// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Port for PPC64 David Engebretsen, IBM Corp.
 * Contains common pci routines for ppc64 platform, pSeries and iSeries brands.
 * 
 * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
 *   Rework, based on alpha PCI code.
 */

#undef DEBUG

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/syscalls.h>
#include <linux/irq.h>
#include <linux/vmalloc.h>

#include <asm/processor.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>
#include <asm/byteorder.h>
#include <asm/machdep.h>
#include <asm/ppc-pci.h>

/* pci_io_base -- the base address from which io bars are offsets.
 * This is the lowest I/O base address (so bar values are always positive),
 * and it *must* be the start of ISA space if an ISA bus exists because
 * ISA drivers use hard coded offsets.  If no ISA bus exists nothing
 * is mapped on the first 64K of IO space
 */
unsigned long pci_io_base;
EXPORT_SYMBOL(pci_io_base);

static int __init pcibios_init(void)
{
        struct pci_controller *hose, *tmp;

        printk(KERN_INFO "PCI: Probing PCI hardware\n");

        /* For now, override phys_mem_access_prot. If we need it,g
         * later, we may move that initialization to each ppc_md
         */
        ppc_md.phys_mem_access_prot = pci_phys_mem_access_prot;

        /* On ppc64, we always enable PCI domains and we keep domain 0
         * backward compatible in /proc for video cards
         */
        pci_add_flags(PCI_ENABLE_PROC_DOMAINS | PCI_COMPAT_DOMAIN_0);

        /* Scan all of the recorded PCI controllers.  */
        list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
                pcibios_scan_phb(hose);

        /* Call common code to handle resource allocation */
        pcibios_resource_survey();

        /* Add devices. */
        list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
                pci_bus_add_devices(hose->bus);

        /* Call machine dependent fixup */
        if (ppc_md.pcibios_fixup)
                ppc_md.pcibios_fixup();

        printk(KERN_DEBUG "PCI: Probing PCI hardware done\n");

        return 0;
}

subsys_initcall(pcibios_init);

int pcibios_unmap_io_space(struct pci_bus *bus)
{
        struct pci_controller *hose;

        WARN_ON(bus == NULL);

        /* If this is not a PHB, we only flush the hash table over
         * the area mapped by this bridge. We don't play with the PTE
         * mappings since we might have to deal with sub-page alignments
         * so flushing the hash table is the only sane way to make sure
         * that no hash entries are covering that removed bridge area
         * while still allowing other busses overlapping those pages
         *
         * Note: If we ever support P2P hotplug on Book3E, we'll have
         * to do an appropriate TLB flush here too
         */
        if (bus->self) {
#ifdef CONFIG_PPC_BOOK3S_64
                struct resource *res = bus->resource[0];
#endif

                pr_debug("IO unmapping for PCI-PCI bridge %s\n",
                         pci_name(bus->self));

#ifdef CONFIG_PPC_BOOK3S_64
                __flush_hash_table_range(res->start + _IO_BASE,
                                         res->end + _IO_BASE + 1);
#endif
                return 0;
        }

        /* Get the host bridge */
        hose = pci_bus_to_host(bus);

        pr_debug("IO unmapping for PHB %pOF\n", hose->dn);
        pr_debug("  alloc=0x%p\n", hose->io_base_alloc);

        iounmap(hose->io_base_alloc);
        return 0;
}
EXPORT_SYMBOL_GPL(pcibios_unmap_io_space);

void __iomem *ioremap_phb(phys_addr_t paddr, unsigned long size)
{
        struct vm_struct *area;
        unsigned long addr;

        WARN_ON_ONCE(paddr & ~PAGE_MASK);
        WARN_ON_ONCE(size & ~PAGE_MASK);

        /*
         * Let's allocate some IO space for that guy. We don't pass VM_IOREMAP
         * because we don't care about alignment tricks that the core does in
         * that case.  Maybe we should due to stupid card with incomplete
         * address decoding but I'd rather not deal with those outside of the
         * reserved 64K legacy region.
         */
        area = __get_vm_area_caller(size, 0, PHB_IO_BASE, PHB_IO_END,
                                    __builtin_return_address(0));
        if (!area)
                return NULL;

        addr = (unsigned long)area->addr;
        if (ioremap_page_range(addr, addr + size, paddr,
                        pgprot_noncached(PAGE_KERNEL))) {
                unmap_kernel_range(addr, size);
                return NULL;
        }

        return (void __iomem *)addr;
}
EXPORT_SYMBOL_GPL(ioremap_phb);

static int pcibios_map_phb_io_space(struct pci_controller *hose)
{
        unsigned long phys_page;
        unsigned long size_page;
        unsigned long io_virt_offset;

        phys_page = ALIGN_DOWN(hose->io_base_phys, PAGE_SIZE);
        size_page = ALIGN(hose->pci_io_size, PAGE_SIZE);

