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
Signed-off-by: Grygorii Strashko
---
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
#include
#include
-
+#include
#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_fnhandler;
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);
+