/*
 * Copyright 2012 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/mmzone.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/msi.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/ctype.h>

#include <asm/processor.h>
#include <asm/sections.h>
#include <asm/byteorder.h>

#include <gxio/iorpc_globals.h>
#include <gxio/kiorpc.h>
#include <gxio/trio.h>
#include <gxio/iorpc_trio.h>
#include <hv/drv_trio_intf.h>

#include <arch/sim.h>

/*
 * This file containes the routines to search for PCI buses,
 * enumerate the buses, and configure any attached devices.
 */

#define DEBUG_PCI_CFG   0

#if DEBUG_PCI_CFG
#define TRACE_CFG_WR(size, val, bus, dev, func, offset) \
        pr_info("CFG WR %d-byte VAL %#x to bus %d dev %d func %d addr %u\n", \
                size, val, bus, dev, func, offset & 0xFFF);
#define TRACE_CFG_RD(size, val, bus, dev, func, offset) \
        pr_info("CFG RD %d-byte VAL %#x from bus %d dev %d func %d addr %u\n", \
                size, val, bus, dev, func, offset & 0xFFF);
#else
#define TRACE_CFG_WR(...)
#define TRACE_CFG_RD(...)
#endif

static int pci_probe = 1;

/* Information on the PCIe RC ports configuration. */
static int pcie_rc[TILEGX_NUM_TRIO][TILEGX_TRIO_PCIES];

/*
 * On some platforms with one or more Gx endpoint ports, we need to
 * delay the PCIe RC port probe for a few seconds to work around
 * a HW PCIe link-training bug. The exact delay is specified with
 * a kernel boot argument in the form of "pcie_rc_delay=T,P,S",
 * where T is the TRIO instance number, P is the port number and S is
 * the delay in seconds. If the delay is not provided, the value
 * will be DEFAULT_RC_DELAY.
 */
static int rc_delay[TILEGX_NUM_TRIO][TILEGX_TRIO_PCIES];

/* Default number of seconds that the PCIe RC port probe can be delayed. */
#define DEFAULT_RC_DELAY        10

/* Max number of seconds that the PCIe RC port probe can be delayed. */
#define MAX_RC_DELAY            20

/* Array of the PCIe ports configuration info obtained from the BIB. */
struct pcie_port_property pcie_ports[TILEGX_NUM_TRIO][TILEGX_TRIO_PCIES];

/* All drivers share the TRIO contexts defined here. */
gxio_trio_context_t trio_contexts[TILEGX_NUM_TRIO];

/* Pointer to an array of PCIe RC controllers. */
struct pci_controller pci_controllers[TILEGX_NUM_TRIO * TILEGX_TRIO_PCIES];
int num_rc_controllers;
static int num_ep_controllers;

static struct pci_ops tile_cfg_ops;

/* Mask of CPUs that should receive PCIe interrupts. */
static struct cpumask intr_cpus_map;

/*
 * 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);


/*
 * Pick a CPU to receive and handle the PCIe interrupts, based on the IRQ #.
 * For now, we simply send interrupts to non-dataplane CPUs.
 * We may implement methods to allow user to specify the target CPUs,
 * e.g. via boot arguments.
 */
static int tile_irq_cpu(int irq)
{
        unsigned int count;
        int i = 0;
        int cpu;

        count = cpumask_weight(&intr_cpus_map);
        if (unlikely(count == 0)) {
                pr_warning("intr_cpus_map empty, interrupts will be"
                           " delievered to dataplane tiles\n");
                return irq % (smp_height * smp_width);
        }

        count = irq % count;
        for_each_cpu(cpu, &intr_cpus_map) {
                if (i++ == count)
                        break;
        }
        return cpu;
}

/*
 * Open a file descriptor to the TRIO shim.
 */
static int tile_pcie_open(int trio_index)
{
        gxio_trio_context_t *context = &trio_contexts[trio_index];
        int ret;

        /*
         * This opens a file descriptor to the TRIO shim.
         */
        ret = gxio_trio_init(context, trio_index);
        if (ret < 0)
                return ret;

        /*
         * Allocate an ASID for the kernel.
         */
        ret = gxio_trio_alloc_asids(context, 1, 0, 0);
        if (ret < 0) {
                pr_err("PCI: ASID alloc failure on TRIO %d, give up\n",
                        trio_index);
                goto asid_alloc_failure;
        }

        context->asid = ret;

#ifdef USE_SHARED_PCIE_CONFIG_REGION
        /*
         * Alloc a PIO region for config access, shared by all MACs per TRIO.
         * This shouldn't fail since the kernel is supposed to the first
         * client of the TRIO's PIO regions.
         */
        ret = gxio_trio_alloc_pio_regions(context, 1, 0, 0);
        if (ret < 0) {
                pr_err("PCI: CFG PIO alloc failure on TRIO %d, give up\n",
                        trio_index);
                goto pio_alloc_failure;
        }

        context->pio_cfg_index = ret;

