking(nor)) {
+ spi_nor_rww_end_rdst(nor);
+ wake_up(&nor->rww.wait);
+ }
+}
+
+/**
* spi_nor_ready() - Query the flash to see if it is ready for new commands.
* @nor: pointer to 'struct spi_nor'.
*
@@ -596,11 +655,21 @@ int spi_nor_sr_ready(struct spi_nor *nor)
*/
static int spi_nor_ready(struct spi_nor *nor)
{
+ int ret;
+
+ ret = spi_nor_lock_rdst(nor);
+ if (ret)
+ return 0;
+
/* Flashes might override the standard routine. */
if (nor->params->ready)
- return nor->params->ready(nor);
+ ret = nor->params->ready(nor);
+ else
+ ret = spi_nor_sr_ready(nor);
- return spi_nor_sr_ready(nor);
+ spi_nor_unlock_rdst(nor);
+
+ return ret;
}
/**
@@ -1086,7 +1155,88 @@ static void spi_nor_unprep(struct spi_nor *nor)
nor->controller_ops->unprepare(nor);
}
+static void spi_nor_offset_to_banks(u64 bank_size, loff_t start, size_t len,
+ u8 *first, u8 *last)
+{
+ /* This is currently safe, the number of banks being very small */
+ *first = DIV_ROUND_DOWN_ULL(start, bank_size);
+ *last = DIV_ROUND_DOWN_ULL(start + len - 1, bank_size);
+}
+
/* Generic helpers for internal locking and serialization */
+static bool spi_nor_rww_start_io(struct spi_nor *nor)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+ bool start = false;
+
+ mutex_lock(&nor->lock);
+
+ if (rww->ongoing_io)
+ goto busy;
+
+ rww->ongoing_io = true;
+ start = true;
+
+busy:
+ mutex_unlock(&nor->lock);
+ return start;
+}
+
+static void spi_nor_rww_end_io(struct spi_nor *nor)
+{
+ mutex_lock(&nor->lock);
+ nor->rww.ongoing_io = false;
+ mutex_unlock(&nor->lock);
+}
+
+static int spi_nor_lock_device(struct spi_nor *nor)
+{
+ if (!spi_nor_use_parallel_locking(nor))
+ return 0;
+
+ return wait_event_killable(nor->rww.wait, spi_nor_rww_start_io(nor));
+}
+
+static void spi_nor_unlock_device(struct spi_nor *nor)
+{
+ if (spi_nor_use_parallel_locking(nor)) {
+ spi_nor_rww_end_io(nor);
+ wake_up(&nor->rww.wait);
+ }
+}
+
+/* Generic helpers for internal locking and serialization */
+static bool spi_nor_rww_start_exclusive(struct spi_nor *nor)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+ bool start = false;
+
+ mutex_lock(&nor->lock);
+
+ if (rww->ongoing_io || rww->ongoing_rd || rww->ongoing_pe)
+ goto busy;
+
+ rww->ongoing_io = true;
+ rww->ongoing_rd = true;
+ rww->ongoing_pe = true;
+ start = true;
+
+busy:
+ mutex_unlock(&nor->lock);
+ return start;
+}
+
+static void spi_nor_rww_end_exclusive(struct spi_nor *nor)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+
+ mutex_lock(&nor->lock);
+ rww->ongoing_io = false;
+ rww->ongoing_rd = false;
+ rww->ongoing_pe = false;
+ mutex_unlock(&nor->lock);
+}
+
int spi_nor_prep_and_lock(struct spi_nor *nor)
{
int ret;
@@ -1095,19 +1245,75 @@ int spi_nor_prep_and_lock(struct spi_nor *nor)
if (ret)
return ret;
- mutex_lock(&nor->lock);
+ if (!spi_nor_use_parallel_locking(nor))
+ mutex_lock(&nor->lock);
+ else
+ ret = wait_event_killable(nor->rww.wait,
+ spi_nor_rww_start_exclusive(nor));
- return 0;
+ return ret;
}
void spi_nor_unlock_and_unprep(struct spi_nor *nor)
{
- mutex_unlock(&nor->lock);
+ if (!spi_nor_use_parallel_locking(nor)) {
+ mutex_unlock(&nor->lock);
+ } else {
+ spi_nor_rww_end_exclusive(nor);
+ wake_up(&nor->rww.wait);
+ }
spi_nor_unprep(nor);
}
/* Internal locking helpers for program and erase operations */
+static bool spi_nor_rww_start_pe(struct spi_nor *nor, loff_t start, size_t len)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+ unsigned int used_banks = 0;
+ bool started = false;
+ u8 first, last;
+ int bank;
+
