[PATCH v2 1/3] PCI: rework pci_enable_ari for support disable ari forwarding

[PATCH v2 1/3] PCI: rework pci_enable_ari for support disable ari forwarding

[Yijing Wang]

pci_enable_ari will be called if an ARI pci device found, set its bridge ARI Forwarding Enable
bit in Device Control 2 Register. But the bridge ARI Forwarding Enable bit will never be cleared
when an ARI device hot removed.
1. Hot add an ARI pci device;
2. Hot remove the ARI pci device;
3. Hot add an non ARI pci device;

In this case, we could only find fun 0 of non ARI pci device because of its bridge ARI Forwarding Enable
bit set.

As PCIe Spec 2.0(6.13/441) recommends:
"Following a hot-plug event below a Downstream Port, it is strongly recommended that software
Clear the ARI Forwarding Enable bit in the Downstream Port until software determines that a
newly added component is in fact an ARI Device"

So, this patch rework pci_enable_ari to support enable/disable ARI when a new device hot add.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
---
 drivers/pci/pci.c   |   21 +++++++++++++--------
 drivers/pci/pci.h   |    2 +-
 drivers/pci/probe.c |    2 +-
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5485883..38f1ad6 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2010,10 +2010,10 @@ void pci_free_cap_save_buffers(struct pci_dev *dev)
 }
 
 /**
- * pci_enable_ari - enable ARI forwarding if hardware support it
+ * pci_configure_ari - enable or disable ARI forwarding if hardware support it
  * @dev: the PCI device
  */
-void pci_enable_ari(struct pci_dev *dev)
+void pci_configure_ari(struct pci_dev *dev)
 {
 	u32 cap;
 	struct pci_dev *bridge;
@@ -2021,9 +2021,6 @@ void pci_enable_ari(struct pci_dev *dev)
 	if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
 		return;
 
-	if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI))
-		return;
-
 	bridge = dev->bus->self;
 	if (!bridge)
 		return;
@@ -2031,10 +2028,18 @@ void pci_enable_ari(struct pci_dev *dev)
 	pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
 	if (!(cap & PCI_EXP_DEVCAP2_ARI))
 		return;
-
-	pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI);
-	bridge->ari_enabled = 1;
+
+	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
+		pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
+				PCI_EXP_DEVCTL2_ARI);
+		bridge->ari_enabled = 1;
+	} else {
+		pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
+				PCI_EXP_DEVCTL2_ARI);
+		bridge->ari_enabled = 0;
+	}
 }
+EXPORT_SYMBOL(pci_configure_ari);
 
 /**
  * pci_enable_ido - enable ID-based Ordering on a device
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index bacbcba..d6eb3d9 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -211,7 +211,7 @@ extern int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 extern int pci_resource_bar(struct pci_dev *dev, int resno,
 			    enum pci_bar_type *type);
 extern int pci_bus_add_child(struct pci_bus *bus);
-extern void pci_enable_ari(struct pci_dev *dev);
+extern void pci_configure_ari(struct pci_dev *dev);
 /**
  * pci_ari_enabled - query ARI forwarding status
  * @bus: the PCI bus
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ec909af..bb7ecf6 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1282,7 +1282,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_vpd_pci22_init(dev);
 
 	/* Alternative Routing-ID Forwarding */
-	pci_enable_ari(dev);
+	pci_configure_ari(dev);
 
 	/* Single Root I/O Virtualization */
 	pci_iov_init(dev);
-- 
1.7.1

[PATCH v2 2/3] PCI: introduce pci_next_fn to get next func number

[Yijing Wang]

Introduce pci_next_fn function to get next fn number.Since
this function maybe used by PCI module(eg. pciehp),so export it.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
---
 drivers/pci/pci.h   |    1 +
 drivers/pci/probe.c |   67 +++++++++++++++++++++++++++++---------------------
 2 files changed, 40 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index d6eb3d9..fe411f4 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -212,6 +212,7 @@ extern int pci_resource_bar(struct pci_dev *dev, int resno,
 			    enum pci_bar_type *type);
 extern int pci_bus_add_child(struct pci_bus *bus);
 extern void pci_configure_ari(struct pci_dev *dev);
+extern int pci_next_fn(struct pci_bus *parent, int devfn);
 /**
  * pci_ari_enabled - query ARI forwarding status
  * @bus: the PCI bus
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index bb7ecf6..435ee60 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1345,33 +1345,49 @@ struct pci_dev *__ref pci_scan_single_device(struct pci_bus *bus, int devfn)
 }
 EXPORT_SYMBOL(pci_scan_single_device);
 
