From: Russell King <rmk+kernel@armlinux.org.uk>
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/8] ARM: riscpc: dma: eliminate "cur_sg" scatterlist usage
Date: Mon, 20 May 2019 15:47:14 +0100 [thread overview]
Message-ID: <E1hSjZK-0000Y9-Gf@rmk-PC.armlinux.org.uk> (raw)
In-Reply-To: <20190520144615.gzrztyhoncyfc5xr@shell.armlinux.org.uk>
All we really need is the DMA address and size, we don't need the
baggage of a full scatterlist structure.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mach-rpc/dma.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)
diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c
index c4c96661eb89..37750c6493b4 100644
--- a/arch/arm/mach-rpc/dma.c
+++ b/arch/arm/mach-rpc/dma.c
@@ -30,7 +30,8 @@ struct iomd_dma {
unsigned int state;
unsigned long base; /* Controller base address */
int irq; /* Controller IRQ */
- struct scatterlist cur_sg; /* Current controller buffer */
+ dma_addr_t cur_addr;
+ unsigned int cur_len;
dma_addr_t dma_addr;
unsigned int dma_len;
};
@@ -53,13 +54,13 @@ typedef enum {
#define CR (IOMD_IO0CR - IOMD_IO0CURA)
#define ST (IOMD_IO0ST - IOMD_IO0CURA)
-static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma)
+static void iomd_get_next_sg(struct iomd_dma *idma)
{
unsigned long end, offset, flags = 0;
if (idma->dma.sg) {
- sg->dma_address = idma->dma_addr;
- offset = sg->dma_address & ~PAGE_MASK;
+ idma->cur_addr = idma->dma_addr;
+ offset = idma->cur_addr & ~PAGE_MASK;
end = offset + idma->dma_len;
@@ -69,7 +70,7 @@ static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma)
if (offset + TRANSFER_SIZE >= end)
flags |= DMA_END_L;
- sg->length = end - TRANSFER_SIZE;
+ idma->cur_len = end - TRANSFER_SIZE;
idma->dma_len -= end - offset;
idma->dma_addr += end - offset;
@@ -87,11 +88,11 @@ static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma)
}
} else {
flags = DMA_END_S | DMA_END_L;
- sg->dma_address = 0;
- sg->length = 0;
+ idma->cur_addr = 0;
+ idma->cur_len = 0;
}
- sg->length |= flags;
+ idma->cur_len |= flags;
}
static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
@@ -107,26 +108,26 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
return IRQ_HANDLED;
if ((idma->state ^ status) & DMA_ST_AB)
- iomd_get_next_sg(&idma->cur_sg, idma);
+ iomd_get_next_sg(idma);
switch (status & (DMA_ST_OFL | DMA_ST_AB)) {
case DMA_ST_OFL: /* OIA */
case DMA_ST_AB: /* .IB */
- iomd_writel(idma->cur_sg.dma_address, base + CURA);
- iomd_writel(idma->cur_sg.length, base + ENDA);
+ iomd_writel(idma->cur_addr, base + CURA);
+ iomd_writel(idma->cur_len, base + ENDA);
idma->state = DMA_ST_AB;
break;
case DMA_ST_OFL | DMA_ST_AB: /* OIB */
case 0: /* .IA */
- iomd_writel(idma->cur_sg.dma_address, base + CURB);
- iomd_writel(idma->cur_sg.length, base + ENDB);
+ iomd_writel(idma->cur_addr, base + CURB);
+ iomd_writel(idma->cur_len, base + ENDB);
idma->state = 0;
break;
}
if (status & DMA_ST_OFL &&
- idma->cur_sg.length == (DMA_END_S|DMA_END_L))
+ idma->cur_len == (DMA_END_S|DMA_END_L))
break;
} while (1);
--
2.7.4
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next prev parent reply other threads:[~2019-05-20 14:48 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-20 14:46 [PATCH 0/8] Resurect RiscPC support Russell King - ARM Linux admin
2019-05-20 14:46 ` [PATCH 1/8] ARM: riscpc: replace gettimeoffset() with clocksource Russell King
2019-05-20 14:46 ` [PATCH 2/8] ARM: riscpc: fix lack of keyboard interrupts after irq conversion Russell King
2019-05-20 14:47 ` [PATCH 3/8] ARM: riscpc: fix ecard printing Russell King
2019-05-20 14:47 ` [PATCH 4/8] ARM: riscpc: fix DMA Russell King
2019-05-20 14:47 ` Russell King [this message]
2019-05-20 14:47 ` [PATCH 6/8] ARM: riscpc: dma: make state a local variable Russell King
2019-05-20 14:47 ` [PATCH 7/8] ARM: riscpc: dma: improve address/length writing Russell King
2019-05-20 14:47 ` [PATCH 8/8] ARM: riscpc: dma: use __iomem pointers for writing DMA Russell King
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