From 7bd903c5ca47fde5ad52370a47776491813c772e Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi Date: Mon, 14 Dec 2015 22:47:39 +0200 Subject: [PATCH 1/3] dmaengine: core: Move and merge the code paths using private_candidate Channel matching with private_candidate() is used in two paths, the error checking is slightly different in them and they are duplicating code also. Move the code under find_candidate() to provide consistent execution and going to allow us to reuse this mode of channel lookup later. Signed-off-by: Peter Ujfalusi Reviewed-by: Andy Shevchenko Reviewed-by: Arnd Bergmann Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.c | 81 +++++++++++++++++++++++++------------------------ 1 file changed, 42 insertions(+), 39 deletions(-) --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -542,6 +542,42 @@ static struct dma_chan *private_candidat 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 + * We first set DMA_PRIVATE to disable balance_ref_count as this + * channel will not be published in the general-purpose + * allocator + */ + dma_cap_set(DMA_PRIVATE, device-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 @@ -580,7 +616,6 @@ struct dma_chan *dma_get_any_slave_chann { dma_cap_mask_t mask; struct dma_chan *chan; - int err; dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); @@ -588,23 +623,11 @@ struct dma_chan *dma_get_any_slave_chann /* 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); @@ -621,35 +644,15 @@ struct dma_chan *__dma_request_channel(c { 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);