        /*
         * For PIO CFG, the bus_address_hi parameter is 0. The mac parameter
         * is also 0 because it is specified in PIO_REGION_SETUP_CFG_ADDR.
         */
        ret = gxio_trio_init_pio_region_aux(context, context->pio_cfg_index,
                0, 0, HV_TRIO_PIO_FLAG_CONFIG_SPACE);
        if (ret < 0) {
                pr_err("PCI: CFG PIO init failure on TRIO %d, give up\n",
                        trio_index);
                goto pio_alloc_failure;
        }
#endif

        return ret;

asid_alloc_failure:
#ifdef USE_SHARED_PCIE_CONFIG_REGION
pio_alloc_failure:
#endif
        hv_dev_close(context->fd);

        return ret;
}

static void
tilegx_legacy_irq_ack(struct irq_data *d)
{
        __insn_mtspr(SPR_IPI_EVENT_RESET_K, 1UL << d->irq);
}

static void
tilegx_legacy_irq_mask(struct irq_data *d)
{
        __insn_mtspr(SPR_IPI_MASK_SET_K, 1UL << d->irq);
}

static void
tilegx_legacy_irq_unmask(struct irq_data *d)
{
        __insn_mtspr(SPR_IPI_MASK_RESET_K, 1UL << d->irq);
}

static struct irq_chip tilegx_legacy_irq_chip = {
        .name                   = "tilegx_legacy_irq",
        .irq_ack                = tilegx_legacy_irq_ack,
        .irq_mask               = tilegx_legacy_irq_mask,
        .irq_unmask             = tilegx_legacy_irq_unmask,

        /* TBD: support set_affinity. */
};

/*
 * This is a wrapper function of the kernel level-trigger interrupt
 * handler handle_level_irq() for PCI legacy interrupts. The TRIO
 * is configured such that only INTx Assert interrupts are proxied
 * to Linux which just calls handle_level_irq() after clearing the
 * MAC INTx Assert status bit associated with this interrupt.
 */
static void
trio_handle_level_irq(unsigned int irq, struct irq_desc *desc)
{
        struct pci_controller *controller = irq_desc_get_handler_data(desc);
        gxio_trio_context_t *trio_context = controller->trio;
        uint64_t intx = (uint64_t)irq_desc_get_chip_data(desc);
        int mac = controller->mac;
        unsigned int reg_offset;
        uint64_t level_mask;

        handle_level_irq(irq, desc);

        /*
         * Clear the INTx Level status, otherwise future interrupts are
         * not sent.
         */
        reg_offset = (TRIO_PCIE_INTFC_MAC_INT_STS <<
                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_INTERFACE <<
                TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

        level_mask = TRIO_PCIE_INTFC_MAC_INT_STS__INT_LEVEL_MASK << intx;

        __gxio_mmio_write(trio_context->mmio_base_mac + reg_offset, level_mask);
}

/*
 * Create kernel irqs and set up the handlers for the legacy interrupts.
 * Also some minimum initialization for the MSI support.
 */
static int tile_init_irqs(struct pci_controller *controller)
{
        int i;
        int j;
        int irq;
        int result;

        cpumask_copy(&intr_cpus_map, cpu_online_mask);


        for (i = 0; i < 4; i++) {
                gxio_trio_context_t *context = controller->trio;
                int cpu;

                /* Ask the kernel to allocate an IRQ. */
                irq = create_irq();
                if (irq < 0) {
                        pr_err("PCI: no free irq vectors, failed for %d\n", i);

                        goto free_irqs;
                }
                controller->irq_intx_table[i] = irq;

                /* Distribute the 4 IRQs to different tiles. */
                cpu = tile_irq_cpu(irq);

                /* Configure the TRIO intr binding for this IRQ. */
                result = gxio_trio_config_legacy_intr(context, cpu_x(cpu),
                                                      cpu_y(cpu), KERNEL_PL,
                                                      irq, controller->mac, i);
                if (result < 0) {
                        pr_err("PCI: MAC intx config failed for %d\n", i);

                        goto free_irqs;
                }

                /*
                 * Register the IRQ handler with the kernel.
                 */
                irq_set_chip_and_handler(irq, &tilegx_legacy_irq_chip,
                                        trio_handle_level_irq);
                irq_set_chip_data(irq, (void *)(uint64_t)i);
                irq_set_handler_data(irq, controller);
        }

        return 0;

free_irqs:
        for (j = 0; j < i; j++)
                destroy_irq(controller->irq_intx_table[j]);

        return -1;
}

/*
 * 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 num_trio_shims = 0;
        int ctl_index = 0;
        int i, j;

        if (!pci_probe) {
                pr_info("PCI: disabled by boot argument\n");
                return 0;
        }

        pr_info("PCI: Searching for controllers...\n");

        /*
         * We loop over all the TRIO shims.
         */
        for (i = 0; i < TILEGX_NUM_TRIO; i++) {
                int ret;

                ret = tile_pcie_open(i);
                if (ret < 0)
                        continue;

                num_trio_shims++;
        }

        if (num_trio_shims == 0 || sim_is_simulator())
                return 0;

        /*
         * Now determine which PCIe ports are configured to operate in RC mode.
         * We look at the Board Information Block first and then see if there
         * are any overriding configuration by the HW strapping pin.
         */
        for (i = 0; i < TILEGX_NUM_TRIO; i++) {
                gxio_trio_context_t *context = &trio_contexts[i];
                int ret;

                if (context->fd < 0)
                        continue;

                ret = hv_dev_pread(context->fd, 0,
                        (HV_VirtAddr)&pcie_ports[i][0],
                        sizeof(struct pcie_port_property) * TILEGX_TRIO_PCIES,
                        GXIO_TRIO_OP_GET_PORT_PROPERTY);
                if (ret < 0) {
                        pr_err("PCI: PCIE_GET_PORT_PROPERTY failure, error %d,"
                                " on TRIO %d\n", ret, i);
                        continue;
                }

                for (j = 0; j < TILEGX_TRIO_PCIES; j++) {
                        if (pcie_ports[i][j].allow_rc) {
                                pcie_rc[i][j] = 1;
                                num_rc_controllers++;
                        }
                        else if (pcie_ports[i][j].allow_ep) {
                                num_ep_controllers++;
                        }
                }
        }

