Re: [kvm-unit-tests PATCH v1 1/5] s390x: css: Store CSS Characteristics

Janosch Frank
2021-02-01T10:02:30Z

On 1/29/21 3:34 PM, Pierre Morel wrote:
> CSS characteristics exposes the features of the Channel SubSystem.
> Let's use Store Channel Subsystem Characteristics to retrieve
> the features of the CSS.
>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
> lib/s390x/css.h | 57 +++++++++++++++++++++++++++++++++++++++++++++
> lib/s390x/css_lib.c | 50 ++++++++++++++++++++++++++++++++++++++-
> s390x/css.c | 12 ++++++++++
> 3 files changed, 118 insertions(+), 1 deletion(-)
>
> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
> index 3e57445..bc0530d 100644
> --- a/lib/s390x/css.h
> +++ b/lib/s390x/css.h
> @@ -288,4 +288,61 @@ int css_residual_count(unsigned int schid);
> void enable_io_isc(uint8_t isc);
> int wait_and_check_io_completion(int schid);
>
> +/*
> + * CHSC definitions
> + */
> +struct chsc_header {
> + u16 len;
> + u16 code;
> +};
> +
> +/* Store Channel Subsystem Characteristics */
> +struct chsc_scsc {
> + struct chsc_header req;
> + u32 reserved1;
> + u32 reserved2;
> + u32 reserved3;

Array?

> + struct chsc_header res;
> + u32 format;
> + u64 general_char[255];
> + u64 chsc_char[254];
> +};
> +extern struct chsc_scsc *chsc_scsc;
> +
> +#define CSS_GENERAL_FEAT_BITLEN (255 * 64)
> +#define CSS_CHSC_FEAT_BITLEN (254 * 64)
> +
> +int get_chsc_scsc(void);
> +
> +static inline int _chsc(void *p)
> +{
> + int cc;
> +
> + asm volatile(
> + " .insn rre,0xb25f0000,%2,0\n"
> + " ipm %0\n"
> + " srl %0,28\n"
> + : "=d" (cc), "=m" (p)
> + : "d" (p), "m" (p)
> + : "cc");
> +
> + return cc;
> +}
> +
> +#define CHSC_SCSC 0x0010
> +#define CHSC_SCSC_LEN 0x0010
> +
> +static inline int chsc(void *p, uint16_t code, uint16_t len)
> +{
> + struct chsc_header *h = p;
> +
> + h->code = code;
> + h->len = len;
> + return _chsc(p);
> +}
> +
> +#include <bitops.h>
> +#define css_general_feature(bit) test_bit_inv(bit, chsc_scsc->general_char)
> +#define css_chsc_feature(bit) test_bit_inv(bit, chsc_scsc->chsc_char)
> +
> #endif
> diff --git a/lib/s390x/css_lib.c b/lib/s390x/css_lib.c
> index 3c24480..fe05021 100644
> --- a/lib/s390x/css_lib.c
> +++ b/lib/s390x/css_lib.c
> @@ -15,11 +15,59 @@
> #include <asm/arch_def.h>
> #include <asm/time.h>
> #include <asm/arch_def.h>
> -
> +#include <alloc_page.h>
> #include <malloc_io.h>
> #include <css.h>
>
> static struct schib schib;
> +struct chsc_scsc *chsc_scsc;
> +
> +int get_chsc_scsc(void)
> +{
> + int i, n;
> + int ret = 0;
> + char buffer[510];
> + char *p;
> +
> + report_prefix_push("Channel Subsystem Call");
> +
> + if (chsc_scsc) {
> + report_info("chsc_scsc already initialized");
> + goto end;
> + }
> +
> + chsc_scsc = alloc_pages(0);

alloc_page() ?

> + report_info("scsc_scsc at: %016lx", (u64)chsc_scsc);
> + if (!chsc_scsc) {
> + ret = -1;
> + report(0, "could not allocate chsc_scsc page!");
> + goto end;
> + }
> +
> + ret = chsc(chsc_scsc, CHSC_SCSC, CHSC_SCSC_LEN);
> + if (ret) {
> + report(0, "chsc: CC %d", ret);
> + goto end;
> + }
> +
> + for (i = 0, p = buffer; i < CSS_GENERAL_FEAT_BITLEN; i++)
> + if (css_general_feature(i)) {
> + n = snprintf(p, sizeof(buffer) - ret, "%d,", i);
> + p += n;
> + }
> + report_info("General features: %s", buffer);
> +
> + for (i = 0, p = buffer, ret = 0; i < CSS_CHSC_FEAT_BITLEN; i++)
> + if (css_chsc_feature(i)) {
> + n = snprintf(p, sizeof(buffer) - ret, "%d,", i);
> + p += n;
> + }
> + report_info("CHSC features: %s", buffer);
> +
> +end:
> + report_prefix_pop();
> + return ret;
> +}
>
> /*
> * css_enumerate:
> diff --git a/s390x/css.c b/s390x/css.c
> index 1a61a5c..18dbf01 100644
> --- a/s390x/css.c
> +++ b/s390x/css.c
> @@ -14,6 +14,7 @@
> #include <string.h>
> #include <interrupt.h>
> #include <asm/arch_def.h>
> +#include <alloc_page.h>
>
> #include <malloc_io.h>
> #include <css.h>
> @@ -140,10 +141,21 @@ error_senseid:
> unregister_io_int_func(css_irq_io);
> }
>
> +static void css_init(void)
> +{
> + int ret;
> +
> + ret = get_chsc_scsc();
> + if (!ret)
> + report(1, " ");
> +}
> +
> static struct {
> const char *name;
> void (*func)(void);
> } tests[] = {
> + /* The css_init test is needed to initialize the CSS Characteristics */
> + { "initialize CSS (chsc)", css_init },
> { "enumerate (stsch)", test_enumerate },
> { "enable (msch)", test_enable },
> { "sense (ssch/tsch)", test_sense },
>