/*
 * Copyright IBM Corp. 2012
 *
 * Author(s):
 *   Jan Glauber <jang@linux.vnet.ibm.com>
 *
 * The System z PCI code is a rewrite from a prototype by
 * the following people (Kudoz!):
 *   Alexander Schmidt
 *   Christoph Raisch
 *   Hannes Hering
 *   Hoang-Nam Nguyen
 *   Jan-Bernd Themann
 *   Stefan Roscher
 *   Thomas Klein
 */

#define COMPONENT "zPCI"
#define pr_fmt(fmt) COMPONENT ": " fmt

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/pci.h>
#include <linux/msi.h>

#include <asm/isc.h>
#include <asm/airq.h>
#include <asm/facility.h>
#include <asm/pci_insn.h>
#include <asm/pci_clp.h>
#include <asm/pci_dma.h>

#define DEBUG                           /* enable pr_debug */

#define SIC_IRQ_MODE_ALL                0
#define SIC_IRQ_MODE_SINGLE             1

#define ZPCI_NR_DMA_SPACES              1
#define ZPCI_NR_DEVICES                 CONFIG_PCI_NR_FUNCTIONS

/* list of all detected zpci devices */
static LIST_HEAD(zpci_list);
static DEFINE_SPINLOCK(zpci_list_lock);

static void zpci_enable_irq(struct irq_data *data);
static void zpci_disable_irq(struct irq_data *data);

static struct irq_chip zpci_irq_chip = {
        .name = "zPCI",
        .irq_unmask = zpci_enable_irq,
        .irq_mask = zpci_disable_irq,
};

static DECLARE_BITMAP(zpci_domain, ZPCI_NR_DEVICES);
static DEFINE_SPINLOCK(zpci_domain_lock);

static struct airq_iv *zpci_aisb_iv;
static struct airq_iv *zpci_aibv[ZPCI_NR_DEVICES];

/* Adapter interrupt definitions */
static void zpci_irq_handler(struct airq_struct *airq);

static struct airq_struct zpci_airq = {
        .handler = zpci_irq_handler,
        .isc = PCI_ISC,
};

/* I/O Map */
static DEFINE_SPINLOCK(zpci_iomap_lock);
static DECLARE_BITMAP(zpci_iomap, ZPCI_IOMAP_MAX_ENTRIES);
struct zpci_iomap_entry *zpci_iomap_start;
EXPORT_SYMBOL_GPL(zpci_iomap_start);

static struct kmem_cache *zdev_fmb_cache;

struct zpci_dev *get_zdev(struct pci_dev *pdev)
{
        return (struct zpci_dev *) pdev->sysdata;
}

struct zpci_dev *get_zdev_by_fid(u32 fid)
{
        struct zpci_dev *tmp, *zdev = NULL;

        spin_lock(&zpci_list_lock);
        list_for_each_entry(tmp, &zpci_list, entry) {
                if (tmp->fid == fid) {
                        zdev = tmp;
                        break;
                }
        }
        spin_unlock(&zpci_list_lock);
        return zdev;
}

static struct zpci_dev *get_zdev_by_bus(struct pci_bus *bus)
{
        return (bus && bus->sysdata) ? (struct zpci_dev *) bus->sysdata : NULL;
}

int pci_domain_nr(struct pci_bus *bus)
{
        return ((struct zpci_dev *) bus->sysdata)->domain;
}
EXPORT_SYMBOL_GPL(pci_domain_nr);

int pci_proc_domain(struct pci_bus *bus)
{
        return pci_domain_nr(bus);
}
EXPORT_SYMBOL_GPL(pci_proc_domain);

/* Modify PCI: Register adapter interruptions */
static int zpci_set_airq(struct zpci_dev *zdev)
{
        u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT);
        struct zpci_fib fib = {0};

        fib.isc = PCI_ISC;
        fib.sum = 1;            /* enable summary notifications */
        fib.noi = airq_iv_end(zdev->aibv);
        fib.aibv = (unsigned long) zdev->aibv->vector;
        fib.aibvo = 0;          /* each zdev has its own interrupt vector */
        fib.aisb = (unsigned long) zpci_aisb_iv->vector + (zdev->aisb/64)*8;
        fib.aisbo = zdev->aisb & 63;

