From kristen.c.accardi@intel.com Fri Apr 13 15:34:20 2007 From: Linas Vepstas Date: Fri, 13 Apr 2007 15:34:22 -0700 Subject: [patch 16/21] PCI: rpaphp: Document is_php_dn() To: gregkh@suse.de Message-ID: <20070413223420.712735502@intel.com> Content-Disposition: inline; filename=pci-rpaphp-document-is_php_dn From: Linas Vepstas 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 Cc: John Rose Signed-off-by: Kristen Carlson Accardi Signed-off-by: Greg Kroah-Hartman --- drivers/pci/hotplug/rpaphp_core.c | 42 ++++++++++++++++++++++++++------------ 1 file changed, 29 insertions(+), 13 deletions(-) --- 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 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 * 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;