MIPS: IP27: use dma_direct_ops

IP27 is coherent and has a reasonably direct mapping, just with a little
per-bus offset added into the dma address.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Patchwork: https://patchwork.linux-mips.org/patch/19542/
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Tom Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-mips@linux-mips.org

arch/mips/Kconfig

@@ -683,11 +683,11 @@ config SGI_IP22
 
 config SGI_IP27
 	bool "SGI IP27 (Origin200/2000)"
+	select ARCH_HAS_PHYS_TO_DMA
 	select FW_ARC
 	select FW_ARC64
 	select BOOT_ELF64
 	select DEFAULT_SGI_PARTITION
-	select MIPS_DMA_DEFAULT
 	select SYS_HAS_EARLY_PRINTK
 	select HW_HAS_PCI
 	select NR_CPUS_DEFAULT_64

arch/mips/pci/pci-ip27.c

@@ -11,6 +11,7 @@
 #include <linux/export.h>
 #include <linux/pci.h>
 #include <linux/smp.h>
+#include <linux/dma-direct.h>
 #include <asm/sn/arch.h>
 #include <asm/pci/bridge.h>
 #include <asm/paccess.h>
@@ -182,6 +183,19 @@ int pcibios_plat_dev_init(struct pci_dev *dev)
 	return 0;
 }
 
+dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(pdev->bus);
+
+	return bc->baddr + paddr;
+}
+
+phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dma_addr)
+{
+	return dma_addr & ~(0xffUL << 56);
+}
+
 /*
  * Device might live on a subordinate PCI bus.	XXX Walk up the chain of buses
  * to find the slot number in sense of the bridge device register.