[PATCH V2 02/11] net: mediatek: fix missing free of scratch memory

From: John Crispin
Date: Fri Jun 10 2016 - 07:29:33 EST


Scratch memory gets allocated in mtk_init_fq_dma() but the corresponding
code to free it is missing inside mtk_dma_free() causing a memory leak.
With this patch applied, we can run ifconfig up/down several thousand
times without any problems.

Signed-off-by: John Crispin <john@xxxxxxxxxxx>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 18 +++++++++++++-----
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 2 ++
2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 6780886..8d79bbf 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -453,14 +453,14 @@ static inline void mtk_rx_get_desc(struct mtk_rx_dma *rxd,
/* the qdma core needs scratch memory to be setup */
static int mtk_init_fq_dma(struct mtk_eth *eth)
{
- dma_addr_t phy_ring_head, phy_ring_tail;
+ dma_addr_t phy_ring_tail;
int cnt = MTK_DMA_SIZE;
dma_addr_t dma_addr;
int i;

eth->scratch_ring = dma_alloc_coherent(eth->dev,
cnt * sizeof(struct mtk_tx_dma),
- &phy_ring_head,
+ &eth->phy_scratch_ring,
GFP_ATOMIC | __GFP_ZERO);
if (unlikely(!eth->scratch_ring))
return -ENOMEM;
@@ -477,19 +477,19 @@ static int mtk_init_fq_dma(struct mtk_eth *eth)
return -ENOMEM;

memset(eth->scratch_ring, 0x0, sizeof(struct mtk_tx_dma) * cnt);
- phy_ring_tail = phy_ring_head +
+ phy_ring_tail = eth->phy_scratch_ring +
(sizeof(struct mtk_tx_dma) * (cnt - 1));

for (i = 0; i < cnt; i++) {
eth->scratch_ring[i].txd1 =
(dma_addr + (i * MTK_QDMA_PAGE_SIZE));
if (i < cnt - 1)
- eth->scratch_ring[i].txd2 = (phy_ring_head +
+ eth->scratch_ring[i].txd2 = (eth->phy_scratch_ring +
((i + 1) * sizeof(struct mtk_tx_dma)));
eth->scratch_ring[i].txd3 = TX_DMA_SDL(MTK_QDMA_PAGE_SIZE);
}

- mtk_w32(eth, phy_ring_head, MTK_QDMA_FQ_HEAD);
+ mtk_w32(eth, eth->phy_scratch_ring, MTK_QDMA_FQ_HEAD);
mtk_w32(eth, phy_ring_tail, MTK_QDMA_FQ_TAIL);
mtk_w32(eth, (cnt << 16) | cnt, MTK_QDMA_FQ_CNT);
mtk_w32(eth, MTK_QDMA_PAGE_SIZE << 16, MTK_QDMA_FQ_BLEN);
@@ -1189,6 +1189,14 @@ static void mtk_dma_free(struct mtk_eth *eth)
for (i = 0; i < MTK_MAC_COUNT; i++)
if (eth->netdev[i])
netdev_reset_queue(eth->netdev[i]);
+ if (eth->scratch_ring) {
+ dma_free_coherent(eth->dev,
+ MTK_DMA_SIZE * sizeof(struct mtk_tx_dma),
+ eth->scratch_ring,
+ eth->phy_scratch_ring);
+ eth->scratch_ring = NULL;
+ eth->phy_scratch_ring = 0;
+ }
mtk_tx_clean(eth);
mtk_rx_clean(eth);
kfree(eth->scratch_head);
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index eed626d..57f7e8a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -357,6 +357,7 @@ struct mtk_rx_ring {
* @rx_ring: Pointer to the memore holding info about the RX ring
* @rx_napi: The NAPI struct
* @scratch_ring: Newer SoCs need memory for a second HW managed TX ring
+ * @phy_scratch_ring: physical address of scratch_ring
* @scratch_head: The scratch memory that scratch_ring points to.
* @clk_ethif: The ethif clock
* @clk_esw: The switch clock
@@ -384,6 +385,7 @@ struct mtk_eth {
struct mtk_rx_ring rx_ring;
struct napi_struct rx_napi;
struct mtk_tx_dma *scratch_ring;
+ dma_addr_t phy_scratch_ring;
void *scratch_head;
struct clk *clk_ethif;
struct clk *clk_esw;
--
1.7.10.4