-static unsigned next_ari_fn(struct pci_dev *dev, unsigned fn)
+/**
+ * pci_next_fn - get next fn number for device
+ * @bus: PCI bus on which desired PCI Function device resides
+ * @devfn: encodes number of pci device
+ *
+ * return next_fn if success, if can not find next fn or fail,
+ * 0 is returned.
+ */
+int pci_next_fn(struct pci_bus *bus, int devfn)
 {
 	u16 cap;
-	unsigned pos, next_fn;
-
+	unsigned pos, next_fn = 0;
+	struct pci_dev *dev;
+
+	if (!bus || devfn < 0)
+		goto out;
+
+	dev = pci_get_slot(bus, devfn);
 	if (!dev)
-		return 0;
+		goto out;
 
-	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
-	if (!pos)
-		return 0;
-	pci_read_config_word(dev, pos + 4, &cap);
-	next_fn = cap >> 8;
-	if (next_fn <= fn)
-		return 0;
+	if (!pci_ari_enabled(bus)) {
+		if (!dev->multifunction)
+			goto release;
+		else
+			next_fn = (PCI_FUNC(devfn) + 1) % 8;
+	} else {
+		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
+		if (!pos)
+			goto release;
+		pci_read_config_word(dev, pos + 4, &cap);
+		next_fn = cap >> 8;
+		if (next_fn <= PCI_FUNC(devfn)) {
+			next_fn = 0;
+			goto release;
+		}
+	}
+release:
+	pci_dev_put(dev);
+out:
 	return next_fn;
 }
-
-static unsigned next_trad_fn(struct pci_dev *dev, unsigned fn)
-{
-	return (fn + 1) % 8;
-}
-
-static unsigned no_next_fn(struct pci_dev *dev, unsigned fn)
-{
-	return 0;
-}
+EXPORT_SYMBOL(pci_next_fn);
 
 static int only_one_child(struct pci_bus *bus)
 {
@@ -1402,7 +1418,6 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
 {
 	unsigned fn, nr = 0;
 	struct pci_dev *dev;
-	unsigned (*next_fn)(struct pci_dev *, unsigned) = no_next_fn;
 
 	if (only_one_child(bus) && (devfn > 0))
 		return 0; /* Already scanned the entire slot */
@@ -1413,12 +1428,8 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
 	if (!dev->is_added)
 		nr++;
 
-	if (pci_ari_enabled(bus))
-		next_fn = next_ari_fn;
-	else if (dev->multifunction)
-		next_fn = next_trad_fn;
-
-	for (fn = next_fn(dev, 0); fn > 0; fn = next_fn(dev, fn)) {
+	for (fn = pci_next_fn(bus, PCI_DEVFN(PCI_SLOT(devfn), 0)); fn > 0;
+			fn = pci_next_fn(bus, PCI_DEVFN(PCI_SLOT(devfn), fn))) {
 		dev = pci_scan_single_device(bus, devfn + fn);
 		if (dev) {
 			if (!dev->is_added)
-- 
1.7.1

[PATCH v2 3/3] PCI, pciehp: ARI device hotplug support

[Yijing Wang]

ARI device supports up to 256 Functions, pciehp now only scan and configure
Functions from 0 to 7, this patch fix this problem for ARI device hotplug.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
 drivers/pci/hotplug/pciehp_pci.c |   40 ++++++++++++++++++++++++++-----------
 1 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index 09cecaf..b37e8a0 100644
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -39,7 +39,7 @@ int pciehp_configure_device(struct slot *p_slot)
 	struct pci_dev *dev;
 	struct pci_dev *bridge = p_slot->ctrl->pcie->port;
 	struct pci_bus *parent = bridge->subordinate;
-	int num, fn;
+	int num, fn = 0;
 	struct controller *ctrl = p_slot->ctrl;
 
 	dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
@@ -56,21 +56,31 @@ int pciehp_configure_device(struct slot *p_slot)
 		ctrl_err(ctrl, "No new device found\n");
 		return -ENODEV;
 	}
-
-	for (fn = 0; fn < 8; fn++) {
-		dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
+
+	do {
+		if (pci_ari_enabled(parent))
+			dev = pci_get_slot(parent, fn);
+		else
+			dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
+
+		fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
 		if (!dev)
 			continue;
 		if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
 				(dev->hdr_type == PCI_HEADER_TYPE_CARDBUS))
 			pci_hp_add_bridge(dev);
 		pci_dev_put(dev);
-	}
+	} while (fn);
 
 	pci_assign_unassigned_bridge_resources(bridge);
 
