On 3/1/21 12:47 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@xxxxxxxxxxxxx>
> Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Acked-by: Janosch Frank <frankja@xxxxxxxxxxxxx>
Small nits below
> ---
> lib/s390x/css.h | 67 ++++++++++++++++++++++++++++++++
> lib/s390x/css_lib.c | 93 ++++++++++++++++++++++++++++++++++++++++++++-
> s390x/css.c | 8 ++++
> 3 files changed, 167 insertions(+), 1 deletion(-)
>
> diff --git a/lib/s390x/css.h b/lib/s390x/css.h
> index 3e57445..4210472 100644
> --- a/lib/s390x/css.h
> +++ b/lib/s390x/css.h
> @@ -288,4 +288,71 @@ 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 {
> + uint16_t len;
> + uint16_t code;
> +};
> +
> +/* Store Channel Subsystem Characteristics */
> +struct chsc_scsc {
> + struct chsc_header req;
> + uint16_t req_fmt;
> + uint8_t cssid;
> + uint8_t res_03;
> + uint32_t res_04[2];
I find the naming a bit weird and it could be one uint8_t field.
> + struct chsc_header res;
> + uint32_t res_fmt;
> + uint64_t general_char[255];
> + uint64_t chsc_char[254];
> +};
> +
> +extern struct chsc_scsc *chsc_scsc;
> +#define CHSC_SCSC 0x0010
> +#define CHSC_SCSC_LEN 0x0010
> +
> +bool get_chsc_scsc(void);
> +
> +#define CSS_GENERAL_FEAT_BITLEN (255 * 64)
> +#define CSS_CHSC_FEAT_BITLEN (254 * 64)
> +
> +#define CHSC_SCSC 0x0010
> +#define CHSC_SCSC_LEN 0x0010
> +
> +#define CHSC_ERROR 0x0000
> +#define CHSC_RSP_OK 0x0001
> +#define CHSC_RSP_INVAL 0x0002
> +#define CHSC_RSP_REQERR 0x0003
> +#define CHSC_RSP_ENOCMD 0x0004
> +#define CHSC_RSP_NODATA 0x0005
> +#define CHSC_RSP_SUP31B 0x0006
> +#define CHSC_RSP_EFRMT 0x0007
> +#define CHSC_RSP_ECSSID 0x0008
> +#define CHSC_RSP_ERFRMT 0x0009
> +#define CHSC_RSP_ESSID 0x000A
> +#define CHSC_RSP_EBUSY 0x000B
> +#define CHSC_RSP_MAX 0x000B
> +
> +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;
> +}
> +
> +bool chsc(void *p, uint16_t code, uint16_t len);
> +
> +#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..f46e871 100644
> --- a/lib/s390x/css_lib.c
> +++ b/lib/s390x/css_lib.c
> @@ -15,11 +15,102 @@
> #include <asm/arch_def.h>
> #include <asm/time.h>
> #include <asm/arch_def.h>
> -
> +#include <alloc_page.h>
Did you intend to remove the newline here?
> #include <malloc_io.h>
> #include <css.h>
>
> static struct schib schib;
> +struct chsc_scsc *chsc_scsc;
> +
> +static const char * const chsc_rsp_description[] = {
> + "CHSC unknown error",
> + "Command executed",
> + "Invalid command",
> + "Request-block error",
> + "Command not installed",
> + "Data not available",
> + "Absolute address of channel-subsystem communication block exceeds 2G - 1.",
> + "Invalid command format",
> + "Invalid channel-subsystem identification (CSSID)",
> + "The command-request block specified an invalid format for the command response block.",
> + "Invalid subchannel-set identification (SSID)",
> + "A busy condition precludes execution.",
> +};
> +
> +static bool check_response(void *p)
> +{
> + struct chsc_header *h = p;
> +
> + if (h->code == CHSC_RSP_OK)
> + return true;
> +
> + if (h->code > CHSC_RSP_MAX)
> + h->code = 0;
> +
> + report_abort("Response code %04x: %s", h->code,
> + chsc_rsp_description[h->code]);
> + return false;
> +}
> +
> +bool chsc(void *p, uint16_t code, uint16_t len)
> +{
> + struct chsc_header *h = p;
> +
> + h->code = code;
> + h->len = len;
> +
> + switch (_chsc(p)) {
> + case 3:
> + report_abort("Subchannel invalid or not enabled.");
> + break;
> + case 2:
> + report_abort("CHSC subchannel busy.");
> + break;
> + case 1:
> + report_abort("Subchannel invalid or not enabled.");
> + break;
> + case 0:
> + return check_response(p + len);
> + }
> + return false;
> +}
> +
> +bool get_chsc_scsc(void)
> +{
> + int i, n;
> + char buffer[510];
> + char *p;
> +
> + if (chsc_scsc) /* chsc_scsc already initialized */
> + return true;
> +
> + chsc_scsc = alloc_page();
> + if (!chsc_scsc) {
> + report_abort("could not allocate chsc_scsc page!");
> + return false;
> + }
> +
> + if (!chsc(chsc_scsc, CHSC_SCSC, CHSC_SCSC_LEN))
> + return false;
> +
> + for (i = 0, p = buffer; i < CSS_GENERAL_FEAT_BITLEN; i++) {
> + if (css_general_feature(i)) {
> + n = snprintf(p, sizeof(buffer), "%d,", i);
> + p += n;
> + }
> + }
> + report_info("General features: %s", buffer);
> +
> + for (i = 0, p = buffer; i < CSS_CHSC_FEAT_BITLEN; i++) {
> + if (css_chsc_feature(i)) {
> + n = snprintf(p, sizeof(buffer), "%d,", i);
> + p += n;
> + }
> + }
> + report_info("CHSC features: %s", buffer);
> +
> + return true;
> +}
>
> /*
> * css_enumerate:
> diff --git a/s390x/css.c b/s390x/css.c
> index 1a61a5c..09703c1 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 +141,17 @@ error_senseid:
> unregister_io_int_func(css_irq_io);
> }
>
> +static void css_init(void)
> +{
> + report(!!get_chsc_scsc(), "Store Channel Characteristics");
get_chsc_scsc() returns a bool, so you shouldn't need the !! here, no?
> +}
> +
> 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 },
>
