/*
 * pci.c - Low-Level PCI Access in IA-64
 *
 * Derived from bios32.c of i386 tree.
 *
 * Copyright (C) 2002 Hewlett-Packard Co
 *      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/config.h>

#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/smp_lock.h>
#include <linux/spinlock.h>

#include <asm/machvec.h>
#include <asm/page.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <asm/io.h>

#include <asm/sal.h>


#ifdef CONFIG_SMP
# include <asm/smp.h>
#endif
#include <asm/irq.h>
#include <asm/hw_irq.h>


#undef DEBUG
#define DEBUG

#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

static int pci_routeirq;

/*
 * 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) | (u64)(bus << 16) |  \
         (u64)(devfn << 8) | (u64)(reg))

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

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

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

        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_read(addr, mode, len, &data);

        *value = (u32) data;

        return result;
}

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

        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;
        }
        return ia64_sal_pci_config_write(addr, mode, len, value);
}

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,
};

#ifdef CONFIG_NUMA
extern acpi_status acpi_map_iosapic(acpi_handle, u32, void *, void **);
static void acpi_map_iosapics(void)
{
        acpi_get_devices(NULL, acpi_map_iosapic, NULL, NULL);
}
#else
static void acpi_map_iosapics(void)
{
        return;
}
#endif /* CONFIG_NUMA */

static int __init
pci_acpi_init (void)
{
        struct pci_dev *dev = NULL;

        printk(KERN_INFO "PCI: Using ACPI for IRQ routing\n");

        acpi_map_iosapics();

        if (pci_routeirq) {
                /*
                 * PCI IRQ routing is set up by pci_enable_device(), but we
                 * also do it here in case there are still broken drivers that
                 * don't use pci_enable_device().
                 */
                printk(KERN_INFO "** Routing PCI interrupts for all devices because \"pci=routeirq\"\n");
                printk(KERN_INFO "** was specified.  If this was required to make a driver work,\n");
                printk(KERN_INFO "** please email the output of \"lspci\" to bjorn.helgaas@hp.com\n");
                printk(KERN_INFO "** so I can fix the driver.\n");
                for_each_pci_dev(dev)
                        acpi_pci_irq_enable(dev);
        } else {
                printk(KERN_INFO "** PCI interrupts are no longer routed automatically.  If this\n");
                printk(KERN_INFO "** causes a device to stop working, it is probably because the\n");
                printk(KERN_INFO "** driver failed to call pci_enable_device().  As a temporary\n");
                printk(KERN_INFO "** workaround, the \"pci=routeirq\" argument restores the old\n");
                printk(KERN_INFO "** behavior.  If this argument makes the device work again,\n");
                printk(KERN_INFO "** please email the output of \"lspci\" to bjorn.helgaas@hp.com\n");
                printk(KERN_INFO "** so I can fix the driver.\n");
        }

        return 0;
}

subsys_initcall(pci_acpi_init);

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

        memset(controller, 0, sizeof(*controller));
        controller->segment = seg;
        return controller;
}

static int __devinit
alloc_resource (char *name, struct resource *root, unsigned long start, unsigned long end,
                unsigned long flags)
{
        struct resource *res;

        res = kmalloc(sizeof(*res), GFP_KERNEL);
        if (!res)
                return -ENOMEM;

        memset(res, 0, sizeof(*res));
        res->name = name;
        res->start = start;
        res->end = end;
        res->flags = flags;

        if (insert_resource(root, res)) {
                kfree(res);
                return -EBUSY;
        }

        return 0;
}

static u64 __devinit
add_io_space (struct acpi_resource_address64 *addr)
{
        u64 offset;
        int sparse = 0;
        int i;

        if (addr->address_translation_offset == 0)
                return IO_SPACE_BASE(0);        /* part of legacy IO space */

        if (addr->attribute.io.translation_attribute == ACPI_SPARSE_TRANSLATION)
                sparse = 1;

        offset = (u64) ioremap(addr->address_translation_offset, 0);
        for (i = 0; i < num_io_spaces; i++)
                if (io_space[i].mmio_base == offset &&
                    io_space[i].sparse == sparse)
                        return IO_SPACE_BASE(i);

        if (num_io_spaces == MAX_IO_SPACES) {
                printk("Too many IO port spaces\n");
                return ~0;
        }

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

        return IO_SPACE_BASE(i);
}

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 = acpi_resource_to_address64(resource, &addr);
        if (ACPI_SUCCESS(status))
                if (addr.resource_type == ACPI_MEMORY_RANGE ||
                    addr.resource_type == ACPI_IO_RANGE)
                        (*windows)++;

        return AE_OK;
}

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

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

        status = acpi_resource_to_address64(res, &addr);
        if (ACPI_SUCCESS(status)) {
                if (!addr.address_length)
                        return AE_OK;

