path: root/arch/microblaze/pci/pci-common.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Contains common pci routines for ALL ppc platform
 * (based on pci_32.c and pci_64.c)
 *
 * 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.
 *
 * Common pmac/prep/chrp pci routines. -- Cort
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/shmem_fs.h>
#include <linux/list.h>
#include <linux/syscalls.h>
#include <linux/irq.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/export.h>

#include <asm/processor.h>
#include <linux/io.h>
#include <asm/pci-bridge.h>
#include <asm/byteorder.h>

static DEFINE_SPINLOCK(hose_spinlock);
LIST_HEAD(hose_list);

/* ISA Memory physical address */
resource_size_t isa_mem_base;

unsigned long isa_io_base;
EXPORT_SYMBOL(isa_io_base);

static int pci_bus_count;

static resource_size_t pcibios_io_size(const struct pci_controller *hose)
{
	return resource_size(&hose->io_resource);
}

int pcibios_vaddr_is_ioport(void __iomem *address)
{
	int ret = 0;
	struct pci_controller *hose;
	resource_size_t size;

	spin_lock(&hose_spinlock);
	list_for_each_entry(hose, &hose_list, list_node) {
		size = pcibios_io_size(hose);
		if (address >= hose->io_base_virt &&
		    address < (hose->io_base_virt + size)) {
			ret = 1;
			break;
		}
	}
	spin_unlock(&hose_spinlock);
	return ret;
}

unsigned long pci_address_to_pio(phys_addr_t address)
{
	struct pci_controller *hose;
	resource_size_t size;
	unsigned long ret = ~0;

	spin_lock(&hose_spinlock);
	list_for_each_entry(hose, &hose_list, list_node) {
		size = pcibios_io_size(hose);
		if (address >= hose->io_base_phys &&
		    address < (hose->io_base_phys + size)) {
			unsigned long base =
				(unsigned long)hose->io_base_virt - _IO_BASE;
			ret = base + (address - hose->io_base_phys);
			break;
		}
	}
	spin_unlock(&hose_spinlock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_address_to_pio);

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

/*
 * Platform support for /proc/bus/pci/X/Y mmap()s.
 */

int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
{
	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
	resource_size_t ioaddr = pci_resource_start(pdev, bar);

	if (!hose)
		return -EINVAL;		/* should never happen */

	/* Convert to an offset within this PCI controller */
	ioaddr -= (unsigned long)hose->io_base_virt - _IO_BASE;

	vma->vm_pgoff += (ioaddr + hose->io_base_phys) >> PAGE_SHIFT;
	return 0;
}

void pci_resource_to_user(const struct pci_dev *dev, int bar,
			  const struct resource *rsrc,
			  resource_size_t *start, resource_size_t *end)
{
	struct pci_bus_region region;

	if (rsrc->flags & IORESOURCE_IO) {
		pcibios_resource_to_bus(dev->bus, &region,
					(struct resource *) rsrc);
		*start = region.start;
		*end = region.end;
		return;
	}

	/* We pass a CPU physical address to userland for MMIO instead of a
	 * BAR value because X is lame and expects to be able to use that
	 * to pass to /dev/mem!
	 *
	 * That means we may have 64-bit values where some apps only expect
	 * 32 (like X itself since it thinks only Sparc has 64-bit MMIO).
	 */
	*start = rsrc->start;
	*end = rsrc->end;
}

/* Display the domain number in /proc */
int pci_proc_domain(struct pci_bus *bus)
{
	return pci_domain_nr(bus);
}

/* This header fixup will do the resource fixup for all devices as they are
 * probed, but not for bridge ranges
 */
static void pcibios_fixup_resources(struct pci_dev *dev)
{
	struct pci_controller *hose = pci_bus_to_host(dev->bus);
	int i;

	if (!hose) {
		pr_err("No host bridge for PCI dev %s !\n",
		       pci_name(dev));
		return;
	}
	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
		struct resource *res = dev->resource + i;
		if (!res->flags)
			continue;
		if (res->start == 0) {
			pr_debug("PCI:%s Resource %d %016llx-%016llx [%x]",
				 pci_name(dev), i,
				 (unsigned long long)res->start,
				 (unsigned long long)res->end,
				 (unsigned int)res->flags);
			pr_debug("is unassigned\n");
			res->end -= res->start;
			res->start = 0;
			res->flags |= IORESOURCE_UNSET;
			continue;
		}

		pr_debug("PCI:%s Resource %d %016llx-%016llx [%x]\n",
			 pci_name(dev), i,
			 (unsigned long long)res->start,
			 (unsigned long long)res->end,
			 (unsigned int)res->flags);
	}
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_resources);

int pcibios_device_add(struct pci_dev *dev)
{
	dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);

	return 0;
}

/*
 * Reparent resource children of pr that conflict with res
 * under res, and make res replace those children.
 */
static int __init reparent_resources(struct resource *parent,
				     struct resource *res)
{
	struct resource *p, **pp;
	struct resource **firstpp = NULL;

	for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
		if (p->end < res->start)
			continue;
		if (res->end < p->start)
			break;
		if (p->start < res->start || p->end > res->end)
			return -1;	/* not completely contained */
		if (firstpp == NULL)
			firstpp = pp;
	}
	if (firstpp == NULL)
		return -1;	/* didn't find any conflicting entries? */
	res->parent = parent;
	res->child = *firstpp;
	res->sibling = *pp;
	*firstpp = res;
	*pp = NULL;
	for (p = res->child; p != NULL; p = p->sibling) {
		p->parent = res;
		pr_debug("PCI: Reparented %s [%llx..%llx] under %s\n",
			 p->name,
			 (unsigned long long)p->start,
			 (unsigned long long)p->end, res->name);
	}
	return 0;
}

/*
 *  Handle resources of PCI devices.  If the world were perfect, we could
 *  just allocate all the resource regions and do nothing more.  It isn't.
 *  On the other hand, we cannot just re-allocate all devices, as it would
 *  require us to know lots of host bridge internals.  So we attempt to
 *  keep as much of the original configuration as possible, but tweak it
 *  when it's found to be wrong.
 *
 *  Known BIOS problems we have to work around:
 *	- I/O or memory regions not configured
 *	- regions configured, but not enabled in the command register
 *	- bogus I/O addresses above 64K used
 *	- expansion ROMs left enabled (this may sound harmless, but given
 *	  the fact the PCI specs explicitly allow address decoders to be
 *	  shared between expansion ROMs and other resource regions, it's
 *	  at least dangerous)
 *
 *  Our solution:
 *	(1) Allocate resources for all buses behind PCI-to-PCI bridges.
 *	    This gives us fixed barriers on where we can allocate.
 *	(2) Allocate resources for all enabled devices.  If there is
 *	    a collision, just mark the resource as unallocated. Also
 *	    disable expansion ROMs during this step.
 *	(3) Try to allocate resources for disabled devices.  If the
 *	    resources were assigned correctly, everything goes well,
 *	    if they weren't, they won't disturb allocation of other
 *	    resources.
 *	(4) Assign new addresses to resources which were either
 *	    not configured at all or misconfigured.  If explicitly
 *	    requested by the user, configure expansion ROM address
 *	    as well.
 */

static void pcibios_allocate_bus_resources(struct pci_bus *bus)
{
	struct pci_bus *b;
	int i;
	struct resource *res, *pr;

	pr_debug("PCI: Allocating bus resources for %04x:%02x...\n",
		 pci_domain_nr(bus), bus->number);

	pci_bus_for_each_resource(bus, res, i) {
		if (!res || !res->flags
		    || res->start > res->end || res->parent)
			continue;
		if (bus->parent == NULL)
			pr = (res->flags & IORESOURCE_IO) ?
				&ioport_resource : &iomem_resource;
		else {
			/* Don't bother with non-root busses when
			 * re-assigning all resources. We clear the
			 * resource flags as if they were colliding
			 * and as such ensure proper re-allocation
			 * later.
			 */
			pr = pci_find_parent_resource(bus->self, res);
			if (pr == res) {
				/* this happens when the generic PCI
				 * code (wrongly) decides that this
				 * bridge is transparent  -- paulus
				 */
				continue;
			}
		}

		pr_debug("PCI: %s (bus %d) bridge rsrc %d: %016llx-%016llx ",
			 bus->self ? pci_name(bus->self) : "PHB",
			 bus->number, i,
			 (unsigned long long)res->start,
			 (unsigned long long)res->end);
		pr_debug("[0x%x], parent %p (%s)\n",
			 (unsigned int)res->flags,
			 pr, (pr && pr->name) ? pr->name : "nil");

		if (pr && !(pr->flags & IORESOURCE_UNSET)) {
			struct pci_dev *dev = bus->self;

			if (request_resource(pr, res) == 0)
				continue;
			/*
			 * Must be a conflict with an existing entry.
			 * Move that entry (or entries) under the
			 * bridge resource and try again.
			 */
			if (reparent_resources(pr, res) == 0)
				continue;

			if (dev && i < PCI_BRIDGE_RESOURCE_NUM &&
			    pci_claim_bridge_resource(dev,
						 i + PCI_BRIDGE_RESOURCES) == 0)
				continue;

		}
		pr_warn("PCI: Cannot allocate resource region ");
		pr_cont("%d of PCI bridge %d, will remap\n", i, bus->number);
		res->start = res->end = 0;
		res->flags = 0;
	}

	list_for_each_entry(b, &bus->children, node)
		pcibios_allocate_bus_resources(b);
}

static inline void alloc_resource(struct pci_dev *dev, int idx)
{
	struct resource *pr, *r = &dev->resource[idx];

	pr_debug("PCI: Allocating %s: Resource %d: %016llx..%016llx [%x]\n",
		 pci_name(dev), idx,
		 (unsigned long long)r->start,
		 (unsigned long long)r->end,
		 (unsigned int)r->flags);

	pr = pci_find_parent_resource(dev, r);
	if (!pr || (pr->flags & IORESOURCE_UNSET) ||
	    request_resource(pr, r) < 0) {
		pr_warn("PCI: Cannot allocate resource region %d ", idx);
		pr_cont("of device %s, will remap\n", pci_name(dev));
		if (pr)
			pr_debug("PCI:  parent is %p: %016llx-%016llx [%x]\n",
				 pr,
				 (unsigned long long)pr->start,
				 (unsigned long long)pr->end,
				 (unsigned int)pr->flags);
		/* We'll assign a new address later */
		r->flags |= IORESOURCE_UNSET;
		r->end -= r->start;
		r->start = 0;
	}
}

static void __init pcibios_allocate_resources(int pass)
{
	struct pci_dev *dev = NULL;
	int idx, disabled;
	u16 command;
	struct resource *r;

	for_each_pci_dev(dev) {
		pci_read_config_word(dev, PCI_COMMAND, &command);
		for (idx = 0; idx <= PCI_ROM_RESOURCE; idx++) {
			r = &dev->resource[idx];
			if (r->parent)		/* Already allocated */
				continue;
			if (!r->flags || (r->flags & IORESOURCE_UNSET))
				continue;	/* Not assigned at all */
			/* We only allocate ROMs on pass 1 just in case they
			 * have been screwed up by firmware
			 */
			if (idx == PCI_ROM_RESOURCE)
				disabled = 1;
			if (r->flags & IORESOURCE_IO)
				disabled = !(command & PCI_COMMAND_IO);
			else
				disabled = !(command & PCI_COMMAND_MEMORY);
			if (pass == disabled)
				alloc_resource(dev, idx);
		}
		if (pass)
			continue;
		r = &dev->resource[PCI_ROM_RESOURCE];
		if (r->flags) {
			/* Turn the ROM off, leave the resource region,
			 * but keep it unregistered.
			 */
			u32 reg;
			pci_read_config_dword(dev, dev->rom_base_reg, &reg);
			if (reg & PCI_ROM_ADDRESS_ENABLE) {
				pr_debug("PCI: Switching off ROM of %s\n",
					 pci_name(dev));
				r->flags &= ~IORESOURCE_ROM_ENABLE;
				pci_write_config_dword(dev, dev->rom_base_reg,
						reg & ~PCI_ROM_ADDRESS_ENABLE);
			}
		}
	}
}

static void __init pcibios_reserve_legacy_regions(struct pci_bus *bus)
{
	struct pci_controller *hose = pci_bus_to_host(bus);
	resource_size_t	offset;
	struct resource *res, *pres;
	int i;

	pr_debug("Reserving legacy ranges for domain %04x\n",
							pci_domain_nr(bus));

