Initial import

1 files changed, 599 insertions, 0 deletions

diff --git a/arch/tile/kernel/pci.c b/arch/tile/kernel/pci.c
new file mode 100644
index 000000000..9475a74cd
--- /dev/null
+++ b/arch/tile/kernel/pci.c
@@ -0,0 +1,599 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/capability.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/export.h>
+
+#include <asm/processor.h>
+#include <asm/sections.h>
+#include <asm/byteorder.h>
+#include <asm/hv_driver.h>
+#include <hv/drv_pcie_rc_intf.h>
+
+
+/*
+ * Initialization flow and process
+ * -------------------------------
+ *
+ * This files contains the routines to search for PCI buses,
+ * enumerate the buses, and configure any attached devices.
+ *
+ * There are two entry points here:
+ * 1) tile_pci_init
+ *    This sets up the pci_controller structs, and opens the
+ *    FDs to the hypervisor.  This is called from setup_arch() early
+ *    in the boot process.
+ * 2) pcibios_init
+ *    This probes the PCI bus(es) for any attached hardware.  It's
+ *    called by subsys_initcall.  All of the real work is done by the
+ *    generic Linux PCI layer.
+ *
+ */
+
+static int pci_probe = 1;
+
+/*
+ * This flag tells if the platform is TILEmpower that needs
+ * special configuration for the PLX switch chip.
+ */
+int __write_once tile_plx_gen1;
+
+static struct pci_controller controllers[TILE_NUM_PCIE];
+static int num_controllers;
+static int pci_scan_flags[TILE_NUM_PCIE];
+
+static struct pci_ops tile_cfg_ops;
+
+
+/*
+ * We don't need to worry about the alignment of resources.
+ */
+resource_size_t pcibios_align_resource(void *data, const struct resource *res,
+			    resource_size_t size, resource_size_t align)
+{
+	return res->start;
+}
+EXPORT_SYMBOL(pcibios_align_resource);
+
+/*
+ * Open a FD to the hypervisor PCI device.
+ *
+ * controller_id is the controller number, config type is 0 or 1 for
+ * config0 or config1 operations.
+ */
+static int tile_pcie_open(int controller_id, int config_type)
+{
+	char filename[32];
+	int fd;
+
+	sprintf(filename, "pcie/%d/config%d", controller_id, config_type);
+
+	fd = hv_dev_open((HV_VirtAddr)filename, 0);
+
+	return fd;
+}
+
+
+/*
+ * Get the IRQ numbers from the HV and set up the handlers for them.
+ */
+static int tile_init_irqs(int controller_id, struct pci_controller *controller)
+{
+	char filename[32];
+	int fd;
+	int ret;
+	int x;
+	struct pcie_rc_config rc_config;
+
+	sprintf(filename, "pcie/%d/ctl", controller_id);
+	fd = hv_dev_open((HV_VirtAddr)filename, 0);
+	if (fd < 0) {
+		pr_err("PCI: hv_dev_open(%s) failed\n", filename);
+		return -1;
+	}
+	ret = hv_dev_pread(fd, 0, (HV_VirtAddr)(&rc_config),
+			   sizeof(rc_config), PCIE_RC_CONFIG_MASK_OFF);
+	hv_dev_close(fd);
+	if (ret != sizeof(rc_config)) {
+		pr_err("PCI: wanted %zd bytes, got %d\n",
+		       sizeof(rc_config), ret);
+		return -1;
+	}
+	/* Record irq_base so that we can map INTx to IRQ # later. */
+	controller->irq_base = rc_config.intr;
+
+	for (x = 0; x < 4; x++)
+		tile_irq_activate(rc_config.intr + x,
+				  TILE_IRQ_HW_CLEAR);
+
+	if (rc_config.plx_gen1)
+		controller->plx_gen1 = 1;
+
+	return 0;
+}
+
+/*
+ * First initialization entry point, called from setup_arch().
