Commit a0ca9909 authored by Ivan Kokshaysky's avatar Ivan Kokshaysky Committed by Linus Torvalds

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: default avatarIvan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: default avatarMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7cf712db
......@@ -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;
......
......@@ -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");
......
......@@ -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;
......
......@@ -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);
/*
......
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