        /* Make sure IO area address is clear */
        hose->io_base_alloc = NULL;

        /* If there's no IO to map on that bus, get away too */
        if (hose->pci_io_size == 0 || hose->io_base_phys == 0)
                return 0;

        /* Let's allocate some IO space for that guy. We don't pass
         * VM_IOREMAP because we don't care about alignment tricks that
         * the core does in that case. Maybe we should due to stupid card
         * with incomplete address decoding but I'd rather not deal with
         * those outside of the reserved 64K legacy region.
         */
        hose->io_base_alloc = ioremap_phb(phys_page, size_page);
        if (!hose->io_base_alloc)
                return -ENOMEM;
        hose->io_base_virt = hose->io_base_alloc +
                                hose->io_base_phys - phys_page;

        pr_debug("IO mapping for PHB %pOF\n", hose->dn);
        pr_debug("  phys=0x%016llx, virt=0x%p (alloc=0x%p)\n",
                 hose->io_base_phys, hose->io_base_virt, hose->io_base_alloc);
        pr_debug("  size=0x%016llx (alloc=0x%016lx)\n",
                 hose->pci_io_size, size_page);

        /* Fixup hose IO resource */
        io_virt_offset = pcibios_io_space_offset(hose);
        hose->io_resource.start += io_virt_offset;
        hose->io_resource.end += io_virt_offset;

        pr_debug("  hose->io_resource=%pR\n", &hose->io_resource);

        return 0;
}

int pcibios_map_io_space(struct pci_bus *bus)
{
        WARN_ON(bus == NULL);

        /* If this not a PHB, nothing to do, page tables still exist and
         * thus HPTEs will be faulted in when needed
         */
        if (bus->self) {
                pr_debug("IO mapping for PCI-PCI bridge %s\n",
                         pci_name(bus->self));
                pr_debug("  virt=0x%016llx...0x%016llx\n",
                         bus->resource[0]->start + _IO_BASE,
                         bus->resource[0]->end + _IO_BASE);
                return 0;
        }

        return pcibios_map_phb_io_space(pci_bus_to_host(bus));
}
EXPORT_SYMBOL_GPL(pcibios_map_io_space);

void pcibios_setup_phb_io_space(struct pci_controller *hose)
{
        pcibios_map_phb_io_space(hose);
}

#define IOBASE_BRIDGE_NUMBER    0
#define IOBASE_MEMORY           1
#define IOBASE_IO               2
#define IOBASE_ISA_IO           3
#define IOBASE_ISA_MEM          4

SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, in_bus,
                          unsigned long, in_devfn)
{
        struct pci_controller* hose;
        struct pci_bus *tmp_bus, *bus = NULL;
        struct device_node *hose_node;

        /* Argh ! Please forgive me for that hack, but that's the
         * simplest way to get existing XFree to not lockup on some
         * G5 machines... So when something asks for bus 0 io base
         * (bus 0 is HT root), we return the AGP one instead.
         */
        if (in_bus == 0 && of_machine_is_compatible("MacRISC4")) {
                struct device_node *agp;

                agp = of_find_compatible_node(NULL, NULL, "u3-agp");
                if (agp)
                        in_bus = 0xf0;
                of_node_put(agp);
        }

        /* That syscall isn't quite compatible with PCI domains, but it's
         * used on pre-domains setup. We return the first match
         */

        list_for_each_entry(tmp_bus, &pci_root_buses, node) {
                if (in_bus >= tmp_bus->number &&
                    in_bus <= tmp_bus->busn_res.end) {
                        bus = tmp_bus;
                        break;
                }
        }
        if (bus == NULL || bus->dev.of_node == NULL)
                return -ENODEV;

        hose_node = bus->dev.of_node;
        hose = PCI_DN(hose_node)->phb;

        switch (which) {
        case IOBASE_BRIDGE_NUMBER:
                return (long)hose->first_busno;
        case IOBASE_MEMORY:
                return (long)hose->mem_offset[0];
        case IOBASE_IO:
                return (long)hose->io_base_phys;
        case IOBASE_ISA_IO:
                return (long)isa_io_base;
        case IOBASE_ISA_MEM:
                return -EINVAL;
        }

        return -EOPNOTSUPP;
}

#ifdef CONFIG_NUMA
int pcibus_to_node(struct pci_bus *bus)
{
        struct pci_controller *phb = pci_bus_to_host(bus);
        return phb->node;
}
EXPORT_SYMBOL(pcibus_to_node);
#endif