Re: [kvm-unit-tests PATCH v1 2/5] s390x: css: simplifications of the tests

Janosch Frank
2021-02-01T10:13:19Z

On 1/29/21 3:34 PM, Pierre Morel wrote:
> In order to ease the writing of tests based on:
> - interrupt
> - enabling a subchannel
> - using multiple I/O on a channel without disabling it
>
> We do the following simplifications:
> - the I/O interrupt handler is registered on CSS initialization
> - We do not enable again a subchannel in senseid if it is already
> enabled
> - we add a css_enabled() function to test if a subchannel is enabled
>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
> lib/s390x/css.h | 1 +
> lib/s390x/css_lib.c | 37 ++++++++++++++++++++++++----------
> s390x/css.c | 49 +++++++++++++++++++++++++--------------------
> 3 files changed, 54 insertions(+), 33 deletions(-)
>
> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
> index bc0530d..f8bfa37 100644
> --- a/lib/s390x/css.h
> +++ b/lib/s390x/css.h
> @@ -278,6 +278,7 @@ int css_enumerate(void);
>
> #define IO_SCH_ISC 3
> int css_enable(int schid, int isc);
> +bool css_enabled(int schid);
>
> /* Library functions */
> int start_ccw1_chain(unsigned int sid, struct ccw1 *ccw);
> diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c
> index fe05021..f300969 100644
> --- a/lib/s390x/css_lib.c
> +++ b/lib/s390x/css_lib.c
> @@ -118,6 +118,31 @@ out:
> return schid;
> }
>
> +/*
> + * css_enable: enable the subchannel with the specified ISC

enabled or enable?

I.e. do you test if it is enabled or do you want to enable it.

> + * @schid: Subchannel Identifier
> + * Return value:
> + * true if the subchannel is enabled
> + * false otherwise
> + */
> +bool css_enabled(int schid)
> +{
> + struct pmcw *pmcw = &schib.pmcw;
> + int cc;
> +
> + cc = stsch(schid, &schib);
> + if (cc) {
> + report_info("stsch: updating sch %08x failed with cc=%d",
> + schid, cc);
> + return false;
> + }
> +
> + if (!(pmcw->flags & PMCW_ENABLE)) {
> + report_info("stsch: sch %08x not enabled", schid);
> + return 0;

Please stay with true/false or change the return type to int and use ints.

> + }
> + return true;
> +}
> /*
> * css_enable: enable the subchannel with the specified ISC
> * @schid: Subchannel Identifier
> @@ -167,18 +192,8 @@ retry:
> /*
> * Read the SCHIB again to verify the enablement
> */
> - cc = stsch(schid, &schib);
> - if (cc) {
> - report_info("stsch: updating sch %08x failed with cc=%d",
> - schid, cc);
> - return cc;
> - }
> -
> - if ((pmcw->flags & flags) == flags) {
> - report_info("stsch: sch %08x successfully modified after %d retries",
> - schid, retry_count);
> + if (css_enabled(schid))
> return 0;
> - }
>
> if (retry_count++ < MAX_ENABLE_RETRIES) {
> mdelay(10); /* the hardware was not ready, give it some time */
> diff --git a/s390x/css.c b/s390x/css.c
> index 18dbf01..230f819 100644
> --- a/s390x/css.c
> +++ b/s390x/css.c
> @@ -56,36 +56,27 @@ static void test_enable(void)
> * - We need the test device as the first recognized
> * device by the enumeration.
> */
> -static void test_sense(void)
> +static bool do_test_sense(void)
> {
> struct ccw1 *ccw;
> + bool retval = false;
> int ret;
> int len;
>
> if (!test_device_sid) {
> report_skip("No device");
> - return;
> + return retval;
> }
>
> - ret = css_enable(test_device_sid, IO_SCH_ISC);
> - if (ret) {
> - report(0, "Could not enable the subchannel: %08x",
> - test_device_sid);
> - return;
> + if (!css_enabled(test_device_sid)) {
> + report(0, "enabled subchannel: %08x", test_device_sid);
> + return retval;
> }
>
> - ret = register_io_int_func(css_irq_io);
> - if (ret) {
> - report(0, "Could not register IRQ handler");
> - return;
> - }
> -
> - lowcore_ptr->io_int_param = 0;
> -
> senseid = alloc_io_mem(sizeof(*senseid), 0);
> if (!senseid) {
> report(0, "Allocation of senseid");
> - goto error_senseid;
> + return retval;
> }
>
> ccw = ccw_alloc(CCW_CMD_SENSE_ID, senseid, sizeof(*senseid), CCW_F_SLI);
> @@ -129,16 +120,21 @@ static void test_sense(void)
> report_info("reserved 0x%02x cu_type 0x%04x cu_model 0x%02x dev_type 0x%04x dev_model 0x%02x",
> senseid->reserved, senseid->cu_type, senseid->cu_model,
> senseid->dev_type, senseid->dev_model);
> + report_info("cu_type expected 0x%04x got 0x%04x", (uint16_t)cu_type,
> + senseid->cu_type);
>
> - report(senseid->cu_type == cu_type, "cu_type expected 0x%04x got 0x%04x",
> - (uint16_t)cu_type, senseid->cu_type);
> + retval = senseid->cu_type == cu_type;
>
> error:
> free_io_mem(ccw, sizeof(*ccw));
> error_ccw:
> free_io_mem(senseid, sizeof(*senseid));
> -error_senseid:
> - unregister_io_int_func(css_irq_io);
> + return retval;

Could you return senseid->cu_type == cu_type here?

> +}
> +
> +static void test_sense(void)
> +{
> + report(do_test_sense(), "Got CU type expected");
> }
>
> static void css_init(void)
> @@ -146,8 +142,17 @@ static void css_init(void)
> int ret;
>
> ret = get_chsc_scsc();
> - if (!ret)
> - report(1, " ");
> + if (ret)
> + return;
> +
> + ret = register_io_int_func(css_irq_io);
> + if (ret) {
> + report(0, "Could not register IRQ handler");
> + return;
> + }
> + lowcore_ptr->io_int_param = 0;
> +
> + report(1, "CSS initialized");
> }
>
> static struct {
>