ioatdma: Adding write back descriptor error status support for ioatdma 3.3

v3.3 provides support for write back descriptor error status. This allows
reporting of errors in a descriptor field. In supporting this, certain
errors such as P/Q validation errors no longer halts the channel. The DMA
engine can continue to execute until the end of the chain and allow software
to report the "errors" up the stack. We are also going to mask those error
interrupts and handle them when the "chain" has completed at the end.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <djbw@fb.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 88 insertions, 23 deletions

diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c
index b00b000f238..28f8957bafe 100644
--- a/drivers/dma/ioat/dma_v3.c
+++ b/drivers/dma/ioat/dma_v3.c
@@ -510,6 +510,36 @@ static bool ioat3_cleanup_preamble(struct ioat_chan_common *chan,
 	return true;
 }
 
+static void
+desc_get_errstat(struct ioat2_dma_chan *ioat, struct ioat_ring_ent *desc)
+{
+	struct ioat_dma_descriptor *hw = desc->hw;
+
+	switch (hw->ctl_f.op) {
+	case IOAT_OP_PQ_VAL:
+	case IOAT_OP_PQ_VAL_16S:
+	{
+		struct ioat_pq_descriptor *pq = desc->pq;
+
+		/* check if there's error written */
+		if (!pq->dwbes_f.wbes)
+			return;
+
+		/* need to set a chanerr var for checking to clear later */
+
+		if (pq->dwbes_f.p_val_err)
+			*desc->result |= SUM_CHECK_P_RESULT;
+
+		if (pq->dwbes_f.q_val_err)
+			*desc->result |= SUM_CHECK_Q_RESULT;
+
+		return;
+	}
+	default:
+		return;
+	}
+}
+
 /**
  * __cleanup - reclaim used descriptors
  * @ioat: channel (ring) to clean
@@ -547,6 +577,11 @@ static void __cleanup(struct ioat2_dma_chan *ioat, dma_addr_t phys_complete)
 		prefetch(ioat2_get_ring_ent(ioat, idx + i + 1));
 		desc = ioat2_get_ring_ent(ioat, idx + i);
 		dump_desc_dbg(ioat, desc);
+
+		/* set err stat if we are using dwbes */
+		if (device->cap & IOAT_CAP_DWBES)
+			desc_get_errstat(ioat, desc);
+
 		tx = &desc->txd;
 		if (tx->cookie) {
 			dma_cookie_complete(tx);
@@ -1090,6 +1125,9 @@ __ioat3_prep_pq_lock(struct dma_chan *c, enum sum_check_flags *result,
 		pq->q_addr = dst[1] + offset;
 		pq->ctl = 0;
 		pq->ctl_f.op = op;
+		/* we turn on descriptor write back error status */
+		if (device->cap & IOAT_CAP_DWBES)
+			pq->ctl_f.wb_en = result ? 1 : 0;
 		pq->ctl_f.src_cnt = src_cnt_to_hw(s);
 		pq->ctl_f.p_disable = !!(flags & DMA_PREP_PQ_DISABLE_P);
 		pq->ctl_f.q_disable = !!(flags & DMA_PREP_PQ_DISABLE_Q);
@@ -1206,6 +1244,9 @@ __ioat3_prep_pq16_lock(struct dma_chan *c, enum sum_check_flags *result,
 		pq->ctl = 0;
 		pq->ctl_f.op = op;
 		pq->ctl_f.src_cnt = src16_cnt_to_hw(s);
+		/* we turn on descriptor write back error status */
+		if (device->cap & IOAT_CAP_DWBES)
+			pq->ctl_f.wb_en = result ? 1 : 0;
 		pq->ctl_f.p_disable = !!(flags & DMA_PREP_PQ_DISABLE_P);
 		pq->ctl_f.q_disable = !!(flags & DMA_PREP_PQ_DISABLE_Q);
 
@@ -1792,6 +1833,32 @@ static int ioat3_reset_hw(struct ioat_chan_common *chan)
 	return err;
 }
 
+static void ioat3_intr_quirk(struct ioatdma_device *device)
+{
+	struct dma_device *dma;
+	struct dma_chan *c;
+	struct ioat_chan_common *chan;
+	u32 errmask;
+
+	dma = &device->common;
+
+	/*
+	 * if we have descriptor write back error status, we mask the
+	 * error interrupts
+	 */
+	if (device->cap & IOAT_CAP_DWBES) {
+		list_for_each_entry(c, &dma->channels, device_node) {
+			chan = to_chan_common(c);
+			errmask = readl(chan->reg_base +
+					IOAT_CHANERR_MASK_OFFSET);
+			errmask |= IOAT_CHANERR_XOR_P_OR_CRC_ERR |
+				   IOAT_CHANERR_XOR_Q_ERR;
+			writel(errmask, chan->reg_base +
+					IOAT_CHANERR_MASK_OFFSET);
+		}
+	}
+}
+
 int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 {
 	struct pci_dev *pdev = device->pdev;
@@ -1801,11 +1868,11 @@ int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 	struct ioat_chan_common *chan;
 	bool is_raid_device = false;
 	int err;
-	u32 cap;
 
