diff options
author | Vinod Koul <vinod.koul@intel.com> | 2016-01-06 15:17:32 +0530 |
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committer | Vinod Koul <vinod.koul@intel.com> | 2016-01-06 15:17:32 +0530 |
commit | 7c7b680fa6b0866af2c4876da261bbfe710315d6 (patch) | |
tree | 6f2449fdecb4edab3309d40959309ca80d2bb71d /drivers/dma/dmaengine.c | |
parent | 5eec94388db40ce45bec028af2e2f62df751c887 (diff) | |
parent | 020c62ae38946cae01571a0b4e6f445dfdb7ec1c (diff) |
Merge branch 'topic/univ_api' into for-linus
Diffstat (limited to 'drivers/dma/dmaengine.c')
-rw-r--r-- | drivers/dma/dmaengine.c | 172 |
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 + * We first set DMA_PRIVATE to disable balance_ref_count as this + * channel will not be published in the general-purpose + * allocator + */ + dma_cap_set(DMA_PRIVATE, device-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); |