MIPS: Octeon: Rewrite DMA mapping functions.

All Octeon chips can support more than 4GB of RAM.  Also due to how Octeon
PCI is setup, even some configurations with less than 4GB of RAM will have
portions that are not accessible from 32-bit devices.

Enable the swiotlb code to handle the cases where a device cannot directly
do DMA.  This is a complete rewrite of the Octeon DMA mapping code.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Patchwork: http://patchwork.linux-mips.org/patch/1639/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

2 files changed, 59 insertions, 6 deletions

diff --git a/arch/mips/pci/pci-octeon.c b/arch/mips/pci/pci-octeon.c
index d248b707eff..2d74fc9ae3b 100644
--- a/arch/mips/pci/pci-octeon.c
+++ b/arch/mips/pci/pci-octeon.c
@@ -11,6 +11,7 @@
 #include <linux/interrupt.h>
 #include <linux/time.h>
 #include <linux/delay.h>
+#include <linux/swiotlb.h>
 
 #include <asm/time.h>
 
@@ -19,6 +20,8 @@
 #include <asm/octeon/cvmx-pci-defs.h>
 #include <asm/octeon/pci-octeon.h>
 
+#include <dma-coherence.h>
+
 #define USE_OCTEON_INTERNAL_ARBITER
 
 /*
@@ -32,6 +35,8 @@
 /* Octeon't PCI controller uses did=3, subdid=3 for PCI memory. */
 #define OCTEON_PCI_MEMSPACE_OFFSET  (0x00011b0000000000ull)
 
+u64 octeon_bar1_pci_phys;
+
 /**
  * This is the bit decoding used for the Octeon PCI controller addresses
  */
@@ -170,6 +175,8 @@ int pcibios_plat_dev_init(struct pci_dev *dev)
 		pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, dconfig);
 	}
 
+	dev->dev.archdata.dma_ops = octeon_pci_dma_map_ops;
+
 	return 0;
 }
 
@@ -618,12 +625,10 @@ static int __init octeon_pci_setup(void)
 	 * before the readl()'s below. We don't want BAR2 overlapping
 	 * with BAR0/BAR1 during these reads.
 	 */
-	octeon_npi_write32(CVMX_NPI_PCI_CFG08, 0);
-	octeon_npi_write32(CVMX_NPI_PCI_CFG09, 0x80);
-
-	/* Disable the BAR1 movable mappings */
-	for (index = 0; index < 32; index++)
-		octeon_npi_write32(CVMX_NPI_PCI_BAR1_INDEXX(index), 0);
+	octeon_npi_write32(CVMX_NPI_PCI_CFG08,
+			   (u32)(OCTEON_BAR2_PCI_ADDRESS & 0xffffffffull));
+	octeon_npi_write32(CVMX_NPI_PCI_CFG09,
+			   (u32)(OCTEON_BAR2_PCI_ADDRESS >> 32));
 
 	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_BIG) {
 		/* Remap the Octeon BAR 0 to 0-2GB */
@@ -637,6 +642,25 @@ static int __init octeon_pci_setup(void)
 		octeon_npi_write32(CVMX_NPI_PCI_CFG06, 2ul << 30);
 		octeon_npi_write32(CVMX_NPI_PCI_CFG07, 0);
 
+		/* BAR1 movable mappings set for identity mapping */
+		octeon_bar1_pci_phys = 0x80000000ull;
+		for (index = 0; index < 32; index++) {
+			union cvmx_pci_bar1_indexx bar1_index;
+
+			bar1_index.u32 = 0;
+			/* Address bits[35:22] sent to L2C */
+			bar1_index.s.addr_idx =
+				(octeon_bar1_pci_phys >> 22) + index;
+			/* Don't put PCI accesses in L2. */
+			bar1_index.s.ca = 1;
+			/* Endian Swap Mode */
+			bar1_index.s.end_swp = 1;
+			/* Set '1' when the selected address range is valid. */
+			bar1_index.s.addr_v = 1;
+			octeon_npi_write32(CVMX_NPI_PCI_BAR1_INDEXX(index),
+					   bar1_index.u32);
+		}
+
 		/* Devices go after BAR1 */
 		octeon_pci_mem_resource.start =
 			OCTEON_PCI_MEMSPACE_OFFSET + (4ul << 30) -
@@ -652,6 +676,27 @@ static int __init octeon_pci_setup(void)
 		octeon_npi_write32(CVMX_NPI_PCI_CFG06, 0);
 		octeon_npi_write32(CVMX_NPI_PCI_CFG07, 0);
 
+		/* BAR1 movable regions contiguous to cover the swiotlb */
+		octeon_bar1_pci_phys =
+			virt_to_phys(octeon_swiotlb) & ~((1ull << 22) - 1);
+
+		for (index = 0; index < 32; index++) {
+			union cvmx_pci_bar1_indexx bar1_index;
+
+			bar1_index.u32 = 0;
+			/* Address bits[35:22] sent to L2C */
+			bar1_index.s.addr_idx =
+				(octeon_bar1_pci_phys >> 22) + index;
+			/* Don't put PCI accesses in L2. */
+			bar1_index.s.ca = 1;
+			/* Endian Swap Mode */
+			bar1_index.s.end_swp = 1;
+			/* Set '1' when the selected address range is valid. */
+			bar1_index.s.addr_v = 1;
+			octeon_npi_write32(CVMX_NPI_PCI_BAR1_INDEXX(index),
+					   bar1_index.u32);
+		}
+
 		/* Devices go after BAR0 */
 		octeon_pci_mem_resource.start =
 			OCTEON_PCI_MEMSPACE_OFFSET + (128ul << 20) +
@@ -667,6 +712,9 @@ static int __init octeon_pci_setup(void)
 	 * was setup properly.
 	 */
 	cvmx_write_csr(CVMX_NPI_PCI_INT_SUM2, -1);
+
+	octeon_pci_dma_init();
+
 	return 0;
 }
 
diff --git a/arch/mips/pci/pcie-octeon.c b/arch/mips/pci/pcie-octeon.c
index 861361e0c9a..385f035b24e 100644
--- a/arch/mips/pci/pcie-octeon.c
+++ b/arch/mips/pci/pcie-octeon.c
@@ -75,6 +75,8 @@ union cvmx_pcie_address {
 	} mem;
 };
 
+#include <dma-coherence.h>
+
 /**
  * Return the Core virtual base address for PCIe IO access. IOs are
  * read/written as an offset from this address.
@@ -1391,6 +1393,9 @@ static int __init octeon_pcie_setup(void)
 			cvmx_pcie_get_io_size(1) - 1;
 		register_pci_controller(&octeon_pcie1_controller);
 	}
+
+	octeon_pci_dma_init();
+
 	return 0;
 }