	/* Check for IO */
	if (!(hose->io_resource.flags & IORESOURCE_IO))
		goto no_io;
	offset = (unsigned long)hose->io_base_virt - _IO_BASE;
	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
	BUG_ON(res == NULL);
	res->name = "Legacy IO";
	res->flags = IORESOURCE_IO;
	res->start = offset;
	res->end = (offset + 0xfff) & 0xfffffffful;
	pr_debug("Candidate legacy IO: %pR\n", res);
	if (request_resource(&hose->io_resource, res)) {
		pr_debug("PCI %04x:%02x Cannot reserve Legacy IO %pR\n",
		       pci_domain_nr(bus), bus->number, res);
		kfree(res);
	}

 no_io:
	/* Check for memory */
	offset = hose->pci_mem_offset;
	pr_debug("hose mem offset: %016llx\n", (unsigned long long)offset);
	for (i = 0; i < 3; i++) {
		pres = &hose->mem_resources[i];
		if (!(pres->flags & IORESOURCE_MEM))
			continue;
		pr_debug("hose mem res: %pR\n", pres);
		if ((pres->start - offset) <= 0xa0000 &&
		    (pres->end - offset) >= 0xbffff)
			break;
	}
	if (i >= 3)
		return;
	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
	BUG_ON(res == NULL);
	res->name = "Legacy VGA memory";
	res->flags = IORESOURCE_MEM;
	res->start = 0xa0000 + offset;
	res->end = 0xbffff + offset;
	pr_debug("Candidate VGA memory: %pR\n", res);
	if (request_resource(pres, res)) {
		pr_debug("PCI %04x:%02x Cannot reserve VGA memory %pR\n",
		       pci_domain_nr(bus), bus->number, res);
		kfree(res);
	}
}

void __init pcibios_resource_survey(void)
{
	struct pci_bus *b;

	/* Allocate and assign resources. If we re-assign everything, then
	 * we skip the allocate phase
	 */
	list_for_each_entry(b, &pci_root_buses, node)
		pcibios_allocate_bus_resources(b);

	pcibios_allocate_resources(0);
	pcibios_allocate_resources(1);

	/* Before we start assigning unassigned resource, we try to reserve
	 * the low IO area and the VGA memory area if they intersect the
	 * bus available resources to avoid allocating things on top of them
	 */
	list_for_each_entry(b, &pci_root_buses, node)
		pcibios_reserve_legacy_regions(b);

	/* Now proceed to assigning things that were left unassigned */
	pr_debug("PCI: Assigning unassigned resources...\n");
	pci_assign_unassigned_resources();
}

static void pcibios_setup_phb_resources(struct pci_controller *hose,
					struct list_head *resources)
{
	unsigned long io_offset;
	struct resource *res;
	int i;

	/* Hookup PHB IO resource */
	res = &hose->io_resource;

	/* Fixup IO space offset */
	io_offset = (unsigned long)hose->io_base_virt - isa_io_base;
	res->start = (res->start + io_offset) & 0xffffffffu;
	res->end = (res->end + io_offset) & 0xffffffffu;

	if (!res->flags) {
		pr_warn("PCI: I/O resource not set for host ");
		pr_cont("bridge %pOF (domain %d)\n",
			hose->dn, hose->global_number);
		/* Workaround for lack of IO resource only on 32-bit */
		res->start = (unsigned long)hose->io_base_virt - isa_io_base;
		res->end = res->start + IO_SPACE_LIMIT;
		res->flags = IORESOURCE_IO;
	}
	pci_add_resource_offset(resources, res,
		(__force resource_size_t)(hose->io_base_virt - _IO_BASE));

	pr_debug("PCI: PHB IO resource    = %016llx-%016llx [%lx]\n",
		 (unsigned long long)res->start,
		 (unsigned long long)res->end,
		 (unsigned long)res->flags);

