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authorVinod Koul <vinod.koul@intel.com>2016-01-06 15:17:32 +0530
committerVinod Koul <vinod.koul@intel.com>2016-01-06 15:17:32 +0530
commit7c7b680fa6b0866af2c4876da261bbfe710315d6 (patch)
tree6f2449fdecb4edab3309d40959309ca80d2bb71d /drivers/dma/dmaengine.c
parent5eec94388db40ce45bec028af2e2f62df751c887 (diff)
parent020c62ae38946cae01571a0b4e6f445dfdb7ec1c (diff)
Merge branch 'topic/univ_api' into for-linus
Diffstat (limited to 'drivers/dma/dmaengine.c')
-rw-r--r--drivers/dma/dmaengine.c172
1 files changed, 120 insertions, 52 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 4aced6689734..21c8c0bce3af 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -43,6 +43,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/module.h>
@@ -512,7 +513,7 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
{
struct dma_chan *chan;
- if (!__dma_device_satisfies_mask(dev, mask)) {
+ if (mask && !__dma_device_satisfies_mask(dev, mask)) {
pr_debug("%s: wrong capabilities\n", __func__);
return NULL;
}
@@ -543,6 +544,42 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
return NULL;
}
+static struct dma_chan *find_candidate(struct dma_device *device,
+ const dma_cap_mask_t *mask,
+ dma_filter_fn fn, void *fn_param)
+{
+ struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
+ int err;
+
+ if (chan) {
+ /* Found a suitable channel, try to grab, prep, and return it.
+ * We first set DMA_PRIVATE to disable balance_ref_count as this
+ * channel will not be published in the general-purpose
+ * allocator
+ */
+ dma_cap_set(DMA_PRIVATE, device->cap_mask);
+ device->privatecnt++;
+ err = dma_chan_get(chan);
+
+ if (err) {
+ if (err == -ENODEV) {
+ pr_debug("%s: %s module removed\n", __func__,
+ dma_chan_name(chan));
+ list_del_rcu(&device->global_node);
+ } else
+ pr_debug("%s: failed to get %s: (%d)\n",
+ __func__, dma_chan_name(chan), err);
+
+ if (--device->privatecnt == 0)
+ dma_cap_clear(DMA_PRIVATE, device->cap_mask);
+
+ chan = ERR_PTR(err);
+ }
+ }
+
+ return chan ? chan : ERR_PTR(-EPROBE_DEFER);
+}
+
/**
* dma_get_slave_channel - try to get specific channel exclusively
* @chan: target channel
@@ -581,7 +618,6 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
{
dma_cap_mask_t mask;
struct dma_chan *chan;
- int err;
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
@@ -589,23 +625,11 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
/* lock against __dma_request_channel */
mutex_lock(&dma_list_mutex);
- chan = private_candidate(&mask, device, NULL, NULL);
- if (chan) {
- dma_cap_set(DMA_PRIVATE, device->cap_mask);
- device->privatecnt++;
- err = dma_chan_get(chan);
- if (err) {
- pr_debug("%s: failed to get %s: (%d)\n",
- __func__, dma_chan_name(chan), err);
- chan = NULL;
- if (--device->privatecnt == 0)
- dma_cap_clear(DMA_PRIVATE, device->cap_mask);
- }
- }
+ chan = find_candidate(device, &mask, NULL, NULL);
mutex_unlock(&dma_list_mutex);
- return chan;
+ return IS_ERR(chan) ? NULL : chan;
}
EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
@@ -622,35 +646,15 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
{
struct dma_device *device, *_d;
struct dma_chan *chan = NULL;
- int err;
/* Find a channel */
mutex_lock(&dma_list_mutex);
list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
- chan = private_candidate(mask, device, fn, fn_param);
- if (chan) {
- /* Found a suitable channel, try to grab, prep, and
- * return it. We first set DMA_PRIVATE to disable
- * balance_ref_count as this channel will not be
- * published in the general-purpose allocator
- */
- dma_cap_set(DMA_PRIVATE, device->cap_mask);
- device->privatecnt++;
- err = dma_chan_get(chan);
+ chan = find_candidate(device, mask, fn, fn_param);
+ if (!IS_ERR(chan))
+ break;
- if (err == -ENODEV) {
- pr_debug("%s: %s module removed\n",
- __func__, dma_chan_name(chan));
- list_del_rcu(&device->global_node);
- } else if (err)
- pr_debug("%s: failed to get %s: (%d)\n",
- __func__, dma_chan_name(chan), err);
- else
- break;
- if (--device->privatecnt == 0)
- dma_cap_clear(DMA_PRIVATE, device->cap_mask);
- chan = NULL;
- }
+ chan = NULL;
}
mutex_unlock(&dma_list_mutex);
@@ -663,27 +667,73 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
}
EXPORT_SYMBOL_GPL(__dma_request_channel);
+static const struct dma_slave_map *dma_filter_match(struct dma_device *device,
+ const char *name,
+ struct device *dev)
+{
+ int i;
+
+ if (!device->filter.mapcnt)
+ return NULL;
+
+ for (i = 0; i < device->filter.mapcnt; i++) {
+ const struct dma_slave_map *map = &device->filter.map[i];
+
+ if (!strcmp(map->devname, dev_name(dev)) &&
+ !strcmp(map->slave, name))
+ return map;
+ }
+
+ return NULL;
+}
+
/**
- * dma_request_slave_channel_reason - try to allocate an exclusive slave channel
+ * dma_request_chan - try to allocate an exclusive slave channel
* @dev: pointer to client device structure
* @name: slave channel name
*
* Returns pointer to appropriate DMA channel on success or an error pointer.
