From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-2.mimecast.com ([205.139.110.61]:51134 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726127AbgAMKm0 (ORCPT ); Mon, 13 Jan 2020 05:42:26 -0500 Subject: Re: [kvm-unit-tests PATCH v7 3/4] s390x: lib: add SPX and STPX instruction wrapper References: <20200110184050.191506-1-imbrenda@linux.ibm.com> <20200110184050.191506-4-imbrenda@linux.ibm.com> From: David Hildenbrand Message-ID: <81301db1-7fd1-c3ef-ded6-fd682fc24af9@redhat.com> Date: Mon, 13 Jan 2020 11:42:18 +0100 MIME-Version: 1.0 In-Reply-To: <20200110184050.191506-4-imbrenda@linux.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Claudio Imbrenda , kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, thuth@redhat.com, borntraeger@de.ibm.com, frankja@linux.ibm.com On 10.01.20 19:40, Claudio Imbrenda wrote: > Add a wