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linux/drivers/pci/setup-res.c
Ivan Kokshaysky 884525655d PCI: clean up resource alignment management 
Done per Linus' request and suggestions. Linus has explained that
better than I'll be able to explain:

On Thu, Mar 27, 2008 at 10:12:10AM -0700, Linus Torvalds wrote:
> Actually, before we go any further, there might be a less intrusive
> alternative: add just a couple of flags to the resource flags field (we
> still have something like 8 unused bits on 32-bit), and use those to
> implement a generic "resource_alignment()" routine.
>
> Two flags would do it:
>
>  - IORESOURCE_SIZEALIGN: size indicates alignment (regular PCI device
>    resources)
>
>  - IORESOURCE_STARTALIGN: start field is alignment (PCI bus resources
>    during probing)
>
> and then the case of both flags zero (or both bits set) would actually be
> "invalid", and we would also clear the IORESOURCE_STARTALIGN flag when we
> actually allocate the resource (so that we don't use the "start" field as
> alignment incorrectly when it no longer indicates alignment).
>
> That wouldn't be totally generic, but it would have the nice property of
> automatically at least add sanity checking for that whole "res->start has
> the odd meaning of 'alignment' during probing" and remove the need for a
> new field, and it would allow us to have a generic "resource_alignment()"
> routine that just gets a resource pointer.

Besides, I removed IORESOURCE_BUS_HAS_VGA flag which was unused for ages.

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-20 21:47:08 -07:00

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/*
* 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;
/*
* Ignore non-moveable resources. This might be legacy resources for
* which no functional BAR register exists or another important
* system resource we should better not move around in system address
* space.
*/
if (res->flags & IORESOURCE_PCI_FIXED)
return;
pcibios_resource_to_bus(dev, &region, res);
pr_debug(" got res [%llx:%llx] bus [%llx:%llx] flags %lx for "
"BAR %d of %s\n", (unsigned long long)res->start,
(unsigned long long)res->end,
(unsigned long long)region.start,
(unsigned long long)region.end,
(unsigned long)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 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;
root = pcibios_select_root(dev, res);
err = -EINVAL;
if (root != NULL)
err = insert_resource(root, res);
if (err) {
printk(KERN_ERR "PCI: %s region %d of %s %s [%llx:%llx]\n",
root ? "Address space collision on" :
"No parent found for",
resource, dtype, pci_name(dev),
(unsigned long long)res->start,
(unsigned long long)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;
resource_size_t size, min, align;
int ret;
size = res->end - res->start + 1;
min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
align = resource_alignment(res);
if (!align) {
printk(KERN_ERR "PCI: Cannot allocate resource (bogus "
"alignment) %d [%llx:%llx] (flags %lx) of %s\n",
resno, (unsigned long long)res->start,
(unsigned long long)res->end, res->flags,
pci_name(dev));
return -EINVAL;
}
/* 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:%llx@%llx for %s\n",
res->flags & IORESOURCE_IO ? "I/O" : "mem",
resno, (unsigned long long)size,
(unsigned long long)res->start, pci_name(dev));
} else {
res->flags &= ~IORESOURCE_STARTALIGN;
if (resno < PCI_BRIDGE_RESOURCES)
pci_update_resource(dev, res, resno);
}
return ret;
}
#if 0
int pci_assign_resource_fixed(struct pci_dev *dev, int resno)
{
struct pci_bus *bus = dev->bus;
struct resource *res = dev->resource + resno;
unsigned int type_mask;
int i, ret = -EBUSY;
type_mask = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH;
for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
struct resource *r = bus->resource[i];
if (!r)
continue;
/* type_mask must match */
if ((res->flags ^ r->flags) & type_mask)
continue;
ret = request_resource(r, res);
if (ret == 0)
break;
}
if (ret) {
printk(KERN_ERR "PCI: Failed to allocate %s resource "
"#%d:%llx@%llx for %s\n",
res->flags & IORESOURCE_IO ? "I/O" : "mem",
resno, (unsigned long long)(res->end - res->start + 1),
(unsigned long long)res->start, pci_name(dev));
} else if (resno < PCI_BRIDGE_RESOURCES) {
pci_update_resource(dev, res, resno);
}
return ret;
}
EXPORT_SYMBOL_GPL(pci_assign_resource_fixed);
#endif
/* Sort resources by alignment */
void 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;
resource_size_t r_align;
r = &dev->resource[i];
if (r->flags & IORESOURCE_PCI_FIXED)
continue;
if (!(r->flags) || r->parent)
continue;
r_align = resource_alignment(r);
if (!r_align) {
printk(KERN_WARNING "PCI: bogus alignment of resource "
"%d [%llx:%llx] (flags %lx) of %s\n",
i, (unsigned long long)r->start,
(unsigned long long)r->end, r->flags,
pci_name(dev));
continue;
}
for (list = head; ; list = list->next) {
resource_size_t align = 0;
struct resource_list *ln = list->next;
if (ln)
align = resource_alignment(ln->res);
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;
}
}
}
}
int pci_enable_resources(struct pci_dev *dev, int mask)
{
u16 cmd, old_cmd;
int i;
struct resource *r;
pci_read_config_word(dev, PCI_COMMAND, &cmd);
old_cmd = cmd;
for (i = 0; i < PCI_NUM_RESOURCES; i++) {
if (!(mask & (1 << i)))
continue;
r = &dev->resource[i];
if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
continue;
if ((i == PCI_ROM_RESOURCE) &&
(!(r->flags & IORESOURCE_ROM_ENABLE)))
continue;
if (!r->parent) {
dev_err(&dev->dev, "device not available because of "
"BAR %d [%llx:%llx] collisions\n", i,
(unsigned long long) r->start,
(unsigned long long) r->end);
return -EINVAL;
}
if (r->flags & IORESOURCE_IO)
cmd |= PCI_COMMAND_IO;
if (r->flags & IORESOURCE_MEM)
cmd |= PCI_COMMAND_MEMORY;
}
if (cmd != old_cmd) {
dev_info(&dev->dev, "enabling device (%04x -> %04x)\n",
old_cmd, cmd);
pci_write_config_word(dev, PCI_COMMAND, cmd);
}
return 0;
}
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