        return zpci_mod_fc(req, &fib);
}

struct mod_pci_args {
        u64 base;
        u64 limit;
        u64 iota;
        u64 fmb_addr;
};

static int mod_pci(struct zpci_dev *zdev, int fn, u8 dmaas, struct mod_pci_args *args)
{
        u64 req = ZPCI_CREATE_REQ(zdev->fh, dmaas, fn);
        struct zpci_fib fib = {0};

        fib.pba = args->base;
        fib.pal = args->limit;
        fib.iota = args->iota;
        fib.fmb_addr = args->fmb_addr;

        return zpci_mod_fc(req, &fib);
}

/* Modify PCI: Register I/O address translation parameters */
int zpci_register_ioat(struct zpci_dev *zdev, u8 dmaas,
                       u64 base, u64 limit, u64 iota)
{
        struct mod_pci_args args = { base, limit, iota, 0 };

        WARN_ON_ONCE(iota & 0x3fff);
        args.iota |= ZPCI_IOTA_RTTO_FLAG;
        return mod_pci(zdev, ZPCI_MOD_FC_REG_IOAT, dmaas, &args);
}

/* Modify PCI: Unregister I/O address translation parameters */
int zpci_unregister_ioat(struct zpci_dev *zdev, u8 dmaas)
{
        struct mod_pci_args args = { 0, 0, 0, 0 };

        return mod_pci(zdev, ZPCI_MOD_FC_DEREG_IOAT, dmaas, &args);
}

/* Modify PCI: Unregister adapter interruptions */
static int zpci_clear_airq(struct zpci_dev *zdev)
{
        struct mod_pci_args args = { 0, 0, 0, 0 };

        return mod_pci(zdev, ZPCI_MOD_FC_DEREG_INT, 0, &args);
}

/* Modify PCI: Set PCI function measurement parameters */
int zpci_fmb_enable_device(struct zpci_dev *zdev)
{
        struct mod_pci_args args = { 0, 0, 0, 0 };

        if (zdev->fmb)
                return -EINVAL;

        zdev->fmb = kmem_cache_zalloc(zdev_fmb_cache, GFP_KERNEL);
        if (!zdev->fmb)
                return -ENOMEM;
        WARN_ON((u64) zdev->fmb & 0xf);

        args.fmb_addr = virt_to_phys(zdev->fmb);
        return mod_pci(zdev, ZPCI_MOD_FC_SET_MEASURE, 0, &args);
}

/* Modify PCI: Disable PCI function measurement */
int zpci_fmb_disable_device(struct zpci_dev *zdev)
{
        struct mod_pci_args args = { 0, 0, 0, 0 };
        int rc;

        if (!zdev->fmb)
                return -EINVAL;

        /* Function measurement is disabled if fmb address is zero */
        rc = mod_pci(zdev, ZPCI_MOD_FC_SET_MEASURE, 0, &args);

        kmem_cache_free(zdev_fmb_cache, zdev->fmb);
        zdev->fmb = NULL;
        return rc;
}

#define ZPCI_PCIAS_CFGSPC       15

static int zpci_cfg_load(struct zpci_dev *zdev, int offset, u32 *val, u8 len)
{
        u64 req = ZPCI_CREATE_REQ(zdev->fh, ZPCI_PCIAS_CFGSPC, len);
        u64 data;
        int rc;

        rc = zpci_load(&data, req, offset);
        if (!rc) {
                data = data << ((8 - len) * 8);
                data = le64_to_cpu(data);
                *val = (u32) data;
        } else
                *val = 0xffffffff;
        return rc;
}

static int zpci_cfg_store(struct zpci_dev *zdev, int offset, u32 val, u8 len)
{
        u64 req = ZPCI_CREATE_REQ(zdev->fh, ZPCI_PCIAS_CFGSPC, len);
        u64 data = val;
        int rc;

        data = cpu_to_le64(data);
        data = data >> ((8 - len) * 8);
        rc = zpci_store(data, req, offset);
        return rc;
}

static int zpci_msi_set_mask_bits(struct msi_desc *msi, u32 mask, u32 flag)
{
        int offset, pos;
        u32 mask_bits;