+ *
+ * Find valid controllers and fill in pci_controller structs for each
+ * of them.
+ *
+ * Returns the number of controllers discovered.
+ */
+int __init tile_pci_init(void)
+{
+	int i;
+
+	if (!pci_probe) {
+		pr_info("PCI: disabled by boot argument\n");
+		return 0;
+	}
+
+	pr_info("PCI: Searching for controllers...\n");
+
+	/* Re-init number of PCIe controllers to support hot-plug feature. */
+	num_controllers = 0;
+
+	/* Do any configuration we need before using the PCIe */
+
+	for (i = 0; i < TILE_NUM_PCIE; i++) {
+		/*
+		 * To see whether we need a real config op based on
+		 * the results of pcibios_init(), to support PCIe hot-plug.
+		 */
+		if (pci_scan_flags[i] == 0) {
+			int hv_cfg_fd0 = -1;
+			int hv_cfg_fd1 = -1;
+			int hv_mem_fd = -1;
+			char name[32];
+			struct pci_controller *controller;
+
+			/*
+			 * Open the fd to the HV.  If it fails then this
+			 * device doesn't exist.
+			 */
+			hv_cfg_fd0 = tile_pcie_open(i, 0);
+			if (hv_cfg_fd0 < 0)
+				continue;
+			hv_cfg_fd1 = tile_pcie_open(i, 1);
+			if (hv_cfg_fd1 < 0) {
+				pr_err("PCI: Couldn't open config fd to HV for controller %d\n",
+				       i);
+				goto err_cont;
+			}
+
+			sprintf(name, "pcie/%d/mem", i);
+			hv_mem_fd = hv_dev_open((HV_VirtAddr)name, 0);
+			if (hv_mem_fd < 0) {
+				pr_err("PCI: Could not open mem fd to HV!\n");
+				goto err_cont;
+			}
+
+			pr_info("PCI: Found PCI controller #%d\n", i);
+
+			controller = &controllers[i];
+
+			controller->index = i;
+			controller->hv_cfg_fd[0] = hv_cfg_fd0;
+			controller->hv_cfg_fd[1] = hv_cfg_fd1;
+			controller->hv_mem_fd = hv_mem_fd;
+			controller->last_busno = 0xff;
+			controller->ops = &tile_cfg_ops;
+
+			num_controllers++;
+			continue;
+
+err_cont:
+			if (hv_cfg_fd0 >= 0)
+				hv_dev_close(hv_cfg_fd0);
+			if (hv_cfg_fd1 >= 0)
+				hv_dev_close(hv_cfg_fd1);
+			if (hv_mem_fd >= 0)
+				hv_dev_close(hv_mem_fd);
+			continue;
+		}
+	}
+
+	/*
+	 * Before using the PCIe, see if we need to do any platform-specific
+	 * configuration, such as the PLX switch Gen 1 issue on TILEmpower.
+	 */
+	for (i = 0; i < num_controllers; i++) {
+		struct pci_controller *controller = &controllers[i];
+
+		if (controller->plx_gen1)
+			tile_plx_gen1 = 1;
+	}
+
+	return num_controllers;
+}
+
+/*
+ * (pin - 1) converts from the PCI standard's [1:4] convention to
+ * a normal [0:3] range.
+ */
+static int tile_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct pci_controller *controller =
+		(struct pci_controller *)dev->sysdata;
+	return (pin - 1) + controller->irq_base;
+}
+
+
+static void fixup_read_and_payload_sizes(void)
+{
+	struct pci_dev *dev = NULL;
+	int smallest_max_payload = 0x1; /* Tile maxes out at 256 bytes. */
+	int max_read_size = PCI_EXP_DEVCTL_READRQ_512B;
+	u16 new_values;
+
+	/* Scan for the smallest maximum payload size. */
+	for_each_pci_dev(dev) {
+		if (!pci_is_pcie(dev))
+			continue;
+
+		if (dev->pcie_mpss < smallest_max_payload)
+			smallest_max_payload = dev->pcie_mpss;
+	}
+
+	/* Now, set the max_payload_size for all devices to that value. */
+	new_values = max_read_size | (smallest_max_payload << 5);
+	for_each_pci_dev(dev)
+		pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
+				PCI_EXP_DEVCTL_PAYLOAD | PCI_EXP_DEVCTL_READRQ,
+				new_values);
+}
+
+
+/*
+ * Second PCI initialization entry point, called by subsys_initcall.
+ *
+ * The controllers have been set up by the time we get here, by a call to
+ * tile_pci_init.
+ */
+int __init pcibios_init(void)
+{
+	int i;
+
+	pr_info("PCI: Probing PCI hardware\n");
+
+	/*
+	 * Delay a bit in case devices aren't ready.  Some devices are
+	 * known to require at least 20ms here, but we use a more
+	 * conservative value.
+	 */
+	msleep(250);
+
+	/* Scan all of the recorded PCI controllers.  */
+	for (i = 0; i < TILE_NUM_PCIE; i++) {
+		/*
+		 * Do real pcibios init ops if the controller is initialized
+		 * by tile_pci_init() successfully and not initialized by
+		 * pcibios_init() yet to support PCIe hot-plug.
+		 */
+		if (pci_scan_flags[i] == 0 && controllers[i].ops != NULL) {
+			struct pci_controller *controller = &controllers[i];
+			struct pci_bus *bus;
+			LIST_HEAD(resources);
+
+			if (tile_init_irqs(i, controller)) {
+				pr_err("PCI: Could not initialize IRQs\n");
+				continue;
+			}
+
+			pr_info("PCI: initializing controller #%d\n", i);
+
+			pci_add_resource(&resources, &ioport_resource);
+			pci_add_resource(&resources, &iomem_resource);
+			bus = pci_scan_root_bus(NULL, 0, controller->ops,
+						controller, &resources);
+			controller->root_bus = bus;
+			controller->last_busno = bus->busn_res.end;
+		}
+	}
+
+	/* Do machine dependent PCI interrupt routing */
+	pci_fixup_irqs(pci_common_swizzle, tile_map_irq);
+
+	/*
+	 * This comes from the generic Linux PCI driver.
+	 *
+	 * It allocates all of the resources (I/O memory, etc)
+	 * associated with the devices read in above.
+	 */
+	pci_assign_unassigned_resources();
+
+	/* Configure the max_read_size and max_payload_size values. */
+	fixup_read_and_payload_sizes();
+
+	/* Record the I/O resources in the PCI controller structure. */
+	for (i = 0; i < TILE_NUM_PCIE; i++) {
+		/*
+		 * Do real pcibios init ops if the controller is initialized
+		 * by tile_pci_init() successfully and not initialized by
+		 * pcibios_init() yet to support PCIe hot-plug.
+		 */
+		if (pci_scan_flags[i] == 0 && controllers[i].ops != NULL) {
+			struct pci_bus *root_bus = controllers[i].root_bus;
+			struct pci_bus *next_bus;
+			struct pci_dev *dev;
+
+			pci_bus_add_devices(root_bus);
+
+			list_for_each_entry(dev, &root_bus->devices, bus_list) {
+				/*
+				 * Find the PCI host controller, ie. the 1st
+				 * bridge.
+				 */
+				if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI &&
+					(PCI_SLOT(dev->devfn) == 0)) {
+					next_bus = dev->subordinate;
+					controllers[i].mem_resources[0] =
+						*next_bus->resource[0];
+					controllers[i].mem_resources[1] =
+						 *next_bus->resource[1];
+					controllers[i].mem_resources[2] =
+						 *next_bus->resource[2];
+
+					/* Setup flags. */
+					pci_scan_flags[i] = 1;
+
+					break;
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+subsys_initcall(pcibios_init);
+
+/*
+ * No bus fixups needed.
