linux-kernel - [PATCH v2 03/15] dmaengine: bcm2835: Add NO_WAIT_RESP, DMA_WIDE_SOURCE and DMA_WIDE

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: <af8732c6640eb8f914b712e819c5fcc23f85b86e.1710226514.git.andrea.porta@suse.com>
Date: Wed, 13 Mar 2024 15:08:28 +0100
From: Andrea della Porta <andrea.porta@...e.com>
To: Vinod Koul <vkoul@...nel.org>,
	Rob Herring <robh+dt@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Florian Fainelli <florian.fainelli@...adcom.com>,
	Ray Jui <rjui@...adcom.com>,
	Scott Branden <sbranden@...adcom.com>,
	Broadcom internal kernel review list <bcm-kernel-feedback-list@...adcom.com>,
	Saenz Julienne <nsaenz@...nel.org>,
	dmaengine@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-rpi-kernel@...ts.infradead.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	dave.stevenson@...pberrypi.com
Cc: Phil Elwell <phil@...pberrypi.org>,
	Maxime Ripard <maxime@...no.tech>,
	Stefan Wahren <stefan.wahren@...e.com>,
	Dom Cobley <popcornmix@...il.com>,
	Phil Elwell <phil@...pberrypi.com>,
	Andrea della Porta <andrea.porta@...e.com>
Subject: [PATCH v2 03/15] dmaengine: bcm2835: Add NO_WAIT_RESP, DMA_WIDE_SOURCE and DMA_WIDE_DEST flag

From: Phil Elwell <phil@...pberrypi.com>

Use bit 27 of the dreq value (the second cell of the DT DMA descriptor)
to request that the WAIT_RESP bit is not set.

Use (reserved) bits 24 and 25 of the dreq value
(the second cell of the DT DMA descriptor) to request
that wide source reads or wide dest writes are required

Originally-by: Dom Cobley <popcornmix@...il.com>
Originally-by: Phil Elwell <phil@...pberrypi.com>
Signed-off-by: Andrea della Porta <andrea.porta@...e.com>
---
 drivers/dma/bcm2835-dma.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 3d9973dd041d..69a77caf78cc 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -145,6 +145,21 @@ struct bcm2835_desc {
 #define BCM2835_DMA_WAIT(x)	(((x) & 31) << 21) /* add DMA-wait cycles */
 #define BCM2835_DMA_NO_WIDE_BURSTS BIT(26) /* no 2 beat write bursts */
 
+/* A fake bit to request that the driver doesn't set the WAIT_RESP bit. */
+#define BCM2835_DMA_NO_WAIT_RESP BIT(27)
+#define WAIT_RESP(x) (((x) & BCM2835_DMA_NO_WAIT_RESP) ? \
+		      0 : BCM2835_DMA_WAIT_RESP)
+
+/* A fake bit to request that the driver requires wide reads */
+#define BCM2835_DMA_WIDE_SOURCE BIT(24)
+#define WIDE_SOURCE(x) (((x) & BCM2835_DMA_WIDE_SOURCE) ? \
+		      BCM2835_DMA_S_WIDTH : 0)
+
+/* A fake bit to request that the driver requires wide writes */
+#define BCM2835_DMA_WIDE_DEST BIT(25)
+#define WIDE_DEST(x) (((x) & BCM2835_DMA_WIDE_DEST) ? \
+		      BCM2835_DMA_D_WIDTH : 0)
+
 /* debug register bits */
 #define BCM2835_DMA_DEBUG_LAST_NOT_SET_ERR	BIT(0)
 #define BCM2835_DMA_DEBUG_FIFO_ERR		BIT(1)
@@ -621,8 +636,9 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_memcpy(
 {
 	struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
 	struct bcm2835_desc *d;
-	u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC;
-	u32 extra = BCM2835_DMA_INT_EN | BCM2835_DMA_WAIT_RESP;
+	u32 info = BCM2835_DMA_D_INC | BCM2835_DMA_S_INC |
+		   WAIT_RESP(c->dreq) | WIDE_SOURCE(c->dreq) | WIDE_DEST(c->dreq);
+	u32 extra = BCM2835_DMA_INT_EN;
 	size_t max_len = bcm2835_dma_max_frame_length(c);
 	size_t frames;
 
@@ -652,7 +668,8 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_slave_sg(
 	struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
 	struct bcm2835_desc *d;
 	dma_addr_t src = 0, dst = 0;
-	u32 info = BCM2835_DMA_WAIT_RESP;
+	u32 info = WAIT_RESP(c->dreq) |
+		   WIDE_SOURCE(c->dreq) | WIDE_DEST(c->dreq);
 	u32 extra = BCM2835_DMA_INT_EN;
 	size_t frames;
 
@@ -704,7 +721,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
 	struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
 	struct bcm2835_desc *d;
 	dma_addr_t src, dst;
-	u32 info = BCM2835_DMA_WAIT_RESP;
+	u32 info = WAIT_RESP(c->dreq) | WIDE_SOURCE(c->dreq) | WIDE_DEST(c->dreq);
 	u32 extra = 0;
 	size_t max_len = bcm2835_dma_max_frame_length(c);
 	size_t frames;
-- 
2.35.3