[kvm-unit-tests PATCH v3 5/6] s390x: Prepare for external calls

[Janosch Frank <frankja@linux.ibm.com>]

With SMP we also get new external interrupts like external call and
emergency call. Let's make them known.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 lib/s390x/asm/arch_def.h  |  5 +++++
 lib/s390x/asm/interrupt.h |  3 +++
 lib/s390x/interrupt.c     | 23 +++++++++++++++++++----
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index d5a7f51..96cca2e 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -19,6 +19,11 @@ struct psw {
 #define PSW_MASK_DAT			0x0400000000000000UL
 #define PSW_MASK_PSTATE			0x0001000000000000UL
 
+#define CR0_EXTM_SCLP			0X0000000000000200UL
+#define CR0_EXTM_EXTC			0X0000000000002000UL
+#define CR0_EXTM_EMGC			0X0000000000004000UL
+#define CR0_EXTM_MASK			0X0000000000006200UL
+
 struct lowcore {
 	uint8_t		pad_0x0000[0x0080 - 0x0000];	/* 0x0000 */
 	uint32_t	ext_int_param;			/* 0x0080 */
diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h
index f485e96..4cfade9 100644
--- a/lib/s390x/asm/interrupt.h
+++ b/lib/s390x/asm/interrupt.h
@@ -11,6 +11,8 @@
 #define _ASMS390X_IRQ_H_
 #include <asm/arch_def.h>
 
+#define EXT_IRQ_EMERGENCY_SIG	0x1201
+#define EXT_IRQ_EXTERNAL_CALL	0x1202
 #define EXT_IRQ_SERVICE_SIG	0x2401
 
 void handle_pgm_int(void);
@@ -19,6 +21,7 @@ void handle_mcck_int(void);
 void handle_io_int(void);
 void handle_svc_int(void);
 void expect_pgm_int(void);
+void expect_ext_int(void);
 uint16_t clear_pgm_int(void);
 void check_pgm_int_code(uint16_t code);
 
diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c
index 7832711..5cade23 100644
--- a/lib/s390x/interrupt.c
+++ b/lib/s390x/interrupt.c
@@ -15,6 +15,7 @@
 #include <sclp.h>
 
 static bool pgm_int_expected;
+static bool ext_int_expected;
 static struct lowcore *lc;
 
 void expect_pgm_int(void)
@@ -24,6 +25,13 @@ void expect_pgm_int(void)
 	mb();
 }
 
+void expect_ext_int(void)
+{
+	ext_int_expected = true;
+	lc->ext_int_code = 0;
+	mb();
+}
+
 uint16_t clear_pgm_int(void)
 {
 	uint16_t code;
@@ -108,15 +116,22 @@ void handle_pgm_int(void)
 
 void handle_ext_int(void)
 {
-	if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
+	if (!ext_int_expected &&
+	    lc->ext_int_code != EXT_IRQ_SERVICE_SIG) {
 		report_abort("Unexpected external call interrupt: at %#lx",
 			     lc->ext_old_psw.addr);
-	} else {
-		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
+		return;
+	}
+
+	if (lc->ext_int_code == EXT_IRQ_SERVICE_SIG) {
 		lc->sw_int_cr0 &= ~(1UL << 9);
 		sclp_handle_ext();
-		lc->ext_int_code = 0;
+	} else {
+		ext_int_expected = false;
 	}
+
+	if (!(lc->sw_int_cr0 & CR0_EXTM_MASK))
+		lc->ext_old_psw.mask &= ~PSW_MASK_EXT;
 }
 
 void handle_mcck_int(void)
-- 
2.17.2