3 files changed, 79 insertions, 21 deletions

diff --git a/arch/powerpc/platforms/pseries/lparcfg.c b/arch/powerpc/platforms/pseries/lparcfg.c
index 507dc0b5987d..63fd925ccbb8 100644
--- a/arch/powerpc/platforms/pseries/lparcfg.c
+++ b/arch/powerpc/platforms/pseries/lparcfg.c
@@ -35,6 +35,7 @@
 #include <asm/drmem.h>
 
 #include "pseries.h"
+#include "vas.h"	/* pseries_vas_dlpar_cpu() */
 
 /*
  * This isn't a module but we expose that to userspace
@@ -748,6 +749,16 @@ static ssize_t lparcfg_write(struct file *file, const char __user * buf,
 			return -EINVAL;
 
 		retval = update_ppp(new_entitled_ptr, NULL);
+
+		if (retval == H_SUCCESS || retval == H_CONSTRAINED) {
+			/*
+			 * The hypervisor assigns VAS resources based
+			 * on entitled capacity for shared mode.
+			 * Reconfig VAS windows based on DLPAR CPU events.
+			 */
+			if (pseries_vas_dlpar_cpu() != 0)
+				retval = H_HARDWARE;
+		}
 	} else if (!strcmp(kbuf, "capacity_weight")) {
 		char *endp;
 		*new_weight_ptr = (u8) simple_strtoul(tmp, &endp, 10);
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c
index 0e0524cbe20c..4ad6e510d405 100644
--- a/arch/powerpc/platforms/pseries/vas.c
+++ b/arch/powerpc/platforms/pseries/vas.c
@@ -200,17 +200,42 @@ static irqreturn_t pseries_vas_fault_thread_fn(int irq, void *data)
 	struct vas_user_win_ref *tsk_ref;
 	int rc;
 
-	rc = h_get_nx_fault(txwin->vas_win.winid, (u64)virt_to_phys(&crb));
-	if (!rc) {
-		tsk_ref = &txwin->vas_win.task_ref;
-		vas_dump_crb(&crb);
-		vas_update_csb(&crb, tsk_ref);
+	while (atomic_read(&txwin->pending_faults)) {
+		rc = h_get_nx_fault(txwin->vas_win.winid, (u64)virt_to_phys(&crb));
+		if (!rc) {
+			tsk_ref = &txwin->vas_win.task_ref;
+			vas_dump_crb(&crb);
+			vas_update_csb(&crb, tsk_ref);
+		}
+		atomic_dec(&txwin->pending_faults);
 	}
 
 	return IRQ_HANDLED;
 }
 
 /*
+ * irq_default_primary_handler() can be used only with IRQF_ONESHOT
+ * which disables IRQ before executing the thread handler and enables
+ * it after. But this disabling interrupt sets the VAS IRQ OFF
+ * state in the hypervisor. If the NX generates fault interrupt
+ * during this window, the hypervisor will not deliver this
+ * interrupt to the LPAR. So use VAS specific IRQ handler instead
+ * of calling the default primary handler.
+ */
+static irqreturn_t pseries_vas_irq_handler(int irq, void *data)
+{
+	struct pseries_vas_window *txwin = data;
+
+	/*
+	 * The thread hanlder will process this interrupt if it is
+	 * already running.
+	 */
+	atomic_inc(&txwin->pending_faults);
+
+	return IRQ_WAKE_THREAD;
+}
+
+/*
  * Allocate window and setup IRQ mapping.
  */
 static int allocate_setup_window(struct pseries_vas_window *txwin,
@@ -240,8 +265,9 @@ static int allocate_setup_window(struct pseries_vas_window *txwin,
 		goto out_irq;
 	}
 
-	rc = request_threaded_irq(txwin->fault_virq, NULL,
-				  pseries_vas_fault_thread_fn, IRQF_ONESHOT,
+	rc = request_threaded_irq(txwin->fault_virq,
+				  pseries_vas_irq_handler,
+				  pseries_vas_fault_thread_fn, 0,
 				  txwin->name, txwin);
 	if (rc) {
 		pr_err("VAS-Window[%d]: Request IRQ(%u) failed with %d\n",
@@ -826,6 +852,25 @@ int vas_reconfig_capabilties(u8 type, int new_nr_creds)
 	mutex_unlock(&vas_pseries_mutex);
 	return rc;
 }
+
+int pseries_vas_dlpar_cpu(void)
+{
+	int new_nr_creds, rc;
+
+	rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES,
+				      vascaps[VAS_GZIP_DEF_FEAT_TYPE].feat,
+				      (u64)virt_to_phys(&hv_cop_caps));
+	if (!rc) {
+		new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
+		rc = vas_reconfig_capabilties(VAS_GZIP_DEF_FEAT_TYPE, new_nr_creds);
+	}
+
+	if (rc)
+		pr_err("Failed reconfig VAS capabilities with DLPAR\n");
+
+	return rc;
+}
+
 /*
  * Total number of default credits available (target_credits)
  * in LPAR depends on number of cores configured. It varies based on
@@ -840,7 +885,15 @@ static int pseries_vas_notifier(struct notifier_block *nb,
 	struct of_reconfig_data *rd = data;
 	struct device_node *dn = rd->dn;
 	const __be32 *intserv = NULL;
-	int new_nr_creds, len, rc = 0;
+	int len;
+
+	/*
+	 * For shared CPU partition, the hypervisor assigns total credits
+	 * based on entitled core capacity. So updating VAS windows will
+	 * be called from lparcfg_write().
+	 */
+	if (is_shared_processor())
+		return NOTIFY_OK;
 
 	if ((action == OF_RECONFIG_ATTACH_NODE) ||
 		(action == OF_RECONFIG_DETACH_NODE))
@@ -852,19 +905,7 @@ static int pseries_vas_notifier(struct notifier_block *nb,
 	if (!intserv)
 		return NOTIFY_OK;
 
-	rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES,
-					vascaps[VAS_GZIP_DEF_FEAT_TYPE].feat,
-					(u64)virt_to_phys(&hv_cop_caps));
-	if (!rc) {
-		new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
-		rc = vas_reconfig_capabilties(VAS_GZIP_DEF_FEAT_TYPE,
-						new_nr_creds);
-	}
-
-	if (rc)
-		pr_err("Failed reconfig VAS capabilities with DLPAR\n");
-
-	return rc;
+	return pseries_vas_dlpar_cpu();
 }
 
 static struct notifier_block pseries_vas_nb = {
diff --git a/arch/powerpc/platforms/pseries/vas.h b/arch/powerpc/platforms/pseries/vas.h
index 333ffa2f9f42..7115043ec488 100644
--- a/arch/powerpc/platforms/pseries/vas.h
+++ b/arch/powerpc/platforms/pseries/vas.h
@@ -132,6 +132,7 @@ struct pseries_vas_window {
 	u64 flags;
 	char *name;
 	int fault_virq;
+	atomic_t pending_faults; /* Number of pending faults */
 };
 
 int sysfs_add_vas_caps(struct vas_cop_feat_caps *caps);
@@ -140,10 +141,15 @@ int __init sysfs_pseries_vas_init(struct vas_all_caps *vas_caps);
 
 #ifdef CONFIG_PPC_VAS
 int vas_migration_handler(int action);
+int pseries_vas_dlpar_cpu(void);
 #else
 static inline int vas_migration_handler(int action)
 {
 	return 0;
 }
+static inline int pseries_vas_dlpar_cpu(void)
+{
+	return 0;
+}
 #endif
 #endif /* _VAS_H */