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MIPS: Alchemy: Determine cohereny at runtime based on cpu type

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All Alchemy chips have coherent DMA, but for example the USB or AC97
peripherals on the Au1000/1500/1100 are not.
This patch uses DMA_MAYBE_COHERENT on Alchemy and sets coherentio based
on CPU type.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/6576/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Manuel Lauss
2014-02-20 14:59:23 +01:00
committed by Ralf Baechle
parent 8005711c8d
commit 88e9a93c9d
4 changed files with 13 additions and 8 deletions
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5
arch/mips/pci/pci-alchemy.c
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@@ -16,6 +16,7 @@
#include <linux/syscore_ops.h>
#include <linux/vmalloc.h>
#include <asm/dma-coherence.h>
#include <asm/mach-au1x00/au1000.h>
#include <asm/tlbmisc.h>
@@ -411,17 +412,15 @@ static int alchemy_pci_probe(struct platform_device *pdev)
}
ctx->alchemy_pci_ctrl.io_map_base = (unsigned long)virt_io;
#ifdef CONFIG_DMA_NONCOHERENT
/* Au1500 revisions older than AD have borked coherent PCI */
if ((alchemy_get_cputype() == ALCHEMY_CPU_AU1500) &&
(read_c0_prid() < 0x01030202)) {
(read_c0_prid() < 0x01030202) && !coherentio) {
val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
val |= PCI_CONFIG_NC;
__raw_writel(val, ctx->regs + PCI_REG_CONFIG);
wmb();
dev_info(&pdev->dev, "non-coherent PCI on Au1500 AA/AB/AC\n");
}
#endif
if (pd->board_map_irq)
ctx->board_map_irq = pd->board_map_irq;