TI CPDMA currently uses a bitmap for tracking descriptors alloactions allocations, but The genalloc already handles the same and can be used as with special memory (SRAM) as with DMA cherent memory chank (dma_alloc_coherent()). Hence, switch to using genalloc and add desc_num property for each channel for limitation of max number of allowed descriptors for each CPDMA channel. This patch do not affect on net throuput. Tested-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx> --- Testing TCP window: 256K, bandwidth in Mbits/sec: host: iperf -s device: iperf -c 172.22.39.17 -t600 -i5 -d -w128K AM437x-idk, 1Gbps link before: : 341.60, after: 232+123=355 am57xx-beagle-x15, 1Gbps link before: : 1112.80, after: 814+321=1135 am335x-boneblack, 100Mbps link before: : 162.40, after: 72+93=165 changes in v2: - reverted change in desc_phys() to keep am3517 which has separate CPPI addresses from EMAC and CPU perspective - minor format changes. link on v1: https://lkml.org/lkml/2016/6/23/353 drivers/net/ethernet/ti/davinci_cpdma.c | 132 +++++++++++++++----------------- 1 file changed, 60 insertions(+), 72 deletions(-) diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c index 63b3009..b40a402 100644 --- a/drivers/net/ethernet/ti/davinci_cpdma.c +++ b/drivers/net/ethernet/ti/davinci_cpdma.c @@ -21,7 +21,7 @@ #include <linux/dma-mapping.h> #include <linux/io.h> #include <linux/delay.h> - +#include <linux/genalloc.h> #include "davinci_cpdma.h" /* DMA Registers */ @@ -87,9 +87,8 @@ struct cpdma_desc_pool { void *cpumap; /* dma_alloc map */ int desc_size, mem_size; int num_desc, used_desc; - unsigned long *bitmap; struct device *dev; - spinlock_t lock; + struct gen_pool *gen_pool; }; enum cpdma_state { @@ -117,6 +116,7 @@ struct cpdma_chan { int chan_num; spinlock_t lock; int count; + u32 desc_num; u32 mask; cpdma_handler_fn handler; enum dma_data_direction dir; @@ -145,6 +145,20 @@ struct cpdma_chan { (directed << CPDMA_TO_PORT_SHIFT)); \ } while (0) +static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool) +{ + if (!pool) + return; + + WARN_ON(pool->used_desc); + if (pool->cpumap) { + dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap, + pool->phys); + } else { + iounmap(pool->iomap); + } +} + /* * Utility constructs for a cpdma descriptor pool. Some devices (e.g. davinci * emac) have dedicated on-chip memory for these descriptors. Some other @@ -155,24 +169,25 @@ static struct cpdma_desc_pool * cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr, int size, int align) { - int bitmap_size; struct cpdma_desc_pool *pool; + int ret; pool = devm_kzalloc(dev, sizeof(*pool), GFP_KERNEL); if (!pool) - goto fail; - - spin_lock_init(&pool->lock); + goto gen_pool_create_fail; pool->dev = dev; pool->mem_size = size; pool->desc_size = ALIGN(sizeof(struct cpdma_desc), align); pool->num_desc = size / pool->desc_size; - bitmap_size = (pool->num_desc / BITS_PER_LONG) * sizeof(long); - pool->bitmap = devm_kzalloc(dev, bitmap_size, GFP_KERNEL); - if (!pool->bitmap) - goto fail; + pool->gen_pool = devm_gen_pool_create(dev, ilog2(pool->desc_size), -1, + "cpdma"); + if (IS_ERR(pool->gen_pool)) { + dev_err(dev, "pool create failed %ld\n", + PTR_ERR(pool->gen_pool)); + goto gen_pool_create_fail; + } if (phys) { pool->phys = phys; @@ -185,24 +200,22 @@ cpdma_desc_pool_create(struct device *dev, u32 phys, dma_addr_t hw_addr, pool->phys = pool->hw_addr; /* assumes no IOMMU, don't use this value */ } - if (pool->iomap) - return pool; -fail: - return NULL; -} - -static void cpdma_desc_pool_destroy(struct cpdma_desc_pool *pool) -{ - if (!pool) - return; + if (!pool->iomap) + goto gen_pool_create_fail; - WARN_ON(pool->used_desc); - if (pool->cpumap) { - dma_free_coherent(pool->dev, pool->mem_size, pool->cpumap, - pool->phys); - } else { - iounmap(pool->iomap); + ret = gen_pool_add_virt(pool->gen_pool, (unsigned long)pool->iomap, + pool->phys, pool->mem_size, -1); + if (ret < 0) { + dev_err(dev, "pool add failed %d\n", ret); + goto gen_pool_add_virt_fail; } + + return pool; + +gen_pool_add_virt_fail: + cpdma_desc_pool_destroy(pool); +gen_pool_create_fail: + return NULL; } static inline dma_addr_t desc_phys(struct cpdma_desc_pool *pool, @@ -220,47 +233,23 @@ desc_from_phys(struct cpdma_desc_pool *pool, dma_addr_t dma) } static struct cpdma_desc __iomem * -cpdma_desc_alloc(struct cpdma_desc_pool *pool, int num_desc, bool is_rx) +cpdma_desc_alloc(struct cpdma_desc_pool *pool) { - unsigned long flags; - int index; - int desc_start; - int desc_end; struct cpdma_desc __iomem *desc = NULL; - spin_lock_irqsave(&pool->lock, flags); - - if (is_rx) { - desc_start = 0; - desc_end = pool->num_desc/2; - } else { - desc_start = pool->num_desc/2; - desc_end = pool->num_desc; - } - - index = bitmap_find_next_zero_area(pool->bitmap, - desc_end, desc_start, num_desc, 0); - if (index < desc_end) { - bitmap_set(pool->bitmap, index, num_desc); - desc = pool->iomap + pool->desc_size * index; + desc = (struct cpdma_desc __iomem *)gen_pool_alloc(pool->gen_pool, + pool->desc_size); + if (desc) pool->used_desc++; - } - spin_unlock_irqrestore(&pool->lock, flags); return desc; } static void cpdma_desc_free(struct cpdma_desc_pool *pool, struct cpdma_desc __iomem *desc, int num_desc) { - unsigned long flags, index; - - index = ((unsigned long)desc - (unsigned long)pool->iomap) / - pool->desc_size; - spin_lock_irqsave(&pool->lock, flags); - bitmap_clear(pool->bitmap, index, num_desc); + gen_pool_free(pool->gen_pool, (unsigned long)desc, pool->desc_size); pool->used_desc--; - spin_unlock_irqrestore(&pool->lock, flags); } struct cpdma_ctlr *cpdma_ctlr_create(struct cpdma_params *params) @@ -516,6 +505,7 @@ struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num, chan->state = CPDMA_STATE_IDLE; chan->chan_num = chan_num; chan->handler = handler; + chan->desc_num = ctlr->pool->num_desc / 2; if (is_rx_chan(chan)) { chan->hdp = ctlr->params.rxhdp + offset; @@ -675,7 +665,13 @@ int cpdma_chan_submit(struct cpdma_chan *chan, void *token, void *data, goto unlock_ret; } - desc = cpdma_desc_alloc(ctlr->pool, 1, is_rx_chan(chan)); + if (chan->count >= chan->desc_num) { + chan->stats.desc_alloc_fail++; + ret = -ENOMEM; + goto unlock_ret; + } + + desc = cpdma_desc_alloc(ctlr->pool); if (!desc) { chan->stats.desc_alloc_fail++; ret = -ENOMEM; @@ -722,24 +718,16 @@ EXPORT_SYMBOL_GPL(cpdma_chan_submit); bool cpdma_check_free_tx_desc(struct cpdma_chan *chan) { - unsigned long flags; - int index; - bool ret; struct cpdma_ctlr *ctlr = chan->ctlr; struct cpdma_desc_pool *pool = ctlr->pool; + bool free_tx_desc; + unsigned long flags; - spin_lock_irqsave(&pool->lock, flags); - - index = bitmap_find_next_zero_area(pool->bitmap, - pool->num_desc, pool->num_desc/2, 1, 0); - - if (index < pool->num_desc) - ret = true; - else - ret = false; - - spin_unlock_irqrestore(&pool->lock, flags); - return ret; + spin_lock_irqsave(&chan->lock, flags); + free_tx_desc = (chan->count < chan->desc_num) && + gen_pool_avail(pool->gen_pool); + spin_unlock_irqrestore(&chan->lock, flags); + return free_tx_desc; } EXPORT_SYMBOL_GPL(cpdma_check_free_tx_desc); -- 2.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
