drivers/pci/setup-bus.c - kernel/msm-4.19 - Gitiles

 /*
  *	drivers/pci/setup-bus.c
  *
  * Extruded from code written by
  *      Dave Rusling (david.rusling@reo.mts.dec.com)
  *      David Mosberger (davidm@cs.arizona.edu)
  *	David Miller (davem@redhat.com)
  *
  * Support routines for initializing a PCI subsystem.
  */

 /*
  * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
  *	     PCI-PCI bridges cleanup, sorted resource allocation.
  * Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
  *	     Converted to allocation in 3 passes, which gives
  *	     tighter packing. Prefetchable range support.
  */

 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/errno.h>
 #include <linux/ioport.h>
 #include <linux/cache.h>
 #include <linux/slab.h>
 #include "pci.h"

 static void pbus_assign_resources_sorted(const struct pci_bus *bus)
 {
 	struct pci_dev *dev;
 	struct resource *res;
 	struct resource_list head, *list, *tmp;
 	int idx;

 	head.next = NULL;
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		u16 class = dev->class >> 8;

 		/* Don't touch classless devices or host bridges or ioapics.  */
 		if (class == PCI_CLASS_NOT_DEFINED ||
 		    class == PCI_CLASS_BRIDGE_HOST)
 			continue;

 		/* Don't touch ioapic devices already enabled by firmware */
 		if (class == PCI_CLASS_SYSTEM_PIC) {
 			u16 command;
 			pci_read_config_word(dev, PCI_COMMAND, &command);
 			if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
 				continue;
 		}

 		pdev_sort_resources(dev, &head);
 	}

 	for (list = head.next; list;) {
 		res = list->res;
 		idx = res - &list->dev->resource[0];
 		if (pci_assign_resource(list->dev, idx)) {
 			res->start = 0;
 			res->end = 0;
 			res->flags = 0;
 		}
 		tmp = list;
 		list = list->next;
 		kfree(tmp);
 	}
 }

 void pci_setup_cardbus(struct pci_bus *bus)
 {
 	struct pci_dev *bridge = bus->self;
 	struct resource *res;
 	struct pci_bus_region region;

 	dev_info(&bridge->dev, "CardBus bridge to [bus %02x-%02x]\n",
 		 bus->secondary, bus->subordinate);

 	res = bus->resource[0];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_IO) {
 		/*
 		 * The IO resource is allocated a range twice as large as it
 		 * would normally need.  This allows us to set both IO regs.
 		 */
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
 		pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
 					region.start);
 		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
 					region.end);
 	}

 	res = bus->resource[1];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_IO) {
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
 		pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
 					region.start);
 		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
 					region.end);
 	}

 	res = bus->resource[2];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_MEM) {
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
 		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
 					region.start);
 		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
 					region.end);
 	}

 	res = bus->resource[3];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_MEM) {
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
 		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
 					region.start);
 		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
 					region.end);
 	}
 }
 EXPORT_SYMBOL(pci_setup_cardbus);

 /* Initialize bridges with base/limit values we have collected.
    PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
    requires that if there is no I/O ports or memory behind the
    bridge, corresponding range must be turned off by writing base
    value greater than limit to the bridge's base/limit registers.

    Note: care must be taken when updating I/O base/limit registers
    of bridges which support 32-bit I/O. This update requires two
    config space writes, so it's quite possible that an I/O window of
    the bridge will have some undesirable address (e.g. 0) after the
    first write. Ditto 64-bit prefetchable MMIO.  */
 static void pci_setup_bridge_io(struct pci_bus *bus)
 {
 	struct pci_dev *bridge = bus->self;
 	struct resource *res;
 	struct pci_bus_region region;
 	u32 l, io_upper16;

 	/* Set up the top and bottom of the PCI I/O segment for this bus. */
 	res = bus->resource[0];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_IO) {
 		pci_read_config_dword(bridge, PCI_IO_BASE, &l);
 		l &= 0xffff0000;
 		l |= (region.start >> 8) & 0x00f0;
 		l |= region.end & 0xf000;
 		/* Set up upper 16 bits of I/O base/limit. */
 		io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
 	} else {
 		/* Clear upper 16 bits of I/O base/limit. */
 		io_upper16 = 0;
 		l = 0x00f0;
 		dev_info(&bridge->dev, "  bridge window [io  disabled]\n");
 	}
 	/* Temporarily disable the I/O range before updating PCI_IO_BASE. */
 	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
 	/* Update lower 16 bits of I/O base/limit. */
 	pci_write_config_dword(bridge, PCI_IO_BASE, l);
 	/* Update upper 16 bits of I/O base/limit. */
 	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
 }

 static void pci_setup_bridge_mmio(struct pci_bus *bus)
 {
 	struct pci_dev *bridge = bus->self;
 	struct resource *res;
 	struct pci_bus_region region;
 	u32 l;

