1 files changed, 195 insertions, 9 deletions

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 78784982b33e..e2106495cc11 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -31,6 +31,8 @@
  * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
  */
 typedef s32 dma_cookie_t;
+#define DMA_MIN_COOKIE  1
+#define DMA_MAX_COOKIE  INT_MAX
 
 #define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
 
@@ -38,11 +40,13 @@ typedef s32 dma_cookie_t;
  * enum dma_status - DMA transaction status
  * @DMA_SUCCESS: transaction completed successfully
  * @DMA_IN_PROGRESS: transaction not yet processed
+ * @DMA_PAUSED: transaction is paused
  * @DMA_ERROR: transaction failed
  */
 enum dma_status {
         DMA_SUCCESS,
         DMA_IN_PROGRESS,
+        DMA_PAUSED,
         DMA_ERROR,
 };
 
@@ -105,6 +109,25 @@ enum dma_ctrl_flags {
 };
 
 /**
+ * enum dma_ctrl_cmd - DMA operations that can optionally be exercised
+ * on a running channel.
+ * @DMA_TERMINATE_ALL: terminate all ongoing transfers
+ * @DMA_PAUSE: pause ongoing transfers
+ * @DMA_RESUME: resume paused transfer
+ * @DMA_SLAVE_CONFIG: this command is only implemented by DMA controllers
+ * that need to runtime reconfigure the slave channels (as opposed to passing
+ * configuration data in statically from the platform). An additional
+ * argument of struct dma_slave_config must be passed in with this
+ * command.
+ */
+enum dma_ctrl_cmd {
+        DMA_TERMINATE_ALL,
+        DMA_PAUSE,
+        DMA_RESUME,
+        DMA_SLAVE_CONFIG,
+};
+
+/**
  * enum sum_check_bits - bit position of pq_check_flags
  */
 enum sum_check_bits {
@@ -162,7 +185,7 @@ struct dma_chan {
         struct dma_chan_dev *dev;
 
         struct list_head device_node;
-        struct dma_chan_percpu *local;
+        struct dma_chan_percpu __percpu *local;
         int client_count;
         int table_count;
         void *private;
@@ -182,6 +205,71 @@ struct dma_chan_dev {
         atomic_t *idr_ref;
 };
 
+/**
+ * enum dma_slave_buswidth - defines bus with of the DMA slave
+ * device, source or target buses
+ */
+enum dma_slave_buswidth {
+        DMA_SLAVE_BUSWIDTH_UNDEFINED = 0,
+        DMA_SLAVE_BUSWIDTH_1_BYTE = 1,
+        DMA_SLAVE_BUSWIDTH_2_BYTES = 2,
+        DMA_SLAVE_BUSWIDTH_4_BYTES = 4,
+        DMA_SLAVE_BUSWIDTH_8_BYTES = 8,
+};
+
+/**
+ * struct dma_slave_config - dma slave channel runtime config
+ * @direction: whether the data shall go in or out on this slave
+ * channel, right now. DMA_TO_DEVICE and DMA_FROM_DEVICE are
+ * legal values, DMA_BIDIRECTIONAL is not acceptable since we
+ * need to differentiate source and target addresses.
+ * @src_addr: this is the physical address where DMA slave data
+ * should be read (RX), if the source is memory this argument is
+ * ignored.
+ * @dst_addr: this is the physical address where DMA slave data
+ * should be written (TX), if the source is memory this argument
+ * is ignored.
+ * @src_addr_width: this is the width in bytes of the source (RX)
+ * register where DMA data shall be read. If the source
+ * is memory this may be ignored depending on architecture.
+ * Legal values: 1, 2, 4, 8.
+ * @dst_addr_width: same as src_addr_width but for destination
+ * target (TX) mutatis mutandis.
+ * @src_maxburst: the maximum number of words (note: words, as in
+ * units of the src_addr_width member, not bytes) that can be sent
+ * in one burst to the device. Typically something like half the
+ * FIFO depth on I/O peripherals so you don't overflow it. This
+ * may or may not be applicable on memory sources.
+ * @dst_maxburst: same as src_maxburst but for destination target
+ * mutatis mutandis.
+ *
+ * This struct is passed in as configuration data to a DMA engine
+ * in order to set up a certain channel for DMA transport at runtime.
+ * The DMA device/engine has to provide support for an additional
+ * command in the channel config interface, DMA_SLAVE_CONFIG
+ * and this struct will then be passed in as an argument to the
+ * DMA engine device_control() function.
+ *
+ * The rationale for adding configuration information to this struct
+ * is as follows: if it is likely that most DMA slave controllers in
+ * the world will support the configuration option, then make it
+ * generic. If not: if it is fixed so that it be sent in static from
+ * the platform data, then prefer to do that. Else, if it is neither
+ * fixed at runtime, nor generic enough (such as bus mastership on
+ * some CPU family and whatnot) then create a custom slave config
+ * struct and pass that, then make this config a member of that
+ * struct, if applicable.
+ */
+struct dma_slave_config {
+        enum dma_data_direction direction;
+        dma_addr_t src_addr;
+        dma_addr_t dst_addr;
+        enum dma_slave_buswidth src_addr_width;
+        enum dma_slave_buswidth dst_addr_width;
+        u32 src_maxburst;
+        u32 dst_maxburst;
+};
+
 static inline const char *dma_chan_name(struct dma_chan *chan)
 {
         return dev_name(&chan->dev->device);
@@ -228,9 +316,84 @@ struct dma_async_tx_descriptor {
         dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
         dma_async_tx_callback callback;
         void *callback_param;
+#ifndef CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH
         struct dma_async_tx_descriptor *next;
         struct dma_async_tx_descriptor *parent;
         spinlock_t lock;
+#endif
+};
+
+#ifdef CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH
+static inline void txd_lock(struct dma_async_tx_descriptor *txd)
+{
+}
+static inline void txd_unlock(struct dma_async_tx_descriptor *txd)
+{
+}
+static inline void txd_chain(struct dma_async_tx_descriptor *txd, struct dma_async_tx_descriptor *next)
+{
+        BUG();
+}
+static inline void txd_clear_parent(struct dma_async_tx_descriptor *txd)
+{
+}
+static inline void txd_clear_next(struct dma_async_tx_descriptor *txd)
+{
+}
+static inline struct dma_async_tx_descriptor *txd_next(struct dma_async_tx_descriptor *txd)
+{
+        return NULL;
+}
+static inline struct dma_async_tx_descriptor *txd_parent(struct dma_async_tx_descriptor *txd)
+{
+        return NULL;
+}
+
+#else
+static inline void txd_lock(struct dma_async_tx_descriptor *txd)
+{
+        spin_lock_bh(&txd->lock);
+}
+static inline void txd_unlock(struct dma_async_tx_descriptor *txd)
+{
+        spin_unlock_bh(&txd->lock);
+}
+static inline void txd_chain(struct dma_async_tx_descriptor *txd, struct dma_async_tx_descriptor *next)
+{
+        txd->next = next;
+        next->parent = txd;
+}
+static inline void txd_clear_parent(struct dma_async_tx_descriptor *txd)
+{
+        txd->parent = NULL;
+}
+static inline void txd_clear_next(struct dma_async_tx_descriptor *txd)
+{
+        txd->next = NULL;
+}
+static inline struct dma_async_tx_descriptor *txd_parent(struct dma_async_tx_descriptor *txd)
+{
+        return txd->parent;
+}
+static inline struct dma_async_tx_descriptor *txd_next(struct dma_async_tx_descriptor *txd)
+{
+        return txd->next;
+}
+#endif
+
+/**
+ * struct dma_tx_state - filled in to report the status of
+ * a transfer.
+ * @last: last completed DMA cookie
+ * @used: last issued DMA cookie (i.e. the one in progress)
+ * @residue: the remaining number of bytes left to transmit
+ *      on the selected transfer for states DMA_IN_PROGRESS and
+ *      DMA_PAUSED if this is implemented in the driver, else 0
+ */
+struct dma_tx_state {
+        dma_cookie_t last;
+        dma_cookie_t used;
+        u32 residue;
 };
 
