Subject: [PATCH V4 3/4] hotplug/drc-info: Add code to search ibm,drc-info property

Message ID 6a94bcc7-20c5-98fc-3f17-ab1b9d4385fa@linux.vnet.ibm.com
State New
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  • Subject: [PATCH V4 3/4] hotplug/drc-info: Add code to search ibm,drc-info property
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Commit Message

Michael Bringmann Nov. 16, 2017, 8:11 p.m.
rpadlpar_core.c: Provide parallel routines to search the older device-
tree properties ("ibm,drc-indexes", "ibm,drc-names", "ibm,drc-types"
and "ibm,drc-power-domains"), or the new property "ibm,drc-info".

The interface to examine the DRC information is changed from a "get"
function that returns values for local verification elsewhere, to a
"check" function that validates the 'name' and/or 'type' of a device
node.  This update hides the format of the underlying device-tree
properties, and concentrates the value checks into a single function
without requiring the user to verify whether a search was successful.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in V4:
  -- Rename of_one_drc_info to of_read_drc_info_cell
  -- Fix some spacing within arguments
---
 drivers/pci/hotplug/rpadlpar_core.c |   13 ++--
 drivers/pci/hotplug/rpaphp.h        |    4 +
 drivers/pci/hotplug/rpaphp_core.c   |  110 +++++++++++++++++++++++++++--------
 3 files changed, 92 insertions(+), 35 deletions(-)

