i386: move pci

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 315 insertions, 0 deletions

diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
new file mode 100644
index 00000000000..bcd2f94b732
--- /dev/null
+++ b/arch/x86/pci/i386.c
@@ -0,0 +1,315 @@
+/*
+ *	Low-Level PCI Access for i386 machines
+ *
+ * Copyright 1993, 1994 Drew Eckhardt
+ *      Visionary Computing
+ *      (Unix and Linux consulting and custom programming)
+ *      Drew@Colorado.EDU
+ *      +1 (303) 786-7975
+ *
+ * Drew's work was sponsored by:
+ *	iX Multiuser Multitasking Magazine
+ *	Hannover, Germany
+ *	hm@ix.de
+ *
+ * Copyright 1997--2000 Martin Mares <mj@ucw.cz>
+ *
+ * For more information, please consult the following manuals (look at
+ * http://www.pcisig.com/ for how to get them):
+ *
+ * PCI BIOS Specification
+ * PCI Local Bus Specification
+ * PCI to PCI Bridge Specification
+ * PCI System Design Guide
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/errno.h>
+
+#include "pci.h"
+
+/*
+ * We need to avoid collisions with `mirrored' VGA ports
+ * and other strange ISA hardware, so we always want the
+ * addresses to be allocated in the 0x000-0x0ff region
+ * modulo 0x400.
+ *
+ * Why? Because some silly external IO cards only decode
+ * the low 10 bits of the IO address. The 0x00-0xff region
+ * is reserved for motherboard devices that decode all 16
+ * bits, so it's ok to allocate at, say, 0x2800-0x28ff,
+ * but we want to try to avoid allocating at 0x2900-0x2bff
+ * which might have be mirrored at 0x0100-0x03ff..
+ */
+void
+pcibios_align_resource(void *data, struct resource *res,
+			resource_size_t size, resource_size_t align)
+{
+	if (res->flags & IORESOURCE_IO) {
+		resource_size_t start = res->start;
+
+		if (start & 0x300) {
+			start = (start + 0x3ff) & ~0x3ff;
+			res->start = start;
+		}
+	}
+}
+
+
+/*
+ *  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 __init pcibios_allocate_bus_resources(struct list_head *bus_list)
+{
+	struct pci_bus *bus;
+	struct pci_dev *dev;
+	int idx;
+	struct resource *r, *pr;
+
+	/* Depth-First Search on bus tree */
+	list_for_each_entry(bus, bus_list, node) {
+		if ((dev = bus->self)) {
+			for (idx = PCI_BRIDGE_RESOURCES;
+			    idx < PCI_NUM_RESOURCES; idx++) {
+				r = &dev->resource[idx];
+				if (!r->flags)
+					continue;
+				pr = pci_find_parent_resource(dev, r);
+				if (!r->start || !pr ||
+				    request_resource(pr, r) < 0) {
+					printk(KERN_ERR "PCI: Cannot allocate "
+						"resource region %d "
+						"of bridge %s\n",
+						idx, pci_name(dev));
+					/*
+					 * Something is wrong with the region.
+					 * Invalidate the resource to prevent
+					 * child resource allocations in this
+					 * range.
+					 */
+					r->flags = 0;
+				}
+			}
+		}
+		pcibios_allocate_bus_resources(&bus->children);
+	}
+}
+
+static void __init pcibios_allocate_resources(int pass)
+{
+	struct pci_dev *dev = NULL;
+	int idx, disabled;
+	u16 command;
+	struct resource *r, *pr;
+
+	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->start)		/* Address not assigned at all */
+				continue;
+			if (r->flags & IORESOURCE_IO)
+				disabled = !(command & PCI_COMMAND_IO);
+			else
+				disabled = !(command & PCI_COMMAND_MEMORY);
+			if (pass == disabled) {
+				DBG("PCI: Resource %08lx-%08lx "
+				    "(f=%lx, d=%d, p=%d)\n",
+				    r->start, r->end, r->flags, disabled, pass);
+				pr = pci_find_parent_resource(dev, r);
+				if (!pr || request_resource(pr, r) < 0) {
+					printk(KERN_ERR "PCI: Cannot allocate "
+						"resource region %d "
+						"of device %s\n",
+						idx, pci_name(dev));
+					/* We'll assign a new address later */
+					r->end -= r->start;
+					r->start = 0;
+				}
+			}
+		}
+		if (!pass) {
+			r = &dev->resource[PCI_ROM_RESOURCE];
+			if (r->flags & IORESOURCE_ROM_ENABLE) {
+				/* Turn the ROM off, leave the resource region,
+				 * but keep it unregistered. */
+				u32 reg;
+				DBG("PCI: Switching off ROM of %s\n",
+					pci_name(dev));
+				r->flags &= ~IORESOURCE_ROM_ENABLE;
+				pci_read_config_dword(dev,
+						dev->rom_base_reg, &reg);
+				pci_write_config_dword(dev, dev->rom_base_reg,
+						reg & ~PCI_ROM_ADDRESS_ENABLE);
+			}
+		}
+	}
+}
+
+static int __init pcibios_assign_resources(void)
+{
+	struct pci_dev *dev = NULL;
+	struct resource *r, *pr;
+
+	if (!(pci_probe & PCI_ASSIGN_ROMS)) {
+		/*
+		 * Try to use BIOS settings for ROMs, otherwise let
+		 * pci_assign_unassigned_resources() allocate the new
+		 * addresses.
