dma copy: trace: Fix locking with DMA trace and refactor API usage.

Fix locking in DMA trace. Also run the DMA trace as delayed work so
we dont block callers. Refactor API so that DMAC and channel are
pre-allocated.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo

src/audio/dma-trace.c

@@ -41,51 +41,22 @@
 
 static struct dma_trace_data *trace_data = NULL;
 
-static int dma_trace_new_buffer(struct dma_trace_data *d, uint32_t buffer_size)
-{
-	struct dma_trace_buf *buffer = &d->dmatb;
-
-	trace_buffer("nlb");
-
-	/* validate request */
-	if (buffer_size == 0 || buffer_size > HEAP_BUFFER_SIZE) {
-		trace_buffer_error("ebg");
-		trace_value(buffer_size);
-		return -ENOMEM;
-	}
-
-	/* allocate new buffer */
-	buffer->addr = rballoc(RZONE_RUNTIME, RFLAGS_NONE, buffer_size);
-	if (buffer->addr == NULL) {
-		trace_buffer_error("ebm");
-		return -ENOMEM;
-	}
-
-	bzero(buffer->addr, buffer_size);
-
-	buffer->size = buffer_size;
-	buffer->w_ptr = buffer->r_ptr = buffer->addr;
-	buffer->end_addr = buffer->addr + buffer->size;
-	buffer->avail = 0;
-
-	return 0;
-}
-
-static void trace_send(struct dma_trace_data *d)
+static uint64_t trace_work(void *data, uint64_t delay)
 {
+	struct dma_trace_data *d = (struct dma_trace_data *)data;
 	struct dma_trace_buf *buffer = &d->dmatb;
 	struct dma_sg_config *config = &d->config;
 	unsigned long flags;
 	int32_t offset = 0;
 	uint32_t avail = buffer->avail;
-	uint32_t bytes_copied = avail;
+	uint32_t bytes_copied = 0;
 	uint32_t size;
 	uint32_t hsize;
 	uint32_t lsize;
 
 	/* any data to copy ? */
 	if (avail == 0)
-		return;
+		return DMA_TRACE_US;
 
 	/* copy to host in sections if we wrap */
 	while (avail > 0) {
@@ -106,12 +77,15 @@ static void trace_send(struct dma_trace_data *d)
 		else
 			size = lsize;
 
+		/* writeback trace data */
+		dcache_writeback_region((void*)buffer->r_ptr, size);
+
 		/* copy this section to host */
-		offset = dma_copy_to_host(config, d->host_offset,
+		offset = dma_copy_to_host(&d->dc, config, d->host_offset,
 			buffer->r_ptr, size);
 		if (offset < 0) {
 			trace_buffer_error("ebb");
-			return;
+			goto out;
 		}
 
 		/* update host pointer and check for wrap */
@@ -125,44 +99,55 @@ static void trace_send(struct dma_trace_data *d)
 			buffer->r_ptr = buffer->addr;
 
 		avail -= size;
+		bytes_copied += size;
 	}
 
+out:
 	spin_lock_irq(&d->lock, flags);
 	buffer->avail -= bytes_copied;
 	spin_unlock_irq(&d->lock, flags);
-}
-
-static uint64_t trace_work(void *data, uint64_t delay)
-{
-	struct dma_trace_data *d = (struct dma_trace_data *)data;
-
-	trace_send(d);
 
 	/* reschedule the trace copying work */
 	return DMA_TRACE_US;
 }
 
 int dma_trace_init(struct dma_trace_data *d)
 {
-	int err;
+	struct dma_trace_buf *buffer = &d->dmatb;
+	int ret;
 
 	trace_buffer("dtn");
 
-	/* init buffer elems */
-	list_init(&d->config.elem_list);
+	/* allocate new buffer */
+	buffer->addr = rballoc(RZONE_RUNTIME, RFLAGS_NONE, DMA_TRACE_LOCAL_SIZE);
+	if (buffer->addr == NULL) {
+		trace_buffer_error("ebm");
+		return -ENOMEM;
+	}
 
-	/* allocate local DMA buffer */
-	err = dma_trace_new_buffer(d, DMA_TRACE_LOCAL_SIZE);
-	if (err < 0) {
-		trace_buffer_error("ePb");
-		return err;
+	/* init DMA copy context */
+	ret = dma_copy_new(&d->dc, PLATFORM_TRACE_DMAC);
+	if (ret < 0) {
+		trace_buffer_error("edm");
+		rfree(buffer->addr);
+		return ret;
 	}
 
