To test a write command with the SSCH instruction we need a QEMU device,
with control unit type 0xC0CA. The PONG device is such a device.
This type of device responds to PONG_WRITE requests by incrementing an
integer, stored as a string at offset 0 of the CCW data.
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
s390x/css.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 50 insertions(+)
diff --git a/s390x/css.c b/s390x/css.c
index 54a7b38..3b5ce9d 100644
--- a/s390x/css.c
+++ b/s390x/css.c
@@ -23,6 +23,10 @@
#define SID_ONE 0x00010000
#define PSW_PRG_MASK (PSW_MASK_IO | PSW_MASK_EA | PSW_MASK_BA)
+/* Channel Commands for PONG device */
+#define PONG_WRITE 0x21 /* Write */
+#define PONG_READ 0x22 /* Read buffer */
+
struct lowcore *lowcore = (void *)0x0;
static struct schib schib;
@@ -259,6 +263,51 @@ unreg_cb:
unregister_io_int_func(irq_io);
}
+static void test_ping(void)
+{
+ int success, result;
+ int cnt = 0, max = 4;
+
+ if (senseid.cu_type != PONG_CU) {
+ report_skip("No PONG, no ping-pong");
+ return;
+ }
+
+ result = register_io_int_func(irq_io);
+ if (result) {
+ report("Could not register IRQ handler", 0);
+ return;
+ }
+
+ while (cnt++ < max) {
+ snprintf(buffer, BUF_SZ, "%08x\n", cnt);
+ success = start_subchannel(PONG_WRITE, buffer, 8);
+ if (!success) {
+ report("start_subchannel failed", 0);
+ goto unreg_cb;
+ }
+ delay(100);
+ success = start_subchannel(PONG_READ, buffer, 8);
+ if (!success) {
+ report("start_subchannel failed", 0);
+ goto unreg_cb;
+ }
+ result = atol(buffer);
+ if (result != (cnt + 1)) {
+ report("Bad answer from pong: %08x - %08x",
+ 0, cnt, result);
+ goto unreg_cb;
+ } else
+ report_info("%08x - %08x", cnt, result);
+
+ delay(100);
+ }
+ report("ping-pong count 0x%08x", 1, cnt);
+
+unreg_cb:
+ unregister_io_int_func(irq_io);
+}
+
static struct {
const char *name;
void (*func)(void);
@@ -266,6 +315,7 @@ static struct {
{ "enumerate (stsch)", test_enumerate },
{ "enable (msch)", test_enable },
{ "sense (ssch/tsch)", test_sense },
+ { "ping-pong (ssch/tsch)", test_ping },
{ NULL, NULL }
};
--
2.17.0
