[PATCH net-next 0/2] Add the capability to allocate hw buffers in SRAM for EN7581 SoC

[PATCH net-next 0/2] Add the capability to allocate hw buffers in SRAM for EN7581 SoC

[Lorenzo Bianconi]

In order to improve packet processing and packet forwarding
performances, EN7581 SoC supports allocating buffers for hw forwarding
queues in SRAM instead of DRAM if available on the system.
Rely on SRAM for buffers allocation if available on the system and use
DRAM as fallback.

---
Lorenzo Bianconi (2):
      dt-bindings: net: airoha: Add EN7581 memory-region property
      net: airoha: Add the capability to allocate hw buffers in SRAM

 .../devicetree/bindings/net/airoha,en7581-eth.yaml | 13 ++++++
 drivers/net/ethernet/airoha/airoha_eth.c           | 48 ++++++++++++++++++----
 2 files changed, 52 insertions(+), 9 deletions(-)
---
base-commit: 9daaf197860055aa26c06d273d317c18c6e3621a
change-id: 20250507-airopha-desc-sram-faeb3ea6cbc5

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

[PATCH net-next 1/2] dt-bindings: net: airoha: Add EN7581 memory-region property

[Lorenzo Bianconi]

Introduce the memory-region and memory-region-names properties for the
ethernet node available on EN7581 SoC. In order to improve performances,
EN7581 SoC supports allocating buffers for hw forwarding queues in SRAM
instead of DRAM if available on the system.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 .../devicetree/bindings/net/airoha,en7581-eth.yaml          | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml b/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml
index 0fdd1126541774acacc783d98e4c089b2d2b85e2..6d22131ac2f9e28390b9e785ce33e8d983eafd0f 100644
--- a/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml
+++ b/Documentation/devicetree/bindings/net/airoha,en7581-eth.yaml
@@ -57,6 +57,16 @@ properties:
       - const: hsi-mac
       - const: xfp-mac
 
+  memory-region:
+    items:
+      - description: QDMA0 buffer memory
+      - description: QDMA1 buffer memory
+
+  memory-region-names:
+    items:
+      - const: qdma0-buf
+      - const: qdma1-buf
+
   "#address-cells":
     const: 1
 
@@ -140,6 +150,9 @@ examples:
                      <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>,
                      <GIC_SPI 64 IRQ_TYPE_LEVEL_HIGH>;
 
+        memory-region = <&qdma0_buf>, <&qdma1_buf>;
+        memory-region-names = "qdma0-buf", "qdma1-buf";
+
         airoha,npu = <&npu>;
 
         #address-cells = <1>;

-- 
2.49.0

[PATCH net-next 2/2] net: airoha: Add the capability to allocate hw buffers in SRAM

[Lorenzo Bianconi]

In order to improve packet processing and packet forwarding
performances, EN7581 SoC supports allocating buffers for hw forwarding
queues in SRAM instead of DRAM if available on the system.
Rely on SRAM for buffers allocation if available on the system and use
DRAM as fallback.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/net/ethernet/airoha/airoha_eth.c | 48 ++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c
index 16c7896f931fd9532aa3b8cc78f41afc676aa117..b1ca8322d4eb34f48a6ed6a3b4596c128324cd50 100644
--- a/drivers/net/ethernet/airoha/airoha_eth.c
+++ b/drivers/net/ethernet/airoha/airoha_eth.c
@@ -5,6 +5,7 @@
  */
 #include <linux/of.h>
 #include <linux/of_net.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/platform_device.h>
 #include <linux/tcp.h>
 #include <linux/u64_stats_sync.h>
@@ -1076,9 +1077,11 @@ static void airoha_qdma_cleanup_tx_queue(struct airoha_queue *q)
 static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 {
 	struct airoha_eth *eth = qdma->eth;
+	int id = qdma - &eth->qdma[0];
 	dma_addr_t dma_addr;
-	u32 status;
-	int size;
+	const char *name;
+	int size, index;
+	u32 status, val;
 
 	size = HW_DSCP_NUM * sizeof(struct airoha_qdma_fwd_desc);
 	qdma->hfwd.desc = dmam_alloc_coherent(eth->dev, size, &dma_addr,
@@ -1088,12 +1091,36 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 
 	airoha_qdma_wr(qdma, REG_FWD_DSCP_BASE, dma_addr);
 