	/* Hookup PHB Memory resources */
	for (i = 0; i < 3; ++i) {
		res = &hose->mem_resources[i];
		if (!res->flags) {
			if (i > 0)
				continue;
			pr_err("PCI: Memory resource 0 not set for ");
			pr_cont("host bridge %pOF (domain %d)\n",
				hose->dn, hose->global_number);

			/* Workaround for lack of MEM resource only on 32-bit */
			res->start = hose->pci_mem_offset;
			res->end = (resource_size_t)-1LL;
			res->flags = IORESOURCE_MEM;

		}
		pci_add_resource_offset(resources, res, hose->pci_mem_offset);

		pr_debug("PCI: PHB MEM resource %d = %016llx-%016llx [%lx]\n",
			i, (unsigned long long)res->start,
			(unsigned long long)res->end,
			(unsigned long)res->flags);
	}

	pr_debug("PCI: PHB MEM offset     = %016llx\n",
		 (unsigned long long)hose->pci_mem_offset);
	pr_debug("PCI: PHB IO  offset     = %08lx\n",
		 (unsigned long)hose->io_base_virt - _IO_BASE);
}

static void pcibios_scan_phb(struct pci_controller *hose)
{
	LIST_HEAD(resources);
	struct pci_bus *bus;
	struct device_node *node = hose->dn;

	pr_debug("PCI: Scanning PHB %pOF\n", node);

	pcibios_setup_phb_resources(hose, &resources);

	bus = pci_scan_root_bus(hose->parent, hose->first_busno,
				hose->ops, hose, &resources);
	if (bus == NULL) {
		pr_err("Failed to create bus for PCI domain %04x\n",
		       hose->global_number);
		pci_free_resource_list(&resources);
		return;
	}
	bus->busn_res.start = hose->first_busno;
	hose->bus = bus;

	hose->last_busno = bus->busn_res.end;
}

static int __init pcibios_init(void)
{
	struct pci_controller *hose, *tmp;
	int next_busno = 0;

	pr_info("PCI: Probing PCI hardware\n");

	/* Scan all of the recorded PCI controllers.  */
	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
		hose->last_busno = 0xff;
		pcibios_scan_phb(hose);
		if (next_busno <= hose->last_busno)
			next_busno = hose->last_busno + 1;
	}
	pci_bus_count = next_busno;

	/* Call common code to handle resource allocation */
	pcibios_resource_survey();
	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
		if (hose->bus)
			pci_bus_add_devices(hose->bus);
	}

	return 0;
}

subsys_initcall(pcibios_init);

static struct pci_controller *pci_bus_to_hose(int bus)
{
	struct pci_controller *hose, *tmp;

	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
		if (bus >= hose->first_busno && bus <= hose->last_busno)
			return hose;
	return NULL;
}

/* Provide information on locations of various I/O regions in physical
 * memory.  Do this on a per-card basis so that we choose the right
 * root bridge.
 * Note that the returned IO or memory base is a physical address
 */

long sys_pciconfig_iobase(long which, unsigned long bus, unsigned long devfn)
{
	struct pci_controller *hose;
	long result = -EOPNOTSUPP;

	hose = pci_bus_to_hose(bus);
	if (!hose)
		return -ENODEV;

	switch (which) {
	case IOBASE_BRIDGE_NUMBER:
		return (long)hose->first_busno;
	case IOBASE_MEMORY:
		return (long)hose->pci_mem_offset;
	case IOBASE_IO:
		return (long)hose->io_base_phys;
	case IOBASE_ISA_IO:
		return (long)isa_io_base;
	case IOBASE_ISA_MEM:
		return (long)isa_mem_base;
	}

	return result;
}