*/
-struct dma_chan *dma_request_slave_channel_reason(struct device *dev,
- const char *name)
+struct dma_chan *dma_request_chan(struct device *dev, const char *name)
{
+ struct dma_device *d, *_d;
+ struct dma_chan *chan = NULL;
+
/* If device-tree is present get slave info from here */
if (dev->of_node)
- return of_dma_request_slave_channel(dev->of_node, name);
+ chan = of_dma_request_slave_channel(dev->of_node, name);
/* If device was enumerated by ACPI get slave info from here */
- if (ACPI_HANDLE(dev))
- return acpi_dma_request_slave_chan_by_name(dev, name);
+ if (has_acpi_companion(dev) && !chan)
+ chan = acpi_dma_request_slave_chan_by_name(dev, name);
- return ERR_PTR(-ENODEV);
+ if (chan) {
+ /* Valid channel found or requester need to be deferred */
+ if (!IS_ERR(chan) || PTR_ERR(chan) == -EPROBE_DEFER)
+ return chan;
+ }
+
+ /* Try to find the channel via the DMA filter map(s) */
+ mutex_lock(&dma_list_mutex);
+ list_for_each_entry_safe(d, _d, &dma_device_list, global_node) {
+ dma_cap_mask_t mask;
+ const struct dma_slave_map *map = dma_filter_match(d, name, dev);
+
+ if (!map)
+ continue;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ chan = find_candidate(d, &mask, d->filter.fn, map->param);
+ if (!IS_ERR(chan))
+ break;
+ }
+ mutex_unlock(&dma_list_mutex);
+
+ return chan ? chan : ERR_PTR(-EPROBE_DEFER);
}
-EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
+EXPORT_SYMBOL_GPL(dma_request_chan);
/**
* dma_request_slave_channel - try to allocate an exclusive slave channel
@@ -695,17 +745,35 @@ EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason);
struct dma_chan *dma_request_slave_channel(struct device *dev,
const char *name)
{
- struct dma_chan *ch = dma_request_slave_channel_reason(dev, name);
+ struct dma_chan *ch = dma_request_chan(dev, name);
if (IS_ERR(ch))
return NULL;
- dma_cap_set(DMA_PRIVATE, ch->device->cap_mask);
- ch->device->privatecnt++;
-
return ch;
}
EXPORT_SYMBOL_GPL(dma_request_slave_channel);
+/**
+ * dma_request_chan_by_mask - allocate a channel satisfying certain capabilities
+ * @mask: capabilities that the channel must satisfy
+ *
+ * Returns pointer to appropriate DMA channel on success or an error pointer.
+ */
+struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
+{
+ struct dma_chan *chan;
+
+ if (!mask)
+ return ERR_PTR(-ENODEV);
+
+ chan = __dma_request_channel(mask, NULL, NULL);
+ if (!chan)
+ chan = ERR_PTR(-ENODEV);
+
+ return chan;
+}
+EXPORT_SYMBOL_GPL(dma_request_chan_by_mask);
+
void dma_release_channel(struct dma_chan *chan)
{
mutex_lock(&dma_list_mutex);