 	/* Set up the top and bottom of the PCI Memory segment for this bus. */
 	res = bus->resource[1];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_MEM) {
 		l = (region.start >> 16) & 0xfff0;
 		l |= region.end & 0xfff00000;
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
 	} else {
 		l = 0x0000fff0;
 		dev_info(&bridge->dev, "  bridge window [mem disabled]\n");
 	}
 	pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
 }

 static void pci_setup_bridge_mmio_pref(struct pci_bus *bus)
 {
 	struct pci_dev *bridge = bus->self;
 	struct resource *res;
 	struct pci_bus_region region;
 	u32 l, bu, lu;

 	/* Clear out the upper 32 bits of PREF limit.
 	   If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
 	   disables PREF range, which is ok. */
 	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);

 	/* Set up PREF base/limit. */
 	bu = lu = 0;
 	res = bus->resource[2];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_PREFETCH) {
 		l = (region.start >> 16) & 0xfff0;
 		l |= region.end & 0xfff00000;
 		if (res->flags & IORESOURCE_MEM_64) {
 			bu = upper_32_bits(region.start);
 			lu = upper_32_bits(region.end);
 		}
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
 	} else {
 		l = 0x0000fff0;
 		dev_info(&bridge->dev, "  bridge window [mem pref disabled]\n");
 	}
 	pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);

 	/* Set the upper 32 bits of PREF base & limit. */
 	pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
 	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
 }

 static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
 {
 	struct pci_dev *bridge = bus->self;

 	if (pci_is_enabled(bridge))
 		return;

 	dev_info(&bridge->dev, "PCI bridge to [bus %02x-%02x]\n",
 		 bus->secondary, bus->subordinate);

 	if (type & IORESOURCE_IO)
 		pci_setup_bridge_io(bus);

 	if (type & IORESOURCE_MEM)
 		pci_setup_bridge_mmio(bus);

 	if (type & IORESOURCE_PREFETCH)
 		pci_setup_bridge_mmio_pref(bus);

 	pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 }

 static void pci_setup_bridge(struct pci_bus *bus)
 {
 	unsigned long type = IORESOURCE_IO | IORESOURCE_MEM |
 				  IORESOURCE_PREFETCH;

 	__pci_setup_bridge(bus, type);
 }

 /* Check whether the bridge supports optional I/O and
    prefetchable memory ranges. If not, the respective
    base/limit registers must be read-only and read as 0. */
 static void pci_bridge_check_ranges(struct pci_bus *bus)
 {
 	u16 io;
 	u32 pmem;
 	struct pci_dev *bridge = bus->self;
 	struct resource *b_res;

 	b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 	b_res[1].flags |= IORESOURCE_MEM;

 	pci_read_config_word(bridge, PCI_IO_BASE, &io);
 	if (!io) {
 		pci_write_config_word(bridge, PCI_IO_BASE, 0xf0f0);
 		pci_read_config_word(bridge, PCI_IO_BASE, &io);
  		pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
  	}
  	if (io)
 		b_res[0].flags |= IORESOURCE_IO;
 	/*  DECchip 21050 pass 2 errata: the bridge may miss an address
 	    disconnect boundary by one PCI data phase.
 	    Workaround: do not use prefetching on this device. */
 	if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
 		return;
 	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
 	if (!pmem) {
 		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
 					       0xfff0fff0);
 		pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
 		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
 	}
 	if (pmem) {
 		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
 		if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64)
 			b_res[2].flags |= IORESOURCE_MEM_64;
 	}

 	/* double check if bridge does support 64 bit pref */
 	if (b_res[2].flags & IORESOURCE_MEM_64) {
 		u32 mem_base_hi, tmp;
 		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32,
 					 &mem_base_hi);
 		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
 					       0xffffffff);
 		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
 		if (!tmp)
 			b_res[2].flags &= ~IORESOURCE_MEM_64;
 		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
 				       mem_base_hi);
 	}
 }

 /* Helper function for sizing routines: find first available
    bus resource of a given type. Note: we intentionally skip
    the bus resources which have already been assigned (that is,
    have non-NULL parent resource). */
 static struct resource *find_free_bus_resource(struct pci_bus *bus, unsigned long type)
 {
 	int i;
 	struct resource *r;
 	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
 				  IORESOURCE_PREFETCH;

 	for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
 		r = bus->resource[i];
 		if (r == &ioport_resource || r == &iomem_resource)
 			continue;
 		if (r && (r->flags & type_mask) == type && !r->parent)
 			return r;
 	}
 	return NULL;
 }

 /* Sizing the IO windows of the PCI-PCI bridge is trivial,
    since these windows have 4K granularity and the IO ranges
    of non-bridge PCI devices are limited to 256 bytes.
    We must be careful with the ISA aliasing though. */
 static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
 {
 	struct pci_dev *dev;
 	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
 	unsigned long size = 0, size1 = 0;

 	if (!b_res)
  		return;

 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		int i;

