--- /dev/null
+/* pci-frv.c: low-level PCI access routines
+ *
+ * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ * - Derived from the i386 equivalent stuff
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#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-frv.h"
+
+#if 0
+void
+pcibios_update_resource(struct pci_dev *dev, struct resource *root,
+ struct resource *res, int resource)
+{
+ u32 new, check;
+ int reg;
+
+ new = res->start | (res->flags & PCI_REGION_FLAG_MASK);
+ if (resource < 6) {
+ reg = PCI_BASE_ADDRESS_0 + 4*resource;
+ } else if (resource == PCI_ROM_RESOURCE) {
+ res->flags |= PCI_ROM_ADDRESS_ENABLE;
+ new |= PCI_ROM_ADDRESS_ENABLE;
+ reg = dev->rom_base_reg;
+ } else {
+ /* Somebody might have asked allocation of a non-standard resource */
+ return;
+ }
+
+ pci_write_config_dword(dev, reg, new);
+ pci_read_config_dword(dev, reg, &check);
+ if ((new ^ check) & ((new & PCI_BASE_ADDRESS_SPACE_IO) ? PCI_BASE_ADDRESS_IO_MASK : PCI_BASE_ADDRESS_MEM_MASK)) {
+ printk(KERN_ERR "PCI: Error while updating region "
+ "%s/%d (%08x != %08x)\n", dev->slot_name, resource,
+ new, check);
+ }
+}
+#endif
+
+/*
+ * 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,
+ unsigned long size, unsigned long align)
+{
+ if (res->flags & IORESOURCE_IO) {
+ unsigned long 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 list_head *ln;
+ struct pci_bus *bus;
+ struct pci_dev *dev;
+ int idx;
+ struct resource *r, *pr;
+
+ /* Depth-First Search on bus tree */
+ for (ln=bus_list->next; ln != bus_list; ln=ln->next) {
+ bus = pci_bus_b(ln);
+ if ((dev = bus->self)) {
+ for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
+ r = &dev->resource[idx];
+ if (!r->start)
+ continue;
+ pr = pci_find_parent_resource(dev, r);
+ if (!pr || request_resource(pr, r) < 0)
+ printk(KERN_ERR "PCI: Cannot allocate resource region %d of bridge %s\n", idx, dev->slot_name);
+ }
+ }
+ 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;
+
+ while (dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev),
+ dev != NULL
+ ) {
+ pci_read_config_word(dev, PCI_COMMAND, &command);
+ for(idx = 0; idx < 6; 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 & PCI_ROM_ADDRESS_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 &= ~PCI_ROM_ADDRESS_ENABLE;
+ pci_read_config_dword(dev, dev->rom_base_reg, ®);
+ pci_write_config_dword(dev, dev->rom_base_reg, reg & ~PCI_ROM_ADDRESS_ENABLE);
+ }
+ }
+ }
+}
+
+static void __init pcibios_assign_resources(void)
+{
+ struct pci_dev *dev = NULL;
+ int idx;
+ struct resource *r;
+
+ while (dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev),
+ dev != NULL
+ ) {
+ int class = dev->class >> 8;
+
+ /* Don't touch classless devices and host bridges */
+ if (!class || class == PCI_CLASS_BRIDGE_HOST)
+ continue;
+
+ for(idx=0; idx<6; idx++) {
+ r = &dev->resource[idx];
+
+ /*
+ * Don't touch IDE controllers and I/O ports of video cards!
+ */
+ if ((class == PCI_CLASS_STORAGE_IDE && idx < 4) ||
+ (class == PCI_CLASS_DISPLAY_VGA && (r->flags & IORESOURCE_IO)))
+ continue;
+
+ /*
+ * We shall assign a new address to this resource, either because
+ * the BIOS forgot to do so or because we have decided the old
+ * address was unusable for some reason.
+ */
+ if (!r->start && r->end)
+ pci_assign_resource(dev, idx);
+ }
+
+ if (pci_probe & PCI_ASSIGN_ROMS) {
+ r = &dev->resource[PCI_ROM_RESOURCE];
+ r->end -= r->start;
+ r->start = 0;
+ if (r->end)
+ pci_assign_resource(dev, PCI_ROM_RESOURCE);
+ }
+ }
+}
+
+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);
+ 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<6; idx++) {
+ /* Only set up the requested stuff */
+ if (!(mask & (1<<idx)))
+ continue;
+
+ r = &dev->resource[idx];
+ if (!r->start && r->end) {
+ printk(KERN_ERR "PCI: Device %s not available because of resource collisions\n", pci_name(dev));
+ return -EINVAL;
+ }
+ if (r->flags & IORESOURCE_IO)
+ cmd |= PCI_COMMAND_IO;
+ if (r->flags & IORESOURCE_MEM)
+ cmd |= PCI_COMMAND_MEMORY;
+ }
+ if (dev->resource[PCI_ROM_RESOURCE].start)
+ 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);
+}
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