linux-kernel - [PATCH v9 15/16] dmaengine: dw-axi-dmac: Set constraint to the Max segment size

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: <20210105004306.13588-16-jee.heng.sia@intel.com>
Date:   Tue,  5 Jan 2021 08:43:05 +0800
From:   Sia Jee Heng <jee.heng.sia@...el.com>
To:     vkoul@...nel.org, Eugeniy.Paltsev@...opsys.com, robh+dt@...nel.org
Cc:     andriy.shevchenko@...ux.intel.com, dmaengine@...r.kernel.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: [PATCH v9 15/16] dmaengine: dw-axi-dmac: Set constraint to the Max segment size

Add support for DMA Scatter-Gather (SG) constraint so that DMA clients can
handle the AxiDMA limitation.

Without supporting DMA constraint the default Max segment size reported by
dmaengine is 64KB, which is not supported by Intel KeemBay AxiDMA.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Signed-off-by: Sia Jee Heng <jee.heng.sia@...el.com>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 8 ++++++++
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h          | 1 +
 2 files changed, 9 insertions(+)

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 ea527b92e0fc..1f9522caf876 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-mapping.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -1341,6 +1342,13 @@ static int dw_probe(struct platform_device *pdev)
 	dw->dma.device_prep_slave_sg = dw_axi_dma_chan_prep_slave_sg;
 	dw->dma.device_prep_dma_cyclic = dw_axi_dma_chan_prep_cyclic;
 
+	/*
+	 * Synopsis DesignWare AxiDMA datasheet mentioned Maximum
+	 * supported blocks is 1024. Device register width is 4 bytes.
+	 * Therefore, set constraint to 1024 * 4.
+	 */
+	dw->dma.dev->dma_parms = &dw->dma_parms;
+	dma_set_max_seg_size(&pdev->dev, MAX_BLOCK_SIZE);
 	platform_set_drvdata(pdev, chip);
 
 	pm_runtime_enable(chip->dev);
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index 3a357f7fda02..1e937ea2a96d 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -54,6 +54,7 @@ struct axi_dma_chan {
 struct dw_axi_dma {
 	struct dma_device	dma;
 	struct dw_axi_dma_hcfg	*hdata;
+	struct device_dma_parameters	dma_parms;
 
 	/* channels */
 	struct axi_dma_chan	*chan;
-- 
2.18.0