 		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 			struct resource *r = &dev->resource[i];
 			unsigned long r_size;

 			if (r->parent || !(r->flags & IORESOURCE_IO))
 				continue;
 			r_size = resource_size(r);

 			if (r_size < 0x400)
 				/* Might be re-aligned for ISA */
 				size += r_size;
 			else
 				size1 += r_size;
 		}
 	}
 	if (size < min_size)
 		size = min_size;
 /* To be fixed in 2.5: we should have sort of HAVE_ISA
    flag in the struct pci_bus. */
 #if defined(CONFIG_ISA) || defined(CONFIG_EISA)
 	size = (size & 0xff) + ((size & ~0xffUL) << 2);
 #endif
 	size = ALIGN(size + size1, 4096);
 	if (!size) {
 		if (b_res->start || b_res->end)
 			dev_info(&bus->self->dev, "disabling bridge window "
 				 "%pR to [bus %02x-%02x] (unused)\n", b_res,
 				 bus->secondary, bus->subordinate);
 		b_res->flags = 0;
 		return;
 	}
 	/* Alignment of the IO window is always 4K */
 	b_res->start = 4096;
 	b_res->end = b_res->start + size - 1;
 	b_res->flags |= IORESOURCE_STARTALIGN;
 }

 /* Calculate the size of the bus and minimal alignment which
    guarantees that all child resources fit in this size. */
 static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 			 unsigned long type, resource_size_t min_size)
 {
 	struct pci_dev *dev;
 	resource_size_t min_align, align, size;
 	resource_size_t aligns[12];	/* Alignments from 1Mb to 2Gb */
 	int order, max_order;
 	struct resource *b_res = find_free_bus_resource(bus, type);
 	unsigned int mem64_mask = 0;

 	if (!b_res)
 		return 0;

 	memset(aligns, 0, sizeof(aligns));
 	max_order = 0;
 	size = 0;

 	mem64_mask = b_res->flags & IORESOURCE_MEM_64;
 	b_res->flags &= ~IORESOURCE_MEM_64;

 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		int i;

 		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 			struct resource *r = &dev->resource[i];
 			resource_size_t r_size;

 			if (r->parent || (r->flags & mask) != type)
 				continue;
 			r_size = resource_size(r);
 			/* For bridges size != alignment */
 			align = pci_resource_alignment(dev, r);
 			order = __ffs(align) - 20;
 			if (order > 11) {
 				dev_warn(&dev->dev, "disabling BAR %d: %pR "
 					 "(bad alignment %#llx)\n", i, r,
 					 (unsigned long long) align);
 				r->flags = 0;
 				continue;
 			}
 			size += r_size;
 			if (order < 0)
 				order = 0;
 			/* Exclude ranges with size > align from
 			   calculation of the alignment. */
 			if (r_size == align)
 				aligns[order] += align;
 			if (order > max_order)
 				max_order = order;
 			mem64_mask &= r->flags & IORESOURCE_MEM_64;
 		}
 	}
 	if (size < min_size)
 		size = min_size;

 	align = 0;
 	min_align = 0;
 	for (order = 0; order <= max_order; order++) {
 		resource_size_t align1 = 1;

 		align1 <<= (order + 20);

 		if (!align)
 			min_align = align1;
 		else if (ALIGN(align + min_align, min_align) < align1)
 			min_align = align1 >> 1;
 		align += aligns[order];
 	}
 	size = ALIGN(size, min_align);
 	if (!size) {
 		if (b_res->start || b_res->end)
 			dev_info(&bus->self->dev, "disabling bridge window "
 				 "%pR to [bus %02x-%02x] (unused)\n", b_res,
 				 bus->secondary, bus->subordinate);
 		b_res->flags = 0;
 		return 1;
 	}
 	b_res->start = min_align;
 	b_res->end = size + min_align - 1;
 	b_res->flags |= IORESOURCE_STARTALIGN;
 	b_res->flags |= mem64_mask;
 	return 1;
 }

 static void pci_bus_size_cardbus(struct pci_bus *bus)
 {
 	struct pci_dev *bridge = bus->self;
 	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 	u16 ctrl;

 	/*
 	 * Reserve some resources for CardBus.  We reserve
 	 * a fixed amount of bus space for CardBus bridges.
 	 */
 	b_res[0].start = 0;
 	b_res[0].end = pci_cardbus_io_size - 1;
 	b_res[0].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;

 	b_res[1].start = 0;
 	b_res[1].end = pci_cardbus_io_size - 1;
 	b_res[1].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;

 	/*
 	 * Check whether prefetchable memory is supported
 	 * by this bridge.
 	 */
 	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
 	if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
 		ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
 		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
 		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
 	}

