When rx_flag == MTK_RX_FLAGS_HWLRO,
rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE.
netdev_alloc_frag is for alloction of page fragment only.
Reference to other drivers and Documentation/vm/page_frags.rst
Branch to use __get_free_pages when ring->frag_size > PAGE_SIZE.
Signed-off-by: Chen Lin <[email protected]>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index b3b3c07..ba9259a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1467,7 +1467,13 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
goto release_desc;
/* alloc new buffer */
- new_data = napi_alloc_frag(ring->frag_size);
+ if (ring->frag_size <= PAGE_SIZE)
+ new_data = napi_alloc_frag(ring->frag_size);
+ else
+ new_data = (void *)__get_free_pages(GFP_ATOMIC |
+ __GFP_COMP | __GFP_NOWARN,
+ get_order(mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH)));
+
if (unlikely(!new_data)) {
netdev->stats.rx_dropped++;
goto release_desc;
@@ -1914,7 +1920,13 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
return -ENOMEM;
for (i = 0; i < rx_dma_size; i++) {
- ring->data[i] = netdev_alloc_frag(ring->frag_size);
+ if (ring->frag_size <= PAGE_SIZE)
+ ring->data[i] = netdev_alloc_frag(ring->frag_size);
+ else
+ ring->data[i] = (void *)__get_free_pages(GFP_KERNEL |
+ __GFP_COMP | __GFP_NOWARN,
+ get_order(mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH)));
+
if (!ring->data[i])
return -ENOMEM;
}
--
1.7.9.5
On Sun, 5 Jun 2022 11:12:37 +0800 Chen Lin wrote:
> + new_data = (void *)__get_free_pages(GFP_ATOMIC |
> + __GFP_COMP | __GFP_NOWARN,
> + get_order(mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH)));
Please make this a helper which takes the gfp flags.
When rx_flag == MTK_RX_FLAGS_HWLRO,
rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE.
netdev_alloc_frag is for alloction of page fragment only.
Reference to other drivers and Documentation/vm/page_frags.rst
Branch to use __get_free_pages when ring->frag_size > PAGE_SIZE.
Signed-off-by: Chen Lin <[email protected]>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index b3b3c07..3da162e 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -899,6 +899,17 @@ static bool mtk_rx_get_desc(struct mtk_eth *eth, struct mtk_rx_dma_v2 *rxd,
return true;
}
+static inline void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
+{
+ void *data;
+
+ data = (void *)__get_free_pages(gfp_mask |
+ __GFP_COMP | __GFP_NOWARN,
+ get_order(mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH)));
+
+ return data;
+}
+
/* the qdma core needs scratch memory to be setup */
static int mtk_init_fq_dma(struct mtk_eth *eth)
{
@@ -1467,7 +1478,10 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
goto release_desc;
/* alloc new buffer */
- new_data = napi_alloc_frag(ring->frag_size);
+ if (ring->frag_size <= PAGE_SIZE)
+ new_data = napi_alloc_frag(ring->frag_size);
+ else
+ new_data = mtk_max_lro_buf_alloc(GFP_ATOMIC);
if (unlikely(!new_data)) {
netdev->stats.rx_dropped++;
goto release_desc;
@@ -1914,7 +1928,10 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
return -ENOMEM;
for (i = 0; i < rx_dma_size; i++) {
- ring->data[i] = netdev_alloc_frag(ring->frag_size);
+ if (ring->frag_size <= PAGE_SIZE)
+ ring->data[i] = netdev_alloc_frag(ring->frag_size);
+ else
+ ring->data[i] = mtk_max_lro_buf_alloc(GFP_KERNEL);
if (!ring->data[i])
return -ENOMEM;
}
--
1.7.9.5
On Tue, 7 Jun 2022 07:39:11 +0800 Chen Lin wrote:
> +static inline void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
No need for inline, compiler will inline this anyway.
> +{
> + void *data;
unsigned long data; then you can move the cast from the long line to
the return statement, saving us from the strange indentation.
> + data = (void *)__get_free_pages(gfp_mask |
> + __GFP_COMP | __GFP_NOWARN,
> + get_order(mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH)));
> +
> + return data;
> +}
At 2022-06-08 07:14:13, "Jakub Kicinski" <[email protected]> wrote:
>On Tue, 7 Jun 2022 07:39:11 +0800 Chen Lin wrote:
>> +static inline void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
>
>No need for inline, compiler will inline this anyway.
>
>> +{
>> + void *data;
>
>unsigned long data; then you can move the cast from the long line to
>the return statement, saving us from the strange indentation.
