From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:49582 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233215AbhBCKNF (ORCPT ); Wed, 3 Feb 2021 05:13:05 -0500 Subject: Re: [kvm-unit-tests PATCH v1 1/5] s390x: css: Store CSS Characteristics References: <1611930869-25745-1-git-send-email-pmorel@linux.ibm.com> <1611930869-25745-2-git-send-email-pmorel@linux.ibm.com> <74ad7962-9217-5110-4089-9b83d519cfc1@redhat.com> From: Pierre Morel Message-ID: <93bea05c-2ee9-4452-c452-0d2bbb1f302f@linux.ibm.com> Date: Wed, 3 Feb 2021 11:12:17 +0100 MIME-Version: 1.0 In-Reply-To: <74ad7962-9217-5110-4089-9b83d519cfc1@redhat.com> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 8bit List-ID: To: Thomas Huth , kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, cohuck@redhat.com, imbrenda@linux.ibm.com On 2/2/21 6:25 PM, Thomas Huth wrote: > On 29/01/2021 15.34, 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 >> --- >>   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; >> +    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 >> +#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 >>   #include >>   #include >> - >> +#include >>   #include >>   #include >>   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); >> +    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; >> +        } > > Please use curly braces for the for-loops here, too. Rationale: Kernel > coding style: > > "Also, use braces when a loop contains more than a single simple statement" OK, is better to read. Thanks, Pierre > >  Thanks, >   Thomas > -- Pierre Morel IBM Lab Boeblingen