// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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/pci-acpi.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/memblock.h>
#include <linux/export.h>

#include <asm/page.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))

int raw_pci_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 if (sal_revision >= SAL_VERSION_CODE(3,2)) {
                addr = PCI_SAL_EXT_ADDRESS(seg, bus, devfn, reg);
                mode = 1;
        } else {
                return -EINVAL;
        }

        result = ia64_sal_pci_config_read(addr, mode, len, &data);
        if (result != 0)
                return -EINVAL;

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

int raw_pci_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 if (sal_revision >= SAL_VERSION_CODE(3,2)) {
                addr = PCI_SAL_EXT_ADDRESS(seg, bus, devfn, reg);
                mode = 1;
        } else {
                return -EINVAL;
        }
        result = ia64_sal_pci_config_write(addr, mode, len, value);
        if (result != 0)
                return -EINVAL;
        return 0;
}

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

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

struct pci_root_info {
        struct acpi_pci_root_info common;
        struct pci_controller controller;
        struct list_head io_resources;
};

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) {
                pr_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 int add_io_space(struct device *dev, struct pci_root_info *info,
                        struct resource_entry *entry)
{
        struct resource_entry *iospace;
        struct resource *resource, *res = entry->res;
        char *name;
        unsigned long base, min, max, base_port;
        unsigned int sparse = 0, space_nr, len;

        len = strlen(info->common.name) + 32;
        iospace = resource_list_create_entry(NULL, len);
        if (!iospace) {
                dev_err(dev, "PCI: No memory for %s I/O port space\n",
                        info->common.name);
                return -ENOMEM;
        }

        if (res->flags & IORESOURCE_IO_SPARSE)
                sparse = 1;
        space_nr = new_space(entry->offset, sparse);
        if (space_nr == ~0)
                goto free_resource;

        name = (char *)(iospace + 1);
        min = res->start - entry->offset;
        max = res->end - entry->offset;
        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->common.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 = iospace->res;
        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);
        if (insert_resource(&iomem_resource, resource)) {
                dev_err(dev,
                        "can't allocate host bridge io space resource  %pR\n",
                        resource);
                goto free_resource;
        }

        entry->offset = base_port;
        res->start = min + base_port;
        res->end = max + base_port;
        resource_list_add_tail(iospace, &info->io_resources);

        return 0;

free_resource:
        resource_list_free_entry(iospace);
        return -ENOSPC;
}

/*
 * An IO port or MMIO resource assigned to a PCI host bridge may be
 * consumed by the host bridge itself or available to its child
 * bus/devices. The ACPI specification defines a bit (Producer/Consumer)
 * to tell whether the resource is consumed by the host bridge itself,
 * but firmware hasn't used that bit consistently, so we can't rely on it.
 *
 * On x86 and IA64 platforms, all IO port and MMIO resources are assumed
 * to be available to child bus/devices except one special case:
 *     IO port [0xCF8-0xCFF] is consumed by the host bridge itself
 *     to access PCI configuration space.
 *
 * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF].
 */
static bool resource_is_pcicfg_ioport(struct resource *res)
{
        return (res->flags & IORESOURCE_IO) &&
                res->start == 0xCF8 && res->end == 0xCFF;
}

static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
{
        struct device *dev = &ci->bridge->dev;
        struct pci_root_info *info;
        struct resource *res;
        struct resource_entry *entry, *tmp;
        int status;

        status = acpi_pci_probe_root_resources(ci);
        if (status > 0) {
                info = container_of(ci, struct pci_root_info, common);
                resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
                        res = entry->res;
                        if (res->flags & IORESOURCE_MEM) {
                                /*
                                 * HP's firmware has a hack to work around a
                                 * Windows bug. Ignore these tiny memory ranges.
                                 */
                                if (resource_size(res) <= 16) {
                                        resource_list_del(entry);
                                        insert_resource(&iomem_resource,
                                                        entry->res);
                                        resource_list_add_tail(entry,
                                                        &info->io_resources);
                                }
                        } else if (res->flags & IORESOURCE_IO) {
                                if (resource_is_pcicfg_ioport(entry->res))
                                        resource_list_destroy_entry(entry);
                                else if (add_io_space(dev, info, entry))
                                        resource_list_destroy_entry(entry);
                        }
                }
        }