>
>> + data = (void *)__get_free_pages(gfp_mask |
>> + __GFP_COMP | __GFP_NOWARN,
>> + get_order(mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH)));
>> +
>> + return data;
>> +}
I'll do it like below :
+static void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
+{
+ unsigned long data;
+ unsigned int size = mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH);
+
+ data = __get_free_pages(gfp_mask | __GFP_COMP | __GFP_NOWARN,
+ get_order(size));
+
+ return (void *)data;
+}
Through analysis of the ASM code from objdump, I confirmed that
the inline is not necessary. Thanks for your tips.
Also, I confirmed that create a new local variable 'size'
will not affect the generation of a constant 'order' parameter at compile time.
ASM code of calling 'mtk_max_lro_buf_alloc':
'mtk_max_lro_buf_alloc' inlined and 'order'(w1) is a constant 0x2
0000000000004530 <mtk_napi_rx>:
...
4a98: 52854400 mov w0, #0x2a20 // #10784
4a9c: 52800041 mov w1, #0x2 // #2
4aa0: 72a00080 movk w0, #0x4, lsl #16
4aa4: 94000000 bl 0 <__get_free_pages>
4aa8: f90033e0 str x0, [sp, #96]
0000000000000730 <mtk_rx_alloc>:
...
7fc: 2a1703e0 mov w0, w23
800: 52800041 mov w1, #0x2 // #2
804: 7140047f cmp w3, #0x1, lsl #12
808: 54fffe49 b.ls 7d0 <mtk_rx_alloc+0xa0> // b.plast
80c: 94000000 bl 0 <__get_free_pages>
The compiler is smart.
When rx_flag == MTK_RX_FLAGS_HWLRO,
rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE.
netdev_alloc_frag is for alloction of page fragment only.
Reference to other drivers and Documentation/vm/page_frags.rst
Branch to use __get_free_pages when ring->frag_size > PAGE_SIZE.
Signed-off-by: Chen Lin <[email protected]>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index b3b3c07..aba0d84 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -899,6 +899,17 @@ static bool mtk_rx_get_desc(struct mtk_eth *eth, struct mtk_rx_dma_v2 *rxd,
return true;
}
+static void *mtk_max_lro_buf_alloc(gfp_t gfp_mask)
+{
+ unsigned long data;
+ unsigned int size = mtk_max_frag_size(MTK_MAX_LRO_RX_LENGTH);
+
+ data = __get_free_pages(gfp_mask | __GFP_COMP | __GFP_NOWARN,
+ get_order(size));
+
+ return (void *)data;
+}
+
/* the qdma core needs scratch memory to be setup */
static int mtk_init_fq_dma(struct mtk_eth *eth)
{
@@ -1467,7 +1478,10 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
goto release_desc;
/* alloc new buffer */
- new_data = napi_alloc_frag(ring->frag_size);
+ if (ring->frag_size <= PAGE_SIZE)
+ new_data = napi_alloc_frag(ring->frag_size);
+ else
+ new_data = mtk_max_lro_buf_alloc(GFP_ATOMIC);
if (unlikely(!new_data)) {
netdev->stats.rx_dropped++;
goto release_desc;
@@ -1914,7 +1928,10 @@ static int mtk_rx_alloc(struct mtk_eth *eth, int ring_no, int rx_flag)
return -ENOMEM;
for (i = 0; i < rx_dma_size; i++) {
- ring->data[i] = netdev_alloc_frag(ring->frag_size);
+ if (ring->frag_size <= PAGE_SIZE)
+ ring->data[i] = netdev_alloc_frag(ring->frag_size);
+ else
+ ring->data[i] = mtk_max_lro_buf_alloc(GFP_KERNEL);
if (!ring->data[i])
return -ENOMEM;
}
--
1.7.9.5
Hello:
This patch was applied to netdev/net.git (master)
by Jakub Kicinski <[email protected]>:
On Wed, 8 Jun 2022 20:46:53 +0800 you wrote:
> When rx_flag == MTK_RX_FLAGS_HWLRO,
> rx_data_len = MTK_MAX_LRO_RX_LENGTH(4096 * 3) > PAGE_SIZE.
> netdev_alloc_frag is for alloction of page fragment only.
> Reference to other drivers and Documentation/vm/page_frags.rst
>
> Branch to use __get_free_pages when ring->frag_size > PAGE_SIZE.
>
> [...]
Here is the summary with links:
- [v5] net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag
https://git.kernel.org/netdev/net/c/2f2c0d2919a1
You are awesome, thank you!
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