MIPS: Add Cavium OCTEON PCI support.

This patch adds support for PCI and PCIe to the base Cavium OCTEON
processor support.

Signed-off-by: David Daney <[email protected]>
Signed-off-by: Ralf Baechle <[email protected]>

Author: David Daney

arch/mips/Kconfig

@@ -618,6 +618,8 @@ config CAVIUM_OCTEON_REFERENCE_BOARD
 	select SYS_HAS_EARLY_PRINTK
 	select SYS_HAS_CPU_CAVIUM_OCTEON
 	select SWAP_IO_SPACE
+	select HW_HAS_PCI
+	select ARCH_SUPPORTS_MSI
 	help
 	  This option supports all of the Octeon reference boards from Cavium
 	  Networks. It builds a kernel that dynamically determines the Octeon

arch/mips/cavium-octeon/Makefile

@@ -14,5 +14,9 @@ obj-y += dma-octeon.o flash_setup.o
 obj-y += octeon-memcpy.o
 
 obj-$(CONFIG_SMP)                     += smp.o
+obj-$(CONFIG_PCI)                     += pci-common.o
+obj-$(CONFIG_PCI)                     += pci.o
+obj-$(CONFIG_PCI)                     += pcie.o
+obj-$(CONFIG_PCI_MSI)                 += msi.o
 
 EXTRA_CFLAGS += -Werror

arch/mips/cavium-octeon/dma-octeon.c

@@ -13,20 +13,327 @@
  */
 #include <linux/types.h>
 #include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/scatterlist.h>
+
+#include <linux/cache.h>
+#include <linux/io.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/octeon/cvmx-npi-defs.h>
+#include <asm/octeon/cvmx-pci-defs.h>
 
