diff options
Diffstat (limited to 'drivers/dma/dw')
| -rw-r--r-- | drivers/dma/dw/core.c | 166 | ||||
| -rw-r--r-- | drivers/dma/dw/regs.h | 1 |
2 files changed, 48 insertions, 119 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index dd47d4b8aad6..78522dcf3a7d 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -58,13 +58,6 @@ | DWC_CTLL_SMS(_sms)); \ }) -/* - * Number of descriptors to allocate for each channel. This should be - * made configurable somehow; preferably, the clients (at least the - * ones using slave transfers) should be able to give us a hint. - */ -#define NR_DESCS_PER_CHANNEL 64 - /* The set of bus widths supported by the DMA controller */ #define DW_DMA_BUSWIDTHS \ BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \ @@ -84,51 +77,65 @@ static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc) return to_dw_desc(dwc->active_list.next); } -static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc) +static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx) { - struct dw_desc *desc, *_desc; - struct dw_desc *ret = NULL; - unsigned int i = 0; - unsigned long flags; + struct dw_desc *desc = txd_to_dw_desc(tx); + struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan); + dma_cookie_t cookie; + unsigned long flags; spin_lock_irqsave(&dwc->lock, flags); - list_for_each_entry_safe(desc, _desc, &dwc->free_list, desc_node) { - i++; - if (async_tx_test_ack(&desc->txd)) { - list_del(&desc->desc_node); - ret = desc; - break; - } - dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc); - } + cookie = dma_cookie_assign(tx); + + /* + * REVISIT: We should attempt to chain as many descriptors as + * possible, perhaps even appending to those already submitted + * for DMA. But this is hard to do in a race-free manner. + */ + + list_add_tail(&desc->desc_node, &dwc->queue); spin_unlock_irqrestore(&dwc->lock, flags); + dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", + __func__, desc->txd.cookie); - dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i); + return cookie; +} - return ret; +static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc) +{ + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + struct dw_desc *desc; + dma_addr_t phys; + + desc = dma_pool_zalloc(dw->desc_pool, GFP_ATOMIC, &phys); + if (!desc) + return NULL; + + dwc->descs_allocated++; + INIT_LIST_HEAD(&desc->tx_list); + dma_async_tx_descriptor_init(&desc->txd, &dwc->chan); + desc->txd.tx_submit = dwc_tx_submit; + desc->txd.flags = DMA_CTRL_ACK; + desc->txd.phys = phys; + return desc; } -/* - * Move a descriptor, including any children, to the free list. - * `desc' must not be on any lists. - */ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc) { - unsigned long flags; + struct dw_dma *dw = to_dw_dma(dwc->chan.device); + struct dw_desc *child, *_next; - if (desc) { - struct dw_desc *child; + if (unlikely(!desc)) + return; - spin_lock_irqsave(&dwc->lock, flags); - list_for_each_entry(child, &desc->tx_list, desc_node) - dev_vdbg(chan2dev(&dwc->chan), - "moving child desc %p to freelist\n", - child); - list_splice_init(&desc->tx_list, &dwc->free_list); - dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc); - list_add(&desc->desc_node, &dwc->free_list); - spin_unlock_irqrestore(&dwc->lock, flags); + list_for_each_entry_safe(child, _next, &desc->tx_list, desc_node) { + list_del(&child->desc_node); + dma_pool_free(dw->desc_pool, child, child->txd.phys); + dwc->descs_allocated--; } + + dma_pool_free(dw->desc_pool, desc, desc->txd.phys); + dwc->descs_allocated--; } static void dwc_initialize(struct dw_dma_chan *dwc) @@ -297,11 +304,7 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc, list_for_each_entry(child, &desc->tx_list, desc_node) async_tx_ack(&child->txd); async_tx_ack(&desc->txd); - - list_splice_init(&desc->tx_list, &dwc->free_list); - list_move(&desc->desc_node, &dwc->free_list); - - dma_descriptor_unmap(txd); + dwc_desc_put(dwc, desc); spin_unlock_irqrestore(&dwc->lock, flags); if (callback) @@ -663,30 +666,6 @@ static irqreturn_t dw_dma_interrupt(int irq, void *dev_id) /*----------------------------------------------------------------------*/ -static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx) -{ - struct dw_desc *desc = txd_to_dw_desc(tx); - struct dw_dma_chan *dwc = to_dw_dma_chan(tx->chan); - dma_cookie_t cookie; - unsigned long flags; - - spin_lock_irqsave(&dwc->lock, flags); - cookie = dma_cookie_assign(tx); - - /* - * REVISIT: We should attempt to chain as many descriptors as - * possible, perhaps even appending to those already submitted - * for DMA. But this is hard to do in a race-free manner. - */ - - dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__, desc->txd.cookie); - list_add_tail(&desc->desc_node, &dwc->queue); - - spin_unlock_irqrestore(&dwc->lock, flags); - - return cookie; -} - static struct dma_async_tx_descriptor * dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, size_t len, unsigned long flags) @@ -1159,9 +1138,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) { struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma *dw = to_dw_dma(chan->device); - struct dw_desc *desc; - int i; - unsigned long flags; dev_vdbg(chan2dev(chan), "%s\n", __func__); @@ -1192,48 +1168,13 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) dw_dma_on(dw); dw->in_use |= dwc->mask; - spin_lock_irqsave(&dwc->lock, flags); - i = dwc->descs_allocated; - while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) { - dma_addr_t phys; - - spin_unlock_irqrestore(&dwc->lock, flags); - - desc = dma_pool_alloc(dw->desc_pool, GFP_ATOMIC, &phys); - if (!desc) - goto err_desc_alloc; - - memset(desc, 0, sizeof(struct dw_desc)); - - INIT_LIST_HEAD(&desc->tx_list); - dma_async_tx_descriptor_init(&desc->txd, chan); - desc->txd.tx_submit = dwc_tx_submit; - desc->txd.flags = DMA_CTRL_ACK; - desc->txd.phys = phys; - - dwc_desc_put(dwc, desc); - - spin_lock_irqsave(&dwc->lock, flags); - i = ++dwc->descs_allocated; - } - - spin_unlock_irqrestore(&dwc->lock, flags); - - dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i); - - return i; - -err_desc_alloc: - dev_info(chan2dev(chan), "only allocated %d descriptors\n", i); - - return i; + return 0; } static void dwc_free_chan_resources(struct dma_chan *chan) { struct dw_dma_chan *dwc = to_dw_dma_chan(chan); struct dw_dma *dw = to_dw_dma(chan->device); - struct dw_desc *desc, *_desc; unsigned long flags; LIST_HEAD(list); @@ -1246,8 +1187,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan) BUG_ON(dma_readl(to_dw_dma(chan->device), CH_EN) & dwc->mask); spin_lock_irqsave(&dwc->lock, flags); - list_splice_init(&dwc->free_list, &list); - dwc->descs_allocated = 0; /* Clear custom channel configuration */ dwc->src_id = 0; @@ -1270,11 +1209,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan) if (!dw->in_use) dw_dma_off(dw); - list_for_each_entry_safe(desc, _desc, &list, desc_node) { - dev_vdbg(chan2dev(chan), " freeing descriptor %p\n", desc); - dma_pool_free(dw->desc_pool, desc, desc->txd.phys); - } - dev_vdbg(chan2dev(chan), "%s: done\n", __func__); } @@ -1406,9 +1340,6 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan, retval = ERR_PTR(-ENOMEM); - if (periods > NR_DESCS_PER_CHANNEL) - goto out_err; - cdesc = kzalloc(sizeof(struct dw_cyclic_desc), GFP_KERNEL); if (!cdesc) goto out_err; @@ -1641,7 +1572,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) INIT_LIST_HEAD(&dwc->active_list); INIT_LIST_HEAD(&dwc->queue); - INIT_LIST_HEAD(&dwc->free_list); channel_clear_bit(dw, CH_EN, dwc->mask); diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h index 96f498188257..0ab02eb23bfc 100644 --- a/drivers/dma/dw/regs.h +++ b/drivers/dma/dw/regs.h @@ -236,7 +236,6 @@ struct dw_dma_chan { unsigned long flags; struct list_head active_list; struct list_head queue; - struct list_head free_list; struct dw_cyclic_desc *cdesc; unsigned int descs_allocated; |