Commit 41a14527 authored by Haren Myneni's avatar Haren Myneni Committed by Madhavan Srinivasan
Browse files

powerpc/pseries/dlpar: Search DRC index from ibm,drc-indexes for IO add 



IO hotplug add event is handled in the user space with drmgr tool.
After the device is enabled, the user space uses /sys/kernel/dlpar
interface with “dt add index <drc_index>” to update the device tree.
The kernel interface (dlpar_hp_dt_add()) finds the parent node for
the specified ‘drc_index’ from ibm,drc-info property. The recent FW
provides this property from 2017 onwards. But KVM guest code in
some releases is still using the older SLOF firmware which has
ibm,drc-indexes property instead of ibm,drc-info.

If the ibm,drc-info is not available, this patch adds changes to
search ‘drc_index’ from the indexes array in ibm,drc-indexes
property to support old FW.

Fixes: 02b98ff4 ("powerpc/pseries/dlpar: Add device tree nodes for DLPAR IO add")
Reported-by: default avatarKowshik Jois <kowsjois@linux.ibm.com>
Signed-off-by: default avatarHaren Myneni <haren@linux.ibm.com>
Tested-by: default avatarAmit Machhiwal <amachhiw@linux.ibm.com>
Reviewed-by: default avatarTyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: default avatarMadhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20250531235002.239213-1-haren@linux.ibm.com
parent c8346079

arch/powerpc/platforms/pseries/dlpar.c

+50 −2
Original line number Diff line number Diff line
@@ -404,6 +404,45 @@ get_device_node_with_drc_info(u32 index) 
	return NULL;

}



static struct device_node *

get_device_node_with_drc_indexes(u32 drc_index)

{

	struct device_node *np = NULL;

	u32 nr_indexes, index;

	int i, rc;



	for_each_node_with_property(np, "ibm,drc-indexes") {

		/*

		 * First element in the array is the total number of

		 * DRC indexes returned.

		 */

		rc = of_property_read_u32_index(np, "ibm,drc-indexes",

				0, &nr_indexes);

		if (rc)

			goto out_put_np;



		/*

		 * Retrieve DRC index from the list and return the

		 * device node if matched with the specified index.

		 */

		for (i = 0; i < nr_indexes; i++) {

			rc = of_property_read_u32_index(np, "ibm,drc-indexes",

							i+1, &index);

			if (rc)

				goto out_put_np;



			if (drc_index == index)

				return np;

		}

	}



	return NULL;



out_put_np:

	of_node_put(np);

	return NULL;

}



static int dlpar_hp_dt_add(u32 index)

{

	struct device_node *np, *nodes;
@@ -423,10 +462,19 @@ static int dlpar_hp_dt_add(u32 index) 
		goto out;

	}



	/*

	 * Recent FW provides ibm,drc-info property. So search

	 * for the user specified DRC index from ibm,drc-info

	 * property. If this property is not available, search

	 * in the indexes array from ibm,drc-indexes property.

	 */

	np = get_device_node_with_drc_info(index);



	if (!np) {

		np = get_device_node_with_drc_indexes(index);

		if (!np)

			return -EIO;

	}



	/* Next, configure the connector. */

	nodes = dlpar_configure_connector(cpu_to_be32(index), np);