        return status;
}

static void pci_acpi_root_release_info(struct acpi_pci_root_info *ci)
{
        struct pci_root_info *info;
        struct resource_entry *entry, *tmp;

        info = container_of(ci, struct pci_root_info, common);
        resource_list_for_each_entry_safe(entry, tmp, &info->io_resources) {
                release_resource(entry->res);
                resource_list_destroy_entry(entry);
        }
        kfree(info);
}

static struct acpi_pci_root_ops pci_acpi_root_ops = {
        .pci_ops = &pci_root_ops,
        .release_info = pci_acpi_root_release_info,
        .prepare_resources = pci_acpi_root_prepare_resources,
};

struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
{
        struct acpi_device *device = root->device;
        struct pci_root_info *info;

        info = kzalloc(sizeof(*info), GFP_KERNEL);
        if (!info) {
                dev_err(&device->dev,
                        "pci_bus %04x:%02x: ignored (out of memory)\n",
                        root->segment, (int)root->secondary.start);
                return NULL;
        }

        info->controller.segment = root->segment;
        info->controller.companion = device;
        info->controller.node = acpi_get_node(device->handle);
        INIT_LIST_HEAD(&info->io_resources);
        return acpi_pci_root_create(root, &pci_acpi_root_ops,
                                    &info->common, &info->controller);
}

int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
        /*
         * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
         * here, pci_create_root_bus() has been called by someone else and
         * sysdata is likely to be different from what we expect.  Let it go in
         * that case.
         */
        if (!bridge->dev.parent) {
                struct pci_controller *controller = bridge->bus->sysdata;
                ACPI_COMPANION_SET(&bridge->dev, controller->companion);
        }
        return 0;
}

void pcibios_fixup_device_resources(struct pci_dev *dev)
{
        int idx;

        if (!dev->bus)
                return;

        for (idx = 0; idx < PCI_BRIDGE_RESOURCES; idx++) {
                struct resource *r = &dev->resource[idx];

                if (!r->flags || r->parent || !r->start)
                        continue;

                pci_claim_resource(dev, idx);
        }
}
EXPORT_SYMBOL_GPL(pcibios_fixup_device_resources);

static void pcibios_fixup_bridge_resources(struct pci_dev *dev)
{
        int idx;

        if (!dev->bus)
                return;

        for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
                struct resource *r = &dev->resource[idx];

                if (!r->flags || r->parent || !r->start)
                        continue;

                pci_claim_bridge_resource(dev, idx);
        }
}

/*
 *  Called after each bus is probed, but before its children are examined.
 */
void 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);
}

void pcibios_add_bus(struct pci_bus *bus)
{
        acpi_pci_add_bus(bus);
}

void pcibios_remove_bus(struct pci_bus *bus)
{
        acpi_pci_remove_bus(bus);
}

void pcibios_set_master (struct pci_dev *dev)
{
        /* No special bus mastering setup handling */
}

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

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

        if (!pci_dev_msi_enabled(dev))
                return acpi_pci_irq_enable(dev);
        return 0;
}

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

/**
 * 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 *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,
                           enum pci_mmap_state mmap_state)
{
        unsigned long size = vma->vm_end - vma->vm_start;
        pgprot_t prot;
        char *addr;

        /* We only support mmap'ing of legacy memory space */
        if (mmap_state != pci_mmap_mem)
                return -ENOSYS;

        /*
         * Avoid attribute aliasing.  See Documentation/ia64/aliasing.rst
         * 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;
}

/**
 * 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 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;
}

/**
 * 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 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;
}

/**
 * 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_dfl_cacheline_size(void)
{
        unsigned long levels, unique_caches;
        long status;
        pal_cache_config_info_t cci;

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

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

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

subsys_initcall(pcibios_init);