-	size = AIROHA_MAX_PACKET_SIZE * HW_DSCP_NUM;
-	qdma->hfwd.q = dmam_alloc_coherent(eth->dev, size, &dma_addr,
-					   GFP_KERNEL);
-	if (!qdma->hfwd.q)
+	name = devm_kasprintf(eth->dev, GFP_KERNEL, "qdma%d-buf", id);
+	if (!name)
 		return -ENOMEM;
 
+	index = of_property_match_string(eth->dev->of_node,
+					 "memory-region-names", name);
+	if (index >= 0) { /* buffers in sram */
+		struct reserved_mem *rmem;
+		struct device_node *np;
+
+		np = of_parse_phandle(eth->dev->of_node, "memory-region",
+				      index);
+		if (!np)
+			return -ENODEV;
+
+		rmem = of_reserved_mem_lookup(np);
+		of_node_put(np);
+
+		dma_addr = rmem->base;
+		qdma->hfwd.q = devm_ioremap(eth->dev, rmem->base, rmem->size);
+		if (!qdma->hfwd.q)
+			return -ENOMEM;
+	} else {
+		size = AIROHA_MAX_PACKET_SIZE * HW_DSCP_NUM;
+		qdma->hfwd.q = dmam_alloc_coherent(eth->dev, size, &dma_addr,
+						   GFP_KERNEL);
+		if (!qdma->hfwd.q)
+			return -ENOMEM;
+	}
+
 	airoha_qdma_wr(qdma, REG_FWD_BUF_BASE, dma_addr);
 
 	airoha_qdma_rmw(qdma, REG_HW_FWD_DSCP_CFG,
@@ -1101,11 +1128,14 @@ static int airoha_qdma_init_hfwd_queues(struct airoha_qdma *qdma)
 			FIELD_PREP(HW_FWD_DSCP_PAYLOAD_SIZE_MASK, 0));
 	airoha_qdma_rmw(qdma, REG_FWD_DSCP_LOW_THR, FWD_DSCP_LOW_THR_MASK,
 			FIELD_PREP(FWD_DSCP_LOW_THR_MASK, 128));
+
+	val = FIELD_PREP(HW_FWD_DESC_NUM_MASK, HW_DSCP_NUM) |
+	      LMGR_INIT_START;
+	if (index >= 0)
+		val |= LMGR_SRAM_MODE_MASK;
 	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) |
-			LMGR_INIT_START);
+			HW_FWD_DESC_NUM_MASK, val);
 
 	return read_poll_timeout(airoha_qdma_rr, status,
 				 !(status & LMGR_INIT_START), USEC_PER_MSEC,

-- 
2.49.0

Re: [PATCH net-next 2/2] net: airoha: Add the capability to allocate hw buffers in SRAM

[Jakub Kicinski]

On Wed, 07 May 2025 19:48:46 +0200 Lorenzo Bianconi wrote:
> In order to improve packet processing and packet forwarding
> performances, EN7581 SoC supports allocating buffers for hw forwarding
> queues in SRAM instead of DRAM if available on the system.
> Rely on SRAM for buffers allocation if available on the system and use
> DRAM as fallback.

drivers/net/ethernet/airoha/airoha_eth.c:1113:30: warning: incorrect type in assignment (different address spaces)
drivers/net/ethernet/airoha/airoha_eth.c:1113:30:    expected void *q
drivers/net/ethernet/airoha/airoha_eth.c:1113:30:    got void [noderef] __iomem *
-- 
pw-bot: cr