Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma
[cascardo/linux.git] / drivers / dma / mv_xor.c
index 7938272..a63837c 100644 (file)
@@ -45,19 +45,18 @@ static void mv_xor_issue_pending(struct dma_chan *chan);
 #define mv_chan_to_devp(chan)           \
        ((chan)->dmadev.dev)
 
-static void mv_desc_init(struct mv_xor_desc_slot *desc, unsigned long flags)
+static void mv_desc_init(struct mv_xor_desc_slot *desc,
+                        dma_addr_t addr, u32 byte_count,
+                        enum dma_ctrl_flags flags)
 {
        struct mv_xor_desc *hw_desc = desc->hw_desc;
 
-       hw_desc->status = (1 << 31);
+       hw_desc->status = XOR_DESC_DMA_OWNED;
        hw_desc->phy_next_desc = 0;
-       hw_desc->desc_command = (1 << 31);
-}
-
-static void mv_desc_set_byte_count(struct mv_xor_desc_slot *desc,
-                                  u32 byte_count)
-{
-       struct mv_xor_desc *hw_desc = desc->hw_desc;
+       /* Enable end-of-descriptor interrupts only for DMA_PREP_INTERRUPT */
+       hw_desc->desc_command = (flags & DMA_PREP_INTERRUPT) ?
+                               XOR_DESC_EOD_INT_EN : 0;
+       hw_desc->phy_dest_addr = addr;
        hw_desc->byte_count = byte_count;
 }
 
@@ -75,20 +74,6 @@ static void mv_desc_clear_next_desc(struct mv_xor_desc_slot *desc)
        hw_desc->phy_next_desc = 0;
 }
 
-static void mv_desc_set_dest_addr(struct mv_xor_desc_slot *desc,
-                                 dma_addr_t addr)
-{
-       struct mv_xor_desc *hw_desc = desc->hw_desc;
-       hw_desc->phy_dest_addr = addr;
-}
-
-static int mv_chan_memset_slot_count(size_t len)
-{
-       return 1;
-}
-
-#define mv_chan_memcpy_slot_count(c) mv_chan_memset_slot_count(c)
-
 static void mv_desc_set_src_addr(struct mv_xor_desc_slot *desc,
                                 int index, dma_addr_t addr)
 {
@@ -123,17 +108,12 @@ static u32 mv_chan_get_intr_cause(struct mv_xor_chan *chan)
        return intr_cause;
 }
 
-static int mv_is_err_intr(u32 intr_cause)
-{
-       if (intr_cause & ((1<<4)|(1<<5)|(1<<6)|(1<<7)|(1<<8)|(1<<9)))
-               return 1;
-
-       return 0;
-}
-
 static void mv_xor_device_clear_eoc_cause(struct mv_xor_chan *chan)
 {
-       u32 val = ~(1 << (chan->idx * 16));
+       u32 val;
+
+       val = XOR_INT_END_OF_DESC | XOR_INT_END_OF_CHAIN | XOR_INT_STOPPED;
+       val = ~(val << (chan->idx * 16));
        dev_dbg(mv_chan_to_devp(chan), "%s, val 0x%08x\n", __func__, val);
        writel_relaxed(val, XOR_INTR_CAUSE(chan));
 }
@@ -144,17 +124,6 @@ static void mv_xor_device_clear_err_status(struct mv_xor_chan *chan)
        writel_relaxed(val, XOR_INTR_CAUSE(chan));
 }
 
-static int mv_can_chain(struct mv_xor_desc_slot *desc)
-{
-       struct mv_xor_desc_slot *chain_old_tail = list_entry(
-               desc->chain_node.prev, struct mv_xor_desc_slot, chain_node);
-
-       if (chain_old_tail->type != desc->type)
-               return 0;
-
-       return 1;
-}
-
 static void mv_set_mode(struct mv_xor_chan *chan,
                               enum dma_transaction_type type)
 {
@@ -206,11 +175,6 @@ static char mv_chan_is_busy(struct mv_xor_chan *chan)
        return (state == 1) ? 1 : 0;
 }
 
-static int mv_chan_xor_slot_count(size_t len, int src_cnt)
-{
-       return 1;
-}
-
 /**
  * mv_xor_free_slots - flags descriptor slots for reuse
  * @slot: Slot to free
@@ -222,7 +186,7 @@ static void mv_xor_free_slots(struct mv_xor_chan *mv_chan,
        dev_dbg(mv_chan_to_devp(mv_chan), "%s %d slot %p\n",
                __func__, __LINE__, slot);
 
-       slot->slots_per_op = 0;
+       slot->slot_used = 0;
 
 }
 
@@ -236,13 +200,11 @@ static void mv_xor_start_new_chain(struct mv_xor_chan *mv_chan,
 {
        dev_dbg(mv_chan_to_devp(mv_chan), "%s %d: sw_desc %p\n",
                __func__, __LINE__, sw_desc);
-       if (sw_desc->type != mv_chan->current_type)
-               mv_set_mode(mv_chan, sw_desc->type);
 
        /* set the hardware chain */
        mv_chan_set_next_descriptor(mv_chan, sw_desc->async_tx.phys);
 
-       mv_chan->pending += sw_desc->slot_cnt;
+       mv_chan->pending++;
        mv_xor_issue_pending(&mv_chan->dmachan);
 }
 
@@ -263,8 +225,6 @@ mv_xor_run_tx_complete_actions(struct mv_xor_desc_slot *desc,
                                desc->async_tx.callback_param);
 
                dma_descriptor_unmap(&desc->async_tx);
-               if (desc->group_head)
-                       desc->group_head = NULL;
        }
 
        /* run dependent operations */
@@ -377,19 +337,16 @@ static void mv_xor_tasklet(unsigned long data)
 }
 
 static struct mv_xor_desc_slot *
-mv_xor_alloc_slots(struct mv_xor_chan *mv_chan, int num_slots,
-                   int slots_per_op)
+mv_xor_alloc_slot(struct mv_xor_chan *mv_chan)
 {
-       struct mv_xor_desc_slot *iter, *_iter, *alloc_start = NULL;
-       LIST_HEAD(chain);
-       int slots_found, retry = 0;
+       struct mv_xor_desc_slot *iter, *_iter;
+       int retry = 0;
 
        /* start search from the last allocated descrtiptor
         * if a contiguous allocation can not be found start searching
         * from the beginning of the list
         */
 retry:
-       slots_found = 0;
        if (retry == 0)
                iter = mv_chan->last_used;
        else
@@ -399,55 +356,29 @@ retry:
 
        list_for_each_entry_safe_continue(
                iter, _iter, &mv_chan->all_slots, slot_node) {
+
                prefetch(_iter);
                prefetch(&_iter->async_tx);
-               if (iter->slots_per_op) {
+               if (iter->slot_used) {
                        /* give up after finding the first busy slot
                         * on the second pass through the list
                         */
                        if (retry)
                                break;
-
-                       slots_found = 0;
                        continue;
                }
 
-               /* start the allocation if the slot is correctly aligned */
-               if (!slots_found++)
-                       alloc_start = iter;
-
-               if (slots_found == num_slots) {
-                       struct mv_xor_desc_slot *alloc_tail = NULL;
-                       struct mv_xor_desc_slot *last_used = NULL;
-                       iter = alloc_start;
-                       while (num_slots) {
-                               int i;
-
-                               /* pre-ack all but the last descriptor */
-                               async_tx_ack(&iter->async_tx);
-
-                               list_add_tail(&iter->chain_node, &chain);
-                               alloc_tail = iter;
-                               iter->async_tx.cookie = 0;
-                               iter->slot_cnt = num_slots;
-                               iter->xor_check_result = NULL;
-                               for (i = 0; i < slots_per_op; i++) {
-                                       iter->slots_per_op = slots_per_op - i;
-                                       last_used = iter;
-                                       iter = list_entry(iter->slot_node.next,
-                                               struct mv_xor_desc_slot,
-                                               slot_node);
-                               }
-                               num_slots -= slots_per_op;
-                       }
-                       alloc_tail->group_head = alloc_start;
-                       alloc_tail->async_tx.cookie = -EBUSY;
-                       list_splice(&chain, &alloc_tail->tx_list);
-                       mv_chan->last_used = last_used;
-                       mv_desc_clear_next_desc(alloc_start);
-                       mv_desc_clear_next_desc(alloc_tail);
-                       return alloc_tail;
-               }
+               /* pre-ack descriptor */
+               async_tx_ack(&iter->async_tx);
+
+               iter->slot_used = 1;
+               INIT_LIST_HEAD(&iter->chain_node);
+               iter->async_tx.cookie = -EBUSY;
+               mv_chan->last_used = iter;
+               mv_desc_clear_next_desc(iter);
+
+               return iter;
+
        }
        if (!retry++)
                goto retry;
@@ -464,7 +395,7 @@ mv_xor_tx_submit(struct dma_async_tx_descriptor *tx)
 {
        struct mv_xor_desc_slot *sw_desc = to_mv_xor_slot(tx);
        struct mv_xor_chan *mv_chan = to_mv_xor_chan(tx->chan);
-       struct mv_xor_desc_slot *grp_start, *old_chain_tail;
+       struct mv_xor_desc_slot *old_chain_tail;
        dma_cookie_t cookie;
        int new_hw_chain = 1;
 