        if (msi->msi_attrib.is_msix) {
                offset = msi->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
                        PCI_MSIX_ENTRY_VECTOR_CTRL;
                msi->masked = readl(msi->mask_base + offset);
                writel(flag, msi->mask_base + offset);
        } else if (msi->msi_attrib.maskbit) {
                pos = (long) msi->mask_base;
                pci_read_config_dword(msi->dev, pos, &mask_bits);
                mask_bits &= ~(mask);
                mask_bits |= flag & mask;
                pci_write_config_dword(msi->dev, pos, mask_bits);
        } else
                return 0;

        msi->msi_attrib.maskbit = !!flag;
        return 1;
}

static void zpci_enable_irq(struct irq_data *data)
{
        struct msi_desc *msi = irq_get_msi_desc(data->irq);

        zpci_msi_set_mask_bits(msi, 1, 0);
}

static void zpci_disable_irq(struct irq_data *data)
{
        struct msi_desc *msi = irq_get_msi_desc(data->irq);

        zpci_msi_set_mask_bits(msi, 1, 1);
}

void pcibios_fixup_bus(struct pci_bus *bus)
{
}

resource_size_t pcibios_align_resource(void *data, const struct resource *res,
                                       resource_size_t size,
                                       resource_size_t align)
{
        return 0;
}

/* combine single writes by using store-block insn */
void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
{
       zpci_memcpy_toio(to, from, count);
}

/* Create a virtual mapping cookie for a PCI BAR */
void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max)
{
        struct zpci_dev *zdev = get_zdev(pdev);
        u64 addr;
        int idx;

        if ((bar & 7) != bar)
                return NULL;

        idx = zdev->bars[bar].map_idx;
        spin_lock(&zpci_iomap_lock);
        zpci_iomap_start[idx].fh = zdev->fh;
        zpci_iomap_start[idx].bar = bar;
        spin_unlock(&zpci_iomap_lock);

        addr = ZPCI_IOMAP_ADDR_BASE | ((u64) idx << 48);
        return (void __iomem *) addr;
}
EXPORT_SYMBOL_GPL(pci_iomap);

void pci_iounmap(struct pci_dev *pdev, void __iomem *addr)
{
        unsigned int idx;

        idx = (((__force u64) addr) & ~ZPCI_IOMAP_ADDR_BASE) >> 48;
        spin_lock(&zpci_iomap_lock);
        zpci_iomap_start[idx].fh = 0;
        zpci_iomap_start[idx].bar = 0;
        spin_unlock(&zpci_iomap_lock);
}
EXPORT_SYMBOL_GPL(pci_iounmap);

static int pci_read(struct pci_bus *bus, unsigned int devfn, int where,
                    int size, u32 *val)
{
        struct zpci_dev *zdev = get_zdev_by_bus(bus);
        int ret;

        if (!zdev || devfn != ZPCI_DEVFN)
                ret = -ENODEV;
        else
                ret = zpci_cfg_load(zdev, where, val, size);

        return ret;
}

static int pci_write(struct pci_bus *bus, unsigned int devfn, int where,
                     int size, u32 val)
{
        struct zpci_dev *zdev = get_zdev_by_bus(bus);
        int ret;

        if (!zdev || devfn != ZPCI_DEVFN)
                ret = -ENODEV;
        else
                ret = zpci_cfg_store(zdev, where, val, size);

        return ret;
}

static struct pci_ops pci_root_ops = {
        .read = pci_read,
        .write = pci_write,
};

static void zpci_irq_handler(struct airq_struct *airq)
{
        unsigned long si, ai;
        struct airq_iv *aibv;
        int irqs_on = 0;

        inc_irq_stat(IRQIO_PCI);
        for (si = 0;;) {
                /* Scan adapter summary indicator bit vector */
                si = airq_iv_scan(zpci_aisb_iv, si, airq_iv_end(zpci_aisb_iv));
                if (si == -1UL) {
                        if (irqs_on++)
                                /* End of second scan with interrupts on. */
                                break;
                        /* First scan complete, reenable interrupts. */
                        zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, NULL, PCI_ISC);
                        si = 0;
                        continue;
                }

