[PATCH] PCI x86: always use conf1 to access config space below 256 bytes
From: Ivan Kokshaysky
Date: Mon Jan 14 2008 - 17:31:09 EST
Thanks to Loic Prylli <loic@xxxxxxxx>, 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@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
---
arch/x86/pci/mmconfig-shared.c | 35 -----------------------------------
arch/x86/pci/mmconfig_32.c | 22 +++++++++-------------
arch/x86/pci/mmconfig_64.c | 22 ++++++++++------------
arch/x86/pci/pci.h | 7 -------
4 files changed, 19 insertions(+), 67 deletions(-)
diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 4df637e..6b521d3 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -22,42 +22,9 @@
#define MMCONFIG_APER_MIN (2 * 1024*1024)
#define MMCONFIG_APER_MAX (256 * 1024*1024)
-DECLARE_BITMAP(pci_mmcfg_fallback_slots, 32*PCI_MMCFG_MAX_CHECK_BUS);
-
/* Indicate if the mmcfg resources have been placed into the resource table. */
static int __initdata pci_mmcfg_resources_inserted;
-/* K8 systems have some devices (typically in the builtin northbridge)
- that are only accessible using type1
- Normally this can be expressed in the MCFG by not listing them
- and assigning suitable _SEGs, but this isn't implemented in some BIOS.
- Instead try to discover all devices on bus 0 that are unreachable using MM
- and fallback for them. */
-static void __init unreachable_devices(void)
-{
- int i, bus;
- /* Use the max bus number from ACPI here? */
- for (bus = 0; bus < PCI_MMCFG_MAX_CHECK_BUS; bus++) {
- for (i = 0; i < 32; i++) {
- unsigned int devfn = PCI_DEVFN(i, 0);
- u32 val1, val2;
-
- pci_conf1_read(0, bus, devfn, 0, 4, &val1);
- if (val1 == 0xffffffff)
- continue;
-
- if (pci_mmcfg_arch_reachable(0, bus, devfn)) {
- raw_pci_ops->read(0, bus, devfn, 0, 4, &val2);
- if (val1 == val2)
- continue;
- }
- set_bit(i + 32 * bus, pci_mmcfg_fallback_slots);
- printk(KERN_NOTICE "PCI: No mmconfig possible on device"
- " %02x:%02x\n", bus, i);
- }
- }
-}
-
static const char __init *pci_mmcfg_e7520(void)
{
u32 win;
@@ -270,8 +237,6 @@ void __init pci_mmcfg_init(int type)
return;
if (pci_mmcfg_arch_init()) {
- if (type == 1)
- unreachable_devices();
if (known_bridge)
pci_mmcfg_insert_resources(IORESOURCE_BUSY);
pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
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 @@ static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
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 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
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 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
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 @@ static struct pci_raw_ops pci_mmcfg = {
.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");
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 *get_virt(unsigned int seg, unsigned bus)
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 @@ static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
/* 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 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
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 @@ static void __iomem * __init mcfg_ioremap(struct acpi_mcfg_allocation *cfg)
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;
diff --git a/arch/x86/pci/pci.h b/arch/x86/pci/pci.h
index ac56d39..36cb44c 100644
--- a/arch/x86/pci/pci.h
+++ b/arch/x86/pci/pci.h
@@ -98,13 +98,6 @@ extern void pcibios_sort(void);
/* pci-mmconfig.c */
-/* Verify the first 16 busses. We assume that systems with more busses
- get MCFG right. */
-#define PCI_MMCFG_MAX_CHECK_BUS 16
-extern DECLARE_BITMAP(pci_mmcfg_fallback_slots, 32*PCI_MMCFG_MAX_CHECK_BUS);
-
-extern int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
- unsigned int devfn);
extern int __init pci_mmcfg_arch_init(void);
/*
--
1.5.2.5
--A6N2fC+uXW/VQSAv
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