linux-kernel - [PATCH v4 3/3] dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <bce96511426a3c63d32530e359c7d966a7321679.1765845252.git.khairul.anuar.romli@altera.com>
Date: Wed, 17 Dec 2025 07:26:18 +0800
From: Khairul Anuar Romli <khairul.anuar.romli@...era.com>
To: Dinh Nguyen <dinguyen@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Eugeniy Paltsev <Eugeniy.Paltsev@...opsys.com>,
	Vinod Koul <vkoul@...nel.org>,
	dmaengine@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Khairul Anuar Romli <khairul.anuar.romli@...era.com>
Subject: [PATCH v4 3/3] dma: dw-axi-dmac: Add support for Agilex5 and dynamic bus width

Add device tree compatible string support for the Altera Agilex5 AXI DMA
controller.

Use common get "dma-ranges" property and calculate the actual number of
addressable bits (bus width) for the DMA engine. This calculated value is
then used to set the coherent mask via 'dma_set_mask_and_coherent()',
allowing the driver to correctly handle devices with bus widths less than
64 bits. Initialize the addressable bits default to 64 if 'dma-ranges' is
not specified or cannot be parsed.

Signed-off-by: Khairul Anuar Romli <khairul.anuar.romli@...era.com>
---
Changes in v4:
	- Simplify the code to use common code to get dma ranges.
	- Narrow the code changes on hw_init.
Changes in v3:
	- Refactor the code to align with dma controller device node move
	  to 1 level down.
Changes in v2:
	- Add driver implementation to set the DMA BIT MAST to 40 based on
	  dma-ranges defined in DT.
	- Add glue for driver and DT.
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 16 +++++++++++++++-
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h          |  1 +
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index b23536645ff7..ac67c18a05c0 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -12,6 +12,7 @@
 #include <linux/device.h>
 #include <linux/dmaengine.h>
 #include <linux/dmapool.h>
+#include <linux/dma-direct.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
@@ -264,14 +265,25 @@ static inline bool axi_chan_is_hw_enable(struct axi_dma_chan *chan)
 
 static void axi_dma_hw_init(struct axi_dma_chip *chip)
 {
+	const struct bus_dma_region *map = NULL;
+	unsigned int addressable_bits = 64;
 	int ret;
+	u64 max_bus;
 	u32 i;
 
 	for (i = 0; i < chip->dw->hdata->nr_channels; i++) {
 		axi_chan_irq_disable(&chip->dw->chan[i], DWAXIDMAC_IRQ_ALL);
 		axi_chan_disable(&chip->dw->chan[i]);
 	}
-	ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(64));
+
+	ret = of_dma_get_range(chip->dev->of_node, &map);
+	if (!ret) {
+		max_bus = map->dma_start + map->size - 1;
+		addressable_bits = fls64(max_bus);
+	}
+
+	dev_dbg(chip->dev, "Addressable bus width: %u\n", addressable_bits);
+	ret = dma_set_mask_and_coherent(chip->dev, DMA_BIT_MASK(addressable_bits));
 	if (ret)
 		dev_warn(chip->dev, "Unable to set coherent mask\n");
 }
@@ -1669,6 +1681,8 @@ static const struct of_device_id dw_dma_of_id_table[] = {
 	}, {
 		.compatible = "starfive,jh8100-axi-dma",
 		.data = (void *)AXI_DMA_FLAG_HAS_RESETS,
+	}, {
+		.compatible = "altr,agilex5-axi-dma"
 	},
 	{}
 };
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index b842e6a8d90d..f9f7ff3f2226 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -143,6 +143,7 @@ static inline struct axi_dma_chan *dchan_to_axi_dma_chan(struct dma_chan *dchan)
 	return vc_to_axi_dma_chan(to_virt_chan(dchan));
 }
 
+int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map);
 
 #define COMMON_REG_LEN		0x100
 #define CHAN_REG_LEN		0x100
-- 
2.43.7