-	for (fn = 0; fn < 8; fn++) {
-		dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
+	do {
+		if (pci_ari_enabled(parent))
+			dev = pci_get_slot(parent, fn);
+		else
+			dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
+
+		fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
 		if (!dev)
 			continue;
 		if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
@@ -79,7 +89,7 @@ int pciehp_configure_device(struct slot *p_slot)
 		}
 		pci_configure_slot(dev);
 		pci_dev_put(dev);
-	}
+	} while (fn);
 
 	pci_bus_add_devices(parent);
 
@@ -89,21 +99,27 @@ int pciehp_configure_device(struct slot *p_slot)
 int pciehp_unconfigure_device(struct slot *p_slot)
 {
 	int ret, rc = 0;
-	int j;
+	int fn = 0;
 	u8 bctl = 0;
 	u8 presence = 0;
 	struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
 	u16 command;
 	struct controller *ctrl = p_slot->ctrl;
+	struct pci_dev *temp;
 
 	ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
 		 __func__, pci_domain_nr(parent), parent->number);
 	ret = pciehp_get_adapter_status(p_slot, &presence);
 	if (ret)
 		presence = 0;
+
+	do {
+		if (pci_ari_enabled(parent))
+			temp = pci_get_slot(parent, fn);
+		else
+			temp = pci_get_slot(parent, PCI_DEVFN(0, fn));
 
-	for (j = 0; j < 8; j++) {
-		struct pci_dev *temp = pci_get_slot(parent, PCI_DEVFN(0, j));
+		fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
 		if (!temp)
 			continue;
 		if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
@@ -129,7 +145,7 @@ int pciehp_unconfigure_device(struct slot *p_slot)
 			pci_write_config_word(temp, PCI_COMMAND, command);
 		}
 		pci_dev_put(temp);
-	}
+	} while (fn);
 
 	return rc;
 }
-- 
1.7.1

Re: [PATCH v2 3/3] PCI, pciehp: ARI device hotplug support

[Bjorn Helgaas]

[+cc Kenji]

On Tue, Oct 16, 2012 at 1:10 AM, Yijing Wang <wangyijing@huawei.com> wrote:
> ARI device supports up to 256 Functions, pciehp now only scan and configure
> Functions from 0 to 7, this patch fix this problem for ARI device hotplug.
>
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> ---
>  drivers/pci/hotplug/pciehp_pci.c |   40 ++++++++++++++++++++++++++-----------
>  1 files changed, 28 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
> index 09cecaf..b37e8a0 100644
> --- a/drivers/pci/hotplug/pciehp_pci.c
> +++ b/drivers/pci/hotplug/pciehp_pci.c
> @@ -39,7 +39,7 @@ int pciehp_configure_device(struct slot *p_slot)
>         struct pci_dev *dev;
>         struct pci_dev *bridge = p_slot->ctrl->pcie->port;
>         struct pci_bus *parent = bridge->subordinate;
> -       int num, fn;
> +       int num, fn = 0;
>         struct controller *ctrl = p_slot->ctrl;
>
>         dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
> @@ -56,21 +56,31 @@ int pciehp_configure_device(struct slot *p_slot)
>                 ctrl_err(ctrl, "No new device found\n");
>                 return -ENODEV;
>         }
> -
> -       for (fn = 0; fn < 8; fn++) {
> -               dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
> +
> +       do {
> +               if (pci_ari_enabled(parent))
> +                       dev = pci_get_slot(parent, fn);
> +               else
> +                       dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
> +
> +               fn = pci_next_fn(parent, PCI_DEVFN(0, fn));

This doesn't make sense to me.  We just called pci_scan_slot(), which
already  used pci_next_fn() to find all the functions.  We shouldn't
have to have the ARI knowledge and pci_next_fn() looping here again
(and yet again after pci_assign_unassigned_bridge_resources()).

