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>

4 files changed, 66 insertions, 3 deletions

diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index f66b7e640610..1d5df2ef148b 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -197,7 +197,8 @@ 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);
-        __ioat_start_null_desc(ioat_chan);
+        if (!test_bit(IOAT_CHAN_DOWN, &ioat_chan->state))
+                __ioat_start_null_desc(ioat_chan);
         spin_unlock_bh(&ioat_chan->prep_lock);
 }
 
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index 1bc084986646..8f4e607d5817 100644
--- a/drivers/dma/ioat/dma.h
+++ b/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];
-        struct ioatdma_chan *idx[4];
+#define IOAT_MAX_CHANS 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
diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c
index 1c3c9b0abf4e..793c5dd6a0e7 100644
--- a/drivers/dma/ioat/init.c
+++ b/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 *
diff --git a/drivers/dma/ioat/prep.c b/drivers/dma/ioat/prep.c
index ad4fb41cd23b..6bb4a13a8fbd 100644
--- a/drivers/dma/ioat/prep.c
+++ b/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