+ mutex_lock(&nor->lock);
+
+ if (rww->ongoing_io || rww->ongoing_rd || rww->ongoing_pe)
+ goto busy;
+
+ spi_nor_offset_to_banks(nor->params->bank_size, start, len, &first, &last);
+ for (bank = first; bank <= last; bank++) {
+ if (rww->used_banks & BIT(bank))
+ goto busy;
+
+ used_banks |= BIT(bank);
+ }
+
+ rww->used_banks |= used_banks;
+ rww->ongoing_pe = true;
+ started = true;
+
+busy:
+ mutex_unlock(&nor->lock);
+ return started;
+}
+
+static void spi_nor_rww_end_pe(struct spi_nor *nor, loff_t start, size_t len)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+ u8 first, last;
+ int bank;
+
+ mutex_lock(&nor->lock);
+
+ spi_nor_offset_to_banks(nor->params->bank_size, start, len, &first, &last);
+ for (bank = first; bank <= last; bank++)
+ rww->used_banks &= ~BIT(bank);
+
+ rww->ongoing_pe = false;
+
+ mutex_unlock(&nor->lock);
+}
+
static int spi_nor_prep_and_lock_pe(struct spi_nor *nor, loff_t start, size_t len)
{
int ret;
@@ -1116,19 +1322,77 @@ static int spi_nor_prep_and_lock_pe(struct spi_nor *nor, loff_t start, size_t le
if (ret)
return ret;
- mutex_lock(&nor->lock);
+ if (!spi_nor_use_parallel_locking(nor))
+ mutex_lock(&nor->lock);
+ else
+ ret = wait_event_killable(nor->rww.wait,
+ spi_nor_rww_start_pe(nor, start, len));
- return 0;
+ return ret;
}
static void spi_nor_unlock_and_unprep_pe(struct spi_nor *nor, loff_t start, size_t len)
{
- mutex_unlock(&nor->lock);
+ if (!spi_nor_use_parallel_locking(nor)) {
+ mutex_unlock(&nor->lock);
+ } else {
+ spi_nor_rww_end_pe(nor, start, len);
+ wake_up(&nor->rww.wait);
+ }
spi_nor_unprep(nor);
}
/* Internal locking helpers for read operations */
+static bool spi_nor_rww_start_rd(struct spi_nor *nor, loff_t start, size_t len)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+ unsigned int used_banks = 0;
+ bool started = false;
+ u8 first, last;
+ int bank;
+
+ mutex_lock(&nor->lock);
+
+ if (rww->ongoing_io || rww->ongoing_rd)
+ goto busy;
+
+ spi_nor_offset_to_banks(nor->params->bank_size, start, len, &first, &last);
+ for (bank = first; bank <= last; bank++) {
+ if (rww->used_banks & BIT(bank))
+ goto busy;
+
+ used_banks |= BIT(bank);
+ }
+
+ rww->used_banks |= used_banks;
+ rww->ongoing_io = true;
+ rww->ongoing_rd = true;
+ started = true;
+
+busy:
+ mutex_unlock(&nor->lock);
+ return started;
+}
+
+static void spi_nor_rww_end_rd(struct spi_nor *nor, loff_t start, size_t len)
+{
+ struct spi_nor_rww *rww = &nor->rww;
+ u8 first, last;
+ int bank;
+
+ mutex_lock(&nor->lock);
+
+ spi_nor_offset_to_banks(nor->params->bank_size, start, len, &first, &last);
+ for (bank = first; bank <= last; bank++)
+ nor->rww.used_banks &= ~BIT(bank);
+
+ rww->ongoing_io = false;
+ rww->ongoing_rd = false;
+
+ mutex_unlock(&nor->lock);
+}
+
static int spi_nor_prep_and_lock_rd(struct spi_nor *nor, loff_t start, size_t len)
{
int ret;
@@ -1137,14 +1401,23 @@ static int spi_nor_prep_and_lock_rd(struct spi_nor *nor, loff_t start, size_t le
if (ret)
return ret;
- mutex_lock(&nor->lock);
+ if (!spi_nor_use_parallel_locking(nor))
+ mutex_lock(&nor->lock);
+ else
+ ret = wait_event_killable(nor->rww.wait,
+ spi_nor_rww_start_rd(nor, start, len));
- return 0;
+ return ret;
}
static void spi_nor_unlock_and_unprep_rd(struct spi_nor *nor, loff_t start, size_t len)
{
- mutex_unlock(&nor->lock);
+ if (!spi_nor_use_parallel_locking(nor)) {
+ mutex_unlock(&nor->lock);
+ } else {
+ spi_nor_rww_end_rd(nor, start, len);
+ wake_up(&nor->rww.wait);
+ }
spi_nor_unprep(nor);
}
@@ -1453,11 +1726,18 @@ static int spi_nor_erase_multi_sectors(struct spi_nor *nor, u64 addr, u32 len)
