On Thu, 2 Jul 2020 18:31:20 +0200
Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
> 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@xxxxxxxxxxxxx>
> ---
> lib/s390x/asm/arch_def.h | 1 +
> lib/s390x/css.h | 32 ++++++++-
> lib/s390x/css_lib.c | 148 ++++++++++++++++++++++++++++++++++++++-
> s390x/css.c | 94 ++++++++++++++++++++++++-
> 4 files changed, 272 insertions(+), 3 deletions(-)
(...)
> -int css_enable(int schid)
> +/*
> + * css_enable: enable Subchannel
> + * @schid: Subchannel Identifier
> + * @isc: Interruption subclass for this subchannel as a number
"number of the interruption subclass to use"?
> + * Return value:
> + * On success: 0
> + * On error the CC of the faulty instruction
> + * or -1 if the retry count is exceeded.
> + *
> + */
> +int css_enable(int schid, int isc)
> {
> struct pmcw *pmcw = &schib.pmcw;
> int retry_count = 0;
> @@ -92,6 +103,9 @@ retry:
> /* Update the SCHIB to enable the channel */
> pmcw->flags |= PMCW_ENABLE;
>
> + /* Set Interruption Subclass to IO_SCH_ISC */
The specified isc, current callers just happen to pass that value.
> + pmcw->flags |= (isc << PMCW_ISC_SHIFT);
> +
> /* Tell the CSS we want to modify the subchannel */
> cc = msch(schid, &schib);
> if (cc) {
> @@ -114,6 +128,7 @@ retry:
> return cc;
> }
>
> + report_info("stsch: flags: %04x", pmcw->flags);
It feels like all of this already should have been included in the
previous patch?
> if (pmcw->flags & PMCW_ENABLE) {
> report_info("stsch: sch %08x enabled after %d retries",
> schid, retry_count);
> @@ -129,3 +144,134 @@ retry:
> schid, retry_count, pmcw->flags);
> return -1;
> }
> +
> +static struct irb irb;
> +
> +void css_irq_io(void)
> +{
> + int ret = 0;
> + char *flags;
> + int sid;
> +
> + report_prefix_push("Interrupt");
> + sid = lowcore_ptr->subsys_id_word;
> + /* Lowlevel set the SID as interrupt parameter. */
> + if (lowcore_ptr->io_int_param != sid) {
> + report(0,
> + "io_int_param: %x differs from subsys_id_word: %x",
> + lowcore_ptr->io_int_param, sid);
> + goto pop;
> + }
> + report_info("subsys_id_word: %08x io_int_param %08x io_int_word %08x",
> + lowcore_ptr->subsys_id_word,
> + lowcore_ptr->io_int_param,
> + lowcore_ptr->io_int_word);
> + report_prefix_pop();
> +
> + report_prefix_push("tsch");
> + 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",
"I/O interrupt, but tsch returns CC 1 for subchannel %08x" ?
> + 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_ptr->io_old_psw.mask &= ~PSW_MASK_WAIT;
> +}
> +
> +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 future, we want to implement support for CCW chains;
> + * for that, we will need to work with ccw1 pointers.
> + */
> +static struct ccw1 unique_ccw;
> +
> +int start_single_ccw(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 */
s/No flags/No additional flags/
> + 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;
> +}
> +
> +/*
> + * css_residual_count
> + * We expect no residual count when the ORB request was successful
If we have a short block, but have suppressed the incorrect length
indication, we may have a successful request with a nonzero count.
Maybe replace this with "Return the residual count, if it is valid."?
> + * The residual count is valid when the subchannel is status pending
> + * with primary status and device status only or device status and
> + * subchannel status with PCI or incorrect length.
> + * Return value:
> + * Success: the residual count
> + * Not meaningful: -1 (-1 can not be a valid count)
> + */
> +int css_residual_count(unsigned int schid)
> +{
> +
> + if (!(irb.scsw.ctrl & (SCSW_SC_PENDING | SCSW_SC_PRIMARY)))
> + goto fail;
s/fail/invalid/ ? It's not really a failure :)
> +
> + if (irb.scsw.dev_stat)
> + if (irb.scsw.sch_stat & ~(SCSW_SCHS_PCI | SCSW_SCHS_IL))
> + goto fail;
> +
> + return irb.scsw.count;
> +
> +fail:
> + report_info("sch status %02x", irb.scsw.sch_stat);
> + report_info("dev status %02x", irb.scsw.dev_stat);
> + report_info("ctrl status %08x", irb.scsw.ctrl);
> + report_info("count %04x", irb.scsw.count);
> + report_info("ccw addr %08x", irb.scsw.ccw_addr);
I don't understand why you dump this data if no valid residual count is
available. But maybe I don't understand the purpose of this function
correctly.
