[PATCH net-next,v2] net: stmmac: remove duplicate dma queue channel macros

[PATCH net-next,v2] net: stmmac: remove duplicate dma queue channel macros

[Junxiao Chang]

It doesn't need extra macros for queue 0 & 4. Same macro could
be used for all 8 queues. Related queue/channel functions could
be combined together.

Original macro which has two same parameters is unsafe macro and
might have potential side effects. Each MTL RxQ DMA channel mask
is 4 bits, so using (0xf << chan) instead of GENMASK(x + 3, x) to
avoid unsafe macro.

Signed-off-by: Junxiao Chang <junxiao.chang@intel.com>
---
v2: combined "if (queue < 4)" and "else" according to Vee Khee's suggestion.
v1: https://lore.kernel.org/r/20221025053555.1883731-1-junxiao.chang@intel.com
---
 drivers/net/ethernet/stmicro/stmmac/dwmac4.h  |  4 +---
 .../net/ethernet/stmicro/stmmac/dwmac4_core.c | 21 ++++++-------------
 2 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index 71dad409f78b0..ccd49346d3b30 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -331,9 +331,7 @@ enum power_event {
 
 #define MTL_RXQ_DMA_MAP0		0x00000c30 /* queue 0 to 3 */
 #define MTL_RXQ_DMA_MAP1		0x00000c34 /* queue 4 to 7 */
-#define MTL_RXQ_DMA_Q04MDMACH_MASK	GENMASK(3, 0)
-#define MTL_RXQ_DMA_Q04MDMACH(x)	((x) << 0)
-#define MTL_RXQ_DMA_QXMDMACH_MASK(x)	GENMASK(11 + (8 * ((x) - 1)), 8 * (x))
+#define MTL_RXQ_DMA_QXMDMACH_MASK(x)	(0xf << 8 * (x))
 #define MTL_RXQ_DMA_QXMDMACH(chan, q)	((chan) << (8 * (q)))
 
 #define MTL_CHAN_BASE_ADDR		0x00000d00
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index c25bfecb4a2df..513f6ea335a82 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -214,26 +214,17 @@ static void dwmac4_map_mtl_dma(struct mac_device_info *hw, u32 queue, u32 chan)
 	void __iomem *ioaddr = hw->pcsr;
 	u32 value;
 
-	if (queue < 4)
+	if (queue < 4) {
 		value = readl(ioaddr + MTL_RXQ_DMA_MAP0);
-	else
-		value = readl(ioaddr + MTL_RXQ_DMA_MAP1);
-
-	if (queue == 0 || queue == 4) {
-		value &= ~MTL_RXQ_DMA_Q04MDMACH_MASK;
-		value |= MTL_RXQ_DMA_Q04MDMACH(chan);
-	} else if (queue > 4) {
-		value &= ~MTL_RXQ_DMA_QXMDMACH_MASK(queue - 4);
-		value |= MTL_RXQ_DMA_QXMDMACH(chan, queue - 4);
-	} else {
 		value &= ~MTL_RXQ_DMA_QXMDMACH_MASK(queue);
 		value |= MTL_RXQ_DMA_QXMDMACH(chan, queue);
-	}
-
-	if (queue < 4)
 		writel(value, ioaddr + MTL_RXQ_DMA_MAP0);
-	else
+	} else {
+		value = readl(ioaddr + MTL_RXQ_DMA_MAP1);
+		value &= ~MTL_RXQ_DMA_QXMDMACH_MASK(queue - 4);
+		value |= MTL_RXQ_DMA_QXMDMACH(chan, queue - 4);
 		writel(value, ioaddr + MTL_RXQ_DMA_MAP1);
+	}
 }
 
 static void dwmac4_config_cbs(struct mac_device_info *hw,
-- 
2.25.1

Re: [PATCH net-next,v2] net: stmmac: remove duplicate dma queue channel macros

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Tue, 25 Oct 2022 16:17:47 +0800 you wrote:
> It doesn't need extra macros for queue 0 & 4. Same macro could
> be used for all 8 queues. Related queue/channel functions could
> be combined together.
> 
> Original macro which has two same parameters is unsafe macro and
> might have potential side effects. Each MTL RxQ DMA channel mask
> is 4 bits, so using (0xf << chan) instead of GENMASK(x + 3, x) to
> avoid unsafe macro.
> 
> [...]

Here is the summary with links:
  - [net-next,v2] net: stmmac: remove duplicate dma queue channel macros
    https://git.kernel.org/netdev/net-next/c/330543d04f2c

You are awesome, thank you!
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