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ARM: riscpc: dma: eliminate "cur_sg" scatterlist usage 

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>
This commit is contained in:
Russell King 2019-05-02 17:37:51 +01:00
parent ffd9a1ba9f
commit 8194468fad
1 changed files with 15 additions and 14 deletions
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29
arch/arm/mach-rpc/dma.c
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@ -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);