According to the pci_scan_slot() function comment, all the
newly-discovered devices should be on the bus->devices list.  And in
fact, the similar code in acpiphp (enable_device()) *does* use the
bus->devices list.

I think cpci_configure_slot(), pciehp_configure_device(),
enable_slot() in sgi_hotplug.c, and shpchp_configure_device() should
be changed to use the bus->devices list.  In addition, I think the
refcount management (pci_get_slot()/pci_dev_put()) should be removed.

>                 if (!dev)
>                         continue;
>                 if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
>                                 (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS))
>                         pci_hp_add_bridge(dev);
>                 pci_dev_put(dev);
> -       }
> +       } while (fn);
>
>         pci_assign_unassigned_bridge_resources(bridge);
>
> -       for (fn = 0; fn < 8; fn++) {
> -               dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
> +       do {
> +               if (pci_ari_enabled(parent))
> +                       dev = pci_get_slot(parent, fn);
> +               else
> +                       dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
> +
> +               fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
>                 if (!dev)
>                         continue;
>                 if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
> @@ -79,7 +89,7 @@ int pciehp_configure_device(struct slot *p_slot)
>                 }
>                 pci_configure_slot(dev);
>                 pci_dev_put(dev);
> -       }
> +       } while (fn);
>
>         pci_bus_add_devices(parent);
>
> @@ -89,21 +99,27 @@ int pciehp_configure_device(struct slot *p_slot)
>  int pciehp_unconfigure_device(struct slot *p_slot)
>  {
>         int ret, rc = 0;
> -       int j;
> +       int fn = 0;
>         u8 bctl = 0;
>         u8 presence = 0;
>         struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
>         u16 command;
>         struct controller *ctrl = p_slot->ctrl;
> +       struct pci_dev *temp;
>
>         ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
>                  __func__, pci_domain_nr(parent), parent->number);
>         ret = pciehp_get_adapter_status(p_slot, &presence);
>         if (ret)
>                 presence = 0;
> +
> +       do {
> +               if (pci_ari_enabled(parent))
> +                       temp = pci_get_slot(parent, fn);
> +               else
> +                       temp = pci_get_slot(parent, PCI_DEVFN(0, fn));
>
> -       for (j = 0; j < 8; j++) {
> -               struct pci_dev *temp = pci_get_slot(parent, PCI_DEVFN(0, j));
> +               fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
>                 if (!temp)
>                         continue;
>                 if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
> @@ -129,7 +145,7 @@ int pciehp_unconfigure_device(struct slot *p_slot)
>                         pci_write_config_word(temp, PCI_COMMAND, command);
>                 }
>                 pci_dev_put(temp);
> -       }
> +       } while (fn);
>
>         return rc;
>  }
> --
> 1.7.1
>
>

Re: [PATCH v2 3/3] PCI, pciehp: ARI device hotplug support

[Yijing Wang]

On 2013/1/9 1:44, Bjorn Helgaas wrote:
> [+cc Kenji]
> 
> On Tue, Oct 16, 2012 at 1:10 AM, Yijing Wang <wangyijing@huawei.com> wrote:
>> ARI device supports up to 256 Functions, pciehp now only scan and configure
>> Functions from 0 to 7, this patch fix this problem for ARI device hotplug.
>>
>> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
>> ---
>>  drivers/pci/hotplug/pciehp_pci.c |   40 ++++++++++++++++++++++++++-----------
>>  1 files changed, 28 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
>> index 09cecaf..b37e8a0 100644
>> --- a/drivers/pci/hotplug/pciehp_pci.c
>> +++ b/drivers/pci/hotplug/pciehp_pci.c
>> @@ -39,7 +39,7 @@ int pciehp_configure_device(struct slot *p_slot)
>>         struct pci_dev *dev;
>>         struct pci_dev *bridge = p_slot->ctrl->pcie->port;
>>         struct pci_bus *parent = bridge->subordinate;
>> -       int num, fn;
>> +       int num, fn = 0;
>>         struct controller *ctrl = p_slot->ctrl;
>>
>>         dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
>> @@ -56,21 +56,31 @@ int pciehp_configure_device(struct slot *p_slot)
>>                 ctrl_err(ctrl, "No new device found\n");
>>                 return -ENODEV;
>>         }
>> -
>> -       for (fn = 0; fn < 8; fn++) {
>> -               dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
>> +
>> +       do {
>> +               if (pci_ari_enabled(parent))
>> +                       dev = pci_get_slot(parent, fn);
>> +               else
>> +                       dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
>> +
>> +               fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
> 
> This doesn't make sense to me.  We just called pci_scan_slot(), which
> already  used pci_next_fn() to find all the functions.  We shouldn't
> have to have the ARI knowledge and pci_next_fn() looping here again
> (and yet again after pci_assign_unassigned_bridge_resources()).
> 
> According to the pci_scan_slot() function comment, all the
> newly-discovered devices should be on the bus->devices list.  And in
> fact, the similar code in acpiphp (enable_device()) *does* use the
> bus->devices list.
> 

