For aesthetics, move the functions that allocate/free and initialize
the mite dma ring. They are currently kind of scattered around the
code.
Add docbook comments for the exported functions.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/mite.c | 274 ++++++++++++++++++----------------
drivers/staging/comedi/drivers/mite.h | 8 +-
2 files changed, 150 insertions(+), 132 deletions(-)
diff --git a/drivers/staging/comedi/drivers/mite.c b/drivers/staging/comedi/drivers/mite.c
index d51a29b..308ceb60 100644
--- a/drivers/staging/comedi/drivers/mite.c
+++ b/drivers/staging/comedi/drivers/mite.c
@@ -228,49 +228,6 @@ static unsigned int mite_fifo_size(struct mite *mite, unsigned int channel)
return empty_count + full_count;
}
-struct mite_ring *mite_alloc_ring(struct mite *mite)
-{
- struct mite_ring *ring;
-
- ring = kmalloc(sizeof(*ring), GFP_KERNEL);
- if (!ring)
- return NULL;
- ring->hw_dev = get_device(&mite->pcidev->dev);
- if (!ring->hw_dev) {
- kfree(ring);
- return NULL;
- }
- ring->n_links = 0;
- ring->descs = NULL;
- ring->dma_addr = 0;
- return ring;
-};
-EXPORT_SYMBOL_GPL(mite_alloc_ring);
-
-static void mite_free_dma_descs(struct mite_ring *ring)
-{
- struct mite_dma_desc *descs = ring->descs;
-
- if (descs) {
- dma_free_coherent(ring->hw_dev,
- ring->n_links * sizeof(*descs),
- descs, ring->dma_addr);
- ring->descs = NULL;
- ring->dma_addr = 0;
- ring->n_links = 0;
- }
-}
-
-void mite_free_ring(struct mite_ring *ring)
-{
- if (ring) {
- mite_free_dma_descs(ring);
- put_device(ring->hw_dev);
- kfree(ring);
- }
-};
-EXPORT_SYMBOL_GPL(mite_free_ring);
-
struct mite_channel *mite_request_channel_in_range(struct mite *mite,
struct mite_ring *ring,
unsigned int min_channel,
@@ -343,92 +300,6 @@ void mite_dma_arm(struct mite_channel *mite_chan)
}
EXPORT_SYMBOL_GPL(mite_dma_arm);
-/**************************************/
-
-int mite_buf_change(struct mite_ring *ring,
- struct comedi_subdevice *s)
-{
- struct comedi_async *async = s->async;
- struct mite_dma_desc *descs;
- unsigned int n_links;
-
- mite_free_dma_descs(ring);
-
- if (async->prealloc_bufsz == 0)
- return 0;
-
- n_links = async->prealloc_bufsz >> PAGE_SHIFT;
-
- descs = dma_alloc_coherent(ring->hw_dev,
- n_links * sizeof(*descs),
- &ring->dma_addr, GFP_KERNEL);
- if (!descs) {
- dev_err(s->device->class_dev,
- "mite: ring buffer allocation failed\n");
- return -ENOMEM;
- }
- ring->descs = descs;
- ring->n_links = n_links;
-
- return mite_init_ring_descriptors(ring, s, n_links << PAGE_SHIFT);
-}
-EXPORT_SYMBOL_GPL(mite_buf_change);
-
-/*
- * initializes the ring buffer descriptors to provide correct DMA transfer links
- * to the exact amount of memory required. When the ring buffer is allocated in
- * mite_buf_change, the default is to initialize the ring to refer to the entire
- * DMA data buffer. A command may call this function later to re-initialize and
- * shorten the amount of memory that will be transferred.
