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_32.c b/arch/x86/pci/mmconfig_32.c
index 1bf5816..7b75e65 100644
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -30,10 +30,6 @@
struct acpi_mcfg_allocation *cfg;
int cfg_num;
- if (seg == 0 && bus < PCI_MMCFG_MAX_CHECK_BUS &&
- test_bit(PCI_SLOT(devfn) + 32*bus, pci_mmcfg_fallback_slots))
- return 0;
-
for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
cfg = &pci_mmcfg_config[cfg_num];
if (cfg->pci_segment == seg &&
@@ -68,13 +64,16 @@
u32 base;
if ((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);
+
base = get_base_addr(seg, bus, devfn);
if (!base)
- return pci_conf1_read(seg,bus,devfn,reg,len,value);
+ goto err;
spin_lock_irqsave(&pci_config_lock, flags);
@@ -105,9 +104,12 @@
if ((bus > 255) || (devfn > 255) || (reg > 4095))
return -EINVAL;
+ if (reg < 256)
+ return pci_conf1_write(seg,bus,devfn,reg,len,value);
+
base = get_base_addr(seg, bus, devfn);
if (!base)
- return pci_conf1_write(seg,bus,devfn,reg,len,value);
+ return -EINVAL;
spin_lock_irqsave(&pci_config_lock, flags);
@@ -134,12 +136,6 @@
.write = pci_mmcfg_write,
};
-int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
- unsigned int devfn)
-{
- return get_base_addr(seg, bus, devfn) != 0;
-}
-
int __init pci_mmcfg_arch_init(void)
{
printk(KERN_INFO "PCI: Using MMCONFIG\n");