/*
 * pci.c - Low-Level PCI Access in IA-64
 *
 * Derived from bios32.c of i386 tree.
 *
 * (c) Copyright 2002, 2005 Hewlett-Packard Development Company, L.P.
 *      David Mosberger-Tang <davidm@hpl.hp.com>
 *      Bjorn Helgaas <bjorn.helgaas@hp.com>
 * Copyright (C) 2004 Silicon Graphics, Inc.
 *
 * Note: Above list of copyright holders is incomplete...
 */

#include <linux/acpi.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <asm/machvec.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/sal.h>
#include <asm/smp.h>
#include <asm/irq.h>
#include <asm/hw_irq.h>

/*
 * Low-level SAL-based PCI configuration access functions. Note that SAL
 * calls are already serialized (via sal_lock), so we don't need another
 * synchronization mechanism here.
 */

#define PCI_SAL_ADDRESS(seg, bus, devfn, reg)           \
        (((u64) seg << 24) | (bus << 16) | (devfn << 8) | (reg))

/* SAL 3.2 adds support for extended config space. */

#define PCI_SAL_EXT_ADDRESS(seg, bus, devfn, reg)       \
        (((u64) seg << 28) | (bus << 20) | (devfn << 12) | (reg))

static int
pci_sal_read (unsigned int seg, unsigned int bus, unsigned int devfn,
              int reg, int len, u32 *value)
{
        u64 addr, data = 0;
        int mode, result;

        if (!value || (seg > 65535) || (bus > 255) || (devfn > 255) || (reg > 4095))
                return -EINVAL;

        if ((seg | reg) <= 255) {
                addr = PCI_SAL_ADDRESS(seg, bus, devfn, reg);
                mode = 0;
        } else {
                addr = PCI_SAL_EXT_ADDRESS(seg, bus, devfn, reg);
                mode = 1;
        }
        result = ia64_sal_pci_config_read(addr, mode, len, &data);
        if (result != 0)
                return -EINVAL;

        *value = (u32) data;
        return 0;
}

static int
pci_sal_write (unsigned int seg, unsigned int bus, unsigned int devfn,
               int reg, int len, u32 value)
{
        u64 addr;
        int mode, result;

        if ((seg > 65535) || (bus > 255) || (devfn > 255) || (reg > 4095))
                return -EINVAL;

        if ((seg | reg) <= 255) {
                addr = PCI_SAL_ADDRESS(seg, bus, devfn, reg);
                mode = 0;
        } else {
                addr = PCI_SAL_EXT_ADDRESS(seg, bus, devfn, reg);
                mode = 1;
        }
        result = ia64_sal_pci_config_write(addr, mode, len, value);
        if (result != 0)
                return -EINVAL;
        return 0;
}

static struct pci_raw_ops pci_sal_ops = {
        .read =         pci_sal_read,
        .write =        pci_sal_write
};

struct pci_raw_ops *raw_pci_ops = &pci_sal_ops;

static int
pci_read (struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
{
        return raw_pci_ops->read(pci_domain_nr(bus), bus->number,
                                 devfn, where, size, value);
}

static int
pci_write (struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
{
        return raw_pci_ops->write(pci_domain_nr(bus), bus->number,
                                  devfn, where, size, value);
}

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

/* Called by ACPI when it finds a new root bus.  */

static struct pci_controller * __devinit
alloc_pci_controller (int seg)
{
        struct pci_controller *controller;

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

        controller->segment = seg;
        controller->node = -1;
        return controller;
}

struct pci_root_info {
        struct pci_controller *controller;
        char *name;
};

static unsigned int
new_space (u64 phys_base, int sparse)
{
        u64 mmio_base;
        int i;

        if (phys_base == 0)
                return 0;       /* legacy I/O port space */

        mmio_base = (u64) ioremap(phys_base, 0);
        for (i = 0; i < num_io_spaces; i++)
                if (io_space[i].mmio_base == mmio_base &&
                    io_space[i].sparse == sparse)
                        return i;

        if (num_io_spaces == MAX_IO_SPACES) {
                printk(KERN_ERR "PCI: Too many IO port spaces "
                        "(MAX_IO_SPACES=%lu)\n", MAX_IO_SPACES);
                return ~0;
        }

        i = num_io_spaces++;
        io_space[i].mmio_base = mmio_base;
        io_space[i].sparse = sparse;

        return i;
}

static u64 __devinit
add_io_space (struct pci_root_info *info, struct acpi_resource_address64 *addr)
{
        struct resource *resource;
        char *name;
        u64 base, min, max, base_port;
        unsigned int sparse = 0, space_nr, len;

