[kvm-unit-tests PATCH v9 12/12] s390x: css: ssch/tsch with sense and interrupt

Pierre Morel
2020-06-15T09:32:20Z

After a channel is enabled we start a SENSE_ID command using
the SSCH instruction to recognize the control unit and device.

This tests the success of SSCH, the I/O interruption and the TSCH
instructions.

The SENSE_ID command response is tested to report 0xff inside
its reserved field and to report the same control unit type
as the cu_type kernel argument.

Without the cu_type kernel argument, the test expects a device
with a default control unit type of 0x3832, a.k.a virtio-net-ccw.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
lib/s390x/css.h | 20 +++++++
lib/s390x/css_lib.c | 46 +++++++++++++++
s390x/css.c | 140 +++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 205 insertions(+), 1 deletion(-)

diff --git a/lib/s390x/css.h b/lib/s390x/css.h
index 0ddceb1..3091d63 100644
--- a/lib/s390x/css.h
+++ b/lib/s390x/css.h
@@ -100,6 +100,19 @@ struct irb {
uint32_t emw[8];
} __attribute__ ((aligned(4)));

+#define CCW_CMD_SENSE_ID 0xe4
+#define CSS_SENSEID_COMMON_LEN 8
+struct senseid {
+ /* common part */
+ uint8_t reserved; /* always 0x'FF' */
+ uint16_t cu_type; /* control unit type */
+ uint8_t cu_model; /* control unit model */
+ uint16_t dev_type; /* device type */
+ uint8_t dev_model; /* device model */
+ uint8_t unused; /* padding byte */
+ uint8_t padding[256 - 10]; /* Extra padding for CCW */
+} __attribute__ ((aligned(4))) __attribute__ ((packed));
+
/* CSS low level access functions */

static inline int ssch(unsigned long schid, struct orb *addr)
@@ -253,4 +266,11 @@ int css_enumerate(void);
#define MAX_ENABLE_RETRIES 5
int css_enable(int schid);

+
+/* Library functions */
+int start_ccw1_chain(unsigned int sid, struct ccw1 *ccw);
+int start_subchannel(unsigned int sid, int code, void *data, int count,
+ unsigned char flags);
+int sch_read_len(int sid);
+
#endif
diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c
index 06a76db..c3d93d3 100644
--- a/lib/s390x/css_lib.c
+++ b/lib/s390x/css_lib.c
@@ -128,3 +128,49 @@ retry:
schid, retry_count, pmcw->flags);
return -1;
}
+
+int start_ccw1_chain(unsigned int sid, struct ccw1 *ccw)
+{
+ struct orb orb = {
+ .intparm = sid,
+ .ctrl = ORB_CTRL_ISIC|ORB_CTRL_FMT|ORB_LPM_DFLT,
+ .cpa = (unsigned int) (unsigned long)ccw,
+ };
+
+ return ssch(sid, &orb);
+}
+
+/*
+ * In the next revisions we will implement the possibility to handle
+ * CCW chains doing this we will need to work with ccw1 pointers.
+ * For now we only need a unique CCW.
+ */
+static struct ccw1 unique_ccw;
+
+int start_subchannel(unsigned int sid, int code, void *data, int count,
+ unsigned char flags)
+{
+ int cc;
+ struct ccw1 *ccw = &unique_ccw;
+
+ report_prefix_push("start_subchannel");
+ /* Build the CCW chain with a single CCW */
+ ccw->code = code;
+ ccw->flags = flags; /* No flags need to be set */
+ ccw->count = count;
+ ccw->data_address = (int)(unsigned long)data;
+
+ cc = start_ccw1_chain(sid, ccw);
+ if (cc) {
+ report(0, "start_ccw_chain failed ret=%d", cc);
+ report_prefix_pop();
+ return cc;
+ }
+ report_prefix_pop();
+ return 0;
+}
+
+int sch_read_len(int sid)
+{
+ return unique_ccw.count;
+}
diff --git a/s390x/css.c b/s390x/css.c
index 6948d73..6b618a1 100644
--- a/s390x/css.c
+++ b/s390x/css.c
@@ -16,10 +16,18 @@
#include <string.h>
#include <interrupt.h>
#include <asm/arch_def.h>
+#include <kernel-args.h>

#include <css.h>

+#define DEFAULT_CU_TYPE 0x3832
+static unsigned long cu_type = DEFAULT_CU_TYPE;
+
+struct lowcore *lowcore = (void *)0x0;
+
static int test_device_sid;
+static struct irb irb;
+static struct senseid senseid;

static void test_enumerate(void)
{
@@ -45,20 +53,150 @@ static void test_enable(void)
report(cc == 0, "Enable subchannel %08x", test_device_sid);
}

