On Thursday 23 June 2016 06:26 PM, Ivan Khoronzhuk wrote:
>
>
> On 23.06.16 15:36, Grygorii Strashko wrote:
>> 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.
>>
>> Cc: 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
>>
>> drivers/net/ethernet/ti/davinci_cpdma.c | 136
>> +++++++++++++++-----------------
>> 1 file changed, 62 insertions(+), 74 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c
>> b/drivers/net/ethernet/ti/davinci_cpdma.c
>> index 18bf3a8..03b9882 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);
>> + }
>> +}
>> +
> single if, brackets?
if() has multiple line statement, so brackets are must.
Regards
Mugunthan V N
>
>> /*
>> * 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,
>> @@ -210,7 +223,7 @@ static inline dma_addr_t desc_phys(struct
>> cpdma_desc_pool *pool,
>> {
>> if (!desc)
>> return 0;
>> - return pool->hw_addr + (__force long)desc - (__force
>> long)pool->iomap;
>> + return gen_pool_virt_to_phys(pool->gen_pool, (unsigned long)desc);
>> }
>>
>> static inline struct cpdma_desc __iomem *
>> @@ -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;
>> @@ -721,24 +717,16 @@ 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;
>> + unsigned long flags;
>> + bool free_tx_desc;
> longer first
>
>>
>> - 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);
>>
>> @@ -772,7 +760,6 @@ static int __cpdma_chan_process(struct cpdma_chan
>> *chan)
>> unsigned long flags;
>>
>> spin_lock_irqsave(&chan->lock, flags);
>> -
> ?
>
>> desc = chan->head;
>> if (!desc) {
>> chan->stats.empty_dequeue++;
>> @@ -796,6 +783,7 @@ static int __cpdma_chan_process(struct cpdma_chan
>> *chan)
>> CPDMA_DESC_PORT_MASK);
>>
>> chan->head = desc_from_phys(pool, desc_read(desc, hw_next));
>> +
> ?
>
>> chan_write(chan, cp, desc_dma);
>> chan->count--;
>> chan->stats.good_dequeue++;
>>
>
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