        resource = kzalloc(sizeof(*resource), GFP_KERNEL);
        if (!resource) {
                printk(KERN_ERR "PCI: No memory for %s I/O port space\n",
                        info->name);
                goto out;
        }

        len = strlen(info->name) + 32;
        name = kzalloc(len, GFP_KERNEL);
        if (!name) {
                printk(KERN_ERR "PCI: No memory for %s I/O port space name\n",
                        info->name);
                goto free_resource;
        }

        min = addr->minimum;
        max = min + addr->address_length - 1;
        if (addr->info.io.translation_type == ACPI_SPARSE_TRANSLATION)
                sparse = 1;

        space_nr = new_space(addr->translation_offset, sparse);
        if (space_nr == ~0)
                goto free_name;

        base = __pa(io_space[space_nr].mmio_base);
        base_port = IO_SPACE_BASE(space_nr);
        snprintf(name, len, "%s I/O Ports %08lx-%08lx", info->name,
                base_port + min, base_port + max);

        /*
         * The SDM guarantees the legacy 0-64K space is sparse, but if the
         * mapping is done by the processor (not the bridge), ACPI may not
         * mark it as sparse.
         */
        if (space_nr == 0)
                sparse = 1;

        resource->name  = name;
        resource->flags = IORESOURCE_MEM;
        resource->start = base + (sparse ? IO_SPACE_SPARSE_ENCODING(min) : min);
        resource->end   = base + (sparse ? IO_SPACE_SPARSE_ENCODING(max) : max);
        insert_resource(&iomem_resource, resource);

        return base_port;

free_name:
        kfree(name);
free_resource:
        kfree(resource);
out:
        return ~0;
}

static acpi_status __devinit resource_to_window(struct acpi_resource *resource,
        struct acpi_resource_address64 *addr)
{
        acpi_status status;

        /*
         * We're only interested in _CRS descriptors that are
         *      - address space descriptors for memory or I/O space
         *      - non-zero size
         *      - producers, i.e., the address space is routed downstream,
         *        not consumed by the bridge itself
         */
        status = acpi_resource_to_address64(resource, addr);
        if (ACPI_SUCCESS(status) &&
            (addr->resource_type == ACPI_MEMORY_RANGE ||
             addr->resource_type == ACPI_IO_RANGE) &&
            addr->address_length &&
            addr->producer_consumer == ACPI_PRODUCER)
                return AE_OK;

        return AE_ERROR;
}

static acpi_status __devinit
count_window (struct acpi_resource *resource, void *data)
{
        unsigned int *windows = (unsigned int *) data;
        struct acpi_resource_address64 addr;
        acpi_status status;

        status = resource_to_window(resource, &addr);
        if (ACPI_SUCCESS(status))
                (*windows)++;

        return AE_OK;
}

static __devinit acpi_status add_window(struct acpi_resource *res, void *data)
{
        struct pci_root_info *info = data;
        struct pci_window *window;
        struct acpi_resource_address64 addr;
        acpi_status status;
        unsigned long flags, offset = 0;
        struct resource *root;

        /* Return AE_OK for non-window resources to keep scanning for more */
        status = resource_to_window(res, &addr);
        if (!ACPI_SUCCESS(status))
                return AE_OK;

        if (addr.resource_type == ACPI_MEMORY_RANGE) {
                flags = IORESOURCE_MEM;
                root = &iomem_resource;
                offset = addr.translation_offset;
        } else if (addr.resource_type == ACPI_IO_RANGE) {
                flags = IORESOURCE_IO;
                root = &ioport_resource;
                offset = add_io_space(info, &addr);
                if (offset == ~0)
                        return AE_OK;
        } else
                return AE_OK;

        window = &info->controller->window[info->controller->windows++];
        window->resource.name = info->name;
        window->resource.flags = flags;
        window->resource.start = addr.minimum + offset;
        window->resource.end = window->resource.start + addr.address_length - 1;
        window->resource.child = NULL;
        window->offset = offset;

        if (insert_resource(root, &window->resource)) {
                printk(KERN_ERR "alloc 0x%lx-0x%lx from %s for %s failed\n",
                        window->resource.start, window->resource.end,
                        root->name, info->name);
        }

        return AE_OK;
}

static void __devinit
pcibios_setup_root_windows(struct pci_bus *bus, struct pci_controller *ctrl)
{
        int i, j;