dev_vdbg(nor->dev, "erase_cmd->size = 0x%08x, erase_cmd->opcode = 0x%02x, erase_cmd->count = %u\n",
cmd->size, cmd->opcode, cmd->count);
- ret = spi_nor_write_enable(nor);
+ ret = spi_nor_lock_device(nor);
if (ret)
goto destroy_erase_cmd_list;
+ ret = spi_nor_write_enable(nor);
+ if (ret) {
+ spi_nor_unlock_device(nor);
+ goto destroy_erase_cmd_list;
+ }
+
ret = spi_nor_erase_sector(nor, addr);
+ spi_nor_unlock_device(nor);
if (ret)
goto destroy_erase_cmd_list;
@@ -1510,11 +1790,18 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
unsigned long timeout;
- ret = spi_nor_write_enable(nor);
+ ret = spi_nor_lock_device(nor);
if (ret)
goto erase_err;
+ ret = spi_nor_write_enable(nor);
+ if (ret) {
+ spi_nor_unlock_device(nor);
+ goto erase_err;
+ }
+
ret = spi_nor_erase_chip(nor);
+ spi_nor_unlock_device(nor);
if (ret)
goto erase_err;
@@ -1539,11 +1826,18 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
/* "sector"-at-a-time erase */
} else if (spi_nor_has_uniform_erase(nor)) {
while (len) {
- ret = spi_nor_write_enable(nor);
+ ret = spi_nor_lock_device(nor);
if (ret)
goto erase_err;
+ ret = spi_nor_write_enable(nor);
+ if (ret) {
+ spi_nor_unlock_device(nor);
+ goto erase_err;
+ }
+
ret = spi_nor_erase_sector(nor, addr);
+ spi_nor_unlock_device(nor);
if (ret)
goto erase_err;
@@ -1836,11 +2130,18 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
addr = spi_nor_convert_addr(nor, addr);
- ret = spi_nor_write_enable(nor);
+ ret = spi_nor_lock_device(nor);
if (ret)
goto write_err;
+ ret = spi_nor_write_enable(nor);
+ if (ret) {
+ spi_nor_unlock_device(nor);
+ goto write_err;
+ }
+
ret = spi_nor_write_data(nor, addr, page_remain, buf + i);
+ spi_nor_unlock_device(nor);
if (ret < 0)
goto write_err;
written = ret;
@@ -2531,7 +2832,8 @@ static void spi_nor_init_flags(struct spi_nor *nor)
if (flags & NO_CHIP_ERASE)
nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
- if (flags & SPI_NOR_RWW)
+ if (flags & SPI_NOR_RWW && nor->info->n_banks > 1 &&
+ !nor->controller_ops)
nor->flags |= SNOR_F_RWW;
}
@@ -3128,6 +3430,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
if (ret)
return ret;
+ if (spi_nor_use_parallel_locking(nor))
+ init_waitqueue_head(&nor->rww.wait);
+
/*
* Configure the SPI memory:
* - select op codes for (Fast) Read, Page Program and Sector Erase.
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index a3f8cdca90c8..82547b4b3708 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -343,6 +343,12 @@ struct spi_nor_flash_parameter;
* struct spi_nor - Structure for defining the SPI NOR layer
* @mtd: an mtd_info structure
* @lock: the lock for the read/write/erase/lock/unlock operations
+ * @rww: Read-While-Write (RWW) sync lock
+ * @rww.wait: wait queue for the RWW sync
+ * @rww.ongoing_io: the bus is busy
+ * @rww.ongoing_rd: a read is ongoing on the chip
+ * @rww.ongoing_pe: a program/erase is ongoing on the chip
+ * @rww.used_banks: bitmap of the banks in use
* @dev: pointer to an SPI device or an SPI NOR controller device
* @spimem: pointer to the SPI memory device
* @bouncebuf: bounce buffer used when the buffer passed by the MTD
@@ -376,6 +382,13 @@ struct spi_nor_flash_parameter;
struct spi_nor {
struct mtd_info mtd;
struct mutex lock;
+ struct spi_nor_rww {
+ wait_queue_head_t wait;
+ bool ongoing_io;
+ bool ongoing_rd;
+ bool ongoing_pe;
+ unsigned int used_banks;
+ } rww;
struct device *dev;
struct spi_mem *spimem;
u8 *bouncebuf;
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