> + return -1;
> +}
> +
> +/*
> + * enable_io_isc: setup ISC in Control Register 6
> + * @isc: The interruption Sub Class as a bitfield
> + */
> +void enable_io_isc(uint8_t isc)
> +{
> + uint64_t value;
> +
> + value = (uint64_t)isc << 24;
> + lctlg(6, value);
> +}
> diff --git a/s390x/css.c b/s390x/css.c
> index 72aec43..60e6434 100644
> --- a/s390x/css.c
> +++ b/s390x/css.c
> @@ -19,7 +19,11 @@
>
> #include <css.h>
>
> +#define DEFAULT_CU_TYPE 0x3832 /* virtio-ccw */
> +static unsigned long cu_type = DEFAULT_CU_TYPE;
> +
> static int test_device_sid;
> +static struct senseid senseid;
>
> static void test_enumerate(void)
> {
> @@ -40,17 +44,104 @@ static void test_enable(void)
> return;
> }
>
> - cc = css_enable(test_device_sid);
> + cc = css_enable(test_device_sid, IO_SCH_ISC);
>
> report(cc == 0, "Enable subchannel %08x", test_device_sid);
> }
>
> +/*
> + * test_sense
> + * Pre-requisits:
s/Pre-requisists/Pre-requisites/
> + * - We need the test device as the first recognized
> + * device by the enumeration.
> + */
> +static void test_sense(void)
> +{
> + int ret;
> + int len;
> +
> + if (!test_device_sid) {
> + report_skip("No device");
> + return;
> + }
> +
> + ret = css_enable(test_device_sid, IO_SCH_ISC);
> + if (ret) {
> + report(0,
> + "Could not enable the subchannel: %08x",
> + test_device_sid);
> + return;
> + }
> +
> + ret = register_io_int_func(css_irq_io);
> + if (ret) {
> + report(0, "Could not register IRQ handler");
> + goto unreg_cb;
> + }
> +
> + lowcore_ptr->io_int_param = 0;
> +
> + memset(&senseid, 0, sizeof(senseid));
> + ret = start_single_ccw(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);
> +
> + if (lowcore_ptr->io_int_param != test_device_sid) {
> + report(0, "ssch succeeded but interrupt parameter is wrong: expect %08x got %08x",
> + test_device_sid, lowcore_ptr->io_int_param);
> + goto unreg_cb;
> + }
> +
> + ret = css_residual_count(test_device_sid);
> + if (ret < 0) {
> + report(0, "ssch succeeded for SENSE ID but can not get a valid residual count");
> + goto unreg_cb;
> + }
I'm not sure what you're testing here. You should first test whether
the I/O concluded normally (i.e., whether you actually get something
like status pending with channel end/device end). If not, it does not
make much sense to look either at the residual count or at the sense id
data.
If css_residual_count does not return something >= 0 for that 'normal'
case, something is definitely fishy, though :)
> +
> + len = sizeof(senseid) - ret;
> + if (ret && len < CSS_SENSEID_COMMON_LEN) {
> + report(0,
> + "ssch succeeded for SENSE ID but report a too short length: %d",
s/report/transferred/ ?
> + ret);
> + goto unreg_cb;
> + }
> +
> + if (ret && len)
> + report_info("ssch succeeded for SENSE ID but report a shorter length: %d",
Same here.
> + len);
> +
> + if (senseid.reserved != 0xff) {
> + report(0,
> + "ssch succeeded for SENSE ID but reports garbage: %x",
> + senseid.reserved);
> + 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(css_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 }
> };
>
> @@ -59,6 +150,7 @@ int main(int argc, char *argv[])
> int i;
>
> report_prefix_push("Channel Subsystem");
> + enable_io_isc(0x80 >> IO_SCH_ISC);
> for (i = 0; tests[i].name; i++) {
> report_prefix_push(tests[i].name);
> tests[i].func();