        j = 0;
        for (i = 0; i < ctrl->windows; i++) {
                struct resource *res = &ctrl->window[i].resource;
                /* HP's firmware has a hack to work around a Windows bug.
                 * Ignore these tiny memory ranges */
                if ((res->flags & IORESOURCE_MEM) &&
                    (res->end - res->start < 16))
                        continue;
                if (j >= PCI_BUS_NUM_RESOURCES) {
                        printk("Ignoring range [%lx-%lx] (%lx)\n", res->start,
                                        res->end, res->flags);
                        continue;
                }
                bus->resource[j++] = res;
        }
}

struct pci_bus * __devinit
pci_acpi_scan_root(struct acpi_device *device, int domain, int bus)
{
        struct pci_root_info info;
        struct pci_controller *controller;
        unsigned int windows = 0;
        struct pci_bus *pbus;
        char *name;
        int pxm;

        controller = alloc_pci_controller(domain);
        if (!controller)
                goto out1;

        controller->acpi_handle = device->handle;

        pxm = acpi_get_pxm(controller->acpi_handle);
#ifdef CONFIG_NUMA
        if (pxm >= 0)
                controller->node = pxm_to_node(pxm);
#endif

        acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_window,
                        &windows);
        if (windows) {
                controller->window =
                        kmalloc_node(sizeof(*controller->window) * windows,
                                     GFP_KERNEL, controller->node);
                if (!controller->window)
                        goto out2;
        }

        name = kmalloc(16, GFP_KERNEL);
        if (!name)
                goto out3;

        sprintf(name, "PCI Bus %04x:%02x", domain, bus);
        info.controller = controller;
        info.name = name;
        acpi_walk_resources(device->handle, METHOD_NAME__CRS, add_window,
                        &info);

        pbus = pci_scan_bus_parented(NULL, bus, &pci_root_ops, controller);
        if (pbus)
                pcibios_setup_root_windows(pbus, controller);

        return pbus;

out3:
        kfree(controller->window);
out2:
        kfree(controller);
out1:
        return NULL;
}

void pcibios_resource_to_bus(struct pci_dev *dev,
                struct pci_bus_region *region, struct resource *res)
{
        struct pci_controller *controller = PCI_CONTROLLER(dev);
        unsigned long offset = 0;
        int i;

        for (i = 0; i < controller->windows; i++) {
                struct pci_window *window = &controller->window[i];
                if (!(window->resource.flags & res->flags))
                        continue;
                if (window->resource.start > res->start)
                        continue;
                if (window->resource.end < res->end)
                        continue;
                offset = window->offset;
                break;
        }

        region->start = res->start - offset;
        region->end = res->end - offset;
}
EXPORT_SYMBOL(pcibios_resource_to_bus);

void pcibios_bus_to_resource(struct pci_dev *dev,
                struct resource *res, struct pci_bus_region *region)
{
        struct pci_controller *controller = PCI_CONTROLLER(dev);
        unsigned long offset = 0;
        int i;

        for (i = 0; i < controller->windows; i++) {
                struct pci_window *window = &controller->window[i];
                if (!(window->resource.flags & res->flags))
                        continue;
                if (window->resource.start - window->offset > region->start)
                        continue;
                if (window->resource.end - window->offset < region->end)
                        continue;
                offset = window->offset;
                break;
        }

        res->start = region->start + offset;
        res->end = region->end + offset;
}
EXPORT_SYMBOL(pcibios_bus_to_resource);

static int __devinit is_valid_resource(struct pci_dev *dev, int idx)
{
        unsigned int i, type_mask = IORESOURCE_IO | IORESOURCE_MEM;
        struct resource *devr = &dev->resource[idx];

        if (!dev->bus)
                return 0;
        for (i=0; i<PCI_BUS_NUM_RESOURCES; i++) {
                struct resource *busr = dev->bus->resource[i];

                if (!busr || ((busr->flags ^ devr->flags) & type_mask))
                        continue;
                if ((devr->start) && (devr->start >= busr->start) &&
                                (devr->end <= busr->end))
                        return 1;
        }
        return 0;
}

static void __devinit
pcibios_fixup_resources(struct pci_dev *dev, int start, int limit)
{
        struct pci_bus_region region;
        int i;

        for (i = start; i < limit; i++) {
                if (!dev->resource[i].flags)
                        continue;
                region.start = dev->resource[i].start;
                region.end = dev->resource[i].end;
                pcibios_bus_to_resource(dev, &dev->resource[i], &region);
                if ((is_valid_resource(dev, i)))
                        pci_claim_resource(dev, i);
        }
}

void __devinit pcibios_fixup_device_resources(struct pci_dev *dev)
{
        pcibios_fixup_resources(dev, 0, PCI_BRIDGE_RESOURCES);
}
EXPORT_SYMBOL_GPL(pcibios_fixup_device_resources);

static void __devinit pcibios_fixup_bridge_resources(struct pci_dev *dev)
{
        pcibios_fixup_resources(dev, PCI_BRIDGE_RESOURCES, PCI_NUM_RESOURCES);
}