 	/*
 	 * If we have prefetchable memory support, allocate
 	 * two regions.  Otherwise, allocate one region of
 	 * twice the size.
 	 */
 	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
 		b_res[2].start = 0;
 		b_res[2].end = pci_cardbus_mem_size - 1;
 		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_SIZEALIGN;

 		b_res[3].start = 0;
 		b_res[3].end = pci_cardbus_mem_size - 1;
 		b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
 	} else {
 		b_res[3].start = 0;
 		b_res[3].end = pci_cardbus_mem_size * 2 - 1;
 		b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
 	}
 }

 void __ref pci_bus_size_bridges(struct pci_bus *bus)
 {
 	struct pci_dev *dev;
 	unsigned long mask, prefmask;
 	resource_size_t min_mem_size = 0, min_io_size = 0;

 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		struct pci_bus *b = dev->subordinate;
 		if (!b)
 			continue;

 		switch (dev->class >> 8) {
 		case PCI_CLASS_BRIDGE_CARDBUS:
 			pci_bus_size_cardbus(b);
 			break;

 		case PCI_CLASS_BRIDGE_PCI:
 		default:
 			pci_bus_size_bridges(b);
 			break;
 		}
 	}

 	/* The root bus? */
 	if (!bus->self)
 		return;

 	switch (bus->self->class >> 8) {
 	case PCI_CLASS_BRIDGE_CARDBUS:
 		/* don't size cardbuses yet. */
 		break;

 	case PCI_CLASS_BRIDGE_PCI:
 		pci_bridge_check_ranges(bus);
 		if (bus->self->is_hotplug_bridge) {
 			min_io_size  = pci_hotplug_io_size;
 			min_mem_size = pci_hotplug_mem_size;
 		}
 	default:
 		pbus_size_io(bus, min_io_size);
 		/* If the bridge supports prefetchable range, size it
 		   separately. If it doesn't, or its prefetchable window
 		   has already been allocated by arch code, try
 		   non-prefetchable range for both types of PCI memory
 		   resources. */
 		mask = IORESOURCE_MEM;
 		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
 		if (pbus_size_mem(bus, prefmask, prefmask, min_mem_size))
 			mask = prefmask; /* Success, size non-prefetch only. */
 		else
 			min_mem_size += min_mem_size;
 		pbus_size_mem(bus, mask, IORESOURCE_MEM, min_mem_size);
 		break;
 	}
 }
 EXPORT_SYMBOL(pci_bus_size_bridges);

 void __ref pci_bus_assign_resources(const struct pci_bus *bus)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;

 	pbus_assign_resources_sorted(bus);

 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		b = dev->subordinate;
 		if (!b)
 			continue;

 		pci_bus_assign_resources(b);

 		switch (dev->class >> 8) {
 		case PCI_CLASS_BRIDGE_PCI:
 			pci_setup_bridge(b);
 			break;

 		case PCI_CLASS_BRIDGE_CARDBUS:
 			pci_setup_cardbus(b);
 			break;

 		default:
 			dev_info(&dev->dev, "not setting up bridge for bus "
 				 "%04x:%02x\n", pci_domain_nr(b), b->number);
 			break;
 		}
 	}
 }
 EXPORT_SYMBOL(pci_bus_assign_resources);

 static void pci_bus_dump_res(struct pci_bus *bus)
 {
         int i;

         for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
                 struct resource *res = bus->resource[i];

 		if (!res || !res->end || !res->flags)
                         continue;

 		dev_printk(KERN_DEBUG, &bus->dev, "resource %d %pR\n", i, res);
         }
 }

 static void pci_bus_dump_resources(struct pci_bus *bus)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;


 	pci_bus_dump_res(bus);

 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		b = dev->subordinate;
 		if (!b)
 			continue;

 		pci_bus_dump_resources(b);
 	}
 }

 void __init
 pci_assign_unassigned_resources(void)
 {
 	struct pci_bus *bus;

 	/* Depth first, calculate sizes and alignments of all
 	   subordinate buses. */
 	list_for_each_entry(bus, &pci_root_buses, node) {
 		pci_bus_size_bridges(bus);
 	}
 	/* Depth last, allocate resources and update the hardware. */
 	list_for_each_entry(bus, &pci_root_buses, node) {
 		pci_bus_assign_resources(bus);
 		pci_enable_bridges(bus);
 	}

 	/* dump the resource on buses */
 	list_for_each_entry(bus, &pci_root_buses, node) {
 		pci_bus_dump_resources(bus);
 	}
 }
	/*
	* drivers/pci/setup-bus.c
	*
	* Extruded from code written by
	* Dave Rusling (david.rusling@reo.mts.dec.com)
	* David Mosberger (davidm@cs.arizona.edu)
	* David Miller (davem@redhat.com)
	*
	* Support routines for initializing a PCI subsystem.
	*/

	/*
	* Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
	* PCI-PCI bridges cleanup, sorted resource allocation.
	* Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
	* Converted to allocation in 3 passes, which gives
	* tighter packing. Prefetchable range support.
	*/

