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authorLinas Vepstas <linas@austin.ibm.com>2007-04-13 15:34:22 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2007-05-02 19:02:40 -0700
commitda65944be2441191539f50ce71cd1f8030699be1 (patch)
tree009e2ef836472f1f184f84dcb1b8cc29a783173a /drivers/pci
parent8485d1a123e0d367bbcbfec36acf134e6895f39a (diff)
PCI: rpaphp: Document is_php_dn()
Fix up the documentation: the rpaphp_add_slot() does not actually handle embedded slots: in fact, it ignores them. Fix the flow of control in the routine that checks for embedded slots. Signed-off-by: Linas Vepstas <linas@austin.ibm.com> Cc: John Rose <johnrose@austin.ibm.com> Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/hotplug/rpaphp_core.c42
1 files changed, 29 insertions, 13 deletions
diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
index 75113d9e84e..aa8d9a60d0a 100644
--- a/drivers/pci/hotplug/rpaphp_core.c
+++ b/drivers/pci/hotplug/rpaphp_core.c
@@ -262,6 +262,14 @@ static int is_php_type(char *drc_type)
return 1;
}
+/**
+ * is_php_dn() - return 1 if this is a hotpluggable pci slot, else 0
+ *
+ * This routine will return true only if the device node is
+ * a hotpluggable slot. This routine will return false
+ * for built-in pci slots (even when the built-in slots are
+ * dlparable.)
+ */
static int is_php_dn(struct device_node *dn, const int **indexes,
const int **names, const int **types, const int **power_domains)
{
@@ -269,24 +277,31 @@ static int is_php_dn(struct device_node *dn, const int **indexes,
int rc;
rc = get_children_props(dn, indexes, names, &drc_types, power_domains);
- if (rc >= 0) {
- if (is_php_type((char *) &drc_types[1])) {
- *types = drc_types;
- return 1;
- }
- }
+ if (rc < 0)
+ return 0;
- return 0;
+ if (!is_php_type((char *) &drc_types[1]))
+ return 0;
+
+ *types = drc_types;
+ return 1;
}
/**
- * rpaphp_add_slot -- add hotplug or dlpar slot
+ * rpaphp_add_slot -- declare a hotplug slot to the hotplug subsystem.
+ * @dn device node of slot
+ *
+ * This subroutine will register a hotplugable slot with the
+ * PCI hotplug infrastructure. This routine is typicaly called
+ * during boot time, if the hotplug slots are present at boot time,
+ * or is called later, by the dlpar add code, if the slot is
+ * being dynamically added during runtime.
+ *
+ * If the device node points at an embedded (built-in) slot, this
+ * routine will just return without doing anything, since embedded
+ * slots cannot be hotplugged.
*
- * rpaphp not only registers PCI hotplug slots(HOTPLUG),
- * but also logical DR slots(EMBEDDED).
- * HOTPLUG slot: An adapter can be physically added/removed.
- * EMBEDDED slot: An adapter can be logically removed/added
- * from/to a partition with the slot.
+ * To remove a slot, it suffices to call rpaphp_deregister_slot()
*/
int rpaphp_add_slot(struct device_node *dn)
{
@@ -299,6 +314,7 @@ int rpaphp_add_slot(struct device_node *dn)
if (!dn->name || strcmp(dn->name, "pci"))
return 0;
+ /* If this is not a hotplug slot, return without doing anything. */
if (!is_php_dn(dn, &indexes, &names, &types, &power_domains))
return 0;