                /* Scan the adapter interrupt vector for this device. */
                aibv = zpci_aibv[si];
                for (ai = 0;;) {
                        ai = airq_iv_scan(aibv, ai, airq_iv_end(aibv));
                        if (ai == -1UL)
                                break;
                        inc_irq_stat(IRQIO_MSI);
                        airq_iv_lock(aibv, ai);
                        generic_handle_irq(airq_iv_get_data(aibv, ai));
                        airq_iv_unlock(aibv, ai);
                }
        }
}

int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
{
        struct zpci_dev *zdev = get_zdev(pdev);
        unsigned int hwirq, irq, msi_vecs;
        unsigned long aisb;
        struct msi_desc *msi;
        struct msi_msg msg;
        int rc;

        if (type == PCI_CAP_ID_MSI && nvec > 1)
                return 1;
        msi_vecs = min(nvec, ZPCI_MSI_VEC_MAX);
        msi_vecs = min_t(unsigned int, msi_vecs, CONFIG_PCI_NR_MSI);

        /* Allocate adapter summary indicator bit */
        rc = -EIO;
        aisb = airq_iv_alloc_bit(zpci_aisb_iv);
        if (aisb == -1UL)
                goto out;
        zdev->aisb = aisb;

        /* Create adapter interrupt vector */
        rc = -ENOMEM;
        zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK);
        if (!zdev->aibv)
                goto out_si;

        /* Wire up shortcut pointer */
        zpci_aibv[aisb] = zdev->aibv;

        /* Request MSI interrupts */
        hwirq = 0;
        list_for_each_entry(msi, &pdev->msi_list, list) {
                rc = -EIO;
                irq = irq_alloc_desc(0);        /* Alloc irq on node 0 */
                if (irq == NO_IRQ)
                        goto out_msi;
                rc = irq_set_msi_desc(irq, msi);
                if (rc)
                        goto out_msi;
                irq_set_chip_and_handler(irq, &zpci_irq_chip,
                                         handle_simple_irq);
                msg.data = hwirq;
                msg.address_lo = zdev->msi_addr & 0xffffffff;
                msg.address_hi = zdev->msi_addr >> 32;
                write_msi_msg(irq, &msg);
                airq_iv_set_data(zdev->aibv, hwirq, irq);
                hwirq++;
        }

        /* Enable adapter interrupts */
        rc = zpci_set_airq(zdev);
        if (rc)
                goto out_msi;

        return (msi_vecs == nvec) ? 0 : msi_vecs;

out_msi:
        list_for_each_entry(msi, &pdev->msi_list, list) {
                if (hwirq-- == 0)
                        break;
                irq_set_msi_desc(msi->irq, NULL);
                irq_free_desc(msi->irq);
                msi->msg.address_lo = 0;
                msi->msg.address_hi = 0;
                msi->msg.data = 0;
                msi->irq = 0;
        }
        zpci_aibv[aisb] = NULL;
        airq_iv_release(zdev->aibv);
out_si:
        airq_iv_free_bit(zpci_aisb_iv, aisb);
out:
        return rc;
}

void arch_teardown_msi_irqs(struct pci_dev *pdev)
{
        struct zpci_dev *zdev = get_zdev(pdev);
        struct msi_desc *msi;
        int rc;

        /* Disable adapter interrupts */
        rc = zpci_clear_airq(zdev);
        if (rc)
                return;

        /* Release MSI interrupts */
        list_for_each_entry(msi, &pdev->msi_list, list) {
                zpci_msi_set_mask_bits(msi, 1, 1);
                irq_set_msi_desc(msi->irq, NULL);
                irq_free_desc(msi->irq);
                msi->msg.address_lo = 0;
                msi->msg.address_hi = 0;
                msi->msg.data = 0;
                msi->irq = 0;
        }

        zpci_aibv[zdev->aisb] = NULL;
        airq_iv_release(zdev->aibv);
        airq_iv_free_bit(zpci_aisb_iv, zdev->aisb);
}

static void zpci_map_resources(struct zpci_dev *zdev)
{
        struct pci_dev *pdev = zdev->pdev;
        resource_size_t len;
        int i;

        for (i = 0; i < PCI_BAR_COUNT; i++) {
                len = pci_resource_len(pdev, i);
                if (!len)
                        continue;
                pdev->resource[i].start = (resource_size_t) pci_iomap(pdev, i, 0);
                pdev->resource[i].end = pdev->resource[i].start + len - 1;
        }
}

static void zpci_unmap_resources(struct zpci_dev *zdev)
{
        struct pci_dev *pdev = zdev->pdev;
        resource_size_t len;
        int i;

