[PATCH net v4 0/2] net: airoha: Improve hwfd buffer/descriptor queues setup

[PATCH net v4 0/2] net: airoha: Improve hwfd buffer/descriptor queues setup

[Lorenzo Bianconi]

Compute the number of hwfd buffers/descriptors according to the reserved
memory size if provided via DTS.
Reduce the required hwfd buffers queue size for QDMA1.

---
Changes in v4:
- Fix commit log for patch 2/2
- Link to v3: https://lore.kernel.org/r/20250618-airoha-hw-num-desc-v3-0-18a6487cd75e@kernel.org

Changes in v3:
- Target net tree instead of net-next one

Changes in v2:
- Rely on div_u64 to compute number of hw descriptors
- Link to v1: https://lore.kernel.org/r/20250615-airoha-hw-num-desc-v1-0-8f88daa4abd7@kernel.org

---
Lorenzo Bianconi (2):
      net: airoha: Compute number of descriptors according to reserved memory size
      net: airoha: Differentiate hwfd buffer size for QDMA0 and QDMA1

 drivers/net/ethernet/airoha/airoha_eth.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)
---
base-commit: 9b70c362a9d4ab93e0b582dad73acb2a953ef797
change-id: 20250618-airoha-hw-num-desc-6f5b6f9f85ae

Best regards,
-- 
Lorenzo Bianconi <lorenzo@kernel.org>

[PATCH net v4 1/2] net: airoha: Compute number of descriptors according to reserved memory size

[Lorenzo Bianconi]

In order to not exceed the reserved memory size for hwfd buffers,
compute the number of hwfd buffers/descriptors according to the
reserved memory size and the size of each hwfd buffer (2KB).

Fixes: 3a1ce9e3d01b ("net: airoha: Add the capability to allocate hwfd buffers via reserved-memory")
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index a7ec609d64dee9c8e901c7eb650bb3fe144ee00a..1b7fd7ee0cbf3e1f7717110c70e9c5183fdd93d4 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -1065,19 +1065,13 @@ static void airoha_qdma_cleanup_tx_queue(struct airoha_queue *q)
 
 static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 {
+	int size, index, num_desc = HW_DSCP_NUM;
 	struct airoha_eth *eth = qdma->eth;
 	int id = qdma - &eth->qdma[0];
 	dma_addr_t dma_addr;
 	const char *name;
-	int size, index;
 	u32 status;
 
-	size = HW_DSCP_NUM * sizeof(struct airoha_qdma_fwd_desc);
-	if (!dmam_alloc_coherent(eth->dev, size, &dma_addr, GFP_KERNEL))
-		return -ENOMEM;
-
-	airoha_qdma_wr(qdma, REG_FWD_DSCP_BASE, dma_addr);
-
 	name = devm_kasprintf(eth->dev, GFP_KERNEL, "qdma%d-buf", id);
 	if (!name)
 		return -ENOMEM;
@@ -1099,8 +1093,12 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 		rmem = of_reserved_mem_lookup(np);
 		of_node_put(np);
 		dma_addr = rmem->base;
+		/* Compute the number of hw descriptors according to the
+		 * reserved memory size and the payload buffer size
+		 */
+		num_desc = rmem->size / AIROHA_MAX_PACKET_SIZE;
 	} else {
-		size = AIROHA_MAX_PACKET_SIZE * HW_DSCP_NUM;
+		size = AIROHA_MAX_PACKET_SIZE * num_desc;
 		if (!dmam_alloc_coherent(eth->dev, size, &dma_addr,
 					 GFP_KERNEL))
 			return -ENOMEM;
@@ -1108,6 +1106,11 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 
 	airoha_qdma_wr(qdma, REG_FWD_BUF_BASE, dma_addr);
 
+	size = num_desc * sizeof(struct airoha_qdma_fwd_desc);
+	if (!dmam_alloc_coherent(eth->dev, size, &dma_addr, GFP_KERNEL))
+		return -ENOMEM;
+
+	airoha_qdma_wr(qdma, REG_FWD_DSCP_BASE, dma_addr);
 	airoha_qdma_rmw(qdma, REG_HW_FWD_DSCP_CFG,
 			HW_FWD_DSCP_PAYLOAD_SIZE_MASK,
 			FIELD_PREP(HW_FWD_DSCP_PAYLOAD_SIZE_MASK, 0));
@@ -1116,7 +1119,7 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 	airoha_qdma_rmw(qdma, REG_LMGR_INIT_CFG,
 			LMGR_INIT_START | LMGR_SRAM_MODE_MASK |
 			HW_FWD_DESC_NUM_MASK,
-			FIELD_PREP(HW_FWD_DESC_NUM_MASK, HW_DSCP_NUM) |
+			FIELD_PREP(HW_FWD_DESC_NUM_MASK, num_desc) |
 			LMGR_INIT_START | LMGR_SRAM_MODE_MASK);
 
 	return read_poll_timeout(airoha_qdma_rr, status,

-- 
2.49.0

[PATCH net v4 2/2] net: airoha: Differentiate hwfd buffer size for QDMA0 and QDMA1

[Lorenzo Bianconi]

EN7581 SoC allows configuring the size and the number of buffers in
hwfd payload queue for both QDMA0 and QDMA1.
In order to reduce the required DRAM used for hwfd buffers queues and
decrease the memory footprint, differentiate hwfd buffer size for QDMA0
and QDMA1 and reduce hwfd buffer size to 1KB for QDMA1 (WAN) while
maintaining 2KB for QDMA0 (LAN).