        /*
         * Return if no PCIe ports are configured to operate in RC mode.
         */
        if (num_rc_controllers == 0)
                return 0;

        /*
         * Set the TRIO pointer and MAC index for each PCIe RC port.
         */
        for (i = 0; i < TILEGX_NUM_TRIO; i++) {
                for (j = 0; j < TILEGX_TRIO_PCIES; j++) {
                        if (pcie_rc[i][j]) {
                                pci_controllers[ctl_index].trio =
                                        &trio_contexts[i];
                                pci_controllers[ctl_index].mac = j;
                                pci_controllers[ctl_index].trio_index = i;
                                ctl_index++;
                                if (ctl_index == num_rc_controllers)
                                        goto out;
                        }
                }
        }

out:
        /*
         * Configure each PCIe RC port.
         */
        for (i = 0; i < num_rc_controllers; i++) {
                /*
                 * Configure the PCIe MAC to run in RC mode.
                 */

                struct pci_controller *controller = &pci_controllers[i];

                controller->index = i;
                controller->ops = &tile_cfg_ops;

                /*
                 * The PCI memory resource is located above the PA space.
                 * For every host bridge, the BAR window or the MMIO aperture
                 * is in range [3GB, 4GB - 1] of a 4GB space beyond the
                 * PA space.
                 */

                controller->mem_offset = TILE_PCI_MEM_START +
                        (i * TILE_PCI_BAR_WINDOW_TOP);
                controller->mem_space.start = controller->mem_offset +
                        TILE_PCI_BAR_WINDOW_TOP - TILE_PCI_BAR_WINDOW_SIZE;
                controller->mem_space.end = controller->mem_offset +
                        TILE_PCI_BAR_WINDOW_TOP - 1;
                controller->mem_space.flags = IORESOURCE_MEM;
                snprintf(controller->mem_space_name,
                         sizeof(controller->mem_space_name),
                         "PCI mem domain %d", i);
                controller->mem_space.name = controller->mem_space_name;
        }

        return num_rc_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 device, u8 pin)
{
        struct pci_controller *controller =
                (struct pci_controller *)dev->sysdata;
        return controller->irq_intx_table[pin - 1];
}


static void fixup_read_and_payload_sizes(struct pci_controller *controller)
{
        gxio_trio_context_t *trio_context = controller->trio;
        struct pci_bus *root_bus = controller->root_bus;
        TRIO_PCIE_RC_DEVICE_CONTROL_t dev_control;
        TRIO_PCIE_RC_DEVICE_CAP_t rc_dev_cap;
        unsigned int reg_offset;
        struct pci_bus *child;
        int mac;
        int err;

        mac = controller->mac;

        /*
         * Set our max read request size to be 4KB.
         */
        reg_offset =
                (TRIO_PCIE_RC_DEVICE_CONTROL <<
                        TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_STANDARD <<
                        TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

        dev_control.word = __gxio_mmio_read32(trio_context->mmio_base_mac +
                                                reg_offset);
        dev_control.max_read_req_sz = 5;
        __gxio_mmio_write32(trio_context->mmio_base_mac + reg_offset,
                                                dev_control.word);

        /*
         * Set the max payload size supported by this Gx PCIe MAC.
         * Though Gx PCIe supports Max Payload Size of up to 1024 bytes,
         * experiments have shown that setting MPS to 256 yields the
         * best performance.
         */
        reg_offset =
                (TRIO_PCIE_RC_DEVICE_CAP <<
                        TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_STANDARD <<
                        TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

        rc_dev_cap.word = __gxio_mmio_read32(trio_context->mmio_base_mac +
                                                reg_offset);
        rc_dev_cap.mps_sup = 1;
        __gxio_mmio_write32(trio_context->mmio_base_mac + reg_offset,
                                                rc_dev_cap.word);

        /* Configure PCI Express MPS setting. */
        list_for_each_entry(child, &root_bus->children, node) {
                struct pci_dev *self = child->self;
                if (!self)
                        continue;

                pcie_bus_configure_settings(child, self->pcie_mpss);
        }

        /*
         * Set the mac_config register in trio based on the MPS/MRS of the link.
         */
        reg_offset =
                (TRIO_PCIE_RC_DEVICE_CONTROL <<
                        TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_STANDARD <<
                        TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

        dev_control.word = __gxio_mmio_read32(trio_context->mmio_base_mac +
                                                reg_offset);

        err = gxio_trio_set_mps_mrs(trio_context,
                                    dev_control.max_payload_size,
                                    dev_control.max_read_req_sz,
                                    mac);
        if (err < 0) {
                pr_err("PCI: PCIE_CONFIGURE_MAC_MPS_MRS failure, "
                        "MAC %d on TRIO %d\n",
                        mac, controller->trio_index);
        }
}

static int setup_pcie_rc_delay(char *str)
{
        unsigned long delay = 0;
        unsigned long trio_index;
        unsigned long mac;

        if (str == NULL || !isdigit(*str))
                return -EINVAL;
        trio_index = simple_strtoul(str, (char **)&str, 10);
        if (trio_index >= TILEGX_NUM_TRIO)
                return -EINVAL;

        if (*str != ',')
                return -EINVAL;

        str++;
        if (!isdigit(*str))
                return -EINVAL;
        mac = simple_strtoul(str, (char **)&str, 10);
        if (mac >= TILEGX_TRIO_PCIES)
                return -EINVAL;

        if (*str != '\0') {
                if (*str != ',')
                        return -EINVAL;

                str++;
                if (!isdigit(*str))
                        return -EINVAL;
                delay = simple_strtoul(str, (char **)&str, 10);
                if (delay > MAX_RC_DELAY)
                        return -EINVAL;
        }

        rc_delay[trio_index][mac] = delay ? : DEFAULT_RC_DELAY;
        pr_info("Delaying PCIe RC link training for %u sec"
                " on MAC %lu on TRIO %lu\n", rc_delay[trio_index][mac],
                mac, trio_index);
        return 0;
}
early_param("pcie_rc_delay", setup_pcie_rc_delay);

