Merge tag 'spi-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "Quite a lot of cleanup and maintainence work going on this release in
  various drivers, and also a fix for a nasty locking issue in the core:

   - A fix for locking issues when external drivers explicitly locked
     the bus with spi_bus_lock() - we were using the same lock to both
     control access to the physical bus in multi-threaded I/O operations
     and exclude multiple callers.

     Confusion between these two caused us to have scenarios where we
     were dropping locks.  These are fixed by splitting into two
     separate locks like should have been done originally, making
     everything much clearer and correct.

   - Support for DMA in spi_flash_read().

   - Support for instantiating spidev on ACPI systems, including some
     test devices used in Windows validation.

   - Use of the core DMA mapping functionality in the McSPI driver.

   - Start of support for ThunderX SPI controllers, involving a very big
     set of changes to the Cavium driver.

   - Support for Braswell, Exynos 5433, Kaby Lake, Merrifield, RK3036,
     RK3228, RK3368 controllers"

* tag 'spi-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (64 commits)
  spi: Split bus and I/O locking
  spi: octeon: Split driver into Octeon specific and common parts
  spi: octeon: Move include file from arch/mips to drivers/spi
  spi: octeon: Put register offsets into a struct
  spi: octeon: Store system clock freqency in struct octeon_spi
  spi: octeon: Convert driver to use readq()/writeq() functions
  spi: pic32-sqi: fixup wait_for_completion_timeout return handling
  spi: pic32: fixup wait_for_completion_timeout return handling
  spi: rockchip: limit transfers to (64K - 1) bytes
  spi: xilinx: Return IRQ_NONE if no interrupts were detected
  spi: xilinx: Handle errors from platform_get_irq()
  spi: s3c64xx: restore removed comments
  spi: s3c64xx: add Exynos5433 compatible for ioclk handling
  spi: s3c64xx: use error code from clk_prepare_enable()
  spi: s3c64xx: rename goto labels to meaningful names
  spi: s3c64xx: document the clocks and the clock-name property
  spi: s3c64xx: add exynos5433 spi compatible
  spi: s3c64xx: fix reference leak to master in s3c64xx_spi_remove()
  spi: spi-sh: Remove deprecated create_singlethread_workqueue
  spi: spi-topcliff-pch: Remove deprecated create_singlethread_workqueue
  ...

1 files changed, 46 insertions, 20 deletions

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 7589c8af4368..51ad42fad567 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -851,6 +851,20 @@ static int __spi_unmap_msg(struct spi_master *master, struct spi_message *msg)
 	return 0;
 }
 #else /* !CONFIG_HAS_DMA */
+static inline int spi_map_buf(struct spi_master *master,
+			      struct device *dev, struct sg_table *sgt,
+			      void *buf, size_t len,
+			      enum dma_data_direction dir)
+{
+	return -EINVAL;
+}
+
+static inline void spi_unmap_buf(struct spi_master *master,
+				 struct device *dev, struct sg_table *sgt,
+				 enum dma_data_direction dir)
+{
+}
+
 static inline int __spi_map_msg(struct spi_master *master,
 				struct spi_message *msg)
 {
@@ -1057,7 +1071,6 @@ EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
  * __spi_pump_messages - function which processes spi message queue
  * @master: master to process queue for
  * @in_kthread: true if we are in the context of the message pump thread
- * @bus_locked: true if the bus mutex is held when calling this function
  *
  * This function checks if there is any spi message in the queue that
  * needs processing and if so call out to the driver to initialize hardware
@@ -1067,8 +1080,7 @@ EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
  * inside spi_sync(); the queue extraction handling at the top of the
  * function should deal with this safely.
  */
-static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
-				bool bus_locked)
+static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
 {
 	unsigned long flags;
 	bool was_busy = false;
@@ -1140,6 +1152,8 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
 		master->busy = true;
 	spin_unlock_irqrestore(&master->queue_lock, flags);
 
+	mutex_lock(&master->io_mutex);
+
 	if (!was_busy && master->auto_runtime_pm) {
 		ret = pm_runtime_get_sync(master->dev.parent);
 		if (ret < 0) {
@@ -1164,9 +1178,6 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
 		}
 	}
 
-	if (!bus_locked)
-		mutex_lock(&master->bus_lock_mutex);
-
 	trace_spi_message_start(master->cur_msg);
 
 	if (master->prepare_message) {
@@ -1196,8 +1207,7 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread,
 	}
 
 out:
-	if (!bus_locked)
-		mutex_unlock(&master->bus_lock_mutex);
+	mutex_unlock(&master->io_mutex);
 
