From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:4970 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726259AbhANOq2 (ORCPT ); Thu, 14 Jan 2021 09:46:28 -0500 Date: Thu, 14 Jan 2021 14:47:33 +0100 From: Claudio Imbrenda Subject: Re: [kvm-unit-tests PATCH v4 3/9] s390x: SCLP feature checking Message-ID: <20210114144733.3ec11445@ibm-vm> In-Reply-To: <20210112132054.49756-4-frankja@linux.ibm.com> References: <20210112132054.49756-1-frankja@linux.ibm.com> <20210112132054.49756-4-frankja@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-ID: To: Janosch Frank Cc: kvm@vger.kernel.org, thuth@redhat.com, david@redhat.com, borntraeger@de.ibm.com, cohuck@redhat.com, linux-s390@vger.kernel.org On Tue, 12 Jan 2021 08:20:48 -0500 Janosch Frank wrote: > Availability of SIE is announced via a feature bit in a SCLP info CPU > entry. Let's add a framework that allows us to easily check for such > facilities. > > Signed-off-by: Janosch Frank > Reviewed-by: Thomas Huth > --- > lib/s390x/io.c | 1 + > lib/s390x/sclp.c | 25 +++++++++++++++++++++++++ > lib/s390x/sclp.h | 13 ++++++++++++- > 3 files changed, 38 insertions(+), 1 deletion(-) > > diff --git a/lib/s390x/io.c b/lib/s390x/io.c > index 6a1da63..ef9f59e 100644 > --- a/lib/s390x/io.c > +++ b/lib/s390x/io.c > @@ -35,6 +35,7 @@ void setup(void) > setup_args_progname(ipl_args); > setup_facilities(); > sclp_read_info(); > + sclp_facilities_setup(); > sclp_console_setup(); > sclp_memory_setup(); > smp_setup(); > diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c > index 12916f5..06819a6 100644 > --- a/lib/s390x/sclp.c > +++ b/lib/s390x/sclp.c > @@ -25,6 +25,7 @@ static uint64_t max_ram_size; > static uint64_t ram_size; > char _read_info[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); > static ReadInfo *read_info; > +struct sclp_facilities sclp_facilities; > > char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096))); > static volatile bool sclp_busy; > @@ -128,6 +129,30 @@ CPUEntry *sclp_get_cpu_entries(void) > return (CPUEntry *)(_read_info + read_info->offset_cpu); > } > > +void sclp_facilities_setup(void) > +{ > + unsigned short cpu0_addr = stap(); > + CPUEntry *cpu; > + int i; > + > + assert(read_info); > + > + cpu = sclp_get_cpu_entries(); > + for (i = 0; i < read_info->entries_cpu; i++, cpu++) { > + /* > + * The logic for only reading the facilities from the > + * boot cpu comes from the kernel. I haven't yet > found > + * documentation that explains why this is necessary > + * but I figure there's a reason behind doing it this > + * way. > + */ > + if (cpu->address == cpu0_addr) { > + sclp_facilities.has_sief2 = cpu->feat_sief2; > + break; > + } > + } > +} > + > /* Perform service call. Return 0 on success, non-zero otherwise. */ > int sclp_service_call(unsigned int command, void *sccb) > { > diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h > index acd86d5..6c86037 100644 > --- a/lib/s390x/sclp.h > +++ b/lib/s390x/sclp.h > @@ -92,12 +92,22 @@ typedef struct SCCBHeader { > typedef struct CPUEntry { > uint8_t address; > uint8_t reserved0; > - uint8_t features[SCCB_CPU_FEATURE_LEN]; > + uint8_t : 4; > + uint8_t feat_sief2 : 1; > + uint8_t : 3; > + uint8_t features_res2 [SCCB_CPU_FEATURE_LEN - 1]; > uint8_t reserved2[6]; > uint8_t type; > uint8_t reserved1; > } __attribute__((packed)) CPUEntry; > > +extern struct sclp_facilities sclp_facilities; > + > +struct sclp_facilities { > + uint64_t has_sief2 : 1; > + uint64_t : 63; > +}; > + > typedef struct ReadInfo { > SCCBHeader h; > uint16_t rnmax; > @@ -271,6 +281,7 @@ void sclp_print(const char *str); > void sclp_read_info(void); > int sclp_get_cpu_num(void); > CPUEntry *sclp_get_cpu_entries(void); > +void sclp_facilities_setup(void); > int sclp_service_call(unsigned int command, void *sccb); > void sclp_memory_setup(void); > uint64_t get_ram_size(void); Reviewed-by: Claudio Imbrenda