+ */
+void pcibios_fixup_bus(struct pci_bus *bus)
+{
+	/* Nothing needs to be done. */
+}
+
+void pcibios_set_master(struct pci_dev *dev)
+{
+	/* No special bus mastering setup handling. */
+}
+
+/* Process any "pci=" kernel boot arguments. */
+char *__init pcibios_setup(char *str)
+{
+	if (!strcmp(str, "off")) {
+		pci_probe = 0;
+		return NULL;
+	}
+	return str;
+}
+
+/*
+ * Enable memory and/or address decoding, as appropriate, for the
+ * device described by the 'dev' struct.
+ *
+ * This is called from the generic PCI layer, and can be called
+ * for bridges or endpoints.
+ */
+int pcibios_enable_device(struct pci_dev *dev, int mask)
+{
+	u16 cmd, old_cmd;
+	u8 header_type;
+	int i;
+	struct resource *r;
+
+	pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	old_cmd = cmd;
+	if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
+		/*
+		 * For bridges, we enable both memory and I/O decoding
+		 * in call cases.
+		 */
+		cmd |= PCI_COMMAND_IO;
+		cmd |= PCI_COMMAND_MEMORY;
+	} else {
+		/*
+		 * For endpoints, we enable memory and/or I/O decoding
+		 * only if they have a memory resource of that type.
+		 */
+		for (i = 0; i < 6; i++) {
+			r = &dev->resource[i];
+			if (r->flags & IORESOURCE_UNSET) {
+				pr_err("PCI: Device %s not available because of resource collisions\n",
+				       pci_name(dev));
+				return -EINVAL;
+			}
+			if (r->flags & IORESOURCE_IO)
+				cmd |= PCI_COMMAND_IO;
+			if (r->flags & IORESOURCE_MEM)
+				cmd |= PCI_COMMAND_MEMORY;
+		}
+	}
+
+	/*
+	 * We only write the command if it changed.
+	 */
+	if (cmd != old_cmd)
+		pci_write_config_word(dev, PCI_COMMAND, cmd);
+	return 0;
+}
+
+/****************************************************************
+ *
+ * Tile PCI config space read/write routines
+ *
+ ****************************************************************/
+
+/*
+ * These are the normal read and write ops
+ * These are expanded with macros from  pci_bus_read_config_byte() etc.
+ *
+ * devfn is the combined PCI slot & function.
+ *
+ * offset is in bytes, from the start of config space for the
+ * specified bus & slot.
+ */
+
+static int tile_cfg_read(struct pci_bus *bus, unsigned int devfn, int offset,
+			 int size, u32 *val)
+{
+	struct pci_controller *controller = bus->sysdata;
+	int busnum = bus->number & 0xff;
+	int slot = (devfn >> 3) & 0x1f;
+	int function = devfn & 0x7;
+	u32 addr;
+	int config_mode = 1;
+
+	/*
+	 * There is no bridge between the Tile and bus 0, so we
+	 * use config0 to talk to bus 0.
+	 *
+	 * If we're talking to a bus other than zero then we
+	 * must have found a bridge.
+	 */
+	if (busnum == 0) {
+		/*
+		 * We fake an empty slot for (busnum == 0) && (slot > 0),
+		 * since there is only one slot on bus 0.
+		 */
+		if (slot) {
+			*val = 0xFFFFFFFF;
+			return 0;
+		}
+		config_mode = 0;
+	}
+
+	addr = busnum << 20;		/* Bus in 27:20 */
+	addr |= slot << 15;		/* Slot (device) in 19:15 */
+	addr |= function << 12;		/* Function is in 14:12 */
+	addr |= (offset & 0xFFF);	/* byte address in 0:11 */
+
+	return hv_dev_pread(controller->hv_cfg_fd[config_mode], 0,
+			    (HV_VirtAddr)(val), size, addr);
+}
+
+
+/*
+ * See tile_cfg_read() for relevant comments.