/*
 * PCI initialization entry point, called by subsys_initcall.
 */
int __init pcibios_init(void)
{
        resource_size_t offset;
        LIST_HEAD(resources);
        int next_busno;
        int i;

        tile_pci_init();

        if (num_rc_controllers == 0 && num_ep_controllers == 0)
                return 0;

        /*
         * We loop over all the TRIO shims and set up the MMIO mappings.
         */
        for (i = 0; i < TILEGX_NUM_TRIO; i++) {
                gxio_trio_context_t *context = &trio_contexts[i];

                if (context->fd < 0)
                        continue;

                /*
                 * Map in the MMIO space for the MAC.
                 */
                offset = 0;
                context->mmio_base_mac =
                        iorpc_ioremap(context->fd, offset,
                                      HV_TRIO_CONFIG_IOREMAP_SIZE);
                if (context->mmio_base_mac == NULL) {
                        pr_err("PCI: MAC map failure on TRIO %d\n", i);

                        hv_dev_close(context->fd);
                        context->fd = -1;
                        continue;
                }
        }

        /*
         * 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 (next_busno = 0, i = 0; i < num_rc_controllers; i++) {
                struct pci_controller *controller = &pci_controllers[i];
                gxio_trio_context_t *trio_context = controller->trio;
                TRIO_PCIE_INTFC_PORT_CONFIG_t port_config;
                TRIO_PCIE_INTFC_PORT_STATUS_t port_status;
                TRIO_PCIE_INTFC_TX_FIFO_CTL_t tx_fifo_ctl;
                struct pci_bus *bus;
                unsigned int reg_offset;
                unsigned int class_code_revision;
                int trio_index;
                int mac;
                int ret;

                if (trio_context->fd < 0)
                        continue;

                trio_index = controller->trio_index;
                mac = controller->mac;

                /*
                 * Check the port strap state which will override the BIB
                 * setting.
                 */

                reg_offset =
                        (TRIO_PCIE_INTFC_PORT_CONFIG <<
                                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                        (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_INTERFACE <<
                                TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                        (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

                port_config.word =
                        __gxio_mmio_read(trio_context->mmio_base_mac +
                                         reg_offset);

                if ((port_config.strap_state !=
                        TRIO_PCIE_INTFC_PORT_CONFIG__STRAP_STATE_VAL_AUTO_CONFIG_RC) &&
                        (port_config.strap_state !=
                        TRIO_PCIE_INTFC_PORT_CONFIG__STRAP_STATE_VAL_AUTO_CONFIG_RC_G1)) {
                        /*
                         * If this is really intended to be an EP port,
                         * record it so that the endpoint driver will know about it.
                         */
                        if (port_config.strap_state ==
                        TRIO_PCIE_INTFC_PORT_CONFIG__STRAP_STATE_VAL_AUTO_CONFIG_ENDPOINT ||
                        port_config.strap_state ==
                        TRIO_PCIE_INTFC_PORT_CONFIG__STRAP_STATE_VAL_AUTO_CONFIG_ENDPOINT_G1)
                                pcie_ports[trio_index][mac].allow_ep = 1;

                        continue;
                }

                /*
                 * Delay the RC link training if needed.
                 */
                if (rc_delay[trio_index][mac])
                        msleep(rc_delay[trio_index][mac] * 1000);

                ret = gxio_trio_force_rc_link_up(trio_context, mac);
                if (ret < 0)
                        pr_err("PCI: PCIE_FORCE_LINK_UP failure, "
                                "MAC %d on TRIO %d\n", mac, trio_index);

                pr_info("PCI: Found PCI controller #%d on TRIO %d MAC %d\n", i,
                        trio_index, controller->mac);

                /*
                 * Wait a bit here because some EP devices take longer
                 * to come up.
                 */
                msleep(1000);

                /*
                 * Check for PCIe link-up status.
                 */

                reg_offset =
                        (TRIO_PCIE_INTFC_PORT_STATUS <<
                                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                        (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_INTERFACE <<
                                TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                        (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

                port_status.word =
                        __gxio_mmio_read(trio_context->mmio_base_mac +
                                         reg_offset);
                if (!port_status.dl_up) {
                        pr_err("PCI: link is down, MAC %d on TRIO %d\n",
                                mac, trio_index);
                        continue;
                }

                /*
                 * Ensure that the link can come out of L1 power down state.
                 * Strictly speaking, this is needed only in the case of
                 * heavy RC-initiated DMAs.
                 */
                reg_offset =
                        (TRIO_PCIE_INTFC_TX_FIFO_CTL <<
                                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                        (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_INTERFACE <<
                                TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                        (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);
                tx_fifo_ctl.word =
                        __gxio_mmio_read(trio_context->mmio_base_mac +
                                         reg_offset);
                tx_fifo_ctl.min_p_credits = 0;
                __gxio_mmio_write(trio_context->mmio_base_mac + reg_offset,
                                  tx_fifo_ctl.word);