 	device->enumerate_channels = ioat2_enumerate_channels;
 	device->reset_hw = ioat3_reset_hw;
 	device->self_test = ioat3_dma_self_test;
+	device->intr_quirk = ioat3_intr_quirk;
 	dma = &device->common;
 	dma->device_prep_dma_memcpy = ioat2_dma_prep_memcpy_lock;
 	dma->device_issue_pending = ioat2_issue_pending;
@@ -1818,16 +1885,16 @@ int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 	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);
+	device->cap = readl(device->reg_base + IOAT_DMA_CAP_OFFSET);
 
 	if (is_bwd_noraid(pdev))
-		cap &= ~(IOAT_CAP_XOR | IOAT_CAP_PQ | IOAT_CAP_RAID16SS);
+		device->cap &= ~(IOAT_CAP_XOR | IOAT_CAP_PQ | IOAT_CAP_RAID16SS);
 
 	/* dca is incompatible with raid operations */
-	if (dca_en && (cap & (IOAT_CAP_XOR|IOAT_CAP_PQ)))
-		cap &= ~(IOAT_CAP_XOR|IOAT_CAP_PQ);
+	if (dca_en && (device->cap & (IOAT_CAP_XOR|IOAT_CAP_PQ)))
+		device->cap &= ~(IOAT_CAP_XOR|IOAT_CAP_PQ);
 
-	if (cap & IOAT_CAP_XOR) {
+	if (device->cap & IOAT_CAP_XOR) {
 		is_raid_device = true;
 		dma->max_xor = 8;
 		dma->xor_align = 6;
@@ -1839,10 +1906,15 @@ int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 		dma->device_prep_dma_xor_val = ioat3_prep_xor_val;
 	}
 
-	if (cap & IOAT_CAP_PQ) {
+	if (device->cap & IOAT_CAP_PQ) {
 		is_raid_device = true;
 
-		if (cap & IOAT_CAP_RAID16SS) {
+		dma->device_prep_dma_pq = ioat3_prep_pq;
+		dma->device_prep_dma_pq_val = ioat3_prep_pq_val;
+		dma_cap_set(DMA_PQ, dma->cap_mask);
+		dma_cap_set(DMA_PQ_VAL, dma->cap_mask);
+
+		if (device->cap & IOAT_CAP_RAID16SS) {
 			dma_set_maxpq(dma, 16, 0);
 			dma->pq_align = 0;
 		} else {
@@ -1853,14 +1925,13 @@ int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 				dma->pq_align = 0;
 		}
 
-		dma_cap_set(DMA_PQ, dma->cap_mask);
-		dma->device_prep_dma_pq = ioat3_prep_pq;
-
-		dma_cap_set(DMA_PQ_VAL, dma->cap_mask);
-		dma->device_prep_dma_pq_val = ioat3_prep_pq_val;
+		if (!(device->cap & IOAT_CAP_XOR)) {
+			dma->device_prep_dma_xor = ioat3_prep_pqxor;
+			dma->device_prep_dma_xor_val = ioat3_prep_pqxor_val;
+			dma_cap_set(DMA_XOR, dma->cap_mask);
+			dma_cap_set(DMA_XOR_VAL, dma->cap_mask);
 
-		if (!(cap & IOAT_CAP_XOR)) {
-			if (cap & IOAT_CAP_RAID16SS) {
+			if (device->cap & IOAT_CAP_RAID16SS) {
 				dma->max_xor = 16;
 				dma->xor_align = 0;
 			} else {
@@ -1870,16 +1941,10 @@ int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 				else
 					dma->xor_align = 0;
 			}
-
-			dma_cap_set(DMA_XOR, dma->cap_mask);
-			dma->device_prep_dma_xor = ioat3_prep_pqxor;
-
-			dma_cap_set(DMA_XOR_VAL, dma->cap_mask);
-			dma->device_prep_dma_xor_val = ioat3_prep_pqxor_val;
 		}
 	}
 
-	if (is_raid_device && (cap & IOAT_CAP_FILL_BLOCK)) {
+	if (is_raid_device && (device->cap & IOAT_CAP_FILL_BLOCK)) {
 		dma_cap_set(DMA_MEMSET, dma->cap_mask);
 		dma->device_prep_dma_memset = ioat3_prep_memset_lock;
 	}
@@ -1898,7 +1963,7 @@ int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 	}
 
 	/* starting with CB3.3 super extended descriptors are supported */
-	if (cap & IOAT_CAP_RAID16SS) {
+	if (device->cap & IOAT_CAP_RAID16SS) {
 		char pool_name[14];
 		int i;