PCI hotplug: introduce functions for ACPI slot detection

Some ACPI related PCI hotplug code can be shared among PCI hotplug
drivers. This patch introduces the following functions in
drivers/pci/hotplug/acpi_pcihp.c to share the code, and changes
acpiphp and pciehp to use them.

- int acpi_pci_detect_ejectable(struct pci_bus *pbus)
  This checks if the specified PCI bus has ejectable slots.

- int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle)
  This checks if the specified handle is ejectable ACPI PCI slot. The
  'pbus' parameter is needed to check if 'handle' is PCI related ACPI
  object.

This patch also introduces the following inline function in
include/linux/pci-acpi.h, which is useful to get ACPI handle of the
PCI bridge from struct pci_bus of the bridge's secondary bus.

- static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)
  This returns ACPI handle of the PCI bridge which generates PCI bus
  specified by 'pbus'.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 15 insertions, 92 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 7a5760426897..f09b1010d477 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -46,6 +46,7 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <linux/pci_hotplug.h>
+#include <linux/pci-acpi.h>
 #include <linux/mutex.h>
 
 #include "../pci.h"
@@ -62,68 +63,6 @@ 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);
 
-
-/*
- * initialization & terminatation routines
- */
-
-/**
- * is_ejectable - determine if a slot is ejectable
- * @handle: handle to acpi namespace
- *
- * Ejectable slot should satisfy at least these conditions:
- *
- *  1. has _ADR method
- *  2. has _EJ0 method or _RMV method
- *
- * optionally
- *
- *  1. has _STA method
- *  2. has _PS0 method
- *  3. has _PS3 method
- *  4. ..
- */
-static int is_ejectable(acpi_handle handle)
-{
-        acpi_status status;
-        acpi_handle tmp;
-        unsigned long long removable;
-
-        status = acpi_get_handle(handle, "_ADR", &tmp);
-        if (ACPI_FAILURE(status))
-                return 0;
-
-        status = acpi_get_handle(handle, "_EJ0", &tmp);
-        if (ACPI_SUCCESS(status))
-                return 1;
-
-        status = acpi_get_handle(handle, "_RMV", &tmp);
-        if (ACPI_SUCCESS(status)) {
-                status = acpi_evaluate_integer(handle, "_RMV", NULL,
-                                               &removable);
-                if (ACPI_SUCCESS(status) && removable)
-                        return 1;
-        }
-
-        return 0;
-}
-
-
-/* callback routine to check for the existence of ejectable slots */
-static acpi_status
-is_ejectable_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
-{
-        int *count = (int *)context;
-
-        if (is_ejectable(handle)) {
-                (*count)++;
-                /* only one ejectable slot is enough */
-                return AE_CTRL_TERMINATE;
-        } else {
-                return AE_OK;
-        }
-}
-
 /* 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)
@@ -138,9 +77,6 @@ is_pci_dock_device(acpi_handle handle, u32 lvl, void *context, void **rv)
         }
 }
 
-
-
-
 /*
  * the _DCK method can do funny things... and sometimes not
  * hah-hah funny.
@@ -191,8 +127,9 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
         acpi_status status = AE_OK;
         unsigned long long adr, sun;
         int device, function, retval;
+        struct pci_bus *pbus = bridge->pci_bus;
 
-        if (!is_ejectable(handle) && !is_dock_device(handle))
+        if (!acpi_pci_check_ejectable(pbus, handle) && !is_dock_device(handle))
                 return AE_OK;
 
         acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
@@ -258,8 +195,7 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
                 bridge->nr_slots++;
 
                 dbg("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
-                                slot->sun, pci_domain_nr(bridge->pci_bus),
-                                bridge->pci_bus->number, slot->device);
+                    slot->sun, pci_domain_nr(pbus), pbus->number, device);
                 retval = acpiphp_register_hotplug_slot(slot);
                 if (retval) {
                         if (retval == -EBUSY)
@@ -276,8 +212,7 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
         list_add_tail(&newfunc->sibling, &slot->funcs);
 
         /* associate corresponding pci_dev */
-        newfunc->pci_dev = pci_get_slot(bridge->pci_bus,
-                                         PCI_DEVFN(device, function));
+        newfunc->pci_dev = pci_get_slot(pbus, PCI_DEVFN(device, function));
         if (newfunc->pci_dev) {
                 slot->flags |= (SLOT_ENABLED | SLOT_POWEREDON);
         }
@@ -326,27 +261,15 @@ 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(acpi_handle *bridge_handle)
+static int detect_ejectable_slots(struct pci_bus *pbus)
 {
-        acpi_status status;
-        int count;
-
-        count = 0;
-
-        /* only check slots defined directly below bridge object */
-        status = acpi_walk_namespace(ACPI_TYPE_DEVICE, bridge_handle, (u32)1,
-                                     is_ejectable_slot, (void *)&count, NULL);
-
-        /*
-         * we also need to add this bridge if there is a dock bridge or
-         * other pci device on a dock station (removable)
-         */
-        if (!count)
-                status = acpi_walk_namespace(ACPI_TYPE_DEVICE, bridge_handle,
-                                (u32)1, is_pci_dock_device, (void *)&count,
-                                NULL);
-
-        return count;
+        int found = acpi_pci_detect_ejectable(pbus);
+        if (!found) {
+                acpi_handle bridge_handle = acpi_pci_get_bridge_handle(pbus);
+                acpi_walk_namespace(ACPI_TYPE_DEVICE, bridge_handle, (u32)1,
+                                    is_pci_dock_device, (void *)&found, NULL);
+        }
+        return found;
 }
 
 
@@ -556,7 +479,7 @@ find_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
                 goto out;
 
         /* check if this bridge has ejectable slots */
-        if ((detect_ejectable_slots(handle) > 0)) {
+        if ((detect_ejectable_slots(dev->subordinate) > 0)) {
                 dbg("found PCI-to-PCI bridge at PCI %s\n", pci_name(dev));
                 add_p2p_bridge(handle, dev);
         }
@@ -617,7 +540,7 @@ static int add_bridge(acpi_handle handle)
         }
 
         /* check if this bridge has ejectable slots */
-        if (detect_ejectable_slots(handle) > 0) {
+        if (detect_ejectable_slots(pci_bus) > 0) {
                 dbg("found PCI host-bus bridge with hot-pluggable slots\n");
                 add_host_bridge(handle, pci_bus);
         }