/*
 *  Called after each bus is probed, but before its children are examined.
 */
void __devinit
pcibios_fixup_bus (struct pci_bus *b)
{
        struct pci_dev *dev;

        if (b->self) {
                pci_read_bridge_bases(b);
                pcibios_fixup_bridge_resources(b->self);
        }
        list_for_each_entry(dev, &b->devices, bus_list)
                pcibios_fixup_device_resources(dev);
        platform_pci_fixup_bus(b);

        return;
}

void __devinit
pcibios_update_irq (struct pci_dev *dev, int irq)
{
        pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);

        /* ??? FIXME -- record old value for shutdown.  */
}

static inline int
pcibios_enable_resources (struct pci_dev *dev, int mask)
{
        u16 cmd, old_cmd;
        int idx;
        struct resource *r;
        unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;

        if (!dev)
                return -EINVAL;

        pci_read_config_word(dev, PCI_COMMAND, &cmd);
        old_cmd = cmd;
        for (idx=0; idx<PCI_NUM_RESOURCES; idx++) {
                /* Only set up the desired resources.  */
                if (!(mask & (1 << idx)))
                        continue;

                r = &dev->resource[idx];
                if (!(r->flags & type_mask))
                        continue;
                if ((idx == PCI_ROM_RESOURCE) &&
                                (!(r->flags & IORESOURCE_ROM_ENABLE)))
                        continue;
                if (!r->start && r->end) {
                        printk(KERN_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;
        }
        if (cmd != old_cmd) {
                printk("PCI: Enabling device %s (%04x -> %04x)\n", pci_name(dev), old_cmd, cmd);
                pci_write_config_word(dev, PCI_COMMAND, cmd);
        }
        return 0;
}

int
pcibios_enable_device (struct pci_dev *dev, int mask)
{
        int ret;

        ret = pcibios_enable_resources(dev, mask);
        if (ret < 0)
                return ret;

        if (!dev->msi_enabled)
                return acpi_pci_irq_enable(dev);
        return 0;
}

void
pcibios_disable_device (struct pci_dev *dev)
{
        BUG_ON(atomic_read(&dev->enable_cnt));
        if (!dev->msi_enabled)
                acpi_pci_irq_disable(dev);
}

void
pcibios_align_resource (void *data, struct resource *res,
                        resource_size_t size, resource_size_t align)
{
}

/*
 * PCI BIOS setup, always defaults to SAL interface
 */
char * __devinit
pcibios_setup (char *str)
{
        return str;
}

int
pci_mmap_page_range (struct pci_dev *dev, struct vm_area_struct *vma,
                     enum pci_mmap_state mmap_state, int write_combine)
{
        unsigned long size = vma->vm_end - vma->vm_start;
        pgprot_t prot;

        /*
         * I/O space cannot be accessed via normal processor loads and
         * stores on this platform.
         */
        if (mmap_state == pci_mmap_io)
                /*
                 * XXX we could relax this for I/O spaces for which ACPI
                 * indicates that the space is 1-to-1 mapped.  But at the
                 * moment, we don't support multiple PCI address spaces and
                 * the legacy I/O space is not 1-to-1 mapped, so this is moot.
                 */
                return -EINVAL;

        if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
                return -EINVAL;

        prot = phys_mem_access_prot(NULL, vma->vm_pgoff, size,
                                    vma->vm_page_prot);