        for (i = 0; i < PCI_BAR_COUNT; i++) {
                len = pci_resource_len(pdev, i);
                if (!len)
                        continue;
                pci_iounmap(pdev, (void *) pdev->resource[i].start);
        }
}

int pcibios_add_platform_entries(struct pci_dev *pdev)
{
        return zpci_sysfs_add_device(&pdev->dev);
}

static int __init zpci_irq_init(void)
{
        int rc;

        rc = register_adapter_interrupt(&zpci_airq);
        if (rc)
                goto out;
        /* Set summary to 1 to be called every time for the ISC. */
        *zpci_airq.lsi_ptr = 1;

        rc = -ENOMEM;
        zpci_aisb_iv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC);
        if (!zpci_aisb_iv)
                goto out_airq;

        zpci_set_irq_ctrl(SIC_IRQ_MODE_SINGLE, NULL, PCI_ISC);
        return 0;

out_airq:
        unregister_adapter_interrupt(&zpci_airq);
out:
        return rc;
}

static void zpci_irq_exit(void)
{
        airq_iv_release(zpci_aisb_iv);
        unregister_adapter_interrupt(&zpci_airq);
}

static int zpci_alloc_iomap(struct zpci_dev *zdev)
{
        int entry;

        spin_lock(&zpci_iomap_lock);
        entry = find_first_zero_bit(zpci_iomap, ZPCI_IOMAP_MAX_ENTRIES);
        if (entry == ZPCI_IOMAP_MAX_ENTRIES) {
                spin_unlock(&zpci_iomap_lock);
                return -ENOSPC;
        }
        set_bit(entry, zpci_iomap);
        spin_unlock(&zpci_iomap_lock);
        return entry;
}

static void zpci_free_iomap(struct zpci_dev *zdev, int entry)
{
        spin_lock(&zpci_iomap_lock);
        memset(&zpci_iomap_start[entry], 0, sizeof(struct zpci_iomap_entry));
        clear_bit(entry, zpci_iomap);
        spin_unlock(&zpci_iomap_lock);
}

static struct resource *__alloc_res(struct zpci_dev *zdev, unsigned long start,
                                    unsigned long size, unsigned long flags)
{
        struct resource *r;

        r = kzalloc(sizeof(*r), GFP_KERNEL);
        if (!r)
                return NULL;

        r->start = start;
        r->end = r->start + size - 1;
        r->flags = flags;
        r->name = zdev->res_name;

        if (request_resource(&iomem_resource, r)) {
                kfree(r);
                return NULL;
        }
        return r;
}

static int zpci_setup_bus_resources(struct zpci_dev *zdev,
                                    struct list_head *resources)
{
        unsigned long addr, size, flags;
        struct resource *res;
        int i, entry;

        snprintf(zdev->res_name, sizeof(zdev->res_name),
                 "PCI Bus %04x:%02x", zdev->domain, ZPCI_BUS_NR);

        for (i = 0; i < PCI_BAR_COUNT; i++) {
                if (!zdev->bars[i].size)
                        continue;
                entry = zpci_alloc_iomap(zdev);
                if (entry < 0)
                        return entry;
                zdev->bars[i].map_idx = entry;

                /* only MMIO is supported */
                flags = IORESOURCE_MEM;
                if (zdev->bars[i].val & 8)
                        flags |= IORESOURCE_PREFETCH;
                if (zdev->bars[i].val & 4)
                        flags |= IORESOURCE_MEM_64;

                addr = ZPCI_IOMAP_ADDR_BASE + ((u64) entry << 48);

                size = 1UL << zdev->bars[i].size;

                res = __alloc_res(zdev, addr, size, flags);
                if (!res) {
                        zpci_free_iomap(zdev, entry);
                        return -ENOMEM;
                }
                zdev->bars[i].res = res;
                pci_add_resource(resources, res);
        }

        return 0;
}

static void zpci_cleanup_bus_resources(struct zpci_dev *zdev)
{
        int i;

        for (i = 0; i < PCI_BAR_COUNT; i++) {
                if (!zdev->bars[i].size)
                        continue;

                zpci_free_iomap(zdev, zdev->bars[i].map_idx);
                release_resource(zdev->bars[i].res);
                kfree(zdev->bars[i].res);
        }
}

