From 2efd7f6eb9b7107e469837d8452e750d7d080a5d Mon Sep 17 00:00:00 2001

From: Nathan Lynch <nathanl@linux.ibm.com>

Date: Mon, 7 Dec 2020 15:52:00 -0600

Subject: [PATCH] powerpc/pseries/mobility: refactor node lookup during DT

 update

References: bsc#1181674 ltc#189159

Patch-mainline: v5.11-rc1

Git-commit: 2efd7f6eb9b7107e469837d8452e750d7d080a5d

In pseries_devicetree_update(), with each call to ibm,update-nodes the

partition firmware communicates the node to be deleted or updated by

placing its phandle in the work buffer. Each of delete_dt_node(),

update_dt_node(), and add_dt_node() have duplicate lookups using the

phandle value and corresponding refcount management.

Move the lookup and of_node_put() into pseries_devicetree_update(),

and emit a warning on any failed lookups.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20201207215200.1785968-29-nathanl@linux.ibm.com

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 arch/powerpc/platforms/pseries/mobility.c | 49 ++++++++---------------

 1 file changed, 17 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c

index e670180f311d..ea4d6a660e0d 100644

--- a/arch/powerpc/platforms/pseries/mobility.c

+++ b/arch/powerpc/platforms/pseries/mobility.c

@@ -61,18 +61,10 @@ static int mobility_rtas_call(int token, char *buf, s32 scope)

 	return rc;

 }

-static int delete_dt_node(__be32 phandle)

+static int delete_dt_node(struct device_node *dn)

 {

-	struct device_node *dn;

-

-	dn = of_find_node_by_phandle(be32_to_cpu(phandle));

-	if (!dn)

-		return -ENOENT;

-

 	pr_debug("removing node %pOFfp\n", dn);

-

 	dlpar_detach_node(dn);

-	of_node_put(dn);

 	return 0;

 }

@@ -137,10 +129,9 @@ static int update_dt_property(struct device_node *dn, struct property **prop,

 	return 0;

 }

-static int update_dt_node(__be32 phandle, s32 scope)

+static int update_dt_node(struct device_node *dn, s32 scope)

 {

 	struct update_props_workarea *upwa;

-	struct device_node *dn;

 	struct property *prop = NULL;

 	int i, rc, rtas_rc;

 	char *prop_data;

@@ -157,14 +148,8 @@ static int update_dt_node(__be32 phandle, s32 scope)

 	if (!rtas_buf)

 		return -ENOMEM;

-	dn = of_find_node_by_phandle(be32_to_cpu(phandle));

-	if (!dn) {

-		kfree(rtas_buf);

-		return -ENOENT;

-	}

-

 	upwa = (struct update_props_workarea *)&rtas_buf[0];

-	upwa->phandle = phandle;

+	upwa->phandle = cpu_to_be32(dn->phandle);

 	do {

 		rtas_rc = mobility_rtas_call(update_properties_token, rtas_buf,

@@ -224,26 +209,18 @@ static int update_dt_node(__be32 phandle, s32 scope)

 		cond_resched();

 	} while (rtas_rc == 1);

-	of_node_put(dn);

 	kfree(rtas_buf);

 	return 0;

 }

-static int add_dt_node(__be32 parent_phandle, __be32 drc_index)

+static int add_dt_node(struct device_node *parent_dn, __be32 drc_index)

 {

 	struct device_node *dn;

-	struct device_node *parent_dn;

 	int rc;

-	parent_dn = of_find_node_by_phandle(be32_to_cpu(parent_phandle));

-	if (!parent_dn)

-		return -ENOENT;

-

 	dn = dlpar_configure_connector(drc_index, parent_dn);

-	if (!dn) {

-		of_node_put(parent_dn);

+	if (!dn)

 		return -ENOENT;

-	}

 	rc = dlpar_attach_node(dn, parent_dn);

 	if (rc)

@@ -251,7 +228,6 @@ static int add_dt_node(__be32 parent_phandle, __be32 drc_index)

 	pr_debug("added node %pOFfp\n", dn);

-	of_node_put(parent_dn);

 	return rc;

 }

@@ -284,22 +260,31 @@ int pseries_devicetree_update(s32 scope)

 			data++;

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

+				struct device_node *np;

 				__be32 phandle = *data++;

 				__be32 drc_index;

+				np = of_find_node_by_phandle(be32_to_cpu(phandle));

+				if (!np) {

+					pr_warn("Failed lookup: phandle 0x%x for action 0x%x\n",

+						be32_to_cpu(phandle), action);

+					continue;

+				}

+

 				switch (action) {

 				case DELETE_DT_NODE:

-					delete_dt_node(phandle);

+					delete_dt_node(np);

 					break;

 				case UPDATE_DT_NODE:

-					update_dt_node(phandle, scope);

+					update_dt_node(np, scope);

 					break;

 				case ADD_DT_NODE:

 					drc_index = *data++;

-					add_dt_node(phandle, drc_index);

+					add_dt_node(np, drc_index);

 					break;

 				}

+				of_node_put(np);

 				cond_resched();

 			}

 		}

-- 

2.26.2