linux/drivers/pci/setup-res.c
John W. Linville 064b53dbcc [PATCH] PCI: restore BAR values after D3hot->D0 for devices that need it
Some PCI devices (e.g. 3c905B, 3c556B) lose all configuration
(including BARs) when transitioning from D3hot->D0.  This leaves such
a device in an inaccessible state.  The patch below causes the BARs
to be restored when enabling such a device, so that its driver will
be able to access it.

The patch also adds pci_restore_bars as a new global symbol, and adds a
correpsonding EXPORT_SYMBOL_GPL for that.

Some firmware (e.g. Thinkpad T21) leaves devices in D3hot after a
(re)boot.  Most drivers call pci_enable_device very early, so devices
left in D3hot that lose configuration during the D3hot->D0 transition
will be inaccessible to their drivers.

Drivers could be modified to account for this, but it would
be difficult to know which drivers need modification.  This is
especially true since often many devices are covered by the same
driver.  It likely would be necessary to replicate code across dozens
of drivers.

The patch below should trigger only when transitioning from D3hot->D0
(or at boot), and only for devices that have the "no soft reset" bit
cleared in the PM control register.  I believe it is safe to include
this patch as part of the PCI infrastructure.

The cleanest implementation of pci_restore_bars was to call
pci_update_resource.  Unfortunately, that does not currently exist
for the sparc64 architecture.  The patch below includes a null
implemenation of pci_update_resource for sparc64.

Some have expressed interest in making general use of the the
pci_restore_bars function, so that has been exported to GPL licensed
modules.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-08 14:57:24 -07:00

208 lines
5.4 KiB
C

/*
* drivers/pci/setup-res.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.
*/
/* fixed for multiple pci buses, 1999 Andrea Arcangeli <andrea@suse.de> */
/*
* Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
* Resource sorting
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/cache.h>
#include <linux/slab.h>
#include "pci.h"
void
pci_update_resource(struct pci_dev *dev, struct resource *res, int resno)
{
struct pci_bus_region region;
u32 new, check, mask;
int reg;
/* Ignore resources for unimplemented BARs and unused resource slots
for 64 bit BARs. */
if (!res->flags)
return;
pcibios_resource_to_bus(dev, &region, res);
pr_debug(" got res [%lx:%lx] bus [%lx:%lx] flags %lx for "
"BAR %d of %s\n", res->start, res->end,
region.start, region.end, res->flags, resno, pci_name(dev));
new = region.start | (res->flags & PCI_REGION_FLAG_MASK);
if (res->flags & IORESOURCE_IO)
mask = (u32)PCI_BASE_ADDRESS_IO_MASK;
else
mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
if (resno < 6) {
reg = PCI_BASE_ADDRESS_0 + 4 * resno;
} else if (resno == PCI_ROM_RESOURCE) {
if (!(res->flags & IORESOURCE_ROM_ENABLE))
return;
new |= PCI_ROM_ADDRESS_ENABLE;
reg = dev->rom_base_reg;
} else {
/* Hmm, non-standard resource. */
return; /* kill uninitialised var warning */
}
pci_write_config_dword(dev, reg, new);
pci_read_config_dword(dev, reg, &check);
if ((new ^ check) & mask) {
printk(KERN_ERR "PCI: Error while updating region "
"%s/%d (%08x != %08x)\n", pci_name(dev), resno,
new, check);
}
if ((new & (PCI_BASE_ADDRESS_SPACE|PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
(PCI_BASE_ADDRESS_SPACE_MEMORY|PCI_BASE_ADDRESS_MEM_TYPE_64)) {
new = region.start >> 16 >> 16;
pci_write_config_dword(dev, reg + 4, new);
pci_read_config_dword(dev, reg + 4, &check);
if (check != new) {
printk(KERN_ERR "PCI: Error updating region "
"%s/%d (high %08x != %08x)\n",
pci_name(dev), resno, new, check);
}
}
res->flags &= ~IORESOURCE_UNSET;
pr_debug("PCI: moved device %s resource %d (%lx) to %x\n",
pci_name(dev), resno, res->flags,
new & ~PCI_REGION_FLAG_MASK);
}
int __devinit
pci_claim_resource(struct pci_dev *dev, int resource)
{
struct resource *res = &dev->resource[resource];
struct resource *root = NULL;
char *dtype = resource < PCI_BRIDGE_RESOURCES ? "device" : "bridge";
int err;
if (res->flags & IORESOURCE_IO)
root = &ioport_resource;
if (res->flags & IORESOURCE_MEM)
root = &iomem_resource;
err = -EINVAL;
if (root != NULL)
err = insert_resource(root, res);
if (err) {
printk(KERN_ERR "PCI: %s region %d of %s %s [%lx:%lx]\n",
root ? "Address space collision on" :
"No parent found for",
resource, dtype, pci_name(dev), res->start, res->end);
}
return err;
}
int pci_assign_resource(struct pci_dev *dev, int resno)
{
struct pci_bus *bus = dev->bus;
struct resource *res = dev->resource + resno;
unsigned long size, min, align;
int ret;
size = res->end - res->start + 1;
min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
/* The bridge resources are special, as their
size != alignment. Sizing routines return
required alignment in the "start" field. */
align = (resno < PCI_BRIDGE_RESOURCES) ? size : res->start;
/* First, try exact prefetching match.. */
ret = pci_bus_alloc_resource(bus, res, size, align, min,
IORESOURCE_PREFETCH,
pcibios_align_resource, dev);
if (ret < 0 && (res->flags & IORESOURCE_PREFETCH)) {
/*
* That failed.
*
* But a prefetching area can handle a non-prefetching
* window (it will just not perform as well).
*/
ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
pcibios_align_resource, dev);
}
if (ret) {
printk(KERN_ERR "PCI: Failed to allocate %s resource #%d:%lx@%lx for %s\n",
res->flags & IORESOURCE_IO ? "I/O" : "mem",
resno, size, res->start, pci_name(dev));
} else if (resno < PCI_BRIDGE_RESOURCES) {
pci_update_resource(dev, res, resno);
}
return ret;
}
/* Sort resources by alignment */
void __devinit
pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
{
int i;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
struct resource *r;
struct resource_list *list, *tmp;
unsigned long r_align;
r = &dev->resource[i];
r_align = r->end - r->start;
if (!(r->flags) || r->parent)
continue;
if (!r_align) {
printk(KERN_WARNING "PCI: Ignore bogus resource %d "
"[%lx:%lx] of %s\n",
i, r->start, r->end, pci_name(dev));
continue;
}
r_align = (i < PCI_BRIDGE_RESOURCES) ? r_align + 1 : r->start;
for (list = head; ; list = list->next) {
unsigned long align = 0;
struct resource_list *ln = list->next;
int idx;
if (ln) {
idx = ln->res - &ln->dev->resource[0];
align = (idx < PCI_BRIDGE_RESOURCES) ?
ln->res->end - ln->res->start + 1 :
ln->res->start;
}
if (r_align > align) {
tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
if (!tmp)
panic("pdev_sort_resources(): "
"kmalloc() failed!\n");
tmp->next = ln;
tmp->res = r;
tmp->dev = dev;
list->next = tmp;
break;
}
}
}
}