+		 */
+		for_each_pci_dev(dev) {
+			r = &dev->resource[PCI_ROM_RESOURCE];
+			if (!r->flags || !r->start)
+				continue;
+			pr = pci_find_parent_resource(dev, r);
+			if (!pr || request_resource(pr, r) < 0) {
+				r->end -= r->start;
+				r->start = 0;
+			}
+		}
+	}
+
+	pci_assign_unassigned_resources();
+
+	return 0;
+}
+
+void __init pcibios_resource_survey(void)
+{
+	DBG("PCI: Allocating resources\n");
+	pcibios_allocate_bus_resources(&pci_root_buses);
+	pcibios_allocate_resources(0);
+	pcibios_allocate_resources(1);
+}
+
+/**
+ * called in fs_initcall (one below subsys_initcall),
+ * give a chance for motherboard reserve resources
+ */
+fs_initcall(pcibios_assign_resources);
+
+int pcibios_enable_resources(struct pci_dev *dev, int mask)
+{
+	u16 cmd, old_cmd;
+	int idx;
+	struct resource *r;
+
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	old_cmd = cmd;
+	for (idx = 0; idx < PCI_NUM_RESOURCES; idx++) {
+		/* Only set up the requested stuff */
+		if (!(mask & (1 << idx)))
+			continue;
+
+		r = &dev->resource[idx];
+		if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
+			continue;
+		if ((idx == PCI_ROM_RESOURCE) &&
+				(!(r->flags & IORESOURCE_ROM_ENABLE)))
+			continue;
+		if (!r->start && r->end) {
+			printk(KERN_ERR "PCI: Device %s not available "
+				"because of resource %d collisions\n",
+				pci_name(dev), idx);
+			return -EINVAL;
+		}
+		if (r->flags & IORESOURCE_IO)
+			cmd |= PCI_COMMAND_IO;
+		if (r->flags & IORESOURCE_MEM)
+			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;
+}
+
+/*
+ *  If we set up a device for bus mastering, we need to check the latency
+ *  timer as certain crappy BIOSes forget to set it properly.
+ */
+unsigned int pcibios_max_latency = 255;
+
+void pcibios_set_master(struct pci_dev *dev)
+{
+	u8 lat;
+	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
+	if (lat < 16)
+		lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency;
+	else if (lat > pcibios_max_latency)
+		lat = pcibios_max_latency;
+	else
+		return;
+	printk(KERN_DEBUG "PCI: Setting latency timer of device %s to %d\n",
+		pci_name(dev), lat);
+	pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat);
+}
+
+int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
+			enum pci_mmap_state mmap_state, int write_combine)
+{
+	unsigned long prot;
+
+	/* I/O space cannot be accessed via normal processor loads and
+	 * stores on this platform.
+	 */
+	if (mmap_state == pci_mmap_io)
+		return -EINVAL;
+
+	/* Leave vm_pgoff as-is, the PCI space address is the physical
+	 * address on this platform.
+	 */
+	prot = pgprot_val(vma->vm_page_prot);
+	if (boot_cpu_data.x86 > 3)
+		prot |= _PAGE_PCD | _PAGE_PWT;
+	vma->vm_page_prot = __pgprot(prot);
+
+	/* Write-combine setting is ignored, it is changed via the mtrr
+	 * interfaces on this platform.
+	 */
+	if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+			       vma->vm_end - vma->vm_start,
+			       vma->vm_page_prot))
+		return -EAGAIN;
+
+	return 0;
+}