MIPS: Loongson64: Enable DMA noncoherent support

There are some Loongson64 systems come with broken coherent DMA
support, firmware will set a bit in boot_param and pass nocoherentio
in cmdline.

However nonconherent support was missed out when spin off Loongson-2EF
form Loongson64, and that boot_param change never made itself into
upstream.

Support DMA noncoherent properly to get those systems working.

Cc: stable@vger.kernel.org
Fixes: 71e2f4dd5a65 ("MIPS: Fork loongson2ef from loongson64")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 76db82542519c5555f384fb2aaa5e5587a6ee820..797ae590ebdba505c313b448720c7207b29673f8 100644 (file)
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -460,6 +460,7 @@ config MACH_LOONGSON2EF
 
 config MACH_LOONGSON64
        bool "Loongson 64-bit family of machines"
+       select ARCH_DMA_DEFAULT_COHERENT
        select ARCH_SPARSEMEM_ENABLE
        select ARCH_MIGHT_HAVE_PC_PARPORT
        select ARCH_MIGHT_HAVE_PC_SERIO
@@ -1251,6 +1252,7 @@ config CPU_LOONGSON64
        select CPU_SUPPORTS_MSA
        select CPU_DIEI_BROKEN if !LOONGSON3_ENHANCEMENT
        select CPU_MIPSR2_IRQ_VI
+       select DMA_NONCOHERENT
        select WEAK_ORDERING
        select WEAK_REORDERING_BEYOND_LLSC
        select MIPS_ASID_BITS_VARIABLE

diff --git a/arch/mips/include/asm/mach-loongson64/boot_param.h b/arch/mips/include/asm/mach-loongson64/boot_param.h
index 035b1a69e2d00dca84bc2a9978978da575dfc991..c454ef734c45cdf9a612f185f1c94d7357fd6238 100644 (file)
--- a/arch/mips/include/asm/mach-loongson64/boot_param.h
+++ b/arch/mips/include/asm/mach-loongson64/boot_param.h
@@ -117,7 +117,8 @@ 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 {

diff --git a/arch/mips/loongson64/env.c b/arch/mips/loongson64/env.c
index c961e2999f15ac83fa0eed2541564799813a94f2..ef3750a6ffacf861ad8c9cabf97ae2deacbd2188 100644 (file)
--- a/arch/mips/loongson64/env.c
+++ b/arch/mips/loongson64/env.c
@@ -13,6 +13,8 @@
  * Copyright (C) 2009 Lemote Inc.
  * Author: Wu Zhangjin, wuzhangjin@gmail.com
  */
+
+#include <linux/dma-map-ops.h>
 #include <linux/export.h>
 #include <linux/pci_ids.h>
 #include <asm/bootinfo.h>
@@ -147,8 +149,14 @@ void __init prom_lefi_init_env(void)
 
        loongson_sysconf.dma_mask_bits = eirq_source->dma_mask_bits;
        if (loongson_sysconf.dma_mask_bits < 32 ||
-               loongson_sysconf.dma_mask_bits > 64)
+                       loongson_sysconf.dma_mask_bits > 64) {
                loongson_sysconf.dma_mask_bits = 32;
+               dma_default_coherent = true;
+       } else {
+               dma_default_coherent = !eirq_source->dma_noncoherent;
+       }
+
+       pr_info("Firmware: Coherent DMA: %s\n", dma_default_coherent ? "on" : "off");
 
        loongson_sysconf.restart_addr = boot_p->reset_system.ResetWarm;
        loongson_sysconf.poweroff_addr = boot_p->reset_system.Shutdown;