dmaengine: ioatdma: adding shutdown support

The ioatdma needs to be queisced and block all additional op submission
during reboots. When NET_DMA was used, this caused issue as ops were still
being sent to ioatdma during reboots even though PCI BME has been turned
off. Even though NET_DMA has been deprecated, we need to prevent similar
situations. The shutdown handler should address that.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ioat/dma.c

@@ -197,6 +197,7 @@ static void __ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
 void ioat_start_null_desc(struct ioatdma_chan *ioat_chan)
 {
 	spin_lock_bh(&ioat_chan->prep_lock);
+	if (!test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
 		__ioat_start_null_desc(ioat_chan);
 	spin_unlock_bh(&ioat_chan->prep_lock);
 }

drivers/dma/ioat/dma.h

@@ -82,8 +82,9 @@ struct ioatdma_device {
 	struct dma_pool *sed_hw_pool[MAX_SED_POOLS];
 	struct dma_device dma_dev;
 	u8 version;
-	struct msix_entry msix_entries[4];
+#define IOAT_MAX_CHANS 4
-	struct ioatdma_chan *idx[4];
+	struct msix_entry msix_entries[IOAT_MAX_CHANS];
+	struct ioatdma_chan *idx[IOAT_MAX_CHANS];
 	struct dca_provider *dca;
 	enum ioat_irq_mode irq_mode;
 	u32 cap;
@@ -95,6 +96,7 @@ struct ioatdma_chan {
 	dma_addr_t last_completion;
 	spinlock_t cleanup_lock;
 	unsigned long state;
+	#define IOAT_CHAN_DOWN 0
 	#define IOAT_COMPLETION_ACK 1
 	#define IOAT_RESET_PENDING 2
 	#define IOAT_KOBJ_INIT_FAIL 3

drivers/dma/ioat/init.c

@@ -1186,6 +1186,31 @@ static int ioat3_dma_probe(struct ioatdma_device *ioat_dma, int dca)
 	return 0;
 }
 
+static void ioat_shutdown(struct pci_dev *pdev)
+{
+	struct ioatdma_device *ioat_dma = pci_get_drvdata(pdev);
+	struct ioatdma_chan *ioat_chan;
+	int i;
+
+	if (!ioat_dma)
+		return;
+
+	for (i = 0; i < IOAT_MAX_CHANS; i++) {
+		ioat_chan = ioat_dma->idx[i];
+		if (!ioat_chan)
+			continue;
+
+		spin_lock_bh(&ioat_chan->prep_lock);
+		set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
+		del_timer_sync(&ioat_chan->timer);
+		spin_unlock_bh(&ioat_chan->prep_lock);
+		/* this should quiesce then reset */
+		ioat_reset_hw(ioat_chan);
+	}
+
+	ioat_disable_interrupts(ioat_dma);
+}
+
 #define DRV_NAME "ioatdma"
 
 static struct pci_driver ioat_pci_driver = {
@@ -1193,6 +1218,7 @@ static struct pci_driver ioat_pci_driver = {
 	.id_table	= ioat_pci_tbl,
 	.probe		= ioat_pci_probe,
 	.remove		= ioat_remove,
+	.shutdown	= ioat_shutdown,
 };
 
 static struct ioatdma_device *

drivers/dma/ioat/prep.c

@@ -121,6 +121,9 @@ ioat_dma_prep_memcpy_lock(struct dma_chan *c, dma_addr_t dma_dest,
 	size_t total_len = len;
 	int num_descs, idx, i;
 
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
+
 	num_descs = ioat_xferlen_to_descs(ioat_chan, len);
 	if (likely(num_descs) &&
 	    ioat_check_space_lock(ioat_chan, num_descs) == 0)
@@ -254,6 +257,11 @@ struct dma_async_tx_descriptor *
 ioat_prep_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 	       unsigned int src_cnt, size_t len, unsigned long flags)
 {
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
+
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
+
 	return __ioat_prep_xor_lock(chan, NULL, dest, src, src_cnt, len, flags);
 }
 
@@ -262,6 +270,11 @@ ioat_prep_xor_val(struct dma_chan *chan, dma_addr_t *src,
 		    unsigned int src_cnt, size_t len,
 		    enum sum_check_flags *result, unsigned long flags)
 {
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
+
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
+
 	/* the cleanup routine only sets bits on validate failure, it
 	 * does not clear bits on validate success... so clear it here
 	 */
@@ -574,6 +587,11 @@ ioat_prep_pq(struct dma_chan *chan, dma_addr_t *dst, dma_addr_t *src,
 	      unsigned int src_cnt, const unsigned char *scf, size_t len,
 	      unsigned long flags)
 {
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
+
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
+
 	/* specify valid address for disabled result */
 	if (flags & DMA_PREP_PQ_DISABLE_P)
 		dst[0] = dst[1];
@@ -614,6 +632,11 @@ ioat_prep_pq_val(struct dma_chan *chan, dma_addr_t *pq, dma_addr_t *src,
 		  unsigned int src_cnt, const unsigned char *scf, size_t len,
 		  enum sum_check_flags *pqres, unsigned long flags)
 {
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
+
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
+
 	/* specify valid address for disabled result */
 	if (flags & DMA_PREP_PQ_DISABLE_P)
 		pq[0] = pq[1];
@@ -638,6 +661,10 @@ ioat_prep_pqxor(struct dma_chan *chan, dma_addr_t dst, dma_addr_t *src,
 {
 	unsigned char scf[MAX_SCF];
 	dma_addr_t pq[2];
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
+
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
 
 	if (src_cnt > MAX_SCF)
 		return NULL;
@@ -661,6 +688,10 @@ ioat_prep_pqxor_val(struct dma_chan *chan, dma_addr_t *src,
 {
 	unsigned char scf[MAX_SCF];
 	dma_addr_t pq[2];
+	struct ioatdma_chan *ioat_chan = to_ioat_chan(chan);
+
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
 
 	if (src_cnt > MAX_SCF)
 		return NULL;
@@ -689,6 +720,9 @@ ioat_prep_interrupt_lock(struct dma_chan *c, unsigned long flags)
 	struct ioat_ring_ent *desc;
 	struct ioat_dma_descriptor *hw;
 
+	if (test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+		return NULL;
+
 	if (ioat_check_space_lock(ioat_chan, 1) == 0)
 		desc = ioat_get_ring_ent(ioat_chan, ioat_chan->head);
 	else