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 --- v2: Style fixes --- arch/mips/Kconfig | 2 ++ arch/mips/include/asm/mach-loongson64/boot_param.h | 3 ++- arch/mips/loongson64/env.c | 10 +++++++++- 3 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 76db82542519..797ae590ebdb 100644 --- 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 035b1a69e2d0..c454ef734c45 100644 --- 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 c961e2999f15..ef3750a6ffac 100644 --- 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;