Comments

Nathan Fontenot Nov. 20, 2017, 3:38 p.m. | #1
On 11/16/2017 02:11 PM, Michael Bringmann wrote:
> rpadlpar_core.c: Provide parallel routines to search the older device-
> tree properties ("ibm,drc-indexes", "ibm,drc-names", "ibm,drc-types"
> and "ibm,drc-power-domains"), or the new property "ibm,drc-info".
> 
> The interface to examine the DRC information is changed from a "get"
> function that returns values for local verification elsewhere, to a
> "check" function that validates the 'name' and/or 'type' of a device
> node.  This update hides the format of the underlying device-tree
> properties, and concentrates the value checks into a single function
> without requiring the user to verify whether a search was successful.
> 
> Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
> ---
> Changes in V4:
>   -- Rename of_one_drc_info to of_read_drc_info_cell
>   -- Fix some spacing within arguments
> ---
>  drivers/pci/hotplug/rpadlpar_core.c |   13 ++--
>  drivers/pci/hotplug/rpaphp.h        |    4 +
>  drivers/pci/hotplug/rpaphp_core.c   |  110 +++++++++++++++++++++++++++--------
>  3 files changed, 92 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
> index a3449d7..fc01d7d 100644
> --- a/drivers/pci/hotplug/rpadlpar_core.c
> +++ b/drivers/pci/hotplug/rpadlpar_core.c
> @@ -27,6 +27,7 @@
>  #include <linux/mutex.h>
>  #include <asm/rtas.h>
>  #include <asm/vio.h>
> +#include <linux/firmware.h>
> 
>  #include "../pci.h"
>  #include "rpaphp.h"
> @@ -44,15 +45,14 @@ static struct device_node *find_vio_slot_node(char *drc_name)
>  {
>  	struct device_node *parent = of_find_node_by_name(NULL, "vdevice");
>  	struct device_node *dn = NULL;
> -	char *name;
>  	int rc;
> 
>  	if (!parent)
>  		return NULL;
> 
>  	while ((dn = of_get_next_child(parent, dn))) {
> -		rc = rpaphp_get_drc_props(dn, NULL, &name, NULL, NULL);
> -		if ((rc == 0) && (!strcmp(drc_name, name)))
> +		rc = rpaphp_check_drc_props(dn, drc_name, NULL);
> +		if (rc == 0)
>  			break;
>  	}
> 
> @@ -64,15 +64,12 @@ static struct device_node *find_php_slot_pci_node(char *drc_name,
>  						  char *drc_type)
>  {
>  	struct device_node *np = NULL;
> -	char *name;
> -	char *type;
>  	int rc;
> 
>  	while ((np = of_find_node_by_name(np, "pci"))) {
> -		rc = rpaphp_get_drc_props(np, NULL, &name, &type, NULL);
> +		rc = rpaphp_check_drc_props(np, drc_name, drc_type);
>  		if (rc == 0)
> -			if (!strcmp(drc_name, name) && !strcmp(drc_type, type))
> -				break;
> +			break;
>  	}
> 
>  	return np;
> diff --git a/drivers/pci/hotplug/rpaphp.h b/drivers/pci/hotplug/rpaphp.h
> index 7db024e..8db5f2e 100644
> --- a/drivers/pci/hotplug/rpaphp.h
> +++ b/drivers/pci/hotplug/rpaphp.h
> @@ -91,8 +91,8 @@ struct slot {
> 
>  /* rpaphp_core.c */
>  int rpaphp_add_slot(struct device_node *dn);
> -int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
> -		char **drc_name, char **drc_type, int *drc_power_domain);
> +int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
> +		char *drc_type);
> 
>  /* rpaphp_slot.c */
>  void dealloc_slot_struct(struct slot *slot);
> diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
> index 1e29aba..0a3b5f5 100644
> --- a/drivers/pci/hotplug/rpaphp_core.c
> +++ b/drivers/pci/hotplug/rpaphp_core.c
> @@ -30,6 +30,7 @@
>  #include <linux/smp.h>
>  #include <linux/init.h>
>  #include <linux/vmalloc.h>
> +#include <asm/firmware.h>
>  #include <asm/eeh.h>       /* for eeh_add_device() */
>  #include <asm/rtas.h>		/* rtas_call */
>  #include <asm/pci-bridge.h>	/* for pci_controller */
> @@ -196,25 +197,21 @@ static int get_children_props(struct device_node *dn, const int **drc_indexes,
>  	return 0;
>  }
> 
> -/* To get the DRC props describing the current node, first obtain it's
> - * my-drc-index property.  Next obtain the DRC list from it's parent.  Use
> - * the my-drc-index for correlation, and obtain the requested properties.
> +
> +/* Verify the existence of 'drc_name' and/or 'drc_type' within the
> + * current node.  First obtain it's my-drc-index property.  Next,
> + * obtain the DRC info from it's parent.  Use the my-drc-index for
> + * correlation, and obtain/validate the requested properties.
>   */
> -int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
> -		char **drc_name, char **drc_type, int *drc_power_domain)
> +
> +static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
> +				char *drc_type, unsigned int my_index)
>  {
> +	char *name_tmp, *type_tmp;
>  	const int *indexes, *names;
>  	const int *types, *domains;
> -	const unsigned int *my_index;
> -	char *name_tmp, *type_tmp;
>  	int i, rc;
> 
> -	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
> -	if (!my_index) {
> -		/* Node isn't DLPAR/hotplug capable */
> -		return -EINVAL;
> -	}
> -
>  	rc = get_children_props(dn->parent, &indexes, &names, &types, &domains);
>  	if (rc < 0) {
>  		return -EINVAL;
> @@ -225,24 +222,87 @@ int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
> 
>  	/* Iterate through parent properties, looking for my-drc-index */
>  	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
> -		if ((unsigned int) indexes[i + 1] == *my_index) {
> -			if (drc_name)
> -				*drc_name = name_tmp;
> -			if (drc_type)
> -				*drc_type = type_tmp;
> -			if (drc_index)
> -				*drc_index = be32_to_cpu(*my_index);
> -			if (drc_power_domain)
> -				*drc_power_domain = be32_to_cpu(domains[i+1]);
> -			return 0;
> -		}
> +		if ((unsigned int) indexes[i + 1] == my_index)
> +			break;
> +
>  		name_tmp += (strlen(name_tmp) + 1);
>  		type_tmp += (strlen(type_tmp) + 1);
>  	}
> 
> +	if (((drc_name == NULL) || (drc_name && !strcmp(drc_name, name_tmp))) &&
> +	    ((drc_type == NULL) || (drc_type && !strcmp(drc_type, type_tmp))))
> +		return 0;
> +
> +	return -EINVAL;
> +}
> +
> +static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
> +				char *drc_type, unsigned int my_index)
> +{
> +	struct property *info;
> +	unsigned int entries;
> +	struct of_drc_info drc;
> +	const __be32 *value;
> +	int j;
> +
> +	info = of_find_property(dn->parent, "ibm,drc-info", NULL);
> +	if (info == NULL)
> +		return -EINVAL;
> +
> +	value = info->value;
> +	value = (void *)of_prop_next_u32(info, value, &entries);
> +	if (!value)
> +		return -EINVAL;
> +
> +	for (j = 0; j < entries; j++) {
> +		of_read_drc_info_cell(&info, &value, &drc);
> +
> +		/* Should now know end of current entry */
> +
> +		WARN_ON((my_index < drc.drc_index_start) ||
> +			(((my_index - drc.drc_index_start) %
> +				drc.sequential_inc) != 0));

This WARN_ON would also fit better in of_read_drc_info_cell()

-Nathan

> +
> +		if (my_index > drc.last_drc_index)
> +			continue;
> +
> +		break;
> +	}
> +	/* Found it */
> +
> +	if (((drc_name == NULL) ||
> +	     (drc_name && !strncmp(drc_name,
> +				drc.drc_name_prefix,
> +				strlen(drc.drc_name_prefix)))) &&
> +	    ((drc_type == NULL) ||
> +	     (drc_type && !strncmp(drc_type,
> +				drc.drc_type,
> +				strlen(drc.drc_type)))))
> +		return 0;
> +
>  	return -EINVAL;
>  }
> -EXPORT_SYMBOL_GPL(rpaphp_get_drc_props);
> +
> +int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
> +			char *drc_type)
> +{
> +	const unsigned int *my_index;
> +
> +	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
> +	if (!my_index) {
> +		/* Node isn't DLPAR/hotplug capable */
> +		return -EINVAL;
> +	}
> +
> +	if (firmware_has_feature(FW_FEATURE_DRC_INFO))
> +		return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
> +						*my_index);
> +	else
> +		return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
> +						*my_index);
> +}
> +EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
> +
> 
>  static int is_php_type(char *drc_type)
>  {
>
Michael Bringmann Nov. 27, 2017, 7:26 p.m. | #2
See below.

On 11/20/2017 09:38 AM, Nathan Fontenot wrote:
> On 11/16/2017 02:11 PM, Michael Bringmann wrote:
>> rpadlpar_core.c: Provide parallel routines to search the older device-
>> tree properties ("ibm,drc-indexes", "ibm,drc-names", "ibm,drc-types"
>> and "ibm,drc-power-domains"), or the new property "ibm,drc-info".
>>
>> The interface to examine the DRC information is changed from a "get"
>> function that returns values for local verification elsewhere, to a
>> "check" function that validates the 'name' and/or 'type' of a device
>> node.  This update hides the format of the underlying device-tree
>> properties, and concentrates the value checks into a single function
>> without requiring the user to verify whether a search was successful.
>>
>> Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
>> ---
>> Changes in V4:
>>   -- Rename of_one_drc_info to of_read_drc_info_cell
>>   -- Fix some spacing within arguments
>> ---
>>  drivers/pci/hotplug/rpadlpar_core.c |   13 ++--
>>  drivers/pci/hotplug/rpaphp.h        |    4 +
>>  drivers/pci/hotplug/rpaphp_core.c   |  110 +++++++++++++++++++++++++++--------
>>  3 files changed, 92 insertions(+), 35 deletions(-)
>>
>> diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
>> index a3449d7..fc01d7d 100644
>> --- a/drivers/pci/hotplug/rpadlpar_core.c
>> +++ b/drivers/pci/hotplug/rpadlpar_core.c
>> @@ -27,6 +27,7 @@
>>  #include <linux/mutex.h>
>>  #include <asm/rtas.h>
>>  #include <asm/vio.h>
>> +#include <linux/firmware.h>
>>
>>  #include "../pci.h"
>>  #include "rpaphp.h"
>> @@ -44,15 +45,14 @@ static struct device_node *find_vio_slot_node(char *drc_name)
>>  {
>>  	struct device_node *parent = of_find_node_by_name(NULL, "vdevice");
>>  	struct device_node *dn = NULL;
>> -	char *name;
>>  	int rc;
>>
>>  	if (!parent)
>>  		return NULL;
>>
>>  	while ((dn = of_get_next_child(parent, dn))) {
>> -		rc = rpaphp_get_drc_props(dn, NULL, &name, NULL, NULL);
>> -		if ((rc == 0) && (!strcmp(drc_name, name)))
>> +		rc = rpaphp_check_drc_props(dn, drc_name, NULL);
>> +		if (rc == 0)
>>  			break;
>>  	}
>>
>> @@ -64,15 +64,12 @@ static struct device_node *find_php_slot_pci_node(char *drc_name,
>>  						  char *drc_type)
>>  {
>>  	struct device_node *np = NULL;
>> -	char *name;
>> -	char *type;
>>  	int rc;
>>
>>  	while ((np = of_find_node_by_name(np, "pci"))) {
>> -		rc = rpaphp_get_drc_props(np, NULL, &name, &type, NULL);
>> +		rc = rpaphp_check_drc_props(np, drc_name, drc_type);
>>  		if (rc == 0)
>> -			if (!strcmp(drc_name, name) && !strcmp(drc_type, type))
>> -				break;
>> +			break;
>>  	}
>>
>>  	return np;
>> diff --git a/drivers/pci/hotplug/rpaphp.h b/drivers/pci/hotplug/rpaphp.h
>> index 7db024e..8db5f2e 100644
>> --- a/drivers/pci/hotplug/rpaphp.h
>> +++ b/drivers/pci/hotplug/rpaphp.h
>> @@ -91,8 +91,8 @@ struct slot {
>>
>>  /* rpaphp_core.c */
>>  int rpaphp_add_slot(struct device_node *dn);
>> -int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
>> -		char **drc_name, char **drc_type, int *drc_power_domain);
>> +int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
>> +		char *drc_type);
>>
>>  /* rpaphp_slot.c */
>>  void dealloc_slot_struct(struct slot *slot);
>> diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
>> index 1e29aba..0a3b5f5 100644
>> --- a/drivers/pci/hotplug/rpaphp_core.c
>> +++ b/drivers/pci/hotplug/rpaphp_core.c
>> @@ -30,6 +30,7 @@
>>  #include <linux/smp.h>
>>  #include <linux/init.h>
>>  #include <linux/vmalloc.h>
>> +#include <asm/firmware.h>
>>  #include <asm/eeh.h>       /* for eeh_add_device() */
>>  #include <asm/rtas.h>		/* rtas_call */
>>  #include <asm/pci-bridge.h>	/* for pci_controller */
>> @@ -196,25 +197,21 @@ static int get_children_props(struct device_node *dn, const int **drc_indexes,
>>  	return 0;
>>  }
>>
>> -/* To get the DRC props describing the current node, first obtain it's
>> - * my-drc-index property.  Next obtain the DRC list from it's parent.  Use
>> - * the my-drc-index for correlation, and obtain the requested properties.
>> +
>> +/* Verify the existence of 'drc_name' and/or 'drc_type' within the
>> + * current node.  First obtain it's my-drc-index property.  Next,
>> + * obtain the DRC info from it's parent.  Use the my-drc-index for
>> + * correlation, and obtain/validate the requested properties.
>>   */
>> -int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
>> -		char **drc_name, char **drc_type, int *drc_power_domain)
>> +
>> +static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
>> +				char *drc_type, unsigned int my_index)
>>  {
>> +	char *name_tmp, *type_tmp;
>>  	const int *indexes, *names;
>>  	const int *types, *domains;
>> -	const unsigned int *my_index;
>> -	char *name_tmp, *type_tmp;
>>  	int i, rc;
>>
>> -	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
>> -	if (!my_index) {
>> -		/* Node isn't DLPAR/hotplug capable */
>> -		return -EINVAL;
>> -	}
>> -
>>  	rc = get_children_props(dn->parent, &indexes, &names, &types, &domains);
>>  	if (rc < 0) {
>>  		return -EINVAL;
>> @@ -225,24 +222,87 @@ int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
>>
>>  	/* Iterate through parent properties, looking for my-drc-index */
>>  	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
>> -		if ((unsigned int) indexes[i + 1] == *my_index) {
>> -			if (drc_name)
>> -				*drc_name = name_tmp;
>> -			if (drc_type)
>> -				*drc_type = type_tmp;
>> -			if (drc_index)
>> -				*drc_index = be32_to_cpu(*my_index);
>> -			if (drc_power_domain)
>> -				*drc_power_domain = be32_to_cpu(domains[i+1]);
>> -			return 0;
>> -		}
>> +		if ((unsigned int) indexes[i + 1] == my_index)
>> +			break;
>> +
>>  		name_tmp += (strlen(name_tmp) + 1);
>>  		type_tmp += (strlen(type_tmp) + 1);
>>  	}
>>
>> +	if (((drc_name == NULL) || (drc_name && !strcmp(drc_name, name_tmp))) &&
>> +	    ((drc_type == NULL) || (drc_type && !strcmp(drc_type, type_tmp))))
>> +		return 0;
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
>> +				char *drc_type, unsigned int my_index)
>> +{
>> +	struct property *info;
>> +	unsigned int entries;
>> +	struct of_drc_info drc;
>> +	const __be32 *value;
>> +	int j;
>> +
>> +	info = of_find_property(dn->parent, "ibm,drc-info", NULL);
>> +	if (info == NULL)
>> +		return -EINVAL;
>> +
>> +	value = info->value;
>> +	value = (void *)of_prop_next_u32(info, value, &entries);
>> +	if (!value)
>> +		return -EINVAL;
>> +
>> +	for (j = 0; j < entries; j++) {
>> +		of_read_drc_info_cell(&info, &value, &drc);
>> +
>> +		/* Should now know end of current entry */
>> +
>> +		WARN_ON((my_index < drc.drc_index_start) ||
>> +			(((my_index - drc.drc_index_start) %
>> +				drc.sequential_inc) != 0));
> 
> This WARN_ON would also fit better in of_read_drc_info_cell()
> 
> -Nathan

Problem with absorbing this check into 'of_read_drc_info_cell()'
is that the function reads an LMB set at a time, and does not
pay attention to the specific drc_index of interest.  it would
be possible to recast the interface of of_read_drc_info_cell()
as,

extern int of_read_drc_info_cell(struct property **prop,
                        const __be32 **curval, const int index,
			struct of_drc_info *data);

where sequential invocations to the LMB set would be like,

	ret = of_read_drc_info_cell(prop, value, -1, &drc);

where invocations to the ith LMB representation would be like,

	ret = of_read_drc_info_cell(prop, value, i, &drc);

Then the function would have the information to report errors
out of range of an LMB set.

Or am I missing something other that you were trying to communicate?

Michael

>> +
>> +		if (my_index > drc.last_drc_index)
>> +			continue;
>> +
>> +		break;
>> +	}
>> +	/* Found it */
>> +
>> +	if (((drc_name == NULL) ||
>> +	     (drc_name && !strncmp(drc_name,
>> +				drc.drc_name_prefix,
>> +				strlen(drc.drc_name_prefix)))) &&
>> +	    ((drc_type == NULL) ||
>> +	     (drc_type && !strncmp(drc_type,
>> +				drc.drc_type,
>> +				strlen(drc.drc_type)))))
>> +		return 0;
>> +
>>  	return -EINVAL;
>>  }
>> -EXPORT_SYMBOL_GPL(rpaphp_get_drc_props);
>> +
>> +int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
>> +			char *drc_type)
>> +{
>> +	const unsigned int *my_index;
>> +
>> +	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
>> +	if (!my_index) {
>> +		/* Node isn't DLPAR/hotplug capable */
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (firmware_has_feature(FW_FEATURE_DRC_INFO))
>> +		return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
>> +						*my_index);
>> +	else
>> +		return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
>> +						*my_index);
>> +}
>> +EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
>> +
>>
>>  static int is_php_type(char *drc_type)
>>  {
>>
> 
>

Patch

diff --git a/drivers/pci/hotplug/rpadlpar_core.c b/drivers/pci/hotplug/rpadlpar_core.c
index a3449d7..fc01d7d 100644
--- a/drivers/pci/hotplug/rpadlpar_core.c
+++ b/drivers/pci/hotplug/rpadlpar_core.c
@@ -27,6 +27,7 @@ 
 #include <linux/mutex.h>
 #include <asm/rtas.h>
 #include <asm/vio.h>
+#include <linux/firmware.h>
 
 #include "../pci.h"
 #include "rpaphp.h"
@@ -44,15 +45,14 @@  static struct device_node *find_vio_slot_node(char *drc_name)
 {
 	struct device_node *parent = of_find_node_by_name(NULL, "vdevice");
 	struct device_node *dn = NULL;
-	char *name;
 	int rc;
 
 	if (!parent)
 		return NULL;
 
 	while ((dn = of_get_next_child(parent, dn))) {
-		rc = rpaphp_get_drc_props(dn, NULL, &name, NULL, NULL);
-		if ((rc == 0) && (!strcmp(drc_name, name)))
+		rc = rpaphp_check_drc_props(dn, drc_name, NULL);
+		if (rc == 0)
 			break;
 	}
 
@@ -64,15 +64,12 @@  static struct device_node *find_php_slot_pci_node(char *drc_name,
 						  char *drc_type)
 {
 	struct device_node *np = NULL;
-	char *name;
-	char *type;
 	int rc;
 
 	while ((np = of_find_node_by_name(np, "pci"))) {
-		rc = rpaphp_get_drc_props(np, NULL, &name, &type, NULL);
+		rc = rpaphp_check_drc_props(np, drc_name, drc_type);
 		if (rc == 0)
-			if (!strcmp(drc_name, name) && !strcmp(drc_type, type))
-				break;
+			break;
 	}
 
 	return np;
diff --git a/drivers/pci/hotplug/rpaphp.h b/drivers/pci/hotplug/rpaphp.h
index 7db024e..8db5f2e 100644
--- a/drivers/pci/hotplug/rpaphp.h
+++ b/drivers/pci/hotplug/rpaphp.h
@@ -91,8 +91,8 @@  struct slot {
 
 /* rpaphp_core.c */
 int rpaphp_add_slot(struct device_node *dn);
-int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
-		char **drc_name, char **drc_type, int *drc_power_domain);
+int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
+		char *drc_type);
 
 /* rpaphp_slot.c */
 void dealloc_slot_struct(struct slot *slot);
diff --git a/drivers/pci/hotplug/rpaphp_core.c b/drivers/pci/hotplug/rpaphp_core.c
index 1e29aba..0a3b5f5 100644
--- a/drivers/pci/hotplug/rpaphp_core.c
+++ b/drivers/pci/hotplug/rpaphp_core.c
@@ -30,6 +30,7 @@ 
 #include <linux/smp.h>
 #include <linux/init.h>
 #include <linux/vmalloc.h>
+#include <asm/firmware.h>
 #include <asm/eeh.h>       /* for eeh_add_device() */
 #include <asm/rtas.h>		/* rtas_call */
 #include <asm/pci-bridge.h>	/* for pci_controller */
@@ -196,25 +197,21 @@  static int get_children_props(struct device_node *dn, const int **drc_indexes,
 	return 0;
 }
 
-/* To get the DRC props describing the current node, first obtain it's
- * my-drc-index property.  Next obtain the DRC list from it's parent.  Use
- * the my-drc-index for correlation, and obtain the requested properties.
+
+/* Verify the existence of 'drc_name' and/or 'drc_type' within the
+ * current node.  First obtain it's my-drc-index property.  Next,
+ * obtain the DRC info from it's parent.  Use the my-drc-index for
+ * correlation, and obtain/validate the requested properties.
  */
-int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
-		char **drc_name, char **drc_type, int *drc_power_domain)
+
+static int rpaphp_check_drc_props_v1(struct device_node *dn, char *drc_name,
+				char *drc_type, unsigned int my_index)
 {
+	char *name_tmp, *type_tmp;
 	const int *indexes, *names;
 	const int *types, *domains;
-	const unsigned int *my_index;
-	char *name_tmp, *type_tmp;
 	int i, rc;
 
-	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
-	if (!my_index) {
-		/* Node isn't DLPAR/hotplug capable */
-		return -EINVAL;
-	}
-
 	rc = get_children_props(dn->parent, &indexes, &names, &types, &domains);
 	if (rc < 0) {
 		return -EINVAL;
@@ -225,24 +222,87 @@  int rpaphp_get_drc_props(struct device_node *dn, int *drc_index,
 
 	/* Iterate through parent properties, looking for my-drc-index */
 	for (i = 0; i < be32_to_cpu(indexes[0]); i++) {
-		if ((unsigned int) indexes[i + 1] == *my_index) {
-			if (drc_name)
-				*drc_name = name_tmp;
-			if (drc_type)
-				*drc_type = type_tmp;
-			if (drc_index)
-				*drc_index = be32_to_cpu(*my_index);
-			if (drc_power_domain)
-				*drc_power_domain = be32_to_cpu(domains[i+1]);
-			return 0;
-		}
+		if ((unsigned int) indexes[i + 1] == my_index)
+			break;
+
 		name_tmp += (strlen(name_tmp) + 1);
 		type_tmp += (strlen(type_tmp) + 1);
 	}
 
+	if (((drc_name == NULL) || (drc_name && !strcmp(drc_name, name_tmp))) &&
+	    ((drc_type == NULL) || (drc_type && !strcmp(drc_type, type_tmp))))
+		return 0;
+
+	return -EINVAL;
+}
+
+static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
+				char *drc_type, unsigned int my_index)
+{
+	struct property *info;
+	unsigned int entries;
+	struct of_drc_info drc;
+	const __be32 *value;
+	int j;
+
+	info = of_find_property(dn->parent, "ibm,drc-info", NULL);
+	if (info == NULL)
+		return -EINVAL;
+
+	value = info->value;
+	value = (void *)of_prop_next_u32(info, value, &entries);
+	if (!value)
+		return -EINVAL;
+
+	for (j = 0; j < entries; j++) {
+		of_read_drc_info_cell(&info, &value, &drc);
+
+		/* Should now know end of current entry */
+
+		WARN_ON((my_index < drc.drc_index_start) ||
+			(((my_index - drc.drc_index_start) %
+				drc.sequential_inc) != 0));
+
+		if (my_index > drc.last_drc_index)
+			continue;
+
+		break;
+	}
+	/* Found it */
+
+	if (((drc_name == NULL) ||
+	     (drc_name && !strncmp(drc_name,
+				drc.drc_name_prefix,
+				strlen(drc.drc_name_prefix)))) &&
+	    ((drc_type == NULL) ||
+	     (drc_type && !strncmp(drc_type,
+				drc.drc_type,
+				strlen(drc.drc_type)))))
+		return 0;
+
 	return -EINVAL;
 }
-EXPORT_SYMBOL_GPL(rpaphp_get_drc_props);
+
+int rpaphp_check_drc_props(struct device_node *dn, char *drc_name,
+			char *drc_type)
+{
+	const unsigned int *my_index;
+
+	my_index = of_get_property(dn, "ibm,my-drc-index", NULL);
+	if (!my_index) {
+		/* Node isn't DLPAR/hotplug capable */
+		return -EINVAL;
+	}
+
+	if (firmware_has_feature(FW_FEATURE_DRC_INFO))
+		return rpaphp_check_drc_props_v2(dn, drc_name, drc_type,
+						*my_index);
+	else
+		return rpaphp_check_drc_props_v1(dn, drc_name, drc_type,
+						*my_index);
+}
+EXPORT_SYMBOL_GPL(rpaphp_check_drc_props);
+
 
 static int is_php_type(char *drc_type)
 {