 #include <dma-coherence.h>
 
+#ifdef CONFIG_PCI
+#include "pci-common.h"
+#endif
+
+#define BAR2_PCI_ADDRESS 0x8000000000ul
+
+struct bar1_index_state {
+	int16_t ref_count;	/* Number of PCI mappings using this index */
+	uint16_t address_bits;	/* Upper bits of physical address. This is
+				   shifted 22 bits */
+};
+
+#ifdef CONFIG_PCI
+static DEFINE_SPINLOCK(bar1_lock);
+static struct bar1_index_state bar1_state[32];
+#endif
+
 dma_addr_t octeon_map_dma_mem(struct device *dev, void *ptr, size_t size)
 {
+#ifndef CONFIG_PCI
 	/* Without PCI/PCIe this function can be called for Octeon internal
 	   devices such as USB. These devices all support 64bit addressing */
 	mb();
 	return virt_to_phys(ptr);
+#else
+	unsigned long flags;
+	uint64_t dma_mask;
+	int64_t start_index;
+	dma_addr_t result = -1;
+	uint64_t physical = virt_to_phys(ptr);
+	int64_t index;
+
+	mb();
+	/*
+	 * Use the DMA masks to determine the allowed memory
+	 * region. For us it doesn't limit the actual memory, just the
+	 * address visible over PCI.  Devices with limits need to use
+	 * lower indexed Bar1 entries.
+	 */
+	if (dev) {
+		dma_mask = dev->coherent_dma_mask;
+		if (dev->dma_mask)
+			dma_mask = *dev->dma_mask;
+	} else {
+		dma_mask = 0xfffffffful;
+	}
+
+	/*
+	 * Platform devices, such as the internal USB, skip all
+	 * translation and use Octeon physical addresses directly.
+	 */
+	if (!dev || dev->bus == &platform_bus_type)
+		return physical;
+
+	switch (octeon_dma_bar_type) {
+	case OCTEON_DMA_BAR_TYPE_PCIE:
+		if (unlikely(physical < (16ul << 10)))
+			panic("dma_map_single: Not allowed to map first 16KB."
+			      " It interferes with BAR0 special area\n");
+		else if ((physical + size >= (256ul << 20)) &&
+			 (physical < (512ul << 20)))
+			panic("dma_map_single: Not allowed to map bootbus\n");
+		else if ((physical + size >= 0x400000000ull) &&
+			 physical < 0x410000000ull)
+			panic("dma_map_single: "
+			      "Attempt to map illegal memory address 0x%llx\n",
+			      physical);
+		else if (physical >= 0x420000000ull)
+			panic("dma_map_single: "
+			      "Attempt to map illegal memory address 0x%llx\n",
+			      physical);
+		else if ((physical + size >=
+			  (4ull<<30) - (OCTEON_PCI_BAR1_HOLE_SIZE<<20))
+			 && physical < (4ull<<30))
+			pr_warning("dma_map_single: Warning: "
+				   "Mapping memory address that might "
+				   "conflict with devices 0x%llx-0x%llx\n",
+				   physical, physical+size-1);
+		/* The 2nd 256MB is mapped at 256<<20 instead of 0x410000000 */
+		if ((physical >= 0x410000000ull) && physical < 0x420000000ull)
+			result = physical - 0x400000000ull;
+		else
+			result = physical;
+		if (((result+size-1) & dma_mask) != result+size-1)
+			panic("dma_map_single: Attempt to map address "
+			      "0x%llx-0x%llx, which can't be accessed "
+			      "according to the dma mask 0x%llx\n",
+			      physical, physical+size-1, dma_mask);
+		goto done;
+
+	case OCTEON_DMA_BAR_TYPE_BIG:
+#ifdef CONFIG_64BIT
+		/* If the device supports 64bit addressing, then use BAR2 */
+		if (dma_mask > BAR2_PCI_ADDRESS) {
+			result = physical + BAR2_PCI_ADDRESS;
+			goto done;
+		}
+#endif
+		if (unlikely(physical < (4ul << 10))) {
+			panic("dma_map_single: Not allowed to map first 4KB. "
+			      "It interferes with BAR0 special area\n");
+		} else if (physical < (256ul << 20)) {
+			if (unlikely(physical + size > (256ul << 20)))
+				panic("dma_map_single: Requested memory spans "
+				      "Bar0 0:256MB and bootbus\n");
+			result = physical;
+			goto done;
+		} else if (unlikely(physical < (512ul << 20))) {
+			panic("dma_map_single: Not allowed to map bootbus\n");
+		} else if (physical < (2ul << 30)) {
+			if (unlikely(physical + size > (2ul << 30)))
+				panic("dma_map_single: Requested memory spans "
+				      "Bar0 512MB:2GB and BAR1\n");
+			result = physical;
+			goto done;
+		} else if (physical < (2ul << 30) + (128 << 20)) {
+			/* Fall through */
+		} else if (physical <
+			   (4ul << 30) - (OCTEON_PCI_BAR1_HOLE_SIZE << 20)) {
+			if (unlikely
+			    (physical + size >
+			     (4ul << 30) - (OCTEON_PCI_BAR1_HOLE_SIZE << 20)))
+				panic("dma_map_single: Requested memory "
+				      "extends past Bar1 (4GB-%luMB)\n",
+				      OCTEON_PCI_BAR1_HOLE_SIZE);
+			result = physical;
+			goto done;
+		} else if ((physical >= 0x410000000ull) &&
+			   (physical < 0x420000000ull)) {
+			if (unlikely(physical + size > 0x420000000ull))
+				panic("dma_map_single: Requested memory spans "
+				      "non existant memory\n");
+			/* BAR0 fixed mapping 256MB:512MB ->
+			 * 16GB+256MB:16GB+512MB */
+			result = physical - 0x400000000ull;
+			goto done;
+		} else {
+			/* Continued below switch statement */
+		}
+		break;
+
+	case OCTEON_DMA_BAR_TYPE_SMALL:
+#ifdef CONFIG_64BIT
+		/* If the device supports 64bit addressing, then use BAR2 */
+		if (dma_mask > BAR2_PCI_ADDRESS) {
+			result = physical + BAR2_PCI_ADDRESS;
+			goto done;
+		}
+#endif
+		/* Continued below switch statement */
+		break;
+
+	default:
+		panic("dma_map_single: Invalid octeon_dma_bar_type\n");
+	}
+
+	/* Don't allow mapping to span multiple Bar entries. The hardware guys
+	   won't guarantee that DMA across boards work */
+	if (unlikely((physical >> 22) != ((physical + size - 1) >> 22)))
+		panic("dma_map_single: "
+		      "Requested memory spans more than one Bar1 entry\n");
+
+	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_BIG)
+		start_index = 31;
+	else if (unlikely(dma_mask < (1ul << 27)))
+		start_index = (dma_mask >> 22);
+	else
+		start_index = 31;
+
+	/* Only one processor can access the Bar register at once */
+	spin_lock_irqsave(&bar1_lock, flags);
+
+	/* Look through Bar1 for existing mapping that will work */
+	for (index = start_index; index >= 0; index--) {
+		if ((bar1_state[index].address_bits == physical >> 22) &&
+		    (bar1_state[index].ref_count)) {
+			/* An existing mapping will work, use it */
+			bar1_state[index].ref_count++;
+			if (unlikely(bar1_state[index].ref_count < 0))
+				panic("dma_map_single: "
+				      "Bar1[%d] reference count overflowed\n",
+				      (int) index);
+			result = (index << 22) | (physical & ((1 << 22) - 1));
+			/* Large BAR1 is offset at 2GB */
+			if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_BIG)
+				result += 2ul << 30;
+			goto done_unlock;
+		}
+	}
+
+	/* No existing mappings, look for a free entry */
+	for (index = start_index; index >= 0; index--) {
+		if (unlikely(bar1_state[index].ref_count == 0)) {
+			union cvmx_pci_bar1_indexx bar1_index;
+			/* We have a free entry, use it */
+			bar1_state[index].ref_count = 1;
+			bar1_state[index].address_bits = physical >> 22;
+			bar1_index.u32 = 0;
+			/* Address bits[35:22] sent to L2C */
+			bar1_index.s.addr_idx = physical >> 22;
+			/* 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);
+			/* An existing mapping will work, use it */
+			result = (index << 22) | (physical & ((1 << 22) - 1));
+			/* Large BAR1 is offset at 2GB */
+			if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_BIG)
+				result += 2ul << 30;
+			goto done_unlock;
+		}
+	}
+
+	pr_err("dma_map_single: "
+	       "Can't find empty BAR1 index for physical mapping 0x%llx\n",
+	       (unsigned long long) physical);
+
+done_unlock:
+	spin_unlock_irqrestore(&bar1_lock, flags);
+done:
+	pr_debug("dma_map_single 0x%llx->0x%llx\n", physical, result);
+	return result;
+#endif
 }
 