                /*
                 * Change the device ID so that Linux bus crawl doesn't confuse
                 * the internal bridge with any Tilera endpoints.
                 */

                reg_offset =
                        (TRIO_PCIE_RC_DEVICE_ID_VEN_ID <<
                                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                        (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_STANDARD <<
                                TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                        (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

                __gxio_mmio_write32(trio_context->mmio_base_mac + reg_offset,
                                    (TILERA_GX36_RC_DEV_ID <<
                                    TRIO_PCIE_RC_DEVICE_ID_VEN_ID__DEV_ID_SHIFT) |
                                    TILERA_VENDOR_ID);

                /*
                 * Set the internal P2P bridge class code.
                 */

                reg_offset =
                        (TRIO_PCIE_RC_REVISION_ID <<
                                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                        (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_STANDARD <<
                                TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                        (mac << TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

                class_code_revision =
                        __gxio_mmio_read32(trio_context->mmio_base_mac +
                                           reg_offset);
                class_code_revision = (class_code_revision & 0xff ) |
                                        (PCI_CLASS_BRIDGE_PCI << 16);

                __gxio_mmio_write32(trio_context->mmio_base_mac +
                                    reg_offset, class_code_revision);

#ifdef USE_SHARED_PCIE_CONFIG_REGION

                /*
                 * Map in the MMIO space for the PIO region.
                 */
                offset = HV_TRIO_PIO_OFFSET(trio_context->pio_cfg_index) |
                        (((unsigned long long)mac) <<
                        TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR__MAC_SHIFT);

#else

                /*
                 * Alloc a PIO region for PCI config access per MAC.
                 */
                ret = gxio_trio_alloc_pio_regions(trio_context, 1, 0, 0);
                if (ret < 0) {
                        pr_err("PCI: PCI CFG PIO alloc failure for mac %d "
                                "on TRIO %d, give up\n", mac, trio_index);

                        continue;
                }

                trio_context->pio_cfg_index[mac] = ret;

                /*
                 * For PIO CFG, the bus_address_hi parameter is 0.
                 */
                ret = gxio_trio_init_pio_region_aux(trio_context,
                        trio_context->pio_cfg_index[mac],
                        mac, 0, HV_TRIO_PIO_FLAG_CONFIG_SPACE);
                if (ret < 0) {
                        pr_err("PCI: PCI CFG PIO init failure for mac %d "
                                "on TRIO %d, give up\n", mac, trio_index);

                        continue;
                }

                offset = HV_TRIO_PIO_OFFSET(trio_context->pio_cfg_index[mac]) |
                        (((unsigned long long)mac) <<
                        TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR__MAC_SHIFT);

#endif

                trio_context->mmio_base_pio_cfg[mac] =
                        iorpc_ioremap(trio_context->fd, offset,
                        (1 << TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR__MAC_SHIFT));
                if (trio_context->mmio_base_pio_cfg[mac] == NULL) {
                        pr_err("PCI: PIO map failure for mac %d on TRIO %d\n",
                                mac, trio_index);

                        continue;
                }

                /*
                 * Initialize the PCIe interrupts.
                 */
                if (tile_init_irqs(controller)) {
                        pr_err("PCI: IRQs init failure for mac %d on TRIO %d\n",
                                mac, trio_index);

                        continue;
                }

                /*
                 * The PCI memory resource is located above the PA space.
                 * The memory range for the PCI root bus should not overlap
                 * with the physical RAM
                 */
                pci_add_resource_offset(&resources, &controller->mem_space,
                                        controller->mem_offset);

                controller->first_busno = next_busno;
                bus = pci_scan_root_bus(NULL, next_busno, controller->ops,
                                        controller, &resources);
                controller->root_bus = bus;
                next_busno = bus->busn_res.end + 1;

        }

        /* 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();

        /* Record the I/O resources in the PCI controller structure. */
        for (i = 0; i < num_rc_controllers; i++) {
                struct pci_controller *controller = &pci_controllers[i];
                gxio_trio_context_t *trio_context = controller->trio;
                struct pci_bus *root_bus = pci_controllers[i].root_bus;
                struct pci_bus *next_bus;
                uint32_t bus_address_hi;
                struct pci_dev *dev;
                int ret;
                int j;

                /*
                 * Skip controllers that are not properly initialized or
                 * have down links.
                 */
                if (root_bus == NULL)
                        continue;

                /* Configure the max_payload_size values for this domain. */
                fixup_read_and_payload_sizes(controller);

                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;
                                pci_controllers[i].mem_resources[0] =
                                        *next_bus->resource[0];
                                pci_controllers[i].mem_resources[1] =
                                         *next_bus->resource[1];
                                pci_controllers[i].mem_resources[2] =
                                         *next_bus->resource[2];

                                break;
                        }
                }

                if (pci_controllers[i].mem_resources[1].flags & IORESOURCE_MEM)
                        bus_address_hi =
                                pci_controllers[i].mem_resources[1].start >> 32;
                else if (pci_controllers[i].mem_resources[2].flags & IORESOURCE_PREFETCH)
                        bus_address_hi =
                                pci_controllers[i].mem_resources[2].start >> 32;
                else {
                        /* This is unlikely. */
                        pr_err("PCI: no memory resources on TRIO %d mac %d\n",
                                controller->trio_index, controller->mac);
                        continue;
                }

                /*
                 * Alloc a PIO region for PCI memory access for each RC port.
                 */
                ret = gxio_trio_alloc_pio_regions(trio_context, 1, 0, 0);
                if (ret < 0) {
                        pr_err("PCI: MEM PIO alloc failure on TRIO %d mac %d, "
                                "give up\n", controller->trio_index,
                                controller->mac);