+ * Note that "val" is the value to write, not a pointer to that value.
+ */
+static int tile_cfg_write(struct pci_bus *bus, unsigned int devfn, int offset,
+			  int size, u32 val)
+{
+	struct pci_controller *controller = bus->sysdata;
+	int busnum = bus->number & 0xff;
+	int slot = (devfn >> 3) & 0x1f;
+	int function = devfn & 0x7;
+	u32 addr;
+	int config_mode = 1;
+	HV_VirtAddr valp = (HV_VirtAddr)&val;
+
+	/*
+	 * For bus 0 slot 0 we use config 0 accesses.
+	 */
+	if (busnum == 0) {
+		/*
+		 * We fake an empty slot for (busnum == 0) && (slot > 0),
+		 * since there is only one slot on bus 0.
+		 */
+		if (slot)
+			return 0;
+		config_mode = 0;
+	}
+
+	addr = busnum << 20;		/* Bus in 27:20 */
+	addr |= slot << 15;		/* Slot (device) in 19:15 */
+	addr |= function << 12;		/* Function is in 14:12 */
+	addr |= (offset & 0xFFF);	/* byte address in 0:11 */
+
+#ifdef __BIG_ENDIAN
+	/* Point to the correct part of the 32-bit "val". */
+	valp += 4 - size;
+#endif
+
+	return hv_dev_pwrite(controller->hv_cfg_fd[config_mode], 0,
+			     valp, size, addr);
+}
+
+
+static struct pci_ops tile_cfg_ops = {
+	.read =         tile_cfg_read,
+	.write =        tile_cfg_write,
+};
+
+
+/*
+ * In the following, each PCI controller's mem_resources[1]
+ * represents its (non-prefetchable) PCI memory resource.
+ * mem_resources[0] and mem_resources[2] refer to its PCI I/O and
+ * prefetchable PCI memory resources, respectively.
+ * For more details, see pci_setup_bridge() in setup-bus.c.
+ * By comparing the target PCI memory address against the
+ * end address of controller 0, we can determine the controller
+ * that should accept the PCI memory access.
+ */
+#define TILE_READ(size, type)						\
+type _tile_read##size(unsigned long addr)				\
+{									\
+	type val;							\
+	int idx = 0;							\
+	if (addr > controllers[0].mem_resources[1].end &&		\
+	    addr > controllers[0].mem_resources[2].end)			\
+		idx = 1;                                                \
+	if (hv_dev_pread(controllers[idx].hv_mem_fd, 0,			\
+			 (HV_VirtAddr)(&val), sizeof(type), addr))	\
+		pr_err("PCI: read %zd bytes at 0x%lX failed\n",		\
+		       sizeof(type), addr);				\
+	return val;							\
+}									\
+EXPORT_SYMBOL(_tile_read##size)
+
+TILE_READ(b, u8);
+TILE_READ(w, u16);
+TILE_READ(l, u32);
+TILE_READ(q, u64);
+
+#define TILE_WRITE(size, type)						\
+void _tile_write##size(type val, unsigned long addr)			\
+{									\
+	int idx = 0;							\
+	if (addr > controllers[0].mem_resources[1].end &&		\
+	    addr > controllers[0].mem_resources[2].end)			\
+		idx = 1;                                                \
+	if (hv_dev_pwrite(controllers[idx].hv_mem_fd, 0,		\
+			  (HV_VirtAddr)(&val), sizeof(type), addr))	\
+		pr_err("PCI: write %zd bytes at 0x%lX failed\n",	\
+		       sizeof(type), addr);				\
+}									\
+EXPORT_SYMBOL(_tile_write##size)
+
+TILE_WRITE(b, u8);
+TILE_WRITE(w, u16);
+TILE_WRITE(l, u32);
+TILE_WRITE(q, u64);