[PATCH 14/18] ioat3: interrupt descriptor support

Dan Williams
2009-09-04T06:46:14Z

The async_tx api uses the DMA_INTERRUPT operation type to terminate a
chain of issued operations with a callback routine.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dma/ioat/dma_v3.c | 39 ++++++++++++++++++++++++++++++++++++++-
1 files changed, 38 insertions(+), 1 deletions(-)

diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c
index bb57491..ff4afdc 100644
--- a/drivers/dma/ioat/dma_v3.c
+++ b/drivers/dma/ioat/dma_v3.c
@@ -120,7 +120,8 @@ static void ioat3_dma_unmap(struct ioat2_dma_chan *ioat,

switch (desc->hw->ctl_f.op) {
case IOAT_OP_COPY:
- ioat_dma_unmap(chan, flags, len, desc->hw);
+ if (!desc->hw->ctl_f.null) /* skip 'interrupt' ops */
+ ioat_dma_unmap(chan, flags, len, desc->hw);
break;
case IOAT_OP_FILL: {
struct ioat_fill_descriptor *hw = desc->fill;
@@ -804,6 +805,38 @@ ioat3_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src,
len, flags);
}

+static struct dma_async_tx_descriptor *
+ioat3_prep_interrupt_lock(struct dma_chan *c, unsigned long flags)
+{
+ struct ioat2_dma_chan *ioat = to_ioat2_chan(c);
+ struct ioat_ring_ent *desc;
+ struct ioat_dma_descriptor *hw;
+ u16 idx;
+
+ if (ioat2_alloc_and_lock(&idx, ioat, 1) == 0)
+ desc = ioat2_get_ring_ent(ioat, idx);
+ else
+ return NULL;
+
+ hw = desc->hw;
+ hw->ctl = 0;
+ hw->ctl_f.null = 1;
+ hw->ctl_f.int_en = 1;
+ hw->ctl_f.fence = !!(flags & DMA_PREP_FENCE);
+ hw->ctl_f.compl_write = 1;
+ hw->size = NULL_DESC_BUFFER_SIZE;
+ hw->src_addr = 0;
+ hw->dst_addr = 0;
+
+ desc->txd.flags = flags;
+ desc->len = 1;
+
+ dump_desc_dbg(ioat, desc);
+
+ /* we leave the channel locked to ensure in order submission */
+ return &desc->txd;
+}
+
static void __devinit ioat3_dma_test_callback(void *dma_async_param)
{
struct completion *cmp = dma_async_param;
@@ -1098,6 +1131,10 @@ int __devinit ioat3_dma_probe(struct ioatdma_device *device, int dca)
dma->device_alloc_chan_resources = ioat2_alloc_chan_resources;
dma->device_free_chan_resources = ioat2_free_chan_resources;
dma->device_is_tx_complete = ioat3_is_complete;
+
+ dma_cap_set(DMA_INTERRUPT, dma->cap_mask);
+ dma->device_prep_dma_interrupt = ioat3_prep_interrupt_lock;
+
cap = readl(device->reg_base + IOAT_DMA_CAP_OFFSET);
if (cap & IOAT_CAP_FILL_BLOCK) {
dma_cap_set(DMA_MEMSET, dma->cap_mask);