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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Marc St-Amand <mstamand@ciena.com>,
        Harini Katakam <harini.katakam@xilinx.com>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Conor Dooley <conor.dooley@microchip.com>,
        "David S . Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>, claudiu.beznea@microchip.com,
        kuba@kernel.org, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.10 22/23] net: macb: Align the dma and coherent dma masks
Date:   Tue, 15 Feb 2022 10:29:56 -0500
Message-Id: <20220215152957.581303-22-sashal@kernel.org>
In-Reply-To: <20220215152957.581303-1-sashal@kernel.org>
References: <20220215152957.581303-1-sashal@kernel.org>
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From: Marc St-Amand <mstamand@ciena.com>

[ Upstream commit 37f7860602b5b2d99fc7465f6407f403f5941988 ]

Single page and coherent memory blocks can use different DMA masks
when the macb accesses physical memory directly. The kernel is clever
enough to allocate pages that fit into the requested address width.

When using the ARM SMMU, the DMA mask must be the same for single
pages and big coherent memory blocks. Otherwise the translation
tables turn into one big mess.

  [   74.959909] macb ff0e0000.ethernet eth0: DMA bus error: HRESP not OK
  [   74.959989] arm-smmu fd800000.smmu: Unhandled context fault: fsr=0x402, iova=0x3165687460, fsynr=0x20001, cbfrsynra=0x877, cb=1
  [   75.173939] macb ff0e0000.ethernet eth0: DMA bus error: HRESP not OK
  [   75.173955] arm-smmu fd800000.smmu: Unhandled context fault: fsr=0x402, iova=0x3165687460, fsynr=0x20001, cbfrsynra=0x877, cb=1

Since using the same DMA mask does not hurt direct 1:1 physical
memory mappings, this commit always aligns DMA and coherent masks.

Signed-off-by: Marc St-Amand <mstamand@ciena.com>
Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/cadence/macb_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 1e8bf6b9834bb..2af464ac250ac 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -4534,7 +4534,7 @@ static int macb_probe(struct platform_device *pdev)
 
 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 	if (GEM_BFEXT(DAW64, gem_readl(bp, DCFG6))) {
-		dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
+		dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(44));
 		bp->hw_dma_cap |= HW_DMA_CAP_64B;
 	}
 #endif
-- 
2.34.1