	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/pci.h>
	#include <linux/errno.h>
	#include <linux/ioport.h>
	#include <linux/cache.h>
	#include <linux/slab.h>
	#include "pci.h"

	static void pbus_assign_resources_sorted(const struct pci_bus *bus)
	{
	struct pci_dev *dev;
	struct resource *res;
	struct resource_list head, list, tmp;
	int idx;

	head.next = NULL;
	list_for_each_entry(dev, &bus->devices, bus_list) {
	u16 class = dev->class >> 8;

	/* Don't touch classless devices or host bridges or ioapics. */
	if (class == PCI_CLASS_NOT_DEFINED \|\|
	class == PCI_CLASS_BRIDGE_HOST)
	continue;

	/* Don't touch ioapic devices already enabled by firmware */
	if (class == PCI_CLASS_SYSTEM_PIC) {
	u16 command;
	pci_read_config_word(dev, PCI_COMMAND, &command);
	if (command & (PCI_COMMAND_IO \| PCI_COMMAND_MEMORY))
	continue;
	}

	pdev_sort_resources(dev, &head);
	}

	for (list = head.next; list;) {
	res = list->res;
	idx = res - &list->dev->resource[0];
	if (pci_assign_resource(list->dev, idx)) {
	res->start = 0;
	res->end = 0;
	res->flags = 0;
	}
	tmp = list;
	list = list->next;
	kfree(tmp);
	}
	}

	void pci_setup_cardbus(struct pci_bus *bus)
	{
	struct pci_dev *bridge = bus->self;
	struct resource *res;
	struct pci_bus_region region;

	dev_info(&bridge->dev, "CardBus bridge to [bus %02x-%02x]\n",
	bus->secondary, bus->subordinate);

	res = bus->resource[0];
	pcibios_resource_to_bus(bridge, &region, res);
	if (res->flags & IORESOURCE_IO) {
	/*
	* The IO resource is allocated a range twice as large as it
	* would normally need. This allows us to set both IO regs.
	*/
	dev_info(&bridge->dev, " bridge window %pR\n", res);
	pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
	region.start);
	pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
	region.end);
	}

	res = bus->resource[1];
	pcibios_resource_to_bus(bridge, &region, res);
	if (res->flags & IORESOURCE_IO) {
	dev_info(&bridge->dev, " bridge window %pR\n", res);
	pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
	region.start);
	pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
	region.end);
	}

	res = bus->resource[2];
	pcibios_resource_to_bus(bridge, &region, res);
	if (res->flags & IORESOURCE_MEM) {
	dev_info(&bridge->dev, " bridge window %pR\n", res);
	pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
	region.start);
	pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
	region.end);
	}

	res = bus->resource[3];
	pcibios_resource_to_bus(bridge, &region, res);
	if (res->flags & IORESOURCE_MEM) {
	dev_info(&bridge->dev, " bridge window %pR\n", res);
	pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
	region.start);
	pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
	region.end);
	}
	}
	EXPORT_SYMBOL(pci_setup_cardbus);

	/* Initialize bridges with base/limit values we have collected.
	PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
	requires that if there is no I/O ports or memory behind the
	bridge, corresponding range must be turned off by writing base
	value greater than limit to the bridge's base/limit registers.

	Note: care must be taken when updating I/O base/limit registers
	of bridges which support 32-bit I/O. This update requires two
	config space writes, so it's quite possible that an I/O window of
	the bridge will have some undesirable address (e.g. 0) after the
	first write. Ditto 64-bit prefetchable MMIO. */
	static void pci_setup_bridge_io(struct pci_bus *bus)
	{
	struct pci_dev *bridge = bus->self;
	struct resource *res;
	struct pci_bus_region region;
	u32 l, io_upper16;

	/* Set up the top and bottom of the PCI I/O segment for this bus. */
	res = bus->resource[0];
	pcibios_resource_to_bus(bridge, &region, res);
	if (res->flags & IORESOURCE_IO) {
	pci_read_config_dword(bridge, PCI_IO_BASE, &l);
	l &= 0xffff0000;
	l \|= (region.start >> 8) & 0x00f0;
	l \|= region.end & 0xf000;
	/* Set up upper 16 bits of I/O base/limit. */
	io_upper16 = (region.end & 0xffff0000) \| (region.start >> 16);
	dev_info(&bridge->dev, " bridge window %pR\n", res);
	} else {
	/* Clear upper 16 bits of I/O base/limit. */
	io_upper16 = 0;
	l = 0x00f0;
	dev_info(&bridge->dev, " bridge window [io disabled]\n");
	}
	/* Temporarily disable the I/O range before updating PCI_IO_BASE. */
	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
	/* Update lower 16 bits of I/O base/limit. */
	pci_write_config_dword(bridge, PCI_IO_BASE, l);
	/* Update upper 16 bits of I/O base/limit. */
	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
	}

	static void pci_setup_bridge_mmio(struct pci_bus *bus)
	{
	struct pci_dev *bridge = bus->self;
	struct resource *res;
	struct pci_bus_region region;
	u32 l;

