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Commit f490682a authored by Huacai Chen's avatar Huacai Chen Committed by Ralf Baechle
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MIPS: Loongson-3: Add PHYS48_TO_HT40 support 



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: default avatarHuacai 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: default avatarRalf Baechle <ralf@linux-mips.org>
parent 432d9ecb

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

+3 −3
Original line number Diff line number Diff line
@@ -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

arch/mips/loongson/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -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

arch/mips/loongson/common/dma-swiotlb.c

+14 −0
Original line number Diff line number Diff line
@@ -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;

}