diff mbox series

[v2,2/2] powerpc/pseries/dlpar: Add device tree nodes for DLPAR IO add

Message ID 20240817035401.125833-2-haren@linux.ibm.com (mailing list archive)
State Changes Requested
Headers show
Series [v2,1/2] powerpc/pseries/dlpar: Remove device tree node for DLPAR IO remove | expand

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Commit Message

Haren Myneni Aug. 17, 2024, 3:54 a.m. UTC 
In the powerpc-pseries specific implementation, the IO hotplug
event is handled in the user space (drmgr tool). For the DLPAR
IO ADD, the corresponding device tree nodes and properties will
be added to the device tree after the device enable. The user
space (drmgr tool) uses configure_connector RTAS call with the
DRC index to retrieve the device nodes and updates the device
tree by writing to /proc/ppc64/ofdt. Under system lockdown,
/dev/mem access to allocate buffers for configure_connector RTAS
call is restricted which means the user space can not issue this
RTAS call and also can not access to /proc/ppc64/ofdt. The
pseries implementation need user interaction to power-on and add
device to the slot during the ADD event handling. So adds
complexity if the complete hotplug ADD event handling moved to
the kernel.

To overcome /dev/mem access restriction, this patch extends the
/sys/kernel/dlpar interface and provides ‘dt add index <drc_index>’
to the user space. The drmgr tool uses this interface to update
the device tree whenever the device is added. This interface
retrieves device tree nodes for the corresponding DRC index using
the configure_connector RTAS call and adds new device nodes /
properties to the device tree.

Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 arch/powerpc/platforms/pseries/dlpar.c | 130 +++++++++++++++++++++++++
 1 file changed, 130 insertions(+)

Comments

kernel test robot Aug. 18, 2024, 3:39 p.m. UTC | #1 
Hi Haren,

kernel test robot noticed the following build warnings:

[auto build test WARNING on powerpc/next]
[also build test WARNING on powerpc/fixes linus/master v6.11-rc3 next-20240816]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Haren-Myneni/powerpc-pseries-dlpar-Add-device-tree-nodes-for-DLPAR-IO-add/20240817-115833
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
patch link:    https://lore.kernel.org/r/20240817035401.125833-2-haren%40linux.ibm.com
patch subject: [PATCH v2 2/2] powerpc/pseries/dlpar: Add device tree nodes for DLPAR IO add
config: powerpc64-randconfig-r121-20240818 (https://download.01.org/0day-ci/archive/20240818/202408182302.o7QRO45S-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 26670e7fa4f032a019d23d56c6a02926e854e8af)
reproduce: (https://download.01.org/0day-ci/archive/20240818/202408182302.o7QRO45S-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202408182302.o7QRO45S-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> arch/powerpc/platforms/pseries/dlpar.c:525:50: sparse: sparse: incorrect type in argument 1 (different base types) @@     expected unsigned int [usertype] index @@     got restricted __be32 [usertype] drc_index @@
   arch/powerpc/platforms/pseries/dlpar.c:525:50: sparse:     expected unsigned int [usertype] index
   arch/powerpc/platforms/pseries/dlpar.c:525:50: sparse:     got restricted __be32 [usertype] drc_index
   arch/powerpc/platforms/pseries/dlpar.c:528:53: sparse: sparse: incorrect type in argument 1 (different base types) @@     expected unsigned int [usertype] drc_index @@     got restricted __be32 [usertype] drc_index @@
   arch/powerpc/platforms/pseries/dlpar.c:528:53: sparse:     expected unsigned int [usertype] drc_index
   arch/powerpc/platforms/pseries/dlpar.c:528:53: sparse:     got restricted __be32 [usertype] drc_index
   arch/powerpc/platforms/pseries/dlpar.c:548:43: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __be32 [usertype] drc_count @@     got unsigned int [usertype] @@
   arch/powerpc/platforms/pseries/dlpar.c:548:43: sparse:     expected restricted __be32 [usertype] drc_count
   arch/powerpc/platforms/pseries/dlpar.c:548:43: sparse:     got unsigned int [usertype]
   arch/powerpc/platforms/pseries/dlpar.c:552:43: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __be32 [usertype] drc_index @@     got unsigned int [usertype] @@
   arch/powerpc/platforms/pseries/dlpar.c:552:43: sparse:     expected restricted __be32 [usertype] drc_index
   arch/powerpc/platforms/pseries/dlpar.c:552:43: sparse:     got unsigned int [usertype]
   arch/powerpc/platforms/pseries/dlpar.c:556:42: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __be32 [usertype] count @@     got unsigned int [usertype] @@
   arch/powerpc/platforms/pseries/dlpar.c:556:42: sparse:     expected restricted __be32 [usertype] count
   arch/powerpc/platforms/pseries/dlpar.c:556:42: sparse:     got unsigned int [usertype]
   arch/powerpc/platforms/pseries/dlpar.c:558:42: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted __be32 [usertype] index @@     got unsigned int [usertype] @@
   arch/powerpc/platforms/pseries/dlpar.c:558:42: sparse:     expected restricted __be32 [usertype] index
   arch/powerpc/platforms/pseries/dlpar.c:558:42: sparse:     got unsigned int [usertype]

vim +525 arch/powerpc/platforms/pseries/dlpar.c

   513	
   514	static int dlpar_hp_dt(struct pseries_hp_errorlog *phpe)
   515	{
   516		int rc;
   517	
   518		if (phpe->id_type != PSERIES_HP_ELOG_ID_DRC_INDEX)
   519			return -EINVAL;
   520	
   521		lock_device_hotplug();
   522	
   523		switch (phpe->action) {
   524		case PSERIES_HP_ELOG_ACTION_ADD:
 > 525			rc = dlpar_hp_dt_add(phpe->_drc_u.drc_index);
   526			break;
   527		case PSERIES_HP_ELOG_ACTION_REMOVE:
   528			rc = dlpar_hp_dt_remove(phpe->_drc_u.drc_index);
   529			break;
   530		default:
   531			pr_err("Invalid action (%d) specified\n", phpe->action);
   532			rc = -EINVAL;
   533			break;
   534		}
   535	
   536		unlock_device_hotplug();
   537	
   538		return rc;
   539	}
   540
diff mbox series

Patch

diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index 59f2a8961946..2d960918cba8 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -23,6 +23,7 @@ 
 #include <linux/uaccess.h>
 #include <asm/rtas.h>
 #include <asm/rtas-work-area.h>
+#include <asm/prom.h>
 
 static struct workqueue_struct *pseries_hp_wq;
 
@@ -264,6 +265,20 @@  int dlpar_detach_node(struct device_node *dn)
 
 	return 0;
 }
+static int dlpar_changeset_attach_cc_nodes(struct of_changeset *ocs,
+					struct device_node *dn)
+{
+	int rc;
+
+	rc = of_changeset_attach_node(ocs, dn);
+
+	if (!rc && dn->child)
+		rc = dlpar_changeset_attach_cc_nodes(ocs, dn->child);
+	if (!rc && dn->sibling)
+		rc = dlpar_changeset_attach_cc_nodes(ocs, dn->sibling);
+
+	return rc;
+}
 
 #define DR_ENTITY_SENSE		9003
 #define DR_ENTITY_PRESENT	1
@@ -330,6 +345,118 @@  int dlpar_unisolate_drc(u32 drc_index)
 	return 0;
 }
 
+static struct device_node *
+get_device_node_with_drc_index(u32 index)
+{
+	struct device_node *np = NULL;
+	u32 node_index;
+	int rc;
+
+	for_each_node_with_property(np, "ibm,my-drc-index") {
+		rc = of_property_read_u32(np, "ibm,my-drc-index",
+					     &node_index);
+		if (rc) {
+			pr_err("%s: %pOF: of_property_read_u32 %s: %d\n",
+			       __func__, np, "ibm,my-drc-index", rc);
+			of_node_put(np);
+			return NULL;
+		}
+
+		if (index == node_index)
+			break;
+	}
+
+	return np;
+}
+
+static struct device_node *
+get_device_node_with_drc_info(u32 index)
+{
+	struct device_node *np = NULL;
+	struct of_drc_info drc;
+	struct property *info;
+	const __be32 *value;
+	u32 node_index;
+	int i, j, count;
+
+	for_each_node_with_property(np, "ibm,drc-info") {
+		info = of_find_property(np, "ibm,drc-info", NULL);
+		if (info == NULL) {
+			/* XXX can this happen? */
+			of_node_put(np);
+			return NULL;
+		}
+		value = of_prop_next_u32(info, NULL, &count);
+		if (value == NULL)
+			continue;
+		value++;
+		for (i = 0; i < count; i++) {
+			if (of_read_drc_info_cell(&info, &value, &drc))
+				break;
+			if (index > drc.last_drc_index)
+				continue;
+			node_index = drc.drc_index_start;
+			for (j = 0; j < drc.num_sequential_elems; j++) {
+				if (index == node_index)
+					return np;
+				node_index += drc.sequential_inc;
+			}
+		}
+	}
+
+	return NULL;
+}
+
+static int dlpar_hp_dt_add(u32 index)
+{
+	struct device_node *np, *nodes;
+	struct of_changeset ocs;
+	int rc;
+
+	/*
+	 * Do not add device node(s) if already exists in the
+	 * device tree.
+	 */
+	np = get_device_node_with_drc_index(index);
+	if (np) {
+		pr_err("%s: Adding device node for index (%d), but "
+				"already exists in the device tree\n",
+				__func__, index);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	np = get_device_node_with_drc_info(index);
+
+	if (!np)
+		return -EIO;
+
+	/* Next, configure the connector. */
+	nodes = dlpar_configure_connector(cpu_to_be32(index), np);
+	if (!nodes) {
+		rc = -EIO;
+		goto out;
+	}
+
+	/*
+	 * Add the new nodes from dlpar_configure_connector() onto
+	 * the device-tree.
+	 */
+	of_changeset_init(&ocs);
+	rc = dlpar_changeset_attach_cc_nodes(&ocs, nodes);
+
+	if (!rc)
+		rc = of_changeset_apply(&ocs);
+	else
+		dlpar_free_cc_nodes(nodes);
+
+	of_changeset_destroy(&ocs);
+
+out:
+	of_node_put(np);
+	return rc;
+}
+
 static int changeset_detach_node_recursive(struct of_changeset *ocs,
 					struct device_node *node)
 {
@@ -394,6 +521,9 @@  static int dlpar_hp_dt(struct pseries_hp_errorlog *phpe)
 	lock_device_hotplug();
 
 	switch (phpe->action) {
+	case PSERIES_HP_ELOG_ACTION_ADD:
+		rc = dlpar_hp_dt_add(phpe->_drc_u.drc_index);
+		break;
 	case PSERIES_HP_ELOG_ACTION_REMOVE:
 		rc = dlpar_hp_dt_remove(phpe->_drc_u.drc_index);
 		break;