From: Russell King <rmk+kernel@armlinux.org.uk>
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 8/8] ARM: riscpc: dma: use __iomem pointers for writing DMA
Date: Mon, 20 May 2019 15:47:29 +0100 [thread overview]
Message-ID: <E1hSjZZ-0000Yb-Sd@rmk-PC.armlinux.org.uk> (raw)
In-Reply-To: <20190520144615.gzrztyhoncyfc5xr@shell.armlinux.org.uk>
Use __iomem pointers for efficiency to write the DMA registers.
This avoids the compiler emitting several instructions for each access
to calculate the register address.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/mach-rpc/dma.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c
index 6140472d148e..eeda808a7320 100644
--- a/arch/arm/mach-rpc/dma.c
+++ b/arch/arm/mach-rpc/dma.c
@@ -27,9 +27,9 @@
struct iomd_dma {
struct dma_struct dma;
- unsigned int state;
- unsigned long base; /* Controller base address */
+ void __iomem *base; /* Controller base address */
int irq; /* Controller IRQ */
+ unsigned int state;
dma_addr_t cur_addr;
unsigned int cur_len;
dma_addr_t dma_addr;
@@ -98,12 +98,12 @@ static void iomd_get_next_sg(struct iomd_dma *idma)
static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
{
struct iomd_dma *idma = dev_id;
- unsigned long base = idma->base;
+ void __iomem *base = idma->base;
unsigned int state = idma->state;
unsigned int status, cur, end;
do {
- status = iomd_readb(base + ST);
+ status = readb(base + ST);
if (!(status & DMA_ST_INT))
goto out;
@@ -119,8 +119,8 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
cur = CURB;
end = ENDB;
}
- iomd_writel(idma->cur_addr, base + cur);
- iomd_writel(idma->cur_len, base + end);
+ writel(idma->cur_addr, base + cur);
+ writel(idma->cur_len, base + end);
if (status & DMA_ST_OFL &&
idma->cur_len == (DMA_END_S|DMA_END_L))
@@ -152,7 +152,7 @@ static void iomd_free_dma(unsigned int chan, dma_t *dma)
static void iomd_enable_dma(unsigned int chan, dma_t *dma)
{
struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
- unsigned long dma_base = idma->base;
+ void __iomem *base = idma->base;
unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E;
if (idma->dma.invalid) {
@@ -175,27 +175,27 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma)
idma->dma_addr = idma->dma.sg->dma_address;
idma->dma_len = idma->dma.sg->length;
- iomd_writeb(DMA_CR_C, dma_base + CR);
+ writeb(DMA_CR_C, base + CR);
idma->state = DMA_ST_AB;
}
if (idma->dma.dma_mode == DMA_MODE_READ)
ctrl |= DMA_CR_D;
- iomd_writeb(ctrl, dma_base + CR);
+ writeb(ctrl, base + CR);
enable_irq(idma->irq);
}
static void iomd_disable_dma(unsigned int chan, dma_t *dma)
{
struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
- unsigned long dma_base = idma->base;
+ void __iomem *base = idma->base;
unsigned long flags;
local_irq_save(flags);
if (idma->state != ~DMA_ST_AB)
disable_irq(idma->irq);
- iomd_writeb(0, dma_base + CR);
+ writeb(0, base + CR);
local_irq_restore(flags);
}
@@ -358,17 +358,17 @@ static int __init rpc_dma_init(void)
*/
iomd_writeb(DMA_EXT_IO3|DMA_EXT_IO2, IOMD_DMAEXT);
- iomd_dma[DMA_0].base = IOMD_IO0CURA;
+ iomd_dma[DMA_0].base = IOMD_BASE + IOMD_IO0CURA;
iomd_dma[DMA_0].irq = IRQ_DMA0;
- iomd_dma[DMA_1].base = IOMD_IO1CURA;
+ iomd_dma[DMA_1].base = IOMD_BASE + IOMD_IO1CURA;
iomd_dma[DMA_1].irq = IRQ_DMA1;
- iomd_dma[DMA_2].base = IOMD_IO2CURA;
+ iomd_dma[DMA_2].base = IOMD_BASE + IOMD_IO2CURA;
iomd_dma[DMA_2].irq = IRQ_DMA2;
- iomd_dma[DMA_3].base = IOMD_IO3CURA;
+ iomd_dma[DMA_3].base = IOMD_BASE + IOMD_IO3CURA;
iomd_dma[DMA_3].irq = IRQ_DMA3;
- iomd_dma[DMA_S0].base = IOMD_SD0CURA;
+ iomd_dma[DMA_S0].base = IOMD_BASE + IOMD_SD0CURA;
iomd_dma[DMA_S0].irq = IRQ_DMAS0;
- iomd_dma[DMA_S1].base = IOMD_SD1CURA;
+ iomd_dma[DMA_S1].base = IOMD_BASE + IOMD_SD1CURA;
iomd_dma[DMA_S1].irq = IRQ_DMAS1;
for (i = DMA_0; i <= DMA_S1; i++) {
--
2.7.4
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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 ` [PATCH 5/8] ARM: riscpc: dma: eliminate "cur_sg" scatterlist usage Russell King
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 ` Russell King [this message]
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