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MIPS: loongson: untangle dma implementations
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Only loongson-3 is DMA coherent and uses swiotlb.  So move the dma
address translations stubs directly to the loongson-3 code, and remove
a few Kconfig indirections.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Patchwork: https://patchwork.linux-mips.org/patch/19539/
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-mips@linux-mips.org
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Christoph Hellwig authored and Paul Burton committed Jun 24, 2018
1 parent a330a9c commit d3bc81b
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Showing 5 changed files with 6 additions and 24 deletions.
2 changes: 1 addition & 1 deletion arch/mips/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -454,7 +454,6 @@ config MACH_LOONGSON32

config MACH_LOONGSON64
bool "Loongson-2/3 family of machines"
select ARCH_HAS_PHYS_TO_DMA
select SYS_SUPPORTS_ZBOOT
help
This enables the support of Loongson-2/3 family of machines.
Expand Down Expand Up @@ -1389,6 +1388,7 @@ choice
config CPU_LOONGSON3
bool "Loongson 3 CPU"
depends on SYS_HAS_CPU_LOONGSON3
select ARCH_HAS_PHYS_TO_DMA
select CPU_SUPPORTS_64BIT_KERNEL
select CPU_SUPPORTS_HIGHMEM
select CPU_SUPPORTS_HUGEPAGES
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5 changes: 0 additions & 5 deletions arch/mips/loongson64/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -93,7 +93,6 @@ config LOONGSON_MACH3X
select LOONGSON_MC146818
select ZONE_DMA32
select LEFI_FIRMWARE_INTERFACE
select PHYS48_TO_HT40
help
Generic Loongson 3 family machines utilize the 3A/3B revision
of Loongson processor and RS780/SBX00 chipset.
Expand Down Expand Up @@ -132,10 +131,6 @@ config LOONGSON_UART_BASE
default y
depends on EARLY_PRINTK || SERIAL_8250

config PHYS48_TO_HT40
bool
default y if CPU_LOONGSON3

config LOONGSON_MC146818
bool
default n
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5 changes: 0 additions & 5 deletions arch/mips/loongson64/common/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -25,8 +25,3 @@ obj-$(CONFIG_CS5536) += cs5536/
#

obj-$(CONFIG_SUSPEND) += pm.o

#
# Big Memory (SWIOTLB) Support
#
obj-$(CONFIG_SWIOTLB) += dma-swiotlb.o
2 changes: 1 addition & 1 deletion arch/mips/loongson64/loongson-3/Makefile
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
#
# Makefile for Loongson-3 family machines
#
obj-y += irq.o cop2-ex.o platform.o acpi_init.o
obj-y += irq.o cop2-ex.o platform.o acpi_init.o dma.o

obj-$(CONFIG_SMP) += smp.o

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Original file line number Diff line number Diff line change
Expand Up @@ -5,26 +5,18 @@

dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
{
long nid;
#ifdef CONFIG_PHYS48_TO_HT40
/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
* Loongson-3's 48bit address space and embed it into 40bit */
nid = (paddr >> 44) & 0x3;
paddr = ((nid << 44) ^ paddr) | (nid << 37);
#endif
return paddr;
long nid = (paddr >> 44) & 0x3;
return ((nid << 44) ^ paddr) | (nid << 37);
}

phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr)
{
long nid;
#ifdef CONFIG_PHYS48_TO_HT40
/* We extract 2bit node id (bit 44~47, only bit 44~45 used now) from
* Loongson-3's 48bit address space and embed it into 40bit */
nid = (daddr >> 37) & 0x3;
daddr = ((nid << 37) ^ daddr) | (nid << 44);
#endif
return daddr;
long nid = (daddr >> 37) & 0x3;
return ((nid << 37) ^ daddr) | (nid << 44);
}

void __init plat_swiotlb_setup(void)
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