                        continue;
                }

                controller->pio_mem_index = ret;

                /*
                 * For PIO MEM, the bus_address_hi parameter is hard-coded 0
                 * because we always assign 32-bit PCI bus BAR ranges.
                 */
                ret = gxio_trio_init_pio_region_aux(trio_context,
                                                    controller->pio_mem_index,
                                                    controller->mac,
                                                    0,
                                                    0);
                if (ret < 0) {
                        pr_err("PCI: MEM PIO init failure on TRIO %d mac %d, "
                                "give up\n", controller->trio_index,
                                controller->mac);

                        continue;
                }

                /*
                 * Configure a Mem-Map region for each memory controller so
                 * that Linux can map all of its PA space to the PCI bus.
                 * Use the IOMMU to handle hash-for-home memory.
                 */
                for_each_online_node(j) {
                        unsigned long start_pfn = node_start_pfn[j];
                        unsigned long end_pfn = node_end_pfn[j];
                        unsigned long nr_pages = end_pfn - start_pfn;

                        ret = gxio_trio_alloc_memory_maps(trio_context, 1, 0,
                                                          0);
                        if (ret < 0) {
                                pr_err("PCI: Mem-Map alloc failure on TRIO %d "
                                        "mac %d for MC %d, give up\n",
                                        controller->trio_index,
                                        controller->mac, j);

                                goto alloc_mem_map_failed;
                        }

                        controller->mem_maps[j] = ret;

                        /*
                         * Initialize the Mem-Map and the I/O MMU so that all
                         * the physical memory can be accessed by the endpoint
                         * devices. The base bus address is set to the base CPA
                         * of this memory controller plus an offset (see pci.h).
                         * The region's base VA is set to the base CPA. The
                         * I/O MMU table essentially translates the CPA to
                         * the real PA. Implicitly, for node 0, we create
                         * a separate Mem-Map region that serves as the inbound
                         * window for legacy 32-bit devices. This is a direct
                         * map of the low 4GB CPA space.
                         */
                        ret = gxio_trio_init_memory_map_mmu_aux(trio_context,
                                controller->mem_maps[j],
                                start_pfn << PAGE_SHIFT,
                                nr_pages << PAGE_SHIFT,
                                trio_context->asid,
                                controller->mac,
                                (start_pfn << PAGE_SHIFT) +
                                TILE_PCI_MEM_MAP_BASE_OFFSET,
                                j,
                                GXIO_TRIO_ORDER_MODE_UNORDERED);
                        if (ret < 0) {
                                pr_err("PCI: Mem-Map init failure on TRIO %d "
                                        "mac %d for MC %d, give up\n",
                                        controller->trio_index,

                                        controller->mac, j);

                                goto alloc_mem_map_failed;
                        }
                        continue;

alloc_mem_map_failed:
                        break;
                }

        }

        return 0;
}
subsys_initcall(pcibios_init);

/* Note: to be deleted after Linux 3.6 merge. */
void pcibios_fixup_bus(struct pci_bus *bus)
{
}

/*
 * This can be called from the generic PCI layer, but doesn't need to
 * do anything.
 */
char *pcibios_setup(char *str)
{
        if (!strcmp(str, "off")) {
                pci_probe = 0;
                return NULL;
        }
        return str;
}

/*
 * Enable memory address decoding, as appropriate, for the
 * device described by the 'dev' struct. The I/O decoding
 * is disabled, though the TILE-Gx supports I/O addressing.
 *
 * 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)
{
        return pci_enable_resources(dev, mask);
}

/* Called for each device after PCI setup is done. */
static void pcibios_fixup_final(struct pci_dev *pdev)
{
        set_dma_ops(&pdev->dev, gx_pci_dma_map_ops);
        set_dma_offset(&pdev->dev, TILE_PCI_MEM_MAP_BASE_OFFSET);
        pdev->dev.archdata.max_direct_dma_addr =
                TILE_PCI_MAX_DIRECT_DMA_ADDRESS;
}
DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_final);

/* Map a PCI MMIO bus address into VA space. */
void __iomem *ioremap(resource_size_t phys_addr, unsigned long size)
{
        struct pci_controller *controller = NULL;
        resource_size_t bar_start;
        resource_size_t bar_end;
        resource_size_t offset;
        resource_size_t start;
        resource_size_t end;
        int trio_fd;
        int i, j;

        start = phys_addr;
        end = phys_addr + size - 1;

        /*
         * In the following, each PCI controller's mem_resources[1]
         * represents its (non-prefetchable) PCI memory resource and
         * mem_resources[2] refers to its prefetchable PCI memory resource.
         * By searching phys_addr in each controller's mem_resources[], we can
         * determine the controller that should accept the PCI memory access.
         */

        for (i = 0; i < num_rc_controllers; i++) {
                /*
                 * Skip controllers that are not properly initialized or
                 * have down links.
                 */
                if (pci_controllers[i].root_bus == NULL)
                        continue;

                for (j = 1; j < 3; j++) {
                        bar_start =
                                pci_controllers[i].mem_resources[j].start;
                        bar_end =
                                pci_controllers[i].mem_resources[j].end;

                        if ((start >= bar_start) && (end <= bar_end)) {

                                controller = &pci_controllers[i];

                                goto got_it;
                        }
                }
        }

        if (controller == NULL)
                return NULL;

got_it:
        trio_fd = controller->trio->fd;

        /* Convert the resource start to the bus address offset. */
        start = phys_addr - controller->mem_offset;

        offset = HV_TRIO_PIO_OFFSET(controller->pio_mem_index) + start;

