diff options
| author | Huacai Chen <chenhc@lemote.com> | 2014-11-04 14:13:24 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2014-11-24 07:45:01 +0100 |
| commit | f490682a6b21ffed5acd7a0d49d8371e5e625d7a (patch) | |
| tree | 23fec41907ba1f5fb8cac1a5d2e0f18af6ee8fa7 /arch/mips/loongson | |
| parent | 432d9ecb9628bdcb20670b2cf0678f3738bd40a5 (diff) | |
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: 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>
Diffstat (limited to 'arch/mips/loongson')
| -rw-r--r-- | arch/mips/loongson/Kconfig | 5 | ||||
| -rw-r--r-- | arch/mips/loongson/common/dma-swiotlb.c | 14 |
2 files changed, 19 insertions, 0 deletions
diff --git a/arch/mips/loongson/Kconfig b/arch/mips/loongson/Kconfig index 1b91fc6a921..72f830ac078 100644 --- a/arch/mips/loongson/Kconfig +++ b/arch/mips/loongson/Kconfig @@ -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 diff --git a/arch/mips/loongson/common/dma-swiotlb.c b/arch/mips/loongson/common/dma-swiotlb.c index c2be01f9157..2c6b989c1bc 100644 --- a/arch/mips/loongson/common/dma-swiotlb.c +++ b/arch/mips/loongson/common/dma-swiotlb.c @@ -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; } |