int pcibios_add_device(struct pci_dev *pdev)
{
        struct zpci_dev *zdev = get_zdev(pdev);
        struct resource *res;
        int i;

        zdev->pdev = pdev;
        zpci_map_resources(zdev);

        for (i = 0; i < PCI_BAR_COUNT; i++) {
                res = &pdev->resource[i];
                if (res->parent || !res->flags)
                        continue;
                pci_claim_resource(pdev, i);
        }

        return 0;
}

int pcibios_enable_device(struct pci_dev *pdev, int mask)
{
        struct zpci_dev *zdev = get_zdev(pdev);
        struct resource *res;
        u16 cmd;
        int i;

        zdev->pdev = pdev;
        zpci_debug_init_device(zdev);
        zpci_fmb_enable_device(zdev);
        zpci_map_resources(zdev);

        pci_read_config_word(pdev, PCI_COMMAND, &cmd);
        for (i = 0; i < PCI_BAR_COUNT; i++) {
                res = &pdev->resource[i];

                if (res->flags & IORESOURCE_IO)
                        return -EINVAL;

                if (res->flags & IORESOURCE_MEM)
                        cmd |= PCI_COMMAND_MEMORY;
        }
        pci_write_config_word(pdev, PCI_COMMAND, cmd);
        return 0;
}

void pcibios_disable_device(struct pci_dev *pdev)
{
        struct zpci_dev *zdev = get_zdev(pdev);

        zpci_unmap_resources(zdev);
        zpci_fmb_disable_device(zdev);
        zpci_debug_exit_device(zdev);
        zdev->pdev = NULL;
}

#ifdef CONFIG_HIBERNATE_CALLBACKS
static int zpci_restore(struct device *dev)
{
        struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));
        int ret = 0;

        if (zdev->state != ZPCI_FN_STATE_ONLINE)
                goto out;

        ret = clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES);
        if (ret)
                goto out;

        zpci_map_resources(zdev);
        zpci_register_ioat(zdev, 0, zdev->start_dma + PAGE_OFFSET,
                           zdev->start_dma + zdev->iommu_size - 1,
                           (u64) zdev->dma_table);

out:
        return ret;
}

static int zpci_freeze(struct device *dev)
{
        struct zpci_dev *zdev = get_zdev(to_pci_dev(dev));

        if (zdev->state != ZPCI_FN_STATE_ONLINE)
                return 0;

        zpci_unregister_ioat(zdev, 0);
        return clp_disable_fh(zdev);
}

struct dev_pm_ops pcibios_pm_ops = {
        .thaw_noirq = zpci_restore,
        .freeze_noirq = zpci_freeze,
        .restore_noirq = zpci_restore,
        .poweroff_noirq = zpci_freeze,
};
#endif /* CONFIG_HIBERNATE_CALLBACKS */

static int zpci_alloc_domain(struct zpci_dev *zdev)
{
        spin_lock(&zpci_domain_lock);
        zdev->domain = find_first_zero_bit(zpci_domain, ZPCI_NR_DEVICES);
        if (zdev->domain == ZPCI_NR_DEVICES) {
                spin_unlock(&zpci_domain_lock);
                return -ENOSPC;
        }
        set_bit(zdev->domain, zpci_domain);
        spin_unlock(&zpci_domain_lock);
        return 0;
}

static void zpci_free_domain(struct zpci_dev *zdev)
{
        spin_lock(&zpci_domain_lock);
        clear_bit(zdev->domain, zpci_domain);
        spin_unlock(&zpci_domain_lock);
}

void pcibios_remove_bus(struct pci_bus *bus)
{
        struct zpci_dev *zdev = get_zdev_by_bus(bus);

        zpci_exit_slot(zdev);
        zpci_cleanup_bus_resources(zdev);
        zpci_free_domain(zdev);

        spin_lock(&zpci_list_lock);
        list_del(&zdev->entry);
        spin_unlock(&zpci_list_lock);

        kfree(zdev);
}

static int zpci_scan_bus(struct zpci_dev *zdev)
{
        LIST_HEAD(resources);
        int ret;

        ret = zpci_setup_bus_resources(zdev, &resources);
        if (ret)
                return ret;

        zdev->bus = pci_scan_root_bus(NULL, ZPCI_BUS_NR, &pci_root_ops,
                                      zdev, &resources);
        if (!zdev->bus) {
                zpci_cleanup_bus_resources(zdev);
                return -EIO;
        }