        /*
         * We need to keep the PCI bus address's in-page offset in the VA.
         */
        return iorpc_ioremap(trio_fd, offset, size) +
                (phys_addr & (PAGE_SIZE - 1));
}
EXPORT_SYMBOL(ioremap);

void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
{
        iounmap(addr);
}
EXPORT_SYMBOL(pci_iounmap);

/****************************************************************
 *
 * 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 device & function.
 *
 * offset is in bytes, from the start of config space for the
 * specified bus & device.
 */

static int tile_cfg_read(struct pci_bus *bus, unsigned int devfn, int offset,
                         int size, u32 *val)
{
        struct pci_controller *controller = bus->sysdata;
        gxio_trio_context_t *trio_context = controller->trio;
        int busnum = bus->number & 0xff;
        int device = PCI_SLOT(devfn);
        int function = PCI_FUNC(devfn);
        int config_type = 1;
        TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR_t cfg_addr;
        void *mmio_addr;

        /*
         * Map all accesses to the local device on root bus into the
         * MMIO space of the MAC. Accesses to the downstream devices
         * go to the PIO space.
         */
        if (pci_is_root_bus(bus)) {
                if (device == 0) {
                        /*
                         * This is the internal downstream P2P bridge,
                         * access directly.
                         */
                        unsigned int reg_offset;

                        reg_offset = ((offset & 0xFFF) <<
                                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                                (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_PROTECTED
                                << TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                                (controller->mac <<
                                        TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

                        mmio_addr = trio_context->mmio_base_mac + reg_offset;

                        goto valid_device;

                } else {
                        /*
                         * We fake an empty device for (device > 0),
                         * since there is only one device on bus 0.
                         */
                        goto invalid_device;
                }
        }

        /*
         * Accesses to the directly attached device have to be
         * sent as type-0 configs.
         */

        if (busnum == (controller->first_busno + 1)) {
                /*
                 * There is only one device off of our built-in P2P bridge.
                 */
                if (device != 0)
                        goto invalid_device;

                config_type = 0;
        }

        cfg_addr.word = 0;
        cfg_addr.reg_addr = (offset & 0xFFF);
        cfg_addr.fn = function;
        cfg_addr.dev = device;
        cfg_addr.bus = busnum;
        cfg_addr.type = config_type;

        /*
         * Note that we don't set the mac field in cfg_addr because the
         * mapping is per port.
         */

        mmio_addr = trio_context->mmio_base_pio_cfg[controller->mac] +
                        cfg_addr.word;

valid_device:

        switch (size) {
        case 4:
                *val = __gxio_mmio_read32(mmio_addr);
                break;

        case 2:
                *val = __gxio_mmio_read16(mmio_addr);
                break;

        case 1:
                *val = __gxio_mmio_read8(mmio_addr);
                break;

        default:
                return PCIBIOS_FUNC_NOT_SUPPORTED;
        }

        TRACE_CFG_RD(size, *val, busnum, device, function, offset);

        return 0;

invalid_device:

        switch (size) {
        case 4:
                *val = 0xFFFFFFFF;
                break;

        case 2:
                *val = 0xFFFF;
                break;

        case 1:
                *val = 0xFF;
                break;

        default:
                return PCIBIOS_FUNC_NOT_SUPPORTED;
        }

        return 0;
}


/*
 * See tile_cfg_read() for relevent 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;
        gxio_trio_context_t *trio_context = controller->trio;
        int busnum = bus->number & 0xff;
        int device = PCI_SLOT(devfn);
        int function = PCI_FUNC(devfn);
        int config_type = 1;
        TRIO_TILE_PIO_REGION_SETUP_CFG_ADDR_t cfg_addr;
        void *mmio_addr;
        u32 val_32 = (u32)val;
        u16 val_16 = (u16)val;
        u8 val_8 = (u8)val;

        /*
         * Map all accesses to the local device on root bus into the
         * MMIO space of the MAC. Accesses to the downstream devices
         * go to the PIO space.
         */
        if (pci_is_root_bus(bus)) {
                if (device == 0) {
                        /*
                         * This is the internal downstream P2P bridge,
                         * access directly.
                         */
                        unsigned int reg_offset;

                        reg_offset = ((offset & 0xFFF) <<
                                TRIO_CFG_REGION_ADDR__REG_SHIFT) |
                                (TRIO_CFG_REGION_ADDR__INTFC_VAL_MAC_PROTECTED
                                << TRIO_CFG_REGION_ADDR__INTFC_SHIFT ) |
                                (controller->mac <<
                                        TRIO_CFG_REGION_ADDR__MAC_SEL_SHIFT);

                        mmio_addr = trio_context->mmio_base_mac + reg_offset;

                        goto valid_device;

                } else {
                        /*
                         * We fake an empty device for (device > 0),
                         * since there is only one device on bus 0.
                         */
                        goto invalid_device;
                }
        }

        /*
         * Accesses to the directly attached device have to be
         * sent as type-0 configs.
         */

        if (busnum == (controller->first_busno + 1)) {
                /*
                 * There is only one device off of our built-in P2P bridge.
                 */
                if (device != 0)
                        goto invalid_device;

                config_type = 0;
        }

        cfg_addr.word = 0;
        cfg_addr.reg_addr = (offset & 0xFFF);
        cfg_addr.fn = function;
        cfg_addr.dev = device;
        cfg_addr.bus = busnum;
        cfg_addr.type = config_type;