+static void enable_io_isc(void)
+{
+ /* Let's enable all ISCs for I/O interrupt */
+ lctlg(6, 0x00000000ff000000);
+}
+
+static void irq_io(void)
+{
+ int ret = 0;
+ char *flags;
+ int sid;
+
+ report_prefix_push("Interrupt");
+ /* Lowlevel set the SID as interrupt parameter. */
+ if (lowcore->io_int_param != test_device_sid) {
+ report(0,
+ "Bad io_int_param: %x expected %x",
+ lowcore->io_int_param, test_device_sid);
+ goto pop;
+ }
+ report_prefix_pop();
+
+ report_prefix_push("tsch");
+ sid = lowcore->subsys_id_word;
+ ret = tsch(sid, &irb);
+ switch (ret) {
+ case 1:
+ dump_irb(&irb);
+ flags = dump_scsw_flags(irb.scsw.ctrl);
+ report(0,
+ "I/O interrupt, CC 1 but tsch reporting sch %08x as not status pending: %s",
+ sid, flags);
+ break;
+ case 2:
+ report(0, "tsch returns unexpected CC 2");
+ break;
+ case 3:
+ report(0, "tsch reporting sch %08x as not operational", sid);
+ break;
+ case 0:
+ /* Stay humble on success */
+ break;
+ }
+pop:
+ report_prefix_pop();
+ lowcore->io_old_psw.mask &= ~PSW_MASK_WAIT;
+}
+
+/*
+ * test_sense
+ * Pre-requisits:
+ * - We need the test device as the first recognized
+ * device by the enumeration.
+ */
+static void test_sense(void)
+{
+ int ret;
+
+ if (!test_device_sid) {
+ report_skip("No device");
+ return;
+ }
+
+ ret = css_enable(test_device_sid);
+ if (ret) {
+ report(0,
+ "Could not enable the subchannel: %08x",
+ test_device_sid);
+ return;
+ }
+
+ ret = register_io_int_func(irq_io);
+ if (ret) {
+ report(0, "Could not register IRQ handler");
+ goto unreg_cb;
+ }
+
+ lowcore->io_int_param = 0;
+
+ memset(&senseid, 0, sizeof(senseid));
+ ret = start_subchannel(test_device_sid, CCW_CMD_SENSE_ID,
+ &senseid, sizeof(senseid), CCW_F_SLI);
+ if (ret) {
+ report(0, "ssch failed for SENSE ID on sch %08x with cc %d",
+ test_device_sid, ret);
+ goto unreg_cb;
+ }
+
+ wait_for_interrupt(PSW_MASK_IO);
+
+ ret = sch_read_len(test_device_sid);
+ if (ret < CSS_SENSEID_COMMON_LEN) {
+ report(0,
+ "ssch succeeded for SENSE ID but report a too short length: %d",
+ ret);
+ goto unreg_cb;
+ }
+
+ if (senseid.reserved != 0xff) {
+ report(0,
+ "ssch succeeded for SENSE ID but reports garbage: %x",
+ senseid.reserved);
+ goto unreg_cb;
+ }
+
+ if (lowcore->io_int_param != test_device_sid)
+ goto unreg_cb;
+
+ report_info("senseid length read: %d", ret);
+ report_info("reserved %02x cu_type %04x cu_model %02x dev_type %04x dev_model %02x",
+ senseid.reserved, senseid.cu_type, senseid.cu_model,
+ senseid.dev_type, senseid.dev_model);
+
+ report(senseid.cu_type == cu_type, "cu_type: expect 0x%04x got 0x%04x",
+ (uint16_t) cu_type, senseid.cu_type);
+
+unreg_cb:
+ unregister_io_int_func(irq_io);
+}
+
static struct {
const char *name;
void (*func)(void);
} tests[] = {
{ "enumerate (stsch)", test_enumerate },
{ "enable (msch)", test_enable },
+ { "sense (ssch/tsch)", test_sense },
{ NULL, NULL }
};

+static unsigned long value;
+
int main(int argc, char *argv[])
{
- int i;
+ int i, ret;
+
+ ret = kernel_arg(argc, argv, "cu_type=", &value);
+ if (!ret)
+ cu_type = (uint16_t)value;
+ else
+ report_info("Using cu_type default value: 0x%04lx", cu_type);

report_prefix_push("Channel Subsystem");
+ enable_io_isc();
for (i = 0; tests[i].name; i++) {
report_prefix_push(tests[i].name);
tests[i].func();
--
2.25.1