 void octeon_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr)
 {
-	/* Without PCI/PCIe this function can be called for Octeon internal
-	 * devices such as USB. These devices all support 64bit addressing */
+#ifndef CONFIG_PCI
+	/*
+	 * Without PCI/PCIe this function can be called for Octeon internal
+	 * devices such as USB. These devices all support 64bit addressing.
+	 */
+	return;
+#else
+	unsigned long flags;
+	uint64_t index;
+
+	/*
+	 * Platform devices, such as the internal USB, skip all
+	 * translation and use Octeon physical addresses directly.
+	 */
+	if (dev->bus == &platform_bus_type)
+		return;
+
+	switch (octeon_dma_bar_type) {
+	case OCTEON_DMA_BAR_TYPE_PCIE:
+		/* Nothing to do, all mappings are static */
+		goto done;
+
+	case OCTEON_DMA_BAR_TYPE_BIG:
+#ifdef CONFIG_64BIT
+		/* Nothing to do for addresses using BAR2 */
+		if (dma_addr >= BAR2_PCI_ADDRESS)
+			goto done;
+#endif
+		if (unlikely(dma_addr < (4ul << 10)))
+			panic("dma_unmap_single: Unexpect DMA address 0x%llx\n",
+			      dma_addr);
+		else if (dma_addr < (2ul << 30))
+			/* Nothing to do for addresses using BAR0 */
+			goto done;
+		else if (dma_addr < (2ul << 30) + (128ul << 20))
+			/* Need to unmap, fall through */
+			index = (dma_addr - (2ul << 30)) >> 22;
+		else if (dma_addr <
+			 (4ul << 30) - (OCTEON_PCI_BAR1_HOLE_SIZE << 20))
+			goto done;	/* Nothing to do for the rest of BAR1 */
+		else
+			panic("dma_unmap_single: Unexpect DMA address 0x%llx\n",
+			      dma_addr);
+		/* Continued below switch statement */
+		break;
+
+	case OCTEON_DMA_BAR_TYPE_SMALL:
+#ifdef CONFIG_64BIT
+		/* Nothing to do for addresses using BAR2 */
+		if (dma_addr >= BAR2_PCI_ADDRESS)
+			goto done;
+#endif
+		index = dma_addr >> 22;
+		/* Continued below switch statement */
+		break;
+
+	default:
+		panic("dma_unmap_single: Invalid octeon_dma_bar_type\n");
+	}
+
+	if (unlikely(index > 31))
+		panic("dma_unmap_single: "
+		      "Attempt to unmap an invalid address (0x%llx)\n",
+		      dma_addr);
+
+	spin_lock_irqsave(&bar1_lock, flags);
+	bar1_state[index].ref_count--;
+	if (bar1_state[index].ref_count == 0)
+		octeon_npi_write32(CVMX_NPI_PCI_BAR1_INDEXX(index), 0);
+	else if (unlikely(bar1_state[index].ref_count < 0))
+		panic("dma_unmap_single: Bar1[%u] reference count < 0\n",
+		      (int) index);
+	spin_unlock_irqrestore(&bar1_lock, flags);
+done:
+	pr_debug("dma_unmap_single 0x%llx\n", dma_addr);
 	return;
+#endif
 }

arch/mips/cavium-octeon/executive/Makefile

@@ -11,3 +11,4 @@
 
 obj-y += cvmx-bootmem.o cvmx-l2c.o cvmx-sysinfo.o octeon-model.o
 
+obj-$(CONFIG_PCI) += cvmx-helper-errata.o cvmx-helper-jtag.o