[kvm-unit-tests PATCH v5 7/7] s390x: smp: Wait for cpu setup to finish

From: Janosch Frank <frankja@linux.ibm.com>
To: kvm@vger.kernel.org
Cc: thuth@redhat.com, borntraeger@de.ibm.com,
	linux-s390@vger.kernel.org, david@redhat.com, cohuck@redhat.com
Subject: [kvm-unit-tests PATCH v5 7/7] s390x: smp: Wait for cpu setup to finish
Date: Sat,  1 Feb 2020 10:28:51 -0500	[thread overview]
Message-ID: <20200201152851.82867-8-frankja@linux.ibm.com> (raw)
In-Reply-To: <20200201152851.82867-1-frankja@linux.ibm.com>

We store the user provided psw address into restart new, so a psw
restart does not lead us through setup again.

Also we wait on smp_cpu_setup() until the cpu has finished setup
before returning. This is necessary for z/VM and LPAR where sigp is
asynchronous.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
---
 lib/s390x/smp.c  | 3 +++
 s390x/cstart64.S | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/lib/s390x/smp.c b/lib/s390x/smp.c
index 4578003..3f86243 100644
--- a/lib/s390x/smp.c
+++ b/lib/s390x/smp.c
@@ -210,6 +210,9 @@ int smp_cpu_setup(uint16_t addr, struct psw psw)
 
 	/* Start processing */
 	smp_cpu_restart_nolock(addr, NULL);
+	/* Wait until the cpu has finished setup and started the provided psw */
+	while (lc->restart_new_psw.addr != psw.addr)
+		mb();
 out:
 	spin_unlock(&lock);
 	return rc;
diff --git a/s390x/cstart64.S b/s390x/cstart64.S
index 86dd4c4..9af6bb3 100644
--- a/s390x/cstart64.S
+++ b/s390x/cstart64.S
@@ -159,6 +159,8 @@ smp_cpu_setup_state:
 	xgr	%r1, %r1
 	lmg     %r0, %r15, GEN_LC_SW_INT_GRS
 	lctlg   %c0, %c0, GEN_LC_SW_INT_CRS
+	/* We should only go once through cpu setup and not for every restart */
+	stg	%r14, GEN_LC_RESTART_NEW_PSW + 8
 	br	%r14
 
 pgm_int:
-- 
2.20.1
