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path: root/kernel/drivers/dma/mic_x100_dma.c
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Diffstat (limited to 'kernel/drivers/dma/mic_x100_dma.c')
-rw-r--r--kernel/drivers/dma/mic_x100_dma.c40
1 files changed, 39 insertions, 1 deletions
diff --git a/kernel/drivers/dma/mic_x100_dma.c b/kernel/drivers/dma/mic_x100_dma.c
index 6de2e677b..068e920ec 100644
--- a/kernel/drivers/dma/mic_x100_dma.c
+++ b/kernel/drivers/dma/mic_x100_dma.c
@@ -22,6 +22,7 @@
#include <linux/module.h>
#include <linux/io.h>
#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
#include "mic_x100_dma.h"
@@ -192,8 +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,
@@ -269,6 +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
@@ -586,6 +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;