        /*
         * Note that we don't set the mac field in cfg_addr because the
         * mapping is per port.
         */

        mmio_addr = trio_context->mmio_base_pio_cfg[controller->mac] +
                        cfg_addr.word;

valid_device:

        switch (size) {
        case 4:
                __gxio_mmio_write32(mmio_addr, val_32);
                TRACE_CFG_WR(size, val_32, busnum, device, function, offset);
                break;

        case 2:
                __gxio_mmio_write16(mmio_addr, val_16);
                TRACE_CFG_WR(size, val_16, busnum, device, function, offset);
                break;

        case 1:
                __gxio_mmio_write8(mmio_addr, val_8);
                TRACE_CFG_WR(size, val_8, busnum, device, function, offset);
                break;

        default:
                return PCIBIOS_FUNC_NOT_SUPPORTED;
        }

invalid_device:

        return 0;
}


static struct pci_ops tile_cfg_ops = {
        .read =         tile_cfg_read,
        .write =        tile_cfg_write,
};


/*
 * MSI support starts here.
 */
static unsigned int
tilegx_msi_startup(struct irq_data *d)
{
        if (d->msi_desc)
                unmask_msi_irq(d);

        return 0;
}

static void
tilegx_msi_ack(struct irq_data *d)
{
        __insn_mtspr(SPR_IPI_EVENT_RESET_K, 1UL << d->irq);
}

static void
tilegx_msi_mask(struct irq_data *d)
{
        mask_msi_irq(d);
        __insn_mtspr(SPR_IPI_MASK_SET_K, 1UL << d->irq);
}

static void
tilegx_msi_unmask(struct irq_data *d)
{
        __insn_mtspr(SPR_IPI_MASK_RESET_K, 1UL << d->irq);
        unmask_msi_irq(d);
}

static struct irq_chip tilegx_msi_chip = {
        .name                   = "tilegx_msi",
        .irq_startup            = tilegx_msi_startup,
        .irq_ack                = tilegx_msi_ack,
        .irq_mask               = tilegx_msi_mask,
        .irq_unmask             = tilegx_msi_unmask,

        /* TBD: support set_affinity. */
};

int arch_setup_msi_irq(struct pci_dev *pdev, struct msi_desc *desc)
{
        struct pci_controller *controller;
        gxio_trio_context_t *trio_context;
        struct msi_msg msg;
        int default_irq;
        uint64_t mem_map_base;
        uint64_t mem_map_limit;
        u64 msi_addr;
        int mem_map;
        int cpu;
        int irq;
        int ret;

        irq = create_irq();
        if (irq < 0)
                return irq;

        /*
         * Since we use a 64-bit Mem-Map to accept the MSI write, we fail
         * devices that are not capable of generating a 64-bit message address.
         * These devices will fall back to using the legacy interrupts.
         * Most PCIe endpoint devices do support 64-bit message addressing.
         */
        if (desc->msi_attrib.is_64 == 0) {
                dev_printk(KERN_INFO, &pdev->dev,
                        "64-bit MSI message address not supported, "
                        "falling back to legacy interrupts.\n");

                ret = -ENOMEM;
                goto is_64_failure;
        }

        default_irq = desc->msi_attrib.default_irq;
        controller = irq_get_handler_data(default_irq);

        BUG_ON(!controller);

        trio_context = controller->trio;

        /*
         * Allocate the Mem-Map that will accept the MSI write and
         * trigger the TILE-side interrupts.
         */
        mem_map = gxio_trio_alloc_memory_maps(trio_context, 1, 0, 0);
        if (mem_map < 0) {
                dev_printk(KERN_INFO, &pdev->dev,
                        "%s Mem-Map alloc failure. "
                        "Failed to initialize MSI interrupts. "
                        "Falling back to legacy interrupts.\n",
                        desc->msi_attrib.is_msix ? "MSI-X" : "MSI");

                ret = -ENOMEM;
                goto msi_mem_map_alloc_failure;
        }

        /* We try to distribute different IRQs to different tiles. */
        cpu = tile_irq_cpu(irq);

        /*
         * Now call up to the HV to configure the Mem-Map interrupt and
         * set up the IPI binding.
         */
        mem_map_base = MEM_MAP_INTR_REGIONS_BASE +
                mem_map * MEM_MAP_INTR_REGION_SIZE;
        mem_map_limit = mem_map_base + MEM_MAP_INTR_REGION_SIZE - 1;

        ret = gxio_trio_config_msi_intr(trio_context, cpu_x(cpu), cpu_y(cpu),
                                        KERNEL_PL, irq, controller->mac,
                                        mem_map, mem_map_base, mem_map_limit,
                                        trio_context->asid);
        if (ret < 0) {
                dev_printk(KERN_INFO, &pdev->dev, "HV MSI config failed.\n");

                goto hv_msi_config_failure;
        }

        irq_set_msi_desc(irq, desc);

        msi_addr = mem_map_base + TRIO_MAP_MEM_REG_INT3 - TRIO_MAP_MEM_REG_INT0;

        msg.address_hi = msi_addr >> 32;
        msg.address_lo = msi_addr & 0xffffffff;

        msg.data = mem_map;

        write_msi_msg(irq, &msg);
        irq_set_chip_and_handler(irq, &tilegx_msi_chip, handle_level_irq);
        irq_set_handler_data(irq, controller);

        return 0;

hv_msi_config_failure:
        /* Free mem-map */
msi_mem_map_alloc_failure:
is_64_failure:
        destroy_irq(irq);
        return ret;
}

void arch_teardown_msi_irq(unsigned int irq)
{
        destroy_irq(irq);
}