Hi Taku,
Thanks for your comments and please refer to inline comments
below.
gerry
On 2012-4-18 14:47, Taku Izumi wrote:
Hi Jiang,
On Wed, 11 Apr 2012 08:11:03 +0800
Jiang Liu<liuj97@xxxxxxxxx> wrote:
This patch enhances pci_root driver to update MMCFG information when
hot-plugging PCI root bridges on x86 platforms.
Signed-off-by: Jiang Liu<jiang.liu@xxxxxxxxxx>
---
arch/x86/include/asm/pci_x86.h | 1 +
arch/x86/pci/acpi.c | 58 ++++++++++++++++++++++++++++++++++++++++
arch/x86/pci/mmconfig_32.c | 2 +-
arch/x86/pci/mmconfig_64.c | 2 +-
drivers/acpi/pci_root.c | 16 +++++++++++
include/acpi/acnames.h | 1 +
include/acpi/acpi_bus.h | 1 +
include/linux/pci-acpi.h | 3 ++
8 files changed, 82 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 3252c97..5e1d9a6 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -100,6 +100,7 @@ struct pci_raw_ops {
extern const struct pci_raw_ops *raw_pci_ops;
extern const struct pci_raw_ops *raw_pci_ext_ops;
+extern const struct pci_raw_ops pci_mmcfg;
extern const struct pci_raw_ops pci_direct_conf1;
extern bool port_cf9_safe;
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index da0149d..729d694 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -4,6 +4,7 @@
#include<linux/irq.h>
#include<linux/dmi.h>
#include<linux/slab.h>
+#include<linux/pci-acpi.h>
#include<asm/numa.h>
#include<asm/pci_x86.h>
@@ -488,6 +489,63 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
return bus;
}
+int __devinit arch_acpi_pci_root_add(struct acpi_pci_root *root)
+{
+ int result = 0;
+ acpi_status status;
+ unsigned long long base_addr;
+
+ /* MMCFG not in use */
+ if (raw_pci_ext_ops&& raw_pci_ext_ops !=&pci_mmcfg)
+ return result;
+
+ status = acpi_evaluate_integer(root->device->handle, METHOD_NAME__CBA,
+ NULL,&base_addr);
+ if (ACPI_FAILURE(status))
+ base_addr = 0;
+ /*
+ * Try to insert MMCFG information for host bridge
+ */
+ result = pci_mmconfig_insert(root->segment, root->secondary.start,
+ root->secondary.end, base_addr);
This logic looks strange.
If the evaluation of "_CBA" failed (for example, "_CBA" didn't exist),
pci_mmconfig_insert() should not be invoked.
Yes, the code looks a little strange here, maybe need more clear
comments here.
For hotplug capable (physical hotplug) host bridges, BIOS should provide
_CBA method for them and we should insert the new MMCFG info here.
For non-hotplug-capable host bridges, we check that MMCFG information
for the host bridge already exists.
So the magic part is in function pci_mmconfig_insert(). The algorithm
for function pci_mmconfig_insert() is
{
if (base_addr is not zero)
return try_to_insert_MMCFG_info();
else if (MMCFG info for (seg, start, bus) already exists)
return -EEXIST;
else
return -EINVAL;
}
We will check for -EEXIST on return from pci_mmconfig_insert() for the
special case.
+ if (result == -EEXIST)
+ result = 0;
+ else if (!result) {
+ root->mmconf_added = true;
+
+ /* Try to enable MMCFG if it hasn't been enabled yet */
+ if (raw_pci_ext_ops == NULL) {
+ if (pci_probe& PCI_PROBE_MMCONF)
+ raw_pci_ext_ops =&pci_mmcfg;
+ else {
+ arch_acpi_pci_root_remove(root);
+ result = -ENODEV;
+ }
+ }
+ }
+ if (result)
+ printk(KERN_ERR
+ "can't add MMCFG information for Bus %04x:%02x\n",
+ root->segment, (unsigned int)root->secondary.start);
+
+ /* still could use conf1 with it */
+ if (!root->segment)
+ result = 0;
+
+ return result;
+}
+
+void arch_acpi_pci_root_remove(struct acpi_pci_root *root)
+{
+ if (root->mmconf_added) {
+ pci_mmconfig_delete(root->segment,
+ root->secondary.start,
+ root->secondary.end);
+ root->mmconf_added = false;
+ }
+}
+
int __init pci_acpi_init(void)
{
struct pci_dev *dev = NULL;
diff --git a/arch/x86/pci/mmconfig_32.c b/arch/x86/pci/mmconfig_32.c
index a22785d..db63ac2 100644
--- a/arch/x86/pci/mmconfig_32.c
+++ b/arch/x86/pci/mmconfig_32.c
@@ -126,7 +126,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
return 0;
}
-static const struct pci_raw_ops pci_mmcfg = {
+const struct pci_raw_ops pci_mmcfg = {
.read = pci_mmcfg_read,
.write = pci_mmcfg_write,
};
diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index 4e05779..34c08dd 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -90,7 +90,7 @@ static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
return 0;
}
-static const struct pci_raw_ops pci_mmcfg = {
+const struct pci_raw_ops pci_mmcfg = {
.read = pci_mmcfg_read,
.write = pci_mmcfg_write,
};
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 4a7d575..b7c0b53 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -448,6 +448,15 @@ out:
}
EXPORT_SYMBOL(acpi_pci_osc_control_set);
+int __weak arch_acpi_pci_root_add(struct acpi_pci_root *root)
+{
+ return 0;
+}
+
+void __weak arch_acpi_pci_root_remove(struct acpi_pci_root *root)
+{
+}
+
static int __devinit acpi_pci_root_add(struct acpi_device *device)
{
unsigned long long segment, bus;
@@ -504,6 +513,11 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
device->driver_data = root;
+ if (arch_acpi_pci_root_add(root)) {
+ result = -ENODEV;
+ goto out_free;
+ }
+
/*
* All supported architectures that use ACPI have support for
* PCI domains, so we indicate this in _OSC support capabilities.
@@ -629,6 +643,7 @@ out_del_root:
list_del_rcu(&root->node);
mutex_unlock(&acpi_pci_root_lock);
synchronize_rcu();
+ arch_acpi_pci_root_remove(root);
out_free:
kfree(root);
return result;
@@ -679,6 +694,7 @@ out:
list_del_rcu(&root->node);
mutex_unlock(&acpi_pci_root_lock);
synchronize_rcu();
+ arch_acpi_pci_root_remove(root);
kfree(root);
return 0;
diff --git a/include/acpi/acnames.h b/include/acpi/acnames.h
index 38f5088..99bda75 100644
--- a/include/acpi/acnames.h
+++ b/include/acpi/acnames.h
@@ -62,6 +62,7 @@
#define METHOD_NAME__AEI "_AEI"
#define METHOD_NAME__PRW "_PRW"
#define METHOD_NAME__SRS "_SRS"
+#define METHOD_NAME__CBA "_CBA"
/* Method names - these methods must appear at the namespace root */
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index f1c8ca6..cb4f402 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -370,6 +370,7 @@ struct acpi_pci_root {
u32 osc_support_set; /* _OSC state of support bits */
u32 osc_control_set; /* _OSC state of control bits */
+ bool mmconf_added;
};
/* helper */
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index ac93634..7745b8a 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -18,6 +18,9 @@ extern acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
struct pci_dev *pci_dev);
extern acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev);
+int arch_acpi_pci_root_add(struct acpi_pci_root *root);
+void arch_acpi_pci_root_remove(struct acpi_pci_root *root);
+
static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
{
struct pci_bus *pbus = pdev->bus;
--
1.7.5.4
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