[PATCH 0/2] PCI Hotplug: internal interface cleanups

[PATCH 0/2] PCI Hotplug: internal interface cleanups

[Alex Chiang]

This is a re-post of an old patch series that wasn't picked up last
time due to being too late in the merge window.

It removes a bunch of copy/paste code in acpiphp by simplifying some
internal interfaces.

Please consider this for .32.

Thanks!

---

Alex Chiang (2):
      PCI Hotplug: acpiphp: find bridges the easy way
      PCI Hotplug: convert acpi_pci_detect_ejectable() to take an acpi_handle


 drivers/pci/hotplug/acpi_pcihp.c   |    9 +--
 drivers/pci/hotplug/acpiphp_glue.c |  104 +++++++++---------------------------
 drivers/pci/hotplug/pciehp_acpi.c  |    5 +-
 include/linux/pci_hotplug.h        |    2 -
 4 files changed, 34 insertions(+), 86 deletions(-)

[PATCH 1/2] PCI Hotplug: acpiphp: find bridges the easy way

[Alex Chiang]

Instead of constantly evaluating _ADR and _SEG over and over again,
let's simplify our lives by using:

	acpi_pci_find_root() for root bridges
	acpi_get_pci_dev() for p2p bridges

This change eliminates some copy 'n paste code and also allows us
to simplify some internal interfaces.

Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/pci/hotplug/acpiphp_glue.c |   81 +++++++++---------------------------
 1 files changed, 21 insertions(+), 60 deletions(-)

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 2e5f259..e72e0ad 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -277,14 +277,15 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 
 
 /* see if it's worth looking at this bridge */
-static int detect_ejectable_slots(struct pci_bus *pbus)
+static int detect_ejectable_slots(acpi_handle handle)
 {
-	int found = acpi_pci_detect_ejectable(pbus);
+	int found;
+	struct pci_bus *pbus;
+
+	pbus = pci_bus_from_handle(handle);
+	found = acpi_pci_detect_ejectable(pbus);
 	if (!found) {
-		acpi_handle bridge_handle = acpi_pci_get_bridge_handle(pbus);
-		if (!bridge_handle)
-			return 0;
-		acpi_walk_namespace(ACPI_TYPE_DEVICE, bridge_handle, (u32)1,
+		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 				    is_pci_dock_device, (void *)&found, NULL);
 	}
 	return found;
@@ -415,9 +416,10 @@ static inline void config_p2p_bridge_flags(struct acpiphp_bridge *bridge)
 
 
 /* allocate and initialize host bridge data structure */
-static void add_host_bridge(acpi_handle *handle, struct pci_bus *pci_bus)
+static void add_host_bridge(acpi_handle *handle)
 {
 	struct acpiphp_bridge *bridge;
+	struct acpi_pci_root *root = acpi_pci_find_root(handle);
 
 	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
 	if (bridge == NULL)
@@ -426,7 +428,7 @@ static void add_host_bridge(acpi_handle *handle, struct pci_bus *pci_bus)
 	bridge->type = BRIDGE_TYPE_HOST;
 	bridge->handle = handle;
 
-	bridge->pci_bus = pci_bus;
+	bridge->pci_bus = root->bus;
 
 	spin_lock_init(&bridge->res_lock);
 
@@ -435,7 +437,7 @@ static void add_host_bridge(acpi_handle *handle, struct pci_bus *pci_bus)
 
 
 /* allocate and initialize PCI-to-PCI bridge data structure */
-static void add_p2p_bridge(acpi_handle *handle, struct pci_dev *pci_dev)
+static void add_p2p_bridge(acpi_handle *handle)
 {
 	struct acpiphp_bridge *bridge;
 
@@ -449,8 +451,8 @@ static void add_p2p_bridge(acpi_handle *handle, struct pci_dev *pci_dev)
 	bridge->handle = handle;
 	config_p2p_bridge_flags(bridge);
 