- */
-int mite_init_ring_descriptors(struct mite_ring *ring,
- struct comedi_subdevice *s,
- unsigned int nbytes)
-{
- struct comedi_async *async = s->async;
- struct mite_dma_desc *desc = NULL;
- unsigned int n_full_links = nbytes >> PAGE_SHIFT;
- unsigned int remainder = nbytes % PAGE_SIZE;
- int i;
-
- dev_dbg(s->device->class_dev,
- "mite: init ring buffer to %u bytes\n", nbytes);
-
- if ((n_full_links + (remainder > 0 ? 1 : 0)) > ring->n_links) {
- dev_err(s->device->class_dev,
- "mite: ring buffer too small for requested init\n");
- return -ENOMEM;
- }
-
- /* We set the descriptors for all full links. */
- for (i = 0; i < n_full_links; ++i) {
- desc = &ring->descs[i];
- desc->count = cpu_to_le32(PAGE_SIZE);
- desc->addr = cpu_to_le32(async->buf_map->page_list[i].dma_addr);
- desc->next = cpu_to_le32(ring->dma_addr +
- (i + 1) * sizeof(*desc));
- }
-
- /* the last link is either a remainder or was a full link. */
- if (remainder > 0) {
- desc = &ring->descs[i];
- /* set the lesser count for the remainder link */
- desc->count = cpu_to_le32(remainder);
- desc->addr = cpu_to_le32(async->buf_map->page_list[i].dma_addr);
- }
-
- /* Assign the last link->next to point back to the head of the list. */
- desc->next = cpu_to_le32(ring->dma_addr);
-
- /*
- * barrier is meant to insure that all the writes to the dma descriptors
- * have completed before the dma controller is commanded to read them
- */
- smp_wmb();
- return 0;
-}
-EXPORT_SYMBOL_GPL(mite_init_ring_descriptors);
-
void mite_prep_dma(struct mite_channel *mite_chan,
unsigned int num_device_bits, unsigned int num_memory_bits)
{
@@ -714,6 +585,151 @@ int mite_done(struct mite_channel *mite_chan)
}
EXPORT_SYMBOL_GPL(mite_done);
+/**
+ * mite_init_ring_descriptors() - Initialize a MITE dma ring descriptors.
+ * @ring: MITE dma ring.
+ * @s: COMEDI subdevice.
+ * @nbytes: the size of the dma ring (in bytes).
+ *
+ * Initializes the ring buffer descriptors to provide correct DMA transfer
+ * links to the exact amount of memory required. When the ring buffer is
+ * allocated by mite_buf_change(), the default is to initialize the ring
+ * to refer to the entire DMA data buffer. A command may call this function
+ * later to re-initialize and shorten the amount of memory that will be
+ * transferred.
+ */
+int mite_init_ring_descriptors(struct mite_ring *ring,
+ struct comedi_subdevice *s,
+ unsigned int nbytes)
+{
+ struct comedi_async *async = s->async;
+ struct mite_dma_desc *desc = NULL;
+ unsigned int n_full_links = nbytes >> PAGE_SHIFT;
+ unsigned int remainder = nbytes % PAGE_SIZE;
+ int i;
+
+ dev_dbg(s->device->class_dev,
+ "mite: init ring buffer to %u bytes\n", nbytes);
+
+ if ((n_full_links + (remainder > 0 ? 1 : 0)) > ring->n_links) {
+ dev_err(s->device->class_dev,
+ "mite: ring buffer too small for requested init\n");
+ return -ENOMEM;
+ }
+
+ /* We set the descriptors for all full links. */
+ for (i = 0; i < n_full_links; ++i) {
+ desc = &ring->descs[i];
+ desc->count = cpu_to_le32(PAGE_SIZE);
+ desc->addr = cpu_to_le32(async->buf_map->page_list[i].dma_addr);
+ desc->next = cpu_to_le32(ring->dma_addr +
+ (i + 1) * sizeof(*desc));
+ }
+
+ /* the last link is either a remainder or was a full link. */
+ if (remainder > 0) {
+ desc = &ring->descs[i];
+ /* set the lesser count for the remainder link */
+ desc->count = cpu_to_le32(remainder);
+ desc->addr = cpu_to_le32(async->buf_map->page_list[i].dma_addr);
+ }
+
+ /* Assign the last link->next to point back to the head of the list. */
+ desc->next = cpu_to_le32(ring->dma_addr);
+
+ /*
+ * barrier is meant to insure that all the writes to the dma descriptors
+ * have completed before the dma controller is commanded to read them
+ */
+ smp_wmb();
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mite_init_ring_descriptors);
+
+static void mite_free_dma_descs(struct mite_ring *ring)
+{
+ struct mite_dma_desc *descs = ring->descs;
+
+ if (descs) {
+ dma_free_coherent(ring->hw_dev,
+ ring->n_links * sizeof(*descs),
+ descs, ring->dma_addr);
+ ring->descs = NULL;
+ ring->dma_addr = 0;
+ ring->n_links = 0;
+ }
+}
+
+/**
+ * mite_buf_change() - COMEDI subdevice (*buf_change) for a MITE dma ring.
