Virqmig: Complete interoperability with hotplug.

Signed-off-by: Achin Gupta <achin.gupta@arm.com>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>

5 files changed, 33 insertions, 26 deletions

diff --git a/big-little/common/pagetable_setup.c b/big-little/common/pagetable_setup.c
index 4a25a8f..431e047 100755
--- a/big-little/common/pagetable_setup.c
+++ b/big-little/common/pagetable_setup.c
@@ -379,6 +379,14 @@ void Create2ndStagePageTables(void)
 	l3_desc.pt_addr = stage2_l3_cpuif_pt;
 	Add4KMapping(&l3_desc);
 
+	/* 4KB Mapping for trapping GIC Distributor accesses */
+	l3_desc.va = GIC_ID_PHY_BASE;
+	l3_desc.pa = GIC_ID_PHY_BASE;
+	l3_desc.attrs = ACCESS_FLAG | SHAREABILITY(0x3) | ACCESS_PERM(0x3) |
+			MEM_ATTR(0x1);
+	l3_desc.pt_addr = stage2_l3_cpuif_pt;
+	Add4KMapping(&l3_desc);
+
 	/* 
 	 * Create a mapping for a device page to be used 
 	 * for Locks, Events & anything that is shared when both
diff --git a/big-little/common/vgic_handle.c b/big-little/common/vgic_handle.c
index 0e20dcf..960f97d 100644
--- a/big-little/common/vgic_handle.c
+++ b/big-little/common/vgic_handle.c
@@ -160,7 +160,9 @@ vm_context *handle_interrupt(vm_context * context)
 			break;
 
 		case IPI_MIGRATE_VIRQS:
-			complete_virq_migration(src_cpu);
+			/* Refer to comments in vgic_trap_handler.c */
+			if (FALSE == async_switchover)
+				complete_virq_migration(src_cpu);
 			return ret_ctx;
 
 		default:
diff --git a/big-little/common/vgiclib.c b/big-little/common/vgiclib.c
index 5f5735b..ffe1be9 100644
--- a/big-little/common/vgiclib.c
+++ b/big-little/common/vgiclib.c
@@ -25,11 +25,13 @@
 #include "virt_helpers.h"
 #include "int_master.h"
 #include "ipi.h"
+#include "events.h"
+
+extern unsigned get_cpuinfo(unsigned);
 
 /*
  * Manage overflowints somehow.. static pool with recycling allocators. 
  */
-
 #define MAXOVERFLOWINTS 200
 
 static struct overflowint *freeoverflows[NUM_CPUS];
@@ -170,6 +172,7 @@ unsigned start_virq_migration(unsigned orig, unsigned curr, unsigned icdiptr_off
 	 */
 	if (virq_mig_mask) {
 		send_hyp_ipi(virq_mig_mask, IPI_MIGRATE_VIRQS);
+		wait_for_events(VIRQ_MIG_DONE, get_cpu_mask(virq_mig_mask));
 		return 1;
 	}
 
@@ -183,16 +186,19 @@ void complete_virq_migration(unsigned src_cpuid)
 {
 	unsigned ctr, cpu_id = read_cpuid();
 	unsigned cluster_id = read_clusterid();
-	unsigned dest_cpuif = get_cpuif(cluster_id, cpu_id);
+	unsigned dest_cpuid = 0;
 
 	for (ctr = 0; ctr < MAX_MIG_IRQS; ctr++) {
-		if (migrated_irqs[src_cpuid][ctr].desc &&
-		    migrated_irqs[src_cpuid][ctr].dest_cpuif == dest_cpuif) {
+		/*
+		 * Compare the cpu id instead of the cpu interface id in case
+		 * a switch took place before the virq migration ipi was recieved.
+		 */
+		dest_cpuid = get_cpuinfo(migrated_irqs[src_cpuid][ctr].dest_cpuif) & 0xf;
+		if (migrated_irqs[src_cpuid][ctr].desc && dest_cpuid == cpu_id)
 			enqueue_interrupt(migrated_irqs[src_cpuid][ctr].desc, cpu_id);
-		}
 	}
 
-//	set_event(VIRQ_MIG_DONE, src_cpuid);
+	set_event(VIRQ_MIG_DONE, src_cpuid);
 	return;
 }
 
diff --git a/big-little/virtualisor/vgic_trap_handler.c b/big-little/virtualisor/vgic_trap_handler.c
index 5e64eea..cd06578 100644
--- a/big-little/virtualisor/vgic_trap_handler.c
+++ b/big-little/virtualisor/vgic_trap_handler.c
@@ -25,6 +25,7 @@
 #include "misc.h"
 #include "virt_helpers.h"
 #include "vgiclib.h"
+#include "int_master.h"
 
 /*
  * Whether A15 or A7, the distributor accesses are virtualised in
@@ -51,7 +52,15 @@ void handle_vgic_distif_abort(unsigned pa, unsigned *data, unsigned write)
 			write32(pa, value);
 			icdiptr_curr = value;
 
-			start_virq_migration(icdiptr_orig, icdiptr_curr, reg_offset - GICD_CPUS);
+			/*
+			 * Virtual irq migration needs communication with another cpu in
+			 * HYP mode. A cluster switch while doing this can cause a deadlock
+			 * and there is no easy way around this. So the assumption is that
+			 * the OS will prevent a switch while an irq migration operation is
+			 * in progress.
+			 */
+			if (FALSE == async_switchover)
+				start_virq_migration(icdiptr_orig, icdiptr_curr, reg_offset - GICD_CPUS);
 
 		} else {
 			value = read32(pa);
diff --git a/big-little/virtualisor/virt_setup.c b/big-little/virtualisor/virt_setup.c
index d35adc6..4403ae2 100644
--- a/big-little/virtualisor/virt_setup.c
+++ b/big-little/virtualisor/virt_setup.c
@@ -130,24 +130,6 @@ void SetupVirtualisor(unsigned first_cpu)
 
 		}
 
-		/*
-		 * Irrespective of what cpu types are present in the
-		 * dual cluster system, the host cluster has to trap
-		 * accesses to the vgic distributor when switching.
-		 */
-		if (switcher && cluster_id == host_cluster) {
-			if (cpu_id == first_cpu) {
-				rc = mem_trap_setup(GIC_ID_PHY_BASE,
-						    &svgic_distif_trap);
-				if (rc) {
-					printf
-					    ("%s: svgic distif trap setup failed \n",
-					     __FUNCTION__);
-					goto out;
-				}
-			}
-		}
-
 		/* 
 		 * If the two clusters have different cpu types, then the
 		 * target saves its midr and the host uses the value to