[PATCH 2/2] MIPS: Loongson64: Add dma iocoherency detection support

[Jiaxun Yang]

Set hw_iocoherency according to parameter passed from firmware.

Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
---
 arch/mips/Kconfig                                  | 1 +
 arch/mips/include/asm/mach-loongson64/boot_param.h | 5 +++--
 arch/mips/loongson64/env.c                         | 4 ++++
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index d0b727daddb3..8b0cd692a43f 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -474,6 +474,7 @@ config MACH_LOONGSON64
 	select CSRC_R4K
 	select CEVT_R4K
 	select CPU_HAS_WB
+	select DMA_MAYBE_COHERENT
 	select FORCE_PCI
 	select ISA
 	select I8259
diff --git a/arch/mips/include/asm/mach-loongson64/boot_param.h b/arch/mips/include/asm/mach-loongson64/boot_param.h
index 8c286bedff3e..2da2be40ad81 100644
--- a/arch/mips/include/asm/mach-loongson64/boot_param.h
+++ b/arch/mips/include/asm/mach-loongson64/boot_param.h
@@ -115,7 +115,8 @@ struct irq_source_routing_table {
 	u64 pci_io_start_addr;
 	u64 pci_io_end_addr;
 	u64 pci_config_addr;
-	u32 dma_mask_bits;
+	u16 dma_mask_bits;
+	u16 dma_noncoherent;
 } __packed;
 
 struct interface_info {
@@ -206,7 +207,7 @@ struct loongson_system_configuration {
 	u64 poweroff_addr;
 	u64 suspend_addr;
 	u64 vgabios_addr;
-	u32 dma_mask_bits;
+	u16 dma_mask_bits;
 	char ecname[32];
 	u32 nr_uarts;
 	struct uart_device uarts[MAX_UARTS];
diff --git a/arch/mips/loongson64/env.c b/arch/mips/loongson64/env.c
index 0daeb7bcf023..61e3d4874fe9 100644
--- a/arch/mips/loongson64/env.c
+++ b/arch/mips/loongson64/env.c
@@ -15,6 +15,7 @@
  */
 #include <linux/export.h>
 #include <asm/bootinfo.h>
+#include <asm/dma-coherence.h>
 #include <loongson.h>
 #include <boot_param.h>
 #include <workarounds.h>
@@ -128,6 +129,9 @@ void __init prom_init_env(void)
 		loongson_sysconf.dma_mask_bits > 64)
 		loongson_sysconf.dma_mask_bits = 32;
 
+	hw_coherentio = !eirq_source->dma_noncoherent;
+	pr_info("Firmware I/O coherency: %s\n", hw_coherentio?"ON":"OFF");
+
 	loongson_sysconf.restart_addr = boot_p->reset_system.ResetWarm;
 	loongson_sysconf.poweroff_addr = boot_p->reset_system.Shutdown;
 	loongson_sysconf.suspend_addr = boot_p->reset_system.DoSuspend;
-- 
2.24.1