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MIPS: Loongson-3: Add PHYS48_TO_HT40 support

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The width of HT-bus is only 40-bit, but Loongson-3 has 48-bit physical
address. This implies only node-0's memory is DMAable because high bits
(Node ID) will lost. Fortunately, by configuring address windows in
firmware, we can extract 2bit Node ID (bit 44~47, only bit 44~45 used
now) from Loongson-3's 48-bit address space and embed it into 40-bit
(bit 37~38). Every NUMA node can do DMA now (however, maximum memory of
each node is reduced to 2^37 = 128GB).

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/8321/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Huacai Chen 2014-11-04 14:13:24 +08:00 committed by Ralf Baechle
parent 432d9ecb96
commit f490682a6b
3 changed files with 22 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
arch/mips/include/asm/mach-loongson/dma-coherence.h
View file

@ -23,7 +23,7 @@ static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
size_t size)
{
#ifdef CONFIG_CPU_LOONGSON3
return virt_to_phys(addr);
return phys_to_dma(dev, virt_to_phys(addr));
#else
return virt_to_phys(addr) | 0x80000000;
#endif
@ -33,7 +33,7 @@ static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
struct page *page)
{
#ifdef CONFIG_CPU_LOONGSON3
return page_to_phys(page);
return phys_to_dma(dev, page_to_phys(page));
#else
return page_to_phys(page) | 0x80000000;
#endif
@ -43,7 +43,7 @@ static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
dma_addr_t dma_addr)
{
#if defined(CONFIG_CPU_LOONGSON3) && defined(CONFIG_64BIT)
return dma_addr;
return dma_to_phys(dev, dma_addr);
#elif defined(CONFIG_CPU_LOONGSON2F) && defined(CONFIG_64BIT)
return (dma_addr > 0x8fffffff) ? dma_addr : (dma_addr & 0x0fffffff);
#else

5
arch/mips/loongson/Kconfig
View file

@ -86,6 +86,7 @@ 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.
@ -131,6 +132,10 @@ config SWIOTLB
select NEED_SG_DMA_LENGTH
select NEED_DMA_MAP_STATE
config PHYS48_TO_HT40
bool
default y if CPU_LOONGSON3
config LOONGSON_MC146818
bool
default n

14
arch/mips/loongson/common/dma-swiotlb.c
View file

@ -105,11 +105,25 @@ static int loongson_dma_set_mask(struct device *dev, u64 mask)
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;
}
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;
}