Merge tag 'char-misc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver update for 4.4-rc1.  Lots of
  different driver and subsystem updates, hwtracing being the largest
  with the addition of some new platforms that are now supported.  Full
  details in the shortlog.

  All of these have been in linux-next for a long time with no reported
  issues"

* tag 'char-misc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (181 commits)
  fpga: socfpga: Fix check of return value of devm_request_irq
  lkdtm: fix ACCESS_USERSPACE test
  mcb: Destroy IDA on module unload
  mcb: Do not return zero on error path in mcb_pci_probe()
  mei: bus: set the device name before running fixup
  mei: bus: use correct lock ordering
  mei: Fix debugfs filename in error output
  char: ipmi: ipmi_ssif: Replace timeval with timespec64
  fpga: zynq-fpga: Fix issue with drvdata being overwritten.
  fpga manager: remove unnecessary null pointer checks
  fpga manager: ensure lifetime with of_fpga_mgr_get
  fpga: zynq-fpga: Change fw format to handle bin instead of bit.
  fpga: zynq-fpga: Fix unbalanced clock handling
  misc: sram: partition base address belongs to __iomem space
  coresight: etm3x: adding documentation for sysFS's cpu interface
  vme: 8-bit status/id takes 256 values, not 255
  fpga manager: Adding FPGA Manager support for Xilinx Zynq 7000
  ARM: zynq: dt: Updated devicetree for Zynq 7000 platform.
  ARM: dt: fpga: Added binding docs for Xilinx Zynq FPGA manager.
  ver_linux: proc/modules, limit text processing to 'sed'
  ...

1 files changed, 38 insertions, 1 deletions

diff --git a/drivers/dma/mic_x100_dma.c b/drivers/dma/mic_x100_dma.c
index 74d9db05a5ad..068e920ecb68 100644
--- a/drivers/dma/mic_x100_dma.c
+++ b/drivers/dma/mic_x100_dma.c
@@ -193,8 +193,16 @@ static void mic_dma_prog_intr(struct mic_dma_chan *ch)
 static int mic_dma_do_dma(struct mic_dma_chan *ch, int flags, dma_addr_t src,
 			  dma_addr_t dst, size_t len)
 {
-	if (-ENOMEM == mic_dma_prog_memcpy_desc(ch, src, dst, len))
+	if (len && -ENOMEM == mic_dma_prog_memcpy_desc(ch, src, dst, len)) {
 		return -ENOMEM;
+	} else {
+		/* 3 is the maximum number of status descriptors */
+		int ret = mic_dma_avail_desc_ring_space(ch, 3);
+
+		if (ret < 0)
+			return ret;
+	}
+
 	/* Above mic_dma_prog_memcpy_desc() makes sure we have enough space */
 	if (flags & DMA_PREP_FENCE) {
 		mic_dma_prep_status_desc(&ch->desc_ring[ch->head], 0,
@@ -270,6 +278,33 @@ allocate_tx(struct mic_dma_chan *ch)
 	return tx;
 }
 
+/* Program a status descriptor with dst as address and value to be written */
+static struct dma_async_tx_descriptor *
+mic_dma_prep_status_lock(struct dma_chan *ch, dma_addr_t dst, u64 src_val,
+			 unsigned long flags)
+{
+	struct mic_dma_chan *mic_ch = to_mic_dma_chan(ch);
+	int result;
+
+	spin_lock(&mic_ch->prep_lock);
+	result = mic_dma_avail_desc_ring_space(mic_ch, 4);
+	if (result < 0)
+		goto error;
+	mic_dma_prep_status_desc(&mic_ch->desc_ring[mic_ch->head], src_val, dst,
+				 false);
+	mic_dma_hw_ring_inc_head(mic_ch);
+	result = mic_dma_do_dma(mic_ch, flags, 0, 0, 0);
+	if (result < 0)
+		goto error;
+
+	return allocate_tx(mic_ch);
+error:
+	dev_err(mic_dma_ch_to_device(mic_ch),
+		"Error enqueueing dma status descriptor, error=%d\n", result);
+	spin_unlock(&mic_ch->prep_lock);
+	return NULL;
+}
+
 /*
  * Prepare a memcpy descriptor to be added to the ring.
  * Note that the temporary descriptor adds an extra overhead of copying the
@@ -587,6 +622,8 @@ static int mic_dma_register_dma_device(struct mic_dma_device *mic_dma_dev,
 		mic_dma_free_chan_resources;
 	mic_dma_dev->dma_dev.device_tx_status = mic_dma_tx_status;
 	mic_dma_dev->dma_dev.device_prep_dma_memcpy = mic_dma_prep_memcpy_lock;
+	mic_dma_dev->dma_dev.device_prep_dma_imm_data =
+		mic_dma_prep_status_lock;
 	mic_dma_dev->dma_dev.device_prep_dma_interrupt =
 		mic_dma_prep_interrupt_lock;
 	mic_dma_dev->dma_dev.device_issue_pending = mic_dma_issue_pending;