 	/* Prod the scheduler in case transfer_one() was busy waiting */
 	if (!ret)
@@ -1213,7 +1223,7 @@ static void spi_pump_messages(struct kthread_work *work)
 	struct spi_master *master =
 		container_of(work, struct spi_master, pump_messages);
 
-	__spi_pump_messages(master, true, master->bus_lock_flag);
+	__spi_pump_messages(master, true);
 }
 
 static int spi_init_queue(struct spi_master *master)
@@ -1886,6 +1896,7 @@ int spi_register_master(struct spi_master *master)
 	spin_lock_init(&master->queue_lock);
 	spin_lock_init(&master->bus_lock_spinlock);
 	mutex_init(&master->bus_lock_mutex);
+	mutex_init(&master->io_mutex);
 	master->bus_lock_flag = 0;
 	init_completion(&master->xfer_completion);
 	if (!master->max_dma_len)
@@ -2738,6 +2749,7 @@ int spi_flash_read(struct spi_device *spi,
 
 {
 	struct spi_master *master = spi->master;
+	struct device *rx_dev = NULL;
 	int ret;
 
 	if ((msg->opcode_nbits == SPI_NBITS_DUAL ||
@@ -2763,9 +2775,24 @@ int spi_flash_read(struct spi_device *spi,
 			return ret;
 		}
 	}
+
 	mutex_lock(&master->bus_lock_mutex);
+	mutex_lock(&master->io_mutex);
+	if (master->dma_rx) {
+		rx_dev = master->dma_rx->device->dev;
+		ret = spi_map_buf(master, rx_dev, &msg->rx_sg,
+				  msg->buf, msg->len,
+				  DMA_FROM_DEVICE);
+		if (!ret)
+			msg->cur_msg_mapped = true;
+	}
 	ret = master->spi_flash_read(spi, msg);
+	if (msg->cur_msg_mapped)
+		spi_unmap_buf(master, rx_dev, &msg->rx_sg,
+			      DMA_FROM_DEVICE);
+	mutex_unlock(&master->io_mutex);
 	mutex_unlock(&master->bus_lock_mutex);
+
 	if (master->auto_runtime_pm)
 		pm_runtime_put(master->dev.parent);
 
@@ -2785,8 +2812,7 @@ static void spi_complete(void *arg)
 	complete(arg);
 }
 
-static int __spi_sync(struct spi_device *spi, struct spi_message *message,
-		      int bus_locked)
+static int __spi_sync(struct spi_device *spi, struct spi_message *message)
 {
 	DECLARE_COMPLETION_ONSTACK(done);
 	int status;
@@ -2804,9 +2830,6 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message,
 	SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, spi_sync);
 	SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
 
-	if (!bus_locked)
-		mutex_lock(&master->bus_lock_mutex);
-
 	/* If we're not using the legacy transfer method then we will
 	 * try to transfer in the calling context so special case.
 	 * This code would be less tricky if we could remove the
@@ -2824,9 +2847,6 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message,
 		status = spi_async_locked(spi, message);
 	}
 
-	if (!bus_locked)
-		mutex_unlock(&master->bus_lock_mutex);
-
 	if (status == 0) {
 		/* Push out the messages in the calling context if we
 		 * can.
@@ -2836,7 +2856,7 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message,
 						       spi_sync_immediate);
 			SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
 						       spi_sync_immediate);
-			__spi_pump_messages(master, false, bus_locked);
+			__spi_pump_messages(master, false);
 		}
 
 		wait_for_completion(&done);
@@ -2869,7 +2889,13 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message,
  */
 int spi_sync(struct spi_device *spi, struct spi_message *message)
 {
-	return __spi_sync(spi, message, spi->master->bus_lock_flag);
+	int ret;
+
+	mutex_lock(&spi->master->bus_lock_mutex);
+	ret = __spi_sync(spi, message);
+	mutex_unlock(&spi->master->bus_lock_mutex);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(spi_sync);
 
@@ -2891,7 +2917,7 @@ EXPORT_SYMBOL_GPL(spi_sync);
  */
 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
 {
-	return __spi_sync(spi, message, 1);
+	return __spi_sync(spi, message);
 }
 EXPORT_SYMBOL_GPL(spi_sync_locked);