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

                window = &info->controller->window[info->controller->windows++];
                window->resource.flags  = flags;
                window->resource.start  = addr.min_address_range;
                window->resource.end    = addr.max_address_range;
                window->offset          = offset;

                if (alloc_resource(info->name, root, addr.min_address_range + offset,
                        addr.max_address_range + offset, flags))
                        printk(KERN_ERR "alloc 0x%lx-0x%lx from %s for %s failed\n",
                                addr.min_address_range + offset, addr.max_address_range + offset,
                                root->name, info->name);
        }

        return AE_OK;
}

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;
        char *name;

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

        controller->acpi_handle = device->handle;

        acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_window, &windows);
        controller->window = kmalloc(sizeof(*controller->window) * windows, GFP_KERNEL);
        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);

        return pci_scan_bus(bus, &pci_root_ops, controller);

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 - window->offset)
                        continue;
                if (window->resource.end < res->end - window->offset)
                        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 > region->start)
                        continue;
                if (window->resource.end < region->end)
                        continue;
                offset = window->offset;
                break;
        }

        res->start = region->start + offset;
        res->end = region->end + offset;
}

static void __devinit pcibios_fixup_device_resources(struct pci_dev *dev)
{
        struct pci_bus_region region;
        int i;
        int limit = (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) ? \
                PCI_BRIDGE_RESOURCES : PCI_NUM_RESOURCES;

        for (i = 0; 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);
                pci_claim_resource(dev, i);
        }
}

/*
 *  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;

        list_for_each_entry(dev, &b->devices, bus_list)
                pcibios_fixup_device_resources(dev);

        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;

        if (!dev)
                return -EINVAL;

        pci_read_config_word(dev, PCI_COMMAND, &cmd);
        old_cmd = cmd;
        for (idx=0; idx<6; idx++) {
                /* Only set up the desired resources.  */
                if (!(mask & (1 << idx)))
                        continue;

                r = &dev->resource[idx];
                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 (dev->resource[PCI_ROM_RESOURCE].start)
                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;

        return acpi_pci_irq_enable(dev);
}

#ifdef CONFIG_ACPI_DEALLOCATE_IRQ
void
pcibios_disable_device (struct pci_dev *dev)
{
        acpi_pci_irq_disable(dev);
}
#endif /* CONFIG_ACPI_DEALLOCATE_IRQ */

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

/*
 * PCI BIOS setup, always defaults to SAL interface
 */
char * __init
pcibios_setup (char *str)
{
        if (!strcmp(str, "routeirq"))
                pci_routeirq = 1;
        return NULL;
}

int
pci_mmap_page_range (struct pci_dev *dev, struct vm_area_struct *vma,
                     enum pci_mmap_state mmap_state, int write_combine)
{
        /*
         * 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;

        /*
         * Leave vm_pgoff as-is, the PCI space address is the physical
         * address on this platform.
         */
        vma->vm_flags |= (VM_SHM | VM_RESERVED | VM_IO);

        if (write_combine && 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 = pgprot_noncached(vma->vm_page_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)
{
        char *addr;

        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 = pgprot_noncached(vma->vm_page_prot);
        vma->vm_flags |= (VM_SHM | VM_RESERVED | VM_IO);

        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_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_dev *bus, u16 port, u32 val, u8 size)
{
        int ret = 0;

        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;
}

/**
 * pci_cacheline_size - determine cacheline size for PCI devices
 * @dev: void
 *
 * 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().
 *
 * RETURNS: An appropriate -ERRNO error value on eror, or zero for success.
 */
static unsigned long
pci_cacheline_size (void)
{
        u64 levels, unique_caches;
        s64 status;
        pal_cache_config_info_t cci;
        static u8 cacheline_size;

        if (cacheline_size)
                return cacheline_size;

        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 SMP_CACHE_BYTES;
        }

        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 SMP_CACHE_BYTES;
        }
        cacheline_size = 1 << cci.pcci_line_size;
        return cacheline_size;
}

/**
 * pcibios_prep_mwi - helper function for drivers/pci/pci.c:pci_set_mwi()
 * @dev: the PCI device for which MWI is enabled
 *
 * For ia64, we can get the cacheline sizes from PAL.
 *
 * RETURNS: An appropriate -ERRNO error value on eror, or zero for success.
 */
int
pcibios_prep_mwi (struct pci_dev *dev)
{
        unsigned long desired_linesize, current_linesize;
        int rc = 0;
        u8 pci_linesize;

        desired_linesize = pci_cacheline_size();

        pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &pci_linesize);
        current_linesize = 4 * pci_linesize;
        if (desired_linesize != current_linesize) {
                printk(KERN_WARNING "PCI: slot %s has incorrect PCI cache line size of %lu bytes,",
                       pci_name(dev), current_linesize);
                if (current_linesize > desired_linesize) {
                        printk(" expected %lu bytes instead\n", desired_linesize);
                        rc = -EINVAL;
                } else {
                        printk(" correcting to %lu\n", desired_linesize);
                        pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, desired_linesize / 4);
                }
        }
        return rc;
}

int pci_vector_resources(int last, int nr_released)
{
        int count = nr_released;

        count += (IA64_LAST_DEVICE_VECTOR - last);

        return count;
}