+	bzero(buffer->addr, DMA_TRACE_LOCAL_SIZE);
+
+	/* initialise the DMA buffer */
+	buffer->size = DMA_TRACE_LOCAL_SIZE;
+	buffer->w_ptr = buffer->r_ptr = buffer->addr;
+	buffer->end_addr = buffer->addr + buffer->size;
+	buffer->avail = 0;
 	d->host_offset = 0;
-	trace_data = d;
+	d->enabled = 0;
 
+	list_init(&d->config.elem_list);
 	work_init(&d->dmat_work, trace_work, d, WORK_ASYNC);
 	spinlock_init(&d->lock);
+	trace_data = d;
+
 	return 0;
 }
 
@@ -183,10 +168,18 @@ int dma_trace_host_buffer(struct dma_trace_data *d, struct dma_sg_elem *elem,
 	return 0;
 }
 
-void dma_trace_config_ready(struct dma_trace_data *d)
+int dma_trace_enable(struct dma_trace_data *d)
 {
+	/* validate DMA context */
+	if (d->dc.dmac == NULL || d->dc.chan < 0) {
+		trace_buffer_error("eem");
+		return -ENODEV;
+	}
+
+	/* TODO: fix crash when enabled */
+	//d->enabled = 1;
 	work_schedule_default(&d->dmat_work, DMA_TRACE_US);
-	d->ready = 1;
+	return 0;
 }
 
 void dtrace_event(const char *e, uint32_t length)
@@ -226,6 +219,6 @@ void dtrace_event(const char *e, uint32_t length)
 	spin_unlock_irq(&trace_data->lock, flags);
 
 	/* schedule copy now if buffer > 50% full */
-	if (trace_data->ready && buffer->avail >= (DMA_TRACE_LOCAL_SIZE / 2))
+	if (trace_data->enabled && buffer->avail >= (DMA_TRACE_LOCAL_SIZE / 2))
 		work_reschedule_default(&trace_data->dmat_work, 100);
 }

src/include/reef/alloc.h

@@ -86,8 +86,8 @@ int rstrlen(const char *s);
 
 /* Heap save/restore contents and context for PM D0/D3 events */
 uint32_t mm_pm_context_size(void);
-int mm_pm_context_save(struct dma_sg_config *sg);
-int mm_pm_context_restore(struct dma_sg_config *sg);
+int mm_pm_context_save(struct dma_copy *dc, struct dma_sg_config *sg);
+int mm_pm_context_restore(struct dma_copy *dc, struct dma_sg_config *sg);
 
 /* heap initialisation */
 void init_heap(struct reef *reef);

src/include/reef/audio/dma-trace.h

@@ -55,17 +55,18 @@ struct dma_trace_buf {
 struct dma_trace_data {
 	struct dma_sg_config config;
 	struct dma_trace_buf dmatb;
+	struct dma_copy dc;
 	int32_t host_offset;
 	uint32_t host_size;
 	struct work dmat_work;
-	uint32_t ready;
+	uint32_t enabled;
 	spinlock_t lock;
 };
 
 int dma_trace_init(struct dma_trace_data *d);
 int dma_trace_host_buffer(struct dma_trace_data *d, struct dma_sg_elem *elem,
 	uint32_t host_size);
-void dma_trace_config_ready(struct dma_trace_data *d);
+int dma_trace_enable(struct dma_trace_data *d);
 
 void dtrace_event(const char *e, uint32_t size);
 

src/include/reef/dma.h

@@ -36,6 +36,7 @@
 #include <reef/list.h>
 #include <reef/lock.h>
 #include <reef/reef.h>
+#include <reef/wait.h>
 
 /* DMA directions */
 #define DMA_DIR_MEM_TO_MEM	0	/* local memcpy */
@@ -228,12 +229,29 @@ static inline uint32_t dma_sg_get_size(struct dma_sg_config *sg)
 	return size;
 }
 
+/* generic DMA DSP <-> Host copier */
+
+struct dma_copy {
+	int chan;
+	struct dma *dmac;
+	completion_t complete;
+};
+
+/* init dma copy context */
+int dma_copy_new(struct dma_copy *dc, int dmac);
+
+/* free dma copy context resources */
+static inline void dma_copy_free(struct dma_copy *dc)
+{
+	dma_channel_put(dc->dmac, dc->chan);
+}
+
 /* DMA copy data from host to DSP */
-int dma_copy_from_host(struct dma_sg_config *host_sg,
+int dma_copy_from_host(struct dma_copy *dc, struct dma_sg_config *host_sg,
 	int32_t host_offset, void *local_ptr, int32_t size);
 
 /* DMA copy data from DSP to host */
-int dma_copy_to_host(struct dma_sg_config *host_sg,
+int dma_copy_to_host(struct dma_copy *dc, struct dma_sg_config *host_sg,
 	int32_t host_offset, void *local_ptr, int32_t size);
 
 #endif