+ * @ring: MITE dma ring.
+ * @s: COMEDI subdevice.
+ */
+int mite_buf_change(struct mite_ring *ring, struct comedi_subdevice *s)
+{
+ struct comedi_async *async = s->async;
+ struct mite_dma_desc *descs;
+ unsigned int n_links;
+
+ mite_free_dma_descs(ring);
+
+ if (async->prealloc_bufsz == 0)
+ return 0;
+
+ n_links = async->prealloc_bufsz >> PAGE_SHIFT;
+
+ descs = dma_alloc_coherent(ring->hw_dev,
+ n_links * sizeof(*descs),
+ &ring->dma_addr, GFP_KERNEL);
+ if (!descs) {
+ dev_err(s->device->class_dev,
+ "mite: ring buffer allocation failed\n");
+ return -ENOMEM;
+ }
+ ring->descs = descs;
+ ring->n_links = n_links;
+
+ return mite_init_ring_descriptors(ring, s, n_links << PAGE_SHIFT);
+}
+EXPORT_SYMBOL_GPL(mite_buf_change);
+
+/**
+ * mite_alloc_ring() - Allocate a MITE dma ring.
+ * @mite: MITE device.
+ */
+struct mite_ring *mite_alloc_ring(struct mite *mite)
+{
+ struct mite_ring *ring;
+
+ ring = kmalloc(sizeof(*ring), GFP_KERNEL);
+ if (!ring)
+ return NULL;
+ ring->hw_dev = get_device(&mite->pcidev->dev);
+ if (!ring->hw_dev) {
+ kfree(ring);
+ return NULL;
+ }
+ ring->n_links = 0;
+ ring->descs = NULL;
+ ring->dma_addr = 0;
+ return ring;
+}
+EXPORT_SYMBOL_GPL(mite_alloc_ring);
+
+/**
+ * mite_free_ring() - Free a MITE dma ring and its descriptors.
+ * @ring: MITE dma ring.
+ */
+void mite_free_ring(struct mite_ring *ring)
+{
+ if (ring) {
+ mite_free_dma_descs(ring);
+ put_device(ring->hw_dev);
+ kfree(ring);
+ }
+}
+EXPORT_SYMBOL_GPL(mite_free_ring);
+
static int mite_setup(struct comedi_device *dev, struct mite *mite,
bool use_win1)
{
diff --git a/drivers/staging/comedi/drivers/mite.h b/drivers/staging/comedi/drivers/mite.h
index 95b645e..b5b11d4 100644
--- a/drivers/staging/comedi/drivers/mite.h
+++ b/drivers/staging/comedi/drivers/mite.h
@@ -60,8 +60,6 @@ struct mite {
spinlock_t lock;
};
-struct mite_ring *mite_alloc_ring(struct mite *);
-void mite_free_ring(struct mite_ring *ring);
struct mite_channel *mite_request_channel_in_range(struct mite *,
struct mite_ring *,
unsigned int min_channel,
@@ -86,9 +84,13 @@ int mite_done(struct mite_channel *mite_chan);
void mite_prep_dma(struct mite_channel *mite_chan,
unsigned int num_device_bits, unsigned int num_memory_bits);
-int mite_buf_change(struct mite_ring *, struct comedi_subdevice *);
+
int mite_init_ring_descriptors(struct mite_ring *, struct comedi_subdevice *,
unsigned int nbytes);
+int mite_buf_change(struct mite_ring *, struct comedi_subdevice *);
+
+struct mite_ring *mite_alloc_ring(struct mite *);
+void mite_free_ring(struct mite_ring *);
struct mite *mite_attach(struct comedi_device *, bool use_win1);
void mite_detach(struct mite *);
--
2.6.3
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