PCI x86: always use conf1 to access config space below 256 bytes
Thanks to Loic Prylli <loic@myri.com>, who originally proposed
this idea.
Always using legacy configuration mechanism for the legacy config space
and extended mechanism (mmconf) for the extended config space is
a simple and very logical approach. It's supposed to resolve all
known mmconf problems. It still allows per-device quirks (tweaking
dev->cfg_size). It also allows to get rid of mmconf fallback code.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index 4095e4d..c4cf318 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -40,9 +40,7 @@
static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
{
char __iomem *addr;
- if (seg == 0 && bus < PCI_MMCFG_MAX_CHECK_BUS &&
- test_bit(32*bus + PCI_SLOT(devfn), pci_mmcfg_fallback_slots))
- return NULL;
+
addr = get_virt(seg, bus);
if (!addr)
return NULL;
@@ -56,13 +54,16 @@
/* Why do we have this when nobody checks it. How about a BUG()!? -AK */
if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
- *value = -1;
+err: *value = -1;
return -EINVAL;
}
+ if (reg < 256)
+ return pci_conf1_read(seg,bus,devfn,reg,len,value);
+
addr = pci_dev_base(seg, bus, devfn);
if (!addr)
- return pci_conf1_read(seg,bus,devfn,reg,len,value);
+ goto err;
switch (len) {
case 1:
@@ -88,9 +89,12 @@
if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
return -EINVAL;
+ if (reg < 256)
+ return pci_conf1_write(seg,bus,devfn,reg,len,value);
+
addr = pci_dev_base(seg, bus, devfn);
if (!addr)
- return pci_conf1_write(seg,bus,devfn,reg,len,value);
+ return -EINVAL;
switch (len) {
case 1:
@@ -126,12 +130,6 @@
return addr;
}
-int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
- unsigned int devfn)
-{
- return pci_dev_base(seg, bus, devfn) != NULL;
-}
-
int __init pci_mmcfg_arch_init(void)
{
int i;