-	bridge->pci_dev = pci_dev_get(pci_dev);
-	bridge->pci_bus = pci_dev->subordinate;
+	bridge->pci_dev = acpi_get_pci_dev(handle);
+	bridge->pci_bus = bridge->pci_dev->subordinate;
 	if (!bridge->pci_bus) {
 		err("This is not a PCI-to-PCI bridge!\n");
 		goto err;
@@ -467,7 +469,7 @@ static void add_p2p_bridge(acpi_handle *handle, struct pci_dev *pci_dev)
 	init_bridge_misc(bridge);
 	return;
  err:
-	pci_dev_put(pci_dev);
+	pci_dev_put(bridge->pci_dev);
 	kfree(bridge);
 	return;
 }
@@ -478,39 +480,21 @@ static acpi_status
 find_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
 	acpi_status status;
-	acpi_handle dummy_handle;
-	unsigned long long tmp;
-	int device, function;
 	struct pci_dev *dev;
-	struct pci_bus *pci_bus = context;
-
-	status = acpi_get_handle(handle, "_ADR", &dummy_handle);
-	if (ACPI_FAILURE(status))
-		return AE_OK;		/* continue */
-
-	status = acpi_evaluate_integer(handle, "_ADR", NULL, &tmp);
-	if (ACPI_FAILURE(status)) {
-		dbg("%s: _ADR evaluation failure\n", __func__);
-		return AE_OK;
-	}
-
-	device = (tmp >> 16) & 0xffff;
-	function = tmp & 0xffff;
-
-	dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
 
+	dev = acpi_get_pci_dev(handle);
 	if (!dev || !dev->subordinate)
 		goto out;
 
 	/* check if this bridge has ejectable slots */
-	if ((detect_ejectable_slots(dev->subordinate) > 0)) {
+	if ((detect_ejectable_slots(handle) > 0)) {
 		dbg("found PCI-to-PCI bridge at PCI %s\n", pci_name(dev));
-		add_p2p_bridge(handle, dev);
+		add_p2p_bridge(handle);
 	}
 
 	/* search P2P bridges under this p2p bridge */
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
-				     find_p2p_bridge, dev->subordinate, NULL);
+				     find_p2p_bridge, NULL, NULL);
 	if (ACPI_FAILURE(status))
 		warn("find_p2p_bridge failed (error code = 0x%x)\n", status);
 
@@ -525,9 +509,7 @@ static int add_bridge(acpi_handle handle)
 {
 	acpi_status status;
 	unsigned long long tmp;
-	int seg, bus;
 	acpi_handle dummy_handle;
-	struct pci_bus *pci_bus;
 
 	/* if the bridge doesn't have _STA, we assume it is always there */
 	status = acpi_get_handle(handle, "_STA", &dummy_handle);
@@ -542,36 +524,15 @@ static int add_bridge(acpi_handle handle)
 			return 0;
 	}
 
-	/* get PCI segment number */
-	status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
-
-	seg = ACPI_SUCCESS(status) ? tmp : 0;
-
-	/* get PCI bus number */
-	status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
-
-	if (ACPI_SUCCESS(status)) {
-		bus = tmp;
-	} else {
-		warn("can't get bus number, assuming 0\n");
-		bus = 0;
-	}
-
-	pci_bus = pci_find_bus(seg, bus);
-	if (!pci_bus) {
-		err("Can't find bus %04x:%02x\n", seg, bus);
-		return 0;
-	}
-
 	/* check if this bridge has ejectable slots */
-	if (detect_ejectable_slots(pci_bus) > 0) {
+	if (detect_ejectable_slots(handle) > 0) {
 		dbg("found PCI host-bus bridge with hot-pluggable slots\n");
-		add_host_bridge(handle, pci_bus);
+		add_host_bridge(handle);
 	}
 
 	/* search P2P bridges under this host bridge */
 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
-				     find_p2p_bridge, pci_bus, NULL);
+				     find_p2p_bridge, NULL, NULL);
 
 	if (ACPI_FAILURE(status))
 		warn("find_p2p_bridge failed (error code = 0x%x)\n", status);

[PATCH 2/2] PCI Hotplug: convert acpi_pci_detect_ejectable() to take an acpi_handle

[Alex Chiang]

acpi_pci_detect_ejectable() goes through effort to convert its
struct pci_bus arg to an acpi_handle, but every time we use this
interface, we already have the handle available.

So let's just use the handle instead of converting back and forth.

Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
---

 drivers/pci/hotplug/acpi_pcihp.c   |    9 +++------
 drivers/pci/hotplug/acpiphp_glue.c |   33 +++++++++++----------------------
 drivers/pci/hotplug/pciehp_acpi.c  |    5 +++--
 include/linux/pci_hotplug.h        |    2 +-
 4 files changed, 18 insertions(+), 31 deletions(-)

diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
index eb15958..80af75c 100644
--- a/drivers/pci/hotplug/acpi_pcihp.c
+++ b/drivers/pci/hotplug/acpi_pcihp.c
@@ -500,18 +500,15 @@ check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
 
 /**
  * acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
- * @pbus - PCI bus to scan
+ * @handle - handle of the PCI bus to scan
  *
  * Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
  */
-int acpi_pci_detect_ejectable(struct pci_bus *pbus)
+int acpi_pci_detect_ejectable(acpi_handle handle)
 {
-	acpi_handle handle;
 	int found = 0;
 
-	if (!(handle = acpi_pci_get_bridge_handle(pbus)))
-		return 0;
-	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
+	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 			    check_hotplug, (void *)&found, NULL);
 	return found;
 }
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index e72e0ad..680c336 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -62,22 +62,6 @@ static void acpiphp_sanitize_bus(struct pci_bus *bus);
 static void acpiphp_set_hpp_values(acpi_handle handle, struct pci_bus *bus);
 static void handle_hotplug_event_func(acpi_handle handle, u32 type, void *context);
 
-static struct pci_bus *pci_bus_from_handle(acpi_handle handle)
-{
-	struct pci_bus *pbus;
-	struct acpi_pci_root *root;
-
-	root = acpi_pci_find_root(handle);
-	if (root)
-		pbus = root->bus;
-	else {
-		struct pci_dev *pdev = acpi_get_pci_dev(handle);
-		pbus = pdev->subordinate;
-		pci_dev_put(pdev);
-	}
-	return pbus;
-}
-
 /* callback routine to check for the existence of a pci dock device */
 static acpi_status
 is_pci_dock_device(acpi_handle handle, u32 lvl, void *context, void **rv)
@@ -279,11 +263,7 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 /* see if it's worth looking at this bridge */
 static int detect_ejectable_slots(acpi_handle handle)
 {
-	int found;
-	struct pci_bus *pbus;
-
-	pbus = pci_bus_from_handle(handle);
-	found = acpi_pci_detect_ejectable(pbus);
+	int found = acpi_pci_detect_ejectable(handle);
 	if (!found) {
 		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
 				    is_pci_dock_device, (void *)&found, NULL);
@@ -1364,7 +1344,16 @@ static void acpiphp_sanitize_bus(struct pci_bus *bus)
 /* Program resources in newly inserted bridge */
 static int acpiphp_configure_bridge (acpi_handle handle)
 {
-	struct pci_bus *bus = pci_bus_from_handle(handle);
+	struct pci_bus *bus;
+
+	if (acpi_is_root_bridge(handle)) {
+		struct acpi_pci_root *root = acpi_pci_find_root(handle);
+		bus = root->bus;
+	} else {
+		struct pci_dev *pdev = acpi_get_pci_dev(handle);
+		bus = pdev->subordinate;
+		pci_dev_put(pdev);
+	}
 
 	pci_bus_size_bridges(bus);
 	pci_bus_assign_resources(bus);
diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c
index 9604801..0c6aa99 100644
--- a/drivers/pci/hotplug/pciehp_acpi.c
+++ b/drivers/pci/hotplug/pciehp_acpi.c
@@ -47,7 +47,7 @@ int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
 {
 	if (slot_detection_mode != PCIEHP_DETECT_ACPI)
 		return 0;
-	if (acpi_pci_detect_ejectable(dev->subordinate))
+	if (acpi_pci_detect_ejectable(dev->dev.archdata.acpi_handle))
 		return 0;
 	return -ENODEV;
 }
@@ -94,7 +94,8 @@ static int __init dummy_probe(struct pcie_device *dev)
 			dup_slot_id++;
 	}
 	list_add_tail(&slot->slot_list, &dummy_slots);
-	if (!acpi_slot_detected && acpi_pci_detect_ejectable(pbus))
+	if (!acpi_slot_detected &&
+		acpi_pci_detect_ejectable(pbus->self->dev.archdata.acpi_handle))
 		acpi_slot_detected = 1;
 	return -ENODEV;         /* dummy driver always returns error */
 }
diff --git a/include/linux/pci_hotplug.h b/include/linux/pci_hotplug.h
index 1b00cc3..f0c31ae 100644
--- a/include/linux/pci_hotplug.h
+++ b/include/linux/pci_hotplug.h
@@ -231,7 +231,7 @@ extern acpi_status acpi_get_hp_params_from_firmware(struct pci_bus *bus,
 				struct hotplug_params *hpp);
 int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags);
 int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle);
-int acpi_pci_detect_ejectable(struct pci_bus *pbus);
+int acpi_pci_detect_ejectable(acpi_handle handle);
 #endif
 #endif
 

