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authorHuacai Chen <chenhuacai@loongson.cn>2022-05-31 13:04:12 +0300
committerHuacai Chen <chenhuacai@loongson.cn>2022-06-03 15:09:29 +0300
commitd4b6f1562a3c3284adcef81d6e4f183d7d34b8a9 (patch)
tree365dc4b9e63fe8b038078a8fe6e8b8acb32527b1 /arch/loongarch/include/asm/dma-direct.h
parent46859ac8af52ae599e1b51992ddef3eb43f295fc (diff)
downloadlinux-d4b6f1562a3c3284adcef81d6e4f183d7d34b8a9.tar.xz
LoongArch: Add Non-Uniform Memory Access (NUMA) support
Add Non-Uniform Memory Access (NUMA) support for LoongArch. LoongArch has 48-bit physical address, but the HyperTransport I/O bus only support 40-bit address, so we need a custom phys_to_dma() and dma_to_phys() to extract the 4-bit node id (bit 44~47) from Loongson-3's 48-bit physical address space and embed it into 40-bit. In the 40-bit dma address, node id offset can be read from the LS7A_DMA_CFG register. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/include/asm/dma-direct.h')
-rw-r--r--arch/loongarch/include/asm/dma-direct.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/dma-direct.h b/arch/loongarch/include/asm/dma-direct.h
new file mode 100644
index 000000000000..75ccd808a2af
--- /dev/null
+++ b/arch/loongarch/include/asm/dma-direct.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _LOONGARCH_DMA_DIRECT_H
+#define _LOONGARCH_DMA_DIRECT_H
+
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
+
+#endif /* _LOONGARCH_DMA_DIRECT_H */