	/* Set up the top and bottom of the PCI Memory segment for this bus. */
	res = bus->resource[1];
	pcibios_resource_to_bus(bridge, &region, res);
	if (res->flags & IORESOURCE_MEM) {
	l = (region.start >> 16) & 0xfff0;
	l \|= region.end & 0xfff00000;
	dev_info(&bridge->dev, " bridge window %pR\n", res);
	} else {
	l = 0x0000fff0;
	dev_info(&bridge->dev, " bridge window [mem disabled]\n");
	}
	pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
	}

	static void pci_setup_bridge_mmio_pref(struct pci_bus *bus)
	{
	struct pci_dev *bridge = bus->self;
	struct resource *res;
	struct pci_bus_region region;
	u32 l, bu, lu;

	/* Clear out the upper 32 bits of PREF limit.
	If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
	disables PREF range, which is ok. */
	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);

	/* Set up PREF base/limit. */
	bu = lu = 0;
	res = bus->resource[2];
	pcibios_resource_to_bus(bridge, &region, res);
	if (res->flags & IORESOURCE_PREFETCH) {
	l = (region.start >> 16) & 0xfff0;
	l \|= region.end & 0xfff00000;
	if (res->flags & IORESOURCE_MEM_64) {
	bu = upper_32_bits(region.start);
	lu = upper_32_bits(region.end);
	}
	dev_info(&bridge->dev, " bridge window %pR\n", res);
	} else {
	l = 0x0000fff0;
	dev_info(&bridge->dev, " bridge window [mem pref disabled]\n");
	}
	pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);

	/* Set the upper 32 bits of PREF base & limit. */
	pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
	}

	static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
	{
	struct pci_dev *bridge = bus->self;

	if (pci_is_enabled(bridge))
	return;

	dev_info(&bridge->dev, "PCI bridge to [bus %02x-%02x]\n",
	bus->secondary, bus->subordinate);

	if (type & IORESOURCE_IO)
	pci_setup_bridge_io(bus);

	if (type & IORESOURCE_MEM)
	pci_setup_bridge_mmio(bus);

	if (type & IORESOURCE_PREFETCH)
	pci_setup_bridge_mmio_pref(bus);

	pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
	}

	static void pci_setup_bridge(struct pci_bus *bus)
	{
	unsigned long type = IORESOURCE_IO \| IORESOURCE_MEM \|
	IORESOURCE_PREFETCH;

	__pci_setup_bridge(bus, type);
	}

	/* Check whether the bridge supports optional I/O and
	prefetchable memory ranges. If not, the respective
	base/limit registers must be read-only and read as 0. */
	static void pci_bridge_check_ranges(struct pci_bus *bus)
	{
	u16 io;
	u32 pmem;
	struct pci_dev *bridge = bus->self;
	struct resource *b_res;

	b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
	b_res[1].flags \|= IORESOURCE_MEM;

	pci_read_config_word(bridge, PCI_IO_BASE, &io);
	if (!io) {
	pci_write_config_word(bridge, PCI_IO_BASE, 0xf0f0);
	pci_read_config_word(bridge, PCI_IO_BASE, &io);
	pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
	}
	if (io)
	b_res[0].flags \|= IORESOURCE_IO;
	/* DECchip 21050 pass 2 errata: the bridge may miss an address
	disconnect boundary by one PCI data phase.
	Workaround: do not use prefetching on this device. */
	if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
	return;
	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
	if (!pmem) {
	pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
	0xfff0fff0);
	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
	pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
	}
	if (pmem) {
	b_res[2].flags \|= IORESOURCE_MEM \| IORESOURCE_PREFETCH;
	if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64)
	b_res[2].flags \|= IORESOURCE_MEM_64;
	}

	/* double check if bridge does support 64 bit pref */
	if (b_res[2].flags & IORESOURCE_MEM_64) {
	u32 mem_base_hi, tmp;
	pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32,
	&mem_base_hi);
	pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
	0xffffffff);
	pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
	if (!tmp)
	b_res[2].flags &= ~IORESOURCE_MEM_64;
	pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
	mem_base_hi);
	}
	}

	/* Helper function for sizing routines: find first available
	bus resource of a given type. Note: we intentionally skip
	the bus resources which have already been assigned (that is,
	have non-NULL parent resource). */
	static struct resource find_free_bus_resource(struct pci_bus bus, unsigned long type)
	{
	int i;
	struct resource *r;
	unsigned long type_mask = IORESOURCE_IO \| IORESOURCE_MEM \|
	IORESOURCE_PREFETCH;

	for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
	r = bus->resource[i];
	if (r == &ioport_resource \|\| r == &iomem_resource)
	continue;
	if (r && (r->flags & type_mask) == type && !r->parent)
	return r;
	}
	return NULL;
	}

