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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/frv/mb93090-mb00/pci-frv.c
Initial import
Diffstat (limited to 'arch/frv/mb93090-mb00/pci-frv.c')
-rw-r--r--arch/frv/mb93090-mb00/pci-frv.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/arch/frv/mb93090-mb00/pci-frv.c b/arch/frv/mb93090-mb00/pci-frv.c
new file mode 100644
index 000000000..0635bd6c2
--- /dev/null
+++ b/arch/frv/mb93090-mb00/pci-frv.c
@@ -0,0 +1,196 @@
+/* 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"
+
+/*
+ * 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..
+ */
+resource_size_t
+pcibios_align_resource(void *data, const struct resource *res,
+ resource_size_t size, resource_size_t align)
+{
+ resource_size_t start = res->start;
+
+ if ((res->flags & IORESOURCE_IO) && (start & 0x300))
+ start = (start + 0x3ff) & ~0x3ff;
+
+ return 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;
+
+ /* Depth-First Search on bus tree */
+ for (ln=bus_list->next; ln != bus_list; ln=ln->next) {
+ bus = list_entry(ln, struct pci_bus, node);
+ if ((dev = bus->self)) {
+ for (idx = PCI_BRIDGE_RESOURCES; idx < PCI_NUM_RESOURCES; idx++) {
+ r = &dev->resource[idx];
+ if (!r->start)
+ continue;
+ pci_claim_bridge_resource(dev, idx);
+ }
+ }
+ 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;
+
+ for_each_pci_dev(dev) {
+ 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);
+ if (pci_claim_resource(dev, idx) < 0) {
+ /* 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 void __init pcibios_assign_resources(void)
+{
+ struct pci_dev *dev = NULL;
+ int idx;
+ struct resource *r;
+
+ for_each_pci_dev(dev) {
+ 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();
+}