Hi Bjorn,
   Thanks for your review and comment! You are right, use bus->devices list is a better solution.
I will update my ARI device hotplug support patchset and send out again.

> I think cpci_configure_slot(), pciehp_configure_device(),
> enable_slot() in sgi_hotplug.c, and shpchp_configure_device() should
> be changed to use the bus->devices list.  In addition, I think the
> refcount management (pci_get_slot()/pci_dev_put()) should be removed.

Remove pci_get_slot()/pci_dev_put() here looks good to me, Because refcount increment when pci_scan_slot,
here remove the refcount management is safe.
I will change this and test in my machine, and send out this patch if test result is ok.


Thanks very much!

Yijing.

> 
>>                 if (!dev)
>>                         continue;
>>                 if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
>>                                 (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS))
>>                         pci_hp_add_bridge(dev);
>>                 pci_dev_put(dev);
>> -       }
>> +       } while (fn);
>>
>>         pci_assign_unassigned_bridge_resources(bridge);
>>
>> -       for (fn = 0; fn < 8; fn++) {
>> -               dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
>> +       do {
>> +               if (pci_ari_enabled(parent))
>> +                       dev = pci_get_slot(parent, fn);
>> +               else
>> +                       dev = pci_get_slot(parent, PCI_DEVFN(0, fn));
>> +
>> +               fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
>>                 if (!dev)
>>                         continue;
>>                 if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {
>> @@ -79,7 +89,7 @@ int pciehp_configure_device(struct slot *p_slot)
>>                 }
>>                 pci_configure_slot(dev);
>>                 pci_dev_put(dev);
>> -       }
>> +       } while (fn);
>>
>>         pci_bus_add_devices(parent);
>>
>> @@ -89,21 +99,27 @@ int pciehp_configure_device(struct slot *p_slot)
>>  int pciehp_unconfigure_device(struct slot *p_slot)
>>  {
>>         int ret, rc = 0;
>> -       int j;
>> +       int fn = 0;
>>         u8 bctl = 0;
>>         u8 presence = 0;
>>         struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
>>         u16 command;
>>         struct controller *ctrl = p_slot->ctrl;
>> +       struct pci_dev *temp;
>>
>>         ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
>>                  __func__, pci_domain_nr(parent), parent->number);
>>         ret = pciehp_get_adapter_status(p_slot, &presence);
>>         if (ret)
>>                 presence = 0;
>> +
>> +       do {
>> +               if (pci_ari_enabled(parent))
>> +                       temp = pci_get_slot(parent, fn);
>> +               else
>> +                       temp = pci_get_slot(parent, PCI_DEVFN(0, fn));
>>
>> -       for (j = 0; j < 8; j++) {
>> -               struct pci_dev *temp = pci_get_slot(parent, PCI_DEVFN(0, j));
>> +               fn = pci_next_fn(parent, PCI_DEVFN(0, fn));
>>                 if (!temp)
>>                         continue;
>>                 if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {
>> @@ -129,7 +145,7 @@ int pciehp_unconfigure_device(struct slot *p_slot)
>>                         pci_write_config_word(temp, PCI_COMMAND, command);
>>                 }
>>                 pci_dev_put(temp);
>> -       }
>> +       } while (fn);
>>
>>         return rc;
>>  }
>> --
>> 1.7.1
>>
>>
> 
> .
> 


-- 
Thanks!
Yijing