@@ -472,30 +403,24 @@ mv_xor_tx_submit(struct dma_async_tx_descriptor *tx)
                "%s sw_desc %p: async_tx %p\n",
                __func__, sw_desc, &sw_desc->async_tx);
 
-       grp_start = sw_desc->group_head;
-
        spin_lock_bh(&mv_chan->lock);
        cookie = dma_cookie_assign(tx);
 
        if (list_empty(&mv_chan->chain))
-               list_splice_init(&sw_desc->tx_list, &mv_chan->chain);
+               list_add_tail(&sw_desc->chain_node, &mv_chan->chain);
        else {
                new_hw_chain = 0;
 
                old_chain_tail = list_entry(mv_chan->chain.prev,
                                            struct mv_xor_desc_slot,
                                            chain_node);
-               list_splice_init(&grp_start->tx_list,
-                                &old_chain_tail->chain_node);
-
-               if (!mv_can_chain(grp_start))
-                       goto submit_done;
+               list_add_tail(&sw_desc->chain_node, &mv_chan->chain);
 
                dev_dbg(mv_chan_to_devp(mv_chan), "Append to last desc %pa\n",
                        &old_chain_tail->async_tx.phys);
 
                /* fix up the hardware chain */
-               mv_desc_set_next_desc(old_chain_tail, grp_start->async_tx.phys);
+               mv_desc_set_next_desc(old_chain_tail, sw_desc->async_tx.phys);
 
                /* if the channel is not busy */
                if (!mv_chan_is_busy(mv_chan)) {
@@ -510,9 +435,8 @@ mv_xor_tx_submit(struct dma_async_tx_descriptor *tx)
        }
 
        if (new_hw_chain)
-               mv_xor_start_new_chain(mv_chan, grp_start);
+               mv_xor_start_new_chain(mv_chan, sw_desc);
 
-submit_done:
        spin_unlock_bh(&mv_chan->lock);
 
        return cookie;
@@ -533,8 +457,9 @@ static int mv_xor_alloc_chan_resources(struct dma_chan *chan)
        while (idx < num_descs_in_pool) {
                slot = kzalloc(sizeof(*slot), GFP_KERNEL);
                if (!slot) {
-                       printk(KERN_INFO "MV XOR Channel only initialized"
-                               " %d descriptor slots", idx);
+                       dev_info(mv_chan_to_devp(mv_chan),
+                                "channel only initialized %d descriptor slots",
+                                idx);
                        break;
                }
                virt_desc = mv_chan->dma_desc_pool_virt;
@@ -544,7 +469,6 @@ static int mv_xor_alloc_chan_resources(struct dma_chan *chan)
                slot->async_tx.tx_submit = mv_xor_tx_submit;
                INIT_LIST_HEAD(&slot->chain_node);
                INIT_LIST_HEAD(&slot->slot_node);
-               INIT_LIST_HEAD(&slot->tx_list);
                dma_desc = mv_chan->dma_desc_pool;
                slot->async_tx.phys = dma_desc + idx * MV_XOR_SLOT_SIZE;
                slot->idx = idx++;
@@ -567,52 +491,12 @@ static int mv_xor_alloc_chan_resources(struct dma_chan *chan)
        return mv_chan->slots_allocated ? : -ENOMEM;
 }
 
