MIPS: Alchemy: Determine cohereny at runtime based on cpu type
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>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index daef670..51f5a09 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -63,6 +63,7 @@
select CEVT_R4K
select CSRC_R4K
select IRQ_CPU
+ select DMA_MAYBE_COHERENT # Au1000,1500,1100 aren't, rest is
select SYS_HAS_CPU_MIPS32_R1
select SYS_SUPPORTS_32BIT_KERNEL
select SYS_SUPPORTS_APM_EMULATION
diff --git a/arch/mips/alchemy/Kconfig b/arch/mips/alchemy/Kconfig
index 7032ac7..4138672 100644
--- a/arch/mips/alchemy/Kconfig
+++ b/arch/mips/alchemy/Kconfig
@@ -20,7 +20,6 @@
config MIPS_MTX1
bool "4G Systems MTX-1 board"
- select DMA_NONCOHERENT
select HW_HAS_PCI
select ALCHEMY_GPIOINT_AU1000
select SYS_SUPPORTS_LITTLE_ENDIAN
@@ -29,7 +28,6 @@
config MIPS_DB1000
bool "Alchemy DB1000/DB1500/DB1100 PB1500/1100 boards"
select ALCHEMY_GPIOINT_AU1000
- select DMA_NONCOHERENT
select HW_HAS_PCI
select SYS_SUPPORTS_BIG_ENDIAN
select SYS_SUPPORTS_LITTLE_ENDIAN
@@ -39,13 +37,11 @@
bool "Alchemy DB1200/PB1200/DB1300/DB1550/PB1550 boards"
select ARCH_REQUIRE_GPIOLIB
select HW_HAS_PCI
- select DMA_COHERENT
select SYS_SUPPORTS_LITTLE_ENDIAN
select SYS_HAS_EARLY_PRINTK
config MIPS_XXS1500
bool "MyCable XXS1500 board"
- select DMA_NONCOHERENT
select ALCHEMY_GPIOINT_AU1000
select SYS_SUPPORTS_LITTLE_ENDIAN
select SYS_HAS_EARLY_PRINTK
@@ -54,7 +50,6 @@
bool "Trapeze ITS GPR board"
select ALCHEMY_GPIOINT_AU1000
select HW_HAS_PCI
- select DMA_NONCOHERENT
select SYS_SUPPORTS_LITTLE_ENDIAN
select SYS_HAS_EARLY_PRINTK
diff --git a/arch/mips/alchemy/common/setup.c b/arch/mips/alchemy/common/setup.c
index 62b4e7b..566a174 100644
--- a/arch/mips/alchemy/common/setup.c
+++ b/arch/mips/alchemy/common/setup.c
@@ -30,6 +30,7 @@
#include <linux/jiffies.h>
#include <linux/module.h>
+#include <asm/dma-coherence.h>
#include <asm/mipsregs.h>
#include <asm/time.h>
@@ -59,6 +60,15 @@
/* Clear to obtain best system bus performance */
clear_c0_config(1 << 19); /* Clear Config[OD] */
+ hw_coherentio = 0;
+ coherentio = 1;
+ switch (alchemy_get_cputype()) {
+ case ALCHEMY_CPU_AU1000:
+ case ALCHEMY_CPU_AU1500:
+ case ALCHEMY_CPU_AU1100:
+ coherentio = 0;
+ }
+
board_setup(); /* board specific setup */
/* IO/MEM resources. */
diff --git a/arch/mips/pci/pci-alchemy.c b/arch/mips/pci/pci-alchemy.c
index d1faece..563d1f6 100644
--- a/arch/mips/pci/pci-alchemy.c
+++ b/arch/mips/pci/pci-alchemy.c
@@ -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 @@
}
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;