        /*
         * If the user requested WC, the kernel uses UC or WC for this region,
         * and the chipset supports WC, we can use WC. Otherwise, we have to
         * use the same attribute the kernel uses.
         */
        if (write_combine &&
            ((pgprot_val(prot) & _PAGE_MA_MASK) == _PAGE_MA_UC ||
             (pgprot_val(prot) & _PAGE_MA_MASK) == _PAGE_MA_WC) &&
            efi_range_is_wc(vma->vm_start, vma->vm_end - vma->vm_start))
                vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
        else
                vma->vm_page_prot = prot;

        if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
                             vma->vm_end - vma->vm_start, vma->vm_page_prot))
                return -EAGAIN;

        return 0;
}

/**
 * ia64_pci_get_legacy_mem - generic legacy mem routine
 * @bus: bus to get legacy memory base address for
 *
 * Find the base of legacy memory for @bus.  This is typically the first
 * megabyte of bus address space for @bus or is simply 0 on platforms whose
 * chipsets support legacy I/O and memory routing.  Returns the base address
 * or an error pointer if an error occurred.
 *
 * This is the ia64 generic version of this routine.  Other platforms
 * are free to override it with a machine vector.
 */
char *ia64_pci_get_legacy_mem(struct pci_bus *bus)
{
        return (char *)__IA64_UNCACHED_OFFSET;
}

/**
 * pci_mmap_legacy_page_range - map legacy memory space to userland
 * @bus: bus whose legacy space we're mapping
 * @vma: vma passed in by mmap
 *
 * Map legacy memory space for this device back to userspace using a machine
 * vector to get the base address.
 */
int
pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma)
{
        unsigned long size = vma->vm_end - vma->vm_start;
        pgprot_t prot;
        char *addr;

        /*
         * Avoid attribute aliasing.  See Documentation/ia64/aliasing.txt
         * for more details.
         */
        if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
                return -EINVAL;
        prot = phys_mem_access_prot(NULL, vma->vm_pgoff, size,
                                    vma->vm_page_prot);

        addr = pci_get_legacy_mem(bus);
        if (IS_ERR(addr))
                return PTR_ERR(addr);

        vma->vm_pgoff += (unsigned long)addr >> PAGE_SHIFT;
        vma->vm_page_prot = prot;

        if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
                            size, vma->vm_page_prot))
                return -EAGAIN;

        return 0;
}

/**
 * ia64_pci_legacy_read - read from legacy I/O space
 * @bus: bus to read
 * @port: legacy port value
 * @val: caller allocated storage for returned value
 * @size: number of bytes to read
 *
 * Simply reads @size bytes from @port and puts the result in @val.
 *
 * Again, this (and the write routine) are generic versions that can be
 * overridden by the platform.  This is necessary on platforms that don't
 * support legacy I/O routing or that hard fail on legacy I/O timeouts.
 */
int ia64_pci_legacy_read(struct pci_bus *bus, u16 port, u32 *val, u8 size)
{
        int ret = size;

        switch (size) {
        case 1:
                *val = inb(port);
                break;
        case 2:
                *val = inw(port);
                break;
        case 4:
                *val = inl(port);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

/**
 * ia64_pci_legacy_write - perform a legacy I/O write
 * @bus: bus pointer
 * @port: port to write
 * @val: value to write
 * @size: number of bytes to write from @val
 *
 * Simply writes @size bytes of @val to @port.
 */
int ia64_pci_legacy_write(struct pci_bus *bus, u16 port, u32 val, u8 size)
{
        int ret = size;

        switch (size) {
        case 1:
                outb(val, port);
                break;
        case 2:
                outw(val, port);
                break;
        case 4:
                outl(val, port);
                break;
        default:
                ret = -EINVAL;
                break;
        }

        return ret;
}

/* It's defined in drivers/pci/pci.c */
extern u8 pci_cache_line_size;

/**
 * set_pci_cacheline_size - determine cacheline size for PCI devices
 *
 * We want to use the line-size of the outer-most cache.  We assume
 * that this line-size is the same for all CPUs.
 *
 * Code mostly taken from arch/ia64/kernel/palinfo.c:cache_info().
 */
static void __init set_pci_cacheline_size(void)
{
        u64 levels, unique_caches;
        s64 status;
        pal_cache_config_info_t cci;

        status = ia64_pal_cache_summary(&levels, &unique_caches);
        if (status != 0) {
                printk(KERN_ERR "%s: ia64_pal_cache_summary() failed "
                        "(status=%ld)\n", __FUNCTION__, status);
                return;
        }

        status = ia64_pal_cache_config_info(levels - 1,
                                /* cache_type (data_or_unified)= */ 2, &cci);
        if (status != 0) {
                printk(KERN_ERR "%s: ia64_pal_cache_config_info() failed "
                        "(status=%ld)\n", __FUNCTION__, status);
                return;
        }
        pci_cache_line_size = (1 << cci.pcci_line_size) / 4;
}

static int __init pcibios_init(void)
{
        set_pci_cacheline_size();
        return 0;
}

subsys_initcall(pcibios_init);