-static struct dma_async_tx_descriptor *
-mv_xor_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
-               size_t len, unsigned long flags)
-{
-       struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
-       struct mv_xor_desc_slot *sw_desc, *grp_start;
-       int slot_cnt;
-
-       dev_dbg(mv_chan_to_devp(mv_chan),
-               "%s dest: %pad src %pad len: %u flags: %ld\n",
-               __func__, &dest, &src, len, flags);
-       if (unlikely(len < MV_XOR_MIN_BYTE_COUNT))
-               return NULL;
-
-       BUG_ON(len > MV_XOR_MAX_BYTE_COUNT);
-
-       spin_lock_bh(&mv_chan->lock);
-       slot_cnt = mv_chan_memcpy_slot_count(len);
-       sw_desc = mv_xor_alloc_slots(mv_chan, slot_cnt, 1);
-       if (sw_desc) {
-               sw_desc->type = DMA_MEMCPY;
-               sw_desc->async_tx.flags = flags;
-               grp_start = sw_desc->group_head;
-               mv_desc_init(grp_start, flags);
-               mv_desc_set_byte_count(grp_start, len);
-               mv_desc_set_dest_addr(sw_desc->group_head, dest);
-               mv_desc_set_src_addr(grp_start, 0, src);
-               sw_desc->unmap_src_cnt = 1;
-               sw_desc->unmap_len = len;
-       }
-       spin_unlock_bh(&mv_chan->lock);
-
-       dev_dbg(mv_chan_to_devp(mv_chan),
-               "%s sw_desc %p async_tx %p\n",
-               __func__, sw_desc, sw_desc ? &sw_desc->async_tx : NULL);
-
-       return sw_desc ? &sw_desc->async_tx : NULL;
-}
-
 static struct dma_async_tx_descriptor *
 mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
                    unsigned int src_cnt, size_t len, unsigned long flags)
 {
        struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
-       struct mv_xor_desc_slot *sw_desc, *grp_start;
-       int slot_cnt;
+       struct mv_xor_desc_slot *sw_desc;
 
        if (unlikely(len < MV_XOR_MIN_BYTE_COUNT))
                return NULL;
@@ -624,20 +508,13 @@ mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
                __func__, src_cnt, len, &dest, flags);
 
        spin_lock_bh(&mv_chan->lock);
-       slot_cnt = mv_chan_xor_slot_count(len, src_cnt);
-       sw_desc = mv_xor_alloc_slots(mv_chan, slot_cnt, 1);
+       sw_desc = mv_xor_alloc_slot(mv_chan);
        if (sw_desc) {
                sw_desc->type = DMA_XOR;
                sw_desc->async_tx.flags = flags;
-               grp_start = sw_desc->group_head;
-               mv_desc_init(grp_start, flags);
-               /* the byte count field is the same as in memcpy desc*/
-               mv_desc_set_byte_count(grp_start, len);
-               mv_desc_set_dest_addr(sw_desc->group_head, dest);
-               sw_desc->unmap_src_cnt = src_cnt;
-               sw_desc->unmap_len = len;
+               mv_desc_init(sw_desc, dest, len, flags);
                while (src_cnt--)
-                       mv_desc_set_src_addr(grp_start, src_cnt, src[src_cnt]);
+                       mv_desc_set_src_addr(sw_desc, src_cnt, src[src_cnt]);
        }
        spin_unlock_bh(&mv_chan->lock);
        dev_dbg(mv_chan_to_devp(mv_chan),
@@ -646,6 +523,35 @@ mv_xor_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
        return sw_desc ? &sw_desc->async_tx : NULL;
 }
 
