Commit 742fb20f authored by Grygorii Strashko's avatar Grygorii Strashko Committed by David S. Miller

net: ethernet: ti: cpdma: switch to use genalloc

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.
Acked-by: default avatarMugunthan V N <mugunthanvnm@ti.com>
Tested-by: default avatarIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c37d4a00
......@@ -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 +145,19 @@ 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 +168,25 @@ 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 +199,22 @@ 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;
}
if (!pool->iomap)
goto gen_pool_create_fail;
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);
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 +232,23 @@ 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 +504,7 @@ 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;
......@@ -681,7 +670,13 @@ 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;
......@@ -727,24 +722,16 @@ 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);
......
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