LoongArch: use arch specific phys_to_dma

To be compatible with OLD firmware which has no _DMA method, we should use arch specific phys_to_dma. Signed-off-by: Hongchen Zhang <[email protected]> Signed-off-by: Yanteng Si <[email protected]>
deepin-community · May 13, 2024 · 43bef49 · 43bef49
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diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
@@ -18,6 +18,7 @@ config LOONGARCH
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_INLINE_READ_LOCK if !PREEMPTION

diff --git a/arch/loongarch/kernel/dma.c b/arch/loongarch/kernel/dma.c
@@ -4,13 +4,40 @@
  */
 #include <linux/acpi.h>
 #include <linux/dma-direct.h>
+#include <asm/loongson.h>
+
+/*
+ * We extract 4bit node id (bit 44~47) from Loongson-3's
+ * 48bit physical address space and embed it into 40bit.
+ */
+
+static int node_id_offset;
+
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	long nid = (paddr >> 44) & 0xf;
+
+	return ((nid << 44) ^ paddr) | (nid << node_id_offset);
+}
+
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
+{
+	long nid = (daddr >> node_id_offset) & 0xf;
+
+	return ((nid << node_id_offset) ^ daddr) | (nid << 44);
+}
 
 void acpi_arch_dma_setup(struct device *dev)
 {
 	int ret;
 	u64 mask, end = 0;
 	const struct bus_dma_region *map = NULL;
 
+	if (node_id_offset == 0) {
+		node_id_offset = ((readl(LS7A_DMA_CFG) & LS7A_DMA_NODE_MASK) >> LS7A_DMA_NODE_SHF);
+		node_id_offset += 36;
+	}
+
 	ret = acpi_dma_get_range(dev, &map);
 	if (!ret && map) {
 		const struct bus_dma_region *r = map;