+static struct dma_async_tx_descriptor *
+mv_xor_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+               size_t len, unsigned long flags)
+{
+       /*
+        * A MEMCPY operation is identical to an XOR operation with only
+        * a single source address.
+        */
+       return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);
+}
+
+static struct dma_async_tx_descriptor *
+mv_xor_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
+{
+       struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
+       dma_addr_t src, dest;
+       size_t len;
+
+       src = mv_chan->dummy_src_addr;
+       dest = mv_chan->dummy_dst_addr;
+       len = MV_XOR_MIN_BYTE_COUNT;
+
+       /*
+        * We implement the DMA_INTERRUPT operation as a minimum sized
+        * XOR operation with a single dummy source address.
+        */
+       return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);
+}
+
 static void mv_xor_free_chan_resources(struct dma_chan *chan)
 {
        struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
@@ -733,18 +639,16 @@ static void mv_dump_xor_regs(struct mv_xor_chan *chan)
 static void mv_xor_err_interrupt_handler(struct mv_xor_chan *chan,
                                         u32 intr_cause)
 {
-       if (intr_cause & (1 << 4)) {
-            dev_dbg(mv_chan_to_devp(chan),
-                    "ignore this error\n");
-            return;
+       if (intr_cause & XOR_INT_ERR_DECODE) {
+               dev_dbg(mv_chan_to_devp(chan), "ignoring address decode error\n");
+               return;
        }
 
-       dev_err(mv_chan_to_devp(chan),
-               "error on chan %d. intr cause 0x%08x\n",
+       dev_err(mv_chan_to_devp(chan), "error on chan %d. intr cause 0x%08x\n",
                chan->idx, intr_cause);
 
        mv_dump_xor_regs(chan);
-       BUG();
+       WARN_ON(1);
 }
 
 static irqreturn_t mv_xor_interrupt_handler(int irq, void *data)
@@ -754,7 +658,7 @@ static irqreturn_t mv_xor_interrupt_handler(int irq, void *data)
 
        dev_dbg(mv_chan_to_devp(chan), "intr cause %x\n", intr_cause);
 
-       if (mv_is_err_intr(intr_cause))
+       if (intr_cause & XOR_INTR_ERRORS)
                mv_xor_err_interrupt_handler(chan, intr_cause);
 
        tasklet_schedule(&chan->irq_tasklet);
@@ -1041,6 +945,10 @@ static int mv_xor_channel_remove(struct mv_xor_chan *mv_chan)
 
        dma_free_coherent(dev, MV_XOR_POOL_SIZE,
                          mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool);
+       dma_unmap_single(dev, mv_chan->dummy_src_addr,
+                        MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);
+       dma_unmap_single(dev, mv_chan->dummy_dst_addr,
+                        MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);
 
        list_for_each_entry_safe(chan, _chan, &mv_chan->dmadev.channels,
                                 device_node) {
@@ -1070,6 +978,16 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
 
        dma_dev = &mv_chan->dmadev;
 
+       /*
+        * These source and destination dummy buffers are used to implement
+        * a DMA_INTERRUPT operation as a minimum-sized XOR operation.
+        * Hence, we only need to map the buffers at initialization-time.
+        */
+       mv_chan->dummy_src_addr = dma_map_single(dma_dev->dev,
+               mv_chan->dummy_src, MV_XOR_MIN_BYTE_COUNT, DMA_FROM_DEVICE);
+       mv_chan->dummy_dst_addr = dma_map_single(dma_dev->dev,
+               mv_chan->dummy_dst, MV_XOR_MIN_BYTE_COUNT, DMA_TO_DEVICE);
+
        /* allocate coherent memory for hardware descriptors
         * note: writecombine gives slightly better performance, but
         * requires that we explicitly flush the writes
@@ -1094,6 +1012,8 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
        dma_dev->dev = &pdev->dev;
 
        /* set prep routines based on capability */
+       if (dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask))
+               dma_dev->device_prep_dma_interrupt = mv_xor_prep_dma_interrupt;
        if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask))
                dma_dev->device_prep_dma_memcpy = mv_xor_prep_dma_memcpy;
        if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
@@ -1116,7 +1036,7 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
 
        mv_chan_unmask_interrupts(mv_chan);
 
-       mv_set_mode(mv_chan, DMA_MEMCPY);
+       mv_set_mode(mv_chan, DMA_XOR);
 
        spin_lock_init(&mv_chan->lock);
        INIT_LIST_HEAD(&mv_chan->chain);