[kvm-unit-tests PATCH v13 5/9] s390x: define function to wait for interrupt

Pierre Morel
2020-07-16T08:23:46Z

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>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
lib/s390x/asm/arch_def.h | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h
index 1b3bb0c..022a564 100644
--- a/lib/s390x/asm/arch_def.h
+++ b/lib/s390x/asm/arch_def.h
@@ -17,6 +17,7 @@ struct psw {

#define PSW_MASK_EXT 0x0100000000000000UL
#define PSW_MASK_DAT 0x0400000000000000UL
+#define PSW_MASK_WAIT 0x0002000000000000UL
#define PSW_MASK_PSTATE 0x0001000000000000UL

#define CR0_EXTM_SCLP 0x0000000000000200UL
@@ -246,6 +247,18 @@ 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