lkml.org 
[lkml]   [2008]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 44/76] PCI x86: always use conf1 to access config space below 256 bytes
-stable review patch.  If anyone has any objections, please let us know.
---------------------

From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>

[upsteam commit: a0ca9909]

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.

This patch fixes a boot hang on Intel Q35 chipset as detailed at:
http://bugs.gentoo.org/198810

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>
Cc: Mike Pagano <mpagano@gentoo.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
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(-)

--- 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;
--- 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 se
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 s
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
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");
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -40,9 +40,7 @@ static char __iomem *get_virt(unsigned i
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 s

/* 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
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_iorema
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;
--- 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);

/*
--


\
 
 \ /
  Last update: 2008-03-22 00:07    [W:0.226 / U:0.128 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site