 /**
@@ -259,8 +422,12 @@ struct dma_async_tx_descriptor {
  * @device_prep_dma_memset: prepares a memset operation
  * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
  * @device_prep_slave_sg: prepares a slave dma operation
- * @device_terminate_all: terminate all pending operations
- * @device_is_tx_complete: poll for transaction completion
+ * @device_control: manipulate all pending operations on a channel, returns
+ *      zero or error code
+ * @device_tx_status: poll for transaction completion, the optional
+ *      txstate parameter can be supplied with a pointer to get a
+ *      struct with auxilary transfer status information, otherwise the call
+ *      will just return a simple status code
  * @device_issue_pending: push pending transactions to hardware
  */
 struct dma_device {
@@ -311,11 +478,12 @@ struct dma_device {
                 struct dma_chan *chan, struct scatterlist *sgl,
                 unsigned int sg_len, enum dma_data_direction direction,
                 unsigned long flags);
-        void (*device_terminate_all)(struct dma_chan *chan);
+        int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+                unsigned long arg);
 
-        enum dma_status (*device_is_tx_complete)(struct dma_chan *chan,
-                        dma_cookie_t cookie, dma_cookie_t *last,
-                        dma_cookie_t *used);
+        enum dma_status (*device_tx_status)(struct dma_chan *chan,
+                                            dma_cookie_t cookie,
+                                            struct dma_tx_state *txstate);
         void (*device_issue_pending)(struct dma_chan *chan);
 };
 
@@ -380,7 +548,7 @@ static inline bool dma_dev_has_pq_continue(struct dma_device *dma)
         return (dma->max_pq & DMA_HAS_PQ_CONTINUE) == DMA_HAS_PQ_CONTINUE;
 }
 
-static unsigned short dma_dev_to_maxpq(struct dma_device *dma)
+static inline unsigned short dma_dev_to_maxpq(struct dma_device *dma)
 {
         return dma->max_pq & ~DMA_HAS_PQ_CONTINUE;
 }
@@ -556,7 +724,15 @@ static inline void dma_async_issue_pending(struct dma_chan *chan)
 static inline enum dma_status dma_async_is_tx_complete(struct dma_chan *chan,
         dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used)
 {
-        return chan->device->device_is_tx_complete(chan, cookie, last, used);
+        struct dma_tx_state state;
+        enum dma_status status;
+
+        status = chan->device->device_tx_status(chan, cookie, &state);
+        if (last)
+                *last = state.last;
+        if (used)
+                *used = state.used;
+        return status;
 }
 
 #define dma_async_memcpy_complete(chan, cookie, last, used)\
@@ -584,6 +760,16 @@ static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
         return DMA_IN_PROGRESS;
 }
 
+static inline void
+dma_set_tx_state(struct dma_tx_state *st, dma_cookie_t last, dma_cookie_t used, u32 residue)
+{
+        if (st) {
+                st->last = last;
+                st->used = used;
+                st->residue = residue;
+        }
+}
+
 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);
 #ifdef CONFIG_DMA_ENGINE
 enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx);