powerpc/pseries/vas: Define global hv_cop_caps struct

The coprocessor capabilities struct is used to get default and
QoS capabilities from the hypervisor during init, DLPAR event and
migration. So instead of allocating this struct for each event,
define global struct and reuse it which allows the migration code
to avoid adding an error path.

Also disable copy/paste feature flag if any capabilities HCALL
is failed.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/57da6a270fcb9308cd57be7c88037029343080f7.camel@linux.ibm.com

arch/powerpc/platforms/pseries/vas.c

@@ -26,6 +26,7 @@
 
 static struct vas_all_caps caps_all;
 static bool copypaste_feat;
+static struct hv_vas_cop_feat_caps hv_cop_caps;
 
 static struct vas_caps vascaps[VAS_MAX_FEAT_TYPE];
 static DEFINE_MUTEX(vas_pseries_mutex);
@@ -724,7 +725,6 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds)
  */
 int vas_reconfig_capabilties(u8 type)
 {
-	struct hv_vas_cop_feat_caps *hv_caps;
 	struct vas_cop_feat_caps *caps;
 	int old_nr_creds, new_nr_creds;
 	struct vas_caps *vcaps;
@@ -738,17 +738,13 @@ int vas_reconfig_capabilties(u8 type)
 	vcaps = &vascaps[type];
 	caps = &vcaps->caps;
 
-	hv_caps = kmalloc(sizeof(*hv_caps), GFP_KERNEL);
-	if (!hv_caps)
-		return -ENOMEM;
-
 	mutex_lock(&vas_pseries_mutex);
 	rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES, vcaps->feat,
-				      (u64)virt_to_phys(hv_caps));
+				      (u64)virt_to_phys(&hv_cop_caps));
 	if (rc)
 		goto out;
 
-	new_nr_creds = be16_to_cpu(hv_caps->target_lpar_creds);
+	new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
 
 	old_nr_creds = atomic_read(&caps->nr_total_credits);
 
@@ -780,7 +776,6 @@ int vas_reconfig_capabilties(u8 type)
 
 out:
 	mutex_unlock(&vas_pseries_mutex);
-	kfree(hv_caps);
 	return rc;
 }
 /*
@@ -822,9 +817,8 @@ static struct notifier_block pseries_vas_nb = {
 
 static int __init pseries_vas_init(void)
 {
-	struct hv_vas_cop_feat_caps *hv_cop_caps;
 	struct hv_vas_all_caps *hv_caps;
-	int rc;
+	int rc = 0;
 
 	/*
 	 * Linux supports user space COPY/PASTE only with Radix
@@ -850,38 +844,37 @@ static int __init pseries_vas_init(void)
 
 	sysfs_pseries_vas_init(&caps_all);
 
-	hv_cop_caps = kmalloc(sizeof(*hv_cop_caps), GFP_KERNEL);
-	if (!hv_cop_caps) {
-		rc = -ENOMEM;
-		goto out;
-	}
 	/*
 	 * QOS capabilities available
 	 */
 	if (caps_all.feat_type & VAS_GZIP_QOS_FEAT_BIT) {
 		rc = get_vas_capabilities(VAS_GZIP_QOS_FEAT,
-					  VAS_GZIP_QOS_FEAT_TYPE, hv_cop_caps);
+					  VAS_GZIP_QOS_FEAT_TYPE, &hv_cop_caps);
 
 		if (rc)
-			goto out_cop;
+			goto out;
 	}
 	/*
 	 * Default capabilities available
 	 */
-	if (caps_all.feat_type & VAS_GZIP_DEF_FEAT_BIT) {
+	if (caps_all.feat_type & VAS_GZIP_DEF_FEAT_BIT)
 		rc = get_vas_capabilities(VAS_GZIP_DEF_FEAT,
-					  VAS_GZIP_DEF_FEAT_TYPE, hv_cop_caps);
-		if (rc)
-			goto out_cop;
-	}
+					  VAS_GZIP_DEF_FEAT_TYPE, &hv_cop_caps);
 
-	if (copypaste_feat && firmware_has_feature(FW_FEATURE_LPAR))
-		of_reconfig_notifier_register(&pseries_vas_nb);
+	if (!rc && copypaste_feat) {
+		if (firmware_has_feature(FW_FEATURE_LPAR))
+			of_reconfig_notifier_register(&pseries_vas_nb);
 
-	pr_info("GZIP feature is available\n");
+		pr_info("GZIP feature is available\n");
+	} else {
+		/*
+		 * Should not happen, but only when get default
+		 * capabilities HCALL failed. So disable copy paste
+		 * feature.
+		 */
+		copypaste_feat = false;
+	}
 
-out_cop:
-	kfree(hv_cop_caps);
 out:
 	kfree(hv_caps);
 	return rc;