Re: [PATCH 2/2] PCI Hotplug: convert acpi_pci_detect_ejectable() to take an acpi_handle

[Kenji Kaneshige]

Alex Chiang wrote:
> acpi_pci_detect_ejectable() goes through effort to convert its
> struct pci_bus arg to an acpi_handle, but every time we use this
> interface, we already have the handle available.
> 
> So let's just use the handle instead of converting back and forth.
> 
> Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
> Signed-off-by: Alex Chiang <achiang@hp.com>
> ---
> 
>  drivers/pci/hotplug/acpi_pcihp.c   |    9 +++------
>  drivers/pci/hotplug/acpiphp_glue.c |   33 +++++++++++----------------------
>  drivers/pci/hotplug/pciehp_acpi.c  |    5 +++--
>  include/linux/pci_hotplug.h        |    2 +-
>  4 files changed, 18 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
> index eb15958..80af75c 100644
> --- a/drivers/pci/hotplug/acpi_pcihp.c
> +++ b/drivers/pci/hotplug/acpi_pcihp.c
> @@ -500,18 +500,15 @@ check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv)
>  
>  /**
>   * acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots
> - * @pbus - PCI bus to scan
> + * @handle - handle of the PCI bus to scan
>   *
>   * Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise.
>   */
> -int acpi_pci_detect_ejectable(struct pci_bus *pbus)
> +int acpi_pci_detect_ejectable(acpi_handle handle)
>  {
> -	acpi_handle handle;
>  	int found = 0;
>  
> -	if (!(handle = acpi_pci_get_bridge_handle(pbus)))
> -		return 0;
> -	acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,

I think we need NULL check here.

	if (!handle)
		return 0;

(snip.)

> diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c
> index 9604801..0c6aa99 100644
> --- a/drivers/pci/hotplug/pciehp_acpi.c
> +++ b/drivers/pci/hotplug/pciehp_acpi.c
> @@ -47,7 +47,7 @@ int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
>  {
>  	if (slot_detection_mode != PCIEHP_DETECT_ACPI)
>  		return 0;
> -	if (acpi_pci_detect_ejectable(dev->subordinate))
> +	if (acpi_pci_detect_ejectable(dev->dev.archdata.acpi_handle))
>  		return 0;

How about:

	handle = DEVICE_ACPI_HANDLE(&dev->dev);
	if (acpi_pci_detect_ejectable(handle))
		return 0;


>  	return -ENODEV;
>  }
> @@ -94,7 +94,8 @@ static int __init dummy_probe(struct pcie_device *dev)
>  			dup_slot_id++;
>  	}
>  	list_add_tail(&slot->slot_list, &dummy_slots);
> -	if (!acpi_slot_detected && acpi_pci_detect_ejectable(pbus))
> +	if (!acpi_slot_detected &&
> +		acpi_pci_detect_ejectable(pbus->self->dev.archdata.acpi_handle))
>  		acpi_slot_detected = 1;

How about:

	handle = DEVICE_ACPI_HANDLE(&pdev->dev);
	if (!acpi_slot_detected && acpi_pci_detect_ejectable(handle))

And the following line at the head of dummy_probe() seems no longer
needed.

	struct pci_bus *pbus = pdev->subordinate;

Thanks,
Kenji Kaneshige

Re: [PATCH 2/2] PCI Hotplug: convert acpi_pci_detect_ejectable() to take an acpi_handle

[Alex Chiang]

Thank you for the review, Kenji-san. I've incorporated your
comments and will send out the revised patchset shortly.

/ac