        zdev->bus->max_bus_speed = zdev->max_bus_speed;
        return 0;
}

int zpci_enable_device(struct zpci_dev *zdev)
{
        int rc;

        rc = clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES);
        if (rc)
                goto out;

        rc = zpci_dma_init_device(zdev);
        if (rc)
                goto out_dma;

        zdev->state = ZPCI_FN_STATE_ONLINE;
        return 0;

out_dma:
        clp_disable_fh(zdev);
out:
        return rc;
}
EXPORT_SYMBOL_GPL(zpci_enable_device);

int zpci_disable_device(struct zpci_dev *zdev)
{
        zpci_dma_exit_device(zdev);
        return clp_disable_fh(zdev);
}
EXPORT_SYMBOL_GPL(zpci_disable_device);

int zpci_create_device(struct zpci_dev *zdev)
{
        int rc;

        rc = zpci_alloc_domain(zdev);
        if (rc)
                goto out;

        if (zdev->state == ZPCI_FN_STATE_CONFIGURED) {
                rc = zpci_enable_device(zdev);
                if (rc)
                        goto out_free;
        }
        rc = zpci_scan_bus(zdev);
        if (rc)
                goto out_disable;

        spin_lock(&zpci_list_lock);
        list_add_tail(&zdev->entry, &zpci_list);
        spin_unlock(&zpci_list_lock);

        zpci_init_slot(zdev);

        return 0;

out_disable:
        if (zdev->state == ZPCI_FN_STATE_ONLINE)
                zpci_disable_device(zdev);
out_free:
        zpci_free_domain(zdev);
out:
        return rc;
}

void zpci_stop_device(struct zpci_dev *zdev)
{
        zpci_dma_exit_device(zdev);
        /*
         * Note: SCLP disables fh via set-pci-fn so don't
         * do that here.
         */
}
EXPORT_SYMBOL_GPL(zpci_stop_device);

static inline int barsize(u8 size)
{
        return (size) ? (1 << size) >> 10 : 0;
}

static int zpci_mem_init(void)
{
        zdev_fmb_cache = kmem_cache_create("PCI_FMB_cache", sizeof(struct zpci_fmb),
                                16, 0, NULL);
        if (!zdev_fmb_cache)
                goto error_zdev;

        /* TODO: use realloc */
        zpci_iomap_start = kzalloc(ZPCI_IOMAP_MAX_ENTRIES * sizeof(*zpci_iomap_start),
                                   GFP_KERNEL);
        if (!zpci_iomap_start)
                goto error_iomap;
        return 0;

error_iomap:
        kmem_cache_destroy(zdev_fmb_cache);
error_zdev:
        return -ENOMEM;
}

static void zpci_mem_exit(void)
{
        kfree(zpci_iomap_start);
        kmem_cache_destroy(zdev_fmb_cache);
}

static unsigned int s390_pci_probe = 1;
static unsigned int s390_pci_initialized;

char * __init pcibios_setup(char *str)
{
        if (!strcmp(str, "off")) {
                s390_pci_probe = 0;
                return NULL;
        }
        return str;
}

bool zpci_is_enabled(void)
{
        return s390_pci_initialized;
}

static int __init pci_base_init(void)
{
        int rc;

        if (!s390_pci_probe)
                return 0;

        if (!test_facility(2) || !test_facility(69)
            || !test_facility(71) || !test_facility(72))
                return 0;

        rc = zpci_debug_init();
        if (rc)
                goto out;

        rc = zpci_mem_init();
        if (rc)
                goto out_mem;

        rc = zpci_irq_init();
        if (rc)
                goto out_irq;

        rc = zpci_dma_init();
        if (rc)
                goto out_dma;

        rc = clp_scan_pci_devices();
        if (rc)
                goto out_find;

        s390_pci_initialized = 1;
        return 0;

out_find:
        zpci_dma_exit();
out_dma:
        zpci_irq_exit();
out_irq:
        zpci_mem_exit();
out_mem:
        zpci_debug_exit();
out:
        return rc;
}
subsys_initcall_sync(pci_base_init);

void zpci_rescan(void)
{
        if (zpci_is_enabled())
                clp_rescan_pci_devices_simple();
}