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 1b7fd7ee0cbf3e1f7717110c70e9c5183fdd93d4..06dea3a13e77ce11f35dbd36966a34c5ef229c11 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -1068,14 +1068,15 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 	int size, index, num_desc = HW_DSCP_NUM;
 	struct airoha_eth *eth = qdma->eth;
 	int id = qdma - &eth->qdma[0];
+	u32 status, buf_size;
 	dma_addr_t dma_addr;
 	const char *name;
-	u32 status;
 
 	name = devm_kasprintf(eth->dev, GFP_KERNEL, "qdma%d-buf", id);
 	if (!name)
 		return -ENOMEM;
 
+	buf_size = id ? AIROHA_MAX_PACKET_SIZE / 2 : AIROHA_MAX_PACKET_SIZE;
 	index = of_property_match_string(eth->dev->of_node,
 					 "memory-region-names", name);
 	if (index >= 0) {
@@ -1096,9 +1097,9 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 		/* Compute the number of hw descriptors according to the
 		 * reserved memory size and the payload buffer size
 		 */
-		num_desc = rmem->size / AIROHA_MAX_PACKET_SIZE;
+		num_desc = div_u64(rmem->size, buf_size);
 	} else {
-		size = AIROHA_MAX_PACKET_SIZE * num_desc;
+		size = buf_size * num_desc;
 		if (!dmam_alloc_coherent(eth->dev, size, &dma_addr,
 					 GFP_KERNEL))
 			return -ENOMEM;
@@ -1111,9 +1112,10 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 		return -ENOMEM;
 
 	airoha_qdma_wr(qdma, REG_FWD_DSCP_BASE, dma_addr);
+	/* QDMA0: 2KB. QDMA1: 1KB */
 	airoha_qdma_rmw(qdma, REG_HW_FWD_DSCP_CFG,
 			HW_FWD_DSCP_PAYLOAD_SIZE_MASK,
-			FIELD_PREP(HW_FWD_DSCP_PAYLOAD_SIZE_MASK, 0));
+			FIELD_PREP(HW_FWD_DSCP_PAYLOAD_SIZE_MASK, !!id));
 	airoha_qdma_rmw(qdma, REG_FWD_DSCP_LOW_THR, FWD_DSCP_LOW_THR_MASK,
 			FIELD_PREP(FWD_DSCP_LOW_THR_MASK, 128));
 	airoha_qdma_rmw(qdma, REG_LMGR_INIT_CFG,

-- 
2.49.0

Re: [PATCH net v4 2/2] net: airoha: Differentiate hwfd buffer size for QDMA0 and QDMA1

[Simon Horman]

On Thu, Jun 19, 2025 at 09:07:25AM +0200, Lorenzo Bianconi wrote:
> EN7581 SoC allows configuring the size and the number of buffers in
> hwfd payload queue for both QDMA0 and QDMA1.
> In order to reduce the required DRAM used for hwfd buffers queues and
> decrease the memory footprint, differentiate hwfd buffer size for QDMA0
> and QDMA1 and reduce hwfd buffer size to 1KB for QDMA1 (WAN) while
> maintaining 2KB for QDMA0 (LAN).
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>

Hi Lorenzo,

Thanks for the updated commit message.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net v4 0/2] net: airoha: Improve hwfd buffer/descriptor queues setup

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 19 Jun 2025 09:07:23 +0200 you wrote:
> Compute the number of hwfd buffers/descriptors according to the reserved
> memory size if provided via DTS.
> Reduce the required hwfd buffers queue size for QDMA1.
> 
> ---
> Changes in v4:
> - Fix commit log for patch 2/2
> - Link to v3: https://lore.kernel.org/r/20250618-airoha-hw-num-desc-v3-0-18a6487cd75e@kernel.org
> 
> [...]

Here is the summary with links:
  - [net,v4,1/2] net: airoha: Compute number of descriptors according to reserved memory size
    https://git.kernel.org/netdev/net/c/edf8afeecfbb
  - [net,v4,2/2] net: airoha: Differentiate hwfd buffer size for QDMA0 and QDMA1
    https://git.kernel.org/netdev/net/c/7b46bdaec00a

You are awesome, thank you!
-- 
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