	/* Sizing the IO windows of the PCI-PCI bridge is trivial,
	since these windows have 4K granularity and the IO ranges
	of non-bridge PCI devices are limited to 256 bytes.
	We must be careful with the ISA aliasing though. */
	static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
	{
	struct pci_dev *dev;
	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
	unsigned long size = 0, size1 = 0;

	if (!b_res)
	return;

	list_for_each_entry(dev, &bus->devices, bus_list) {
	int i;

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
	struct resource *r = &dev->resource[i];
	unsigned long r_size;

	if (r->parent \|\| !(r->flags & IORESOURCE_IO))
	continue;
	r_size = resource_size(r);

	if (r_size < 0x400)
	/* Might be re-aligned for ISA */
	size += r_size;
	else
	size1 += r_size;
	}
	}
	if (size < min_size)
	size = min_size;
	/* To be fixed in 2.5: we should have sort of HAVE_ISA
	flag in the struct pci_bus. */
	#if defined(CONFIG_ISA) \|\| defined(CONFIG_EISA)
	size = (size & 0xff) + ((size & ~0xffUL) << 2);
	#endif
	size = ALIGN(size + size1, 4096);
	if (!size) {
	if (b_res->start \|\| b_res->end)
	dev_info(&bus->self->dev, "disabling bridge window "
	"%pR to [bus %02x-%02x] (unused)\n", b_res,
	bus->secondary, bus->subordinate);
	b_res->flags = 0;
	return;
	}
	/* Alignment of the IO window is always 4K */
	b_res->start = 4096;
	b_res->end = b_res->start + size - 1;
	b_res->flags \|= IORESOURCE_STARTALIGN;
	}

	/* Calculate the size of the bus and minimal alignment which
	guarantees that all child resources fit in this size. */
	static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
	unsigned long type, resource_size_t min_size)
	{
	struct pci_dev *dev;
	resource_size_t min_align, align, size;
	resource_size_t aligns[12]; /* Alignments from 1Mb to 2Gb */
	int order, max_order;
	struct resource *b_res = find_free_bus_resource(bus, type);
	unsigned int mem64_mask = 0;

	if (!b_res)
	return 0;

	memset(aligns, 0, sizeof(aligns));
	max_order = 0;
	size = 0;

	mem64_mask = b_res->flags & IORESOURCE_MEM_64;
	b_res->flags &= ~IORESOURCE_MEM_64;

	list_for_each_entry(dev, &bus->devices, bus_list) {
	int i;

	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
	struct resource *r = &dev->resource[i];
	resource_size_t r_size;

	if (r->parent \|\| (r->flags & mask) != type)
	continue;
	r_size = resource_size(r);
	/* For bridges size != alignment */
	align = pci_resource_alignment(dev, r);
	order = __ffs(align) - 20;
	if (order > 11) {
	dev_warn(&dev->dev, "disabling BAR %d: %pR "
	"(bad alignment %#llx)\n", i, r,
	(unsigned long long) align);
	r->flags = 0;
	continue;
	}
	size += r_size;
	if (order < 0)
	order = 0;
	/* Exclude ranges with size > align from
	calculation of the alignment. */
	if (r_size == align)
	aligns[order] += align;
	if (order > max_order)
	max_order = order;
	mem64_mask &= r->flags & IORESOURCE_MEM_64;
	}
	}
	if (size < min_size)
	size = min_size;

	align = 0;
	min_align = 0;
	for (order = 0; order <= max_order; order++) {
	resource_size_t align1 = 1;

	align1 <<= (order + 20);

	if (!align)
	min_align = align1;
	else if (ALIGN(align + min_align, min_align) < align1)
	min_align = align1 >> 1;
	align += aligns[order];
	}
	size = ALIGN(size, min_align);
	if (!size) {
	if (b_res->start \|\| b_res->end)
	dev_info(&bus->self->dev, "disabling bridge window "
	"%pR to [bus %02x-%02x] (unused)\n", b_res,
	bus->secondary, bus->subordinate);
	b_res->flags = 0;
	return 1;
	}
	b_res->start = min_align;
	b_res->end = size + min_align - 1;
	b_res->flags \|= IORESOURCE_STARTALIGN;
	b_res->flags \|= mem64_mask;
	return 1;
	}

	static void pci_bus_size_cardbus(struct pci_bus *bus)
	{
	struct pci_dev *bridge = bus->self;
	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
	u16 ctrl;

	/*
	* Reserve some resources for CardBus. We reserve
	* a fixed amount of bus space for CardBus bridges.
	*/
	b_res[0].start = 0;
	b_res[0].end = pci_cardbus_io_size - 1;
	b_res[0].flags \|= IORESOURCE_IO \| IORESOURCE_SIZEALIGN;

	b_res[1].start = 0;
	b_res[1].end = pci_cardbus_io_size - 1;
	b_res[1].flags \|= IORESOURCE_IO \| IORESOURCE_SIZEALIGN;

	/*
	* Check whether prefetchable memory is supported
	* by this bridge.
	*/
	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
	if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
	ctrl \|= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
	pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
	}

	/*
	* If we have prefetchable memory support, allocate
	* two regions. Otherwise, allocate one region of
	* twice the size.
	*/
	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
	b_res[2].start = 0;
	b_res[2].end = pci_cardbus_mem_size - 1;
	b_res[2].flags \|= IORESOURCE_MEM \| IORESOURCE_PREFETCH \| IORESOURCE_SIZEALIGN;

	b_res[3].start = 0;
	b_res[3].end = pci_cardbus_mem_size - 1;
	b_res[3].flags \|= IORESOURCE_MEM \| IORESOURCE_SIZEALIGN;
	} else {
	b_res[3].start = 0;
	b_res[3].end = pci_cardbus_mem_size * 2 - 1;
	b_res[3].flags \|= IORESOURCE_MEM \| IORESOURCE_SIZEALIGN;
	}
	}

	void __ref pci_bus_size_bridges(struct pci_bus *bus)
	{
	struct pci_dev *dev;
	unsigned long mask, prefmask;
	resource_size_t min_mem_size = 0, min_io_size = 0;

	list_for_each_entry(dev, &bus->devices, bus_list) {
	struct pci_bus *b = dev->subordinate;
	if (!b)
	continue;

	switch (dev->class >> 8) {
	case PCI_CLASS_BRIDGE_CARDBUS:
	pci_bus_size_cardbus(b);
	break;

	case PCI_CLASS_BRIDGE_PCI:
	default:
	pci_bus_size_bridges(b);
	break;
	}
	}

	/* The root bus? */
	if (!bus->self)
	return;

	switch (bus->self->class >> 8) {
	case PCI_CLASS_BRIDGE_CARDBUS:
	/* don't size cardbuses yet. */
	break;

	case PCI_CLASS_BRIDGE_PCI:
	pci_bridge_check_ranges(bus);
	if (bus->self->is_hotplug_bridge) {
	min_io_size = pci_hotplug_io_size;
	min_mem_size = pci_hotplug_mem_size;
	}
	default:
	pbus_size_io(bus, min_io_size);
	/* If the bridge supports prefetchable range, size it
	separately. If it doesn't, or its prefetchable window
	has already been allocated by arch code, try
	non-prefetchable range for both types of PCI memory
	resources. */
	mask = IORESOURCE_MEM;
	prefmask = IORESOURCE_MEM \| IORESOURCE_PREFETCH;
	if (pbus_size_mem(bus, prefmask, prefmask, min_mem_size))
	mask = prefmask; /* Success, size non-prefetch only. */
	else
	min_mem_size += min_mem_size;
	pbus_size_mem(bus, mask, IORESOURCE_MEM, min_mem_size);
	break;
	}
	}
	EXPORT_SYMBOL(pci_bus_size_bridges);

	void __ref pci_bus_assign_resources(const struct pci_bus *bus)
	{
	struct pci_bus *b;
	struct pci_dev *dev;

	pbus_assign_resources_sorted(bus);

	list_for_each_entry(dev, &bus->devices, bus_list) {
	b = dev->subordinate;
	if (!b)
	continue;

	pci_bus_assign_resources(b);

	switch (dev->class >> 8) {
	case PCI_CLASS_BRIDGE_PCI:
	pci_setup_bridge(b);
	break;

	case PCI_CLASS_BRIDGE_CARDBUS:
	pci_setup_cardbus(b);
	break;

	default:
	dev_info(&dev->dev, "not setting up bridge for bus "
	"%04x:%02x\n", pci_domain_nr(b), b->number);
	break;
	}
	}
	}
	EXPORT_SYMBOL(pci_bus_assign_resources);

	static void pci_bus_dump_res(struct pci_bus *bus)
	{
	int i;

	for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
	struct resource *res = bus->resource[i];

	if (!res \|\| !res->end \|\| !res->flags)
	continue;

	dev_printk(KERN_DEBUG, &bus->dev, "resource %d %pR\n", i, res);
	}
	}

	static void pci_bus_dump_resources(struct pci_bus *bus)
	{
	struct pci_bus *b;
	struct pci_dev *dev;


	pci_bus_dump_res(bus);

	list_for_each_entry(dev, &bus->devices, bus_list) {
	b = dev->subordinate;
	if (!b)
	continue;

	pci_bus_dump_resources(b);
	}
	}

	void __init
	pci_assign_unassigned_resources(void)
	{
	struct pci_bus *bus;

	/* Depth first, calculate sizes and alignments of all
	subordinate buses. */
	list_for_each_entry(bus, &pci_root_buses, node) {
	pci_bus_size_bridges(bus);
	}
	/* Depth last, allocate resources and update the hardware. */
	list_for_each_entry(bus, &pci_root_buses, node) {
	pci_bus_assign_resources(bus);
	pci_enable_bridges(bus);
	}

	/* dump the resource on buses */
	list_for_each_entry(bus, &pci_root_buses, node) {
	pci_bus_dump_resources(bus);
	}
	}