[kvm-unit-tests PATCH v8 07/12] s390x: define function to wait for interrupt

Pierre Morel
2020-06-08T08:13:12Z

Allow the program to wait for an interrupt.

The interrupt handler is in charge to remove the WAIT bit
when it finished handling the interrupt.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
---
lib/s390x/asm/arch_def.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index 12045ff..e0ced12 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -10,9 +10,11 @@
#ifndef _ASM_S390X_ARCH_DEF_H_
#define _ASM_S390X_ARCH_DEF_H_

+#define PSW_MASK_IO 0x0200000000000000UL
#define PSW_MASK_EXT 0x0100000000000000UL
#define PSW_MASK_DAT 0x0400000000000000UL
#define PSW_MASK_SHORT_PSW 0x0008000000000000UL
+#define PSW_MASK_WAIT 0x0002000000000000UL
#define PSW_MASK_PSTATE 0x0001000000000000UL
#define PSW_MASK_BA 0x0000000080000000UL
#define PSW_MASK_EA 0x0000000100000000UL
@@ -253,6 +255,18 @@ static inline void load_psw_mask(uint64_t mask)
: "+r" (tmp) : "a" (&psw) : "memory", "cc" );
}

+static inline void wait_for_interrupt(uint64_t irq_mask)
+{
+ uint64_t psw_mask = extract_psw_mask();
+
+ load_psw_mask(psw_mask | irq_mask | PSW_MASK_WAIT);
+ /*
+ * After being woken and having processed the interrupt, let's restore
+ * the PSW mask.
+ */
+ load_psw_mask(psw_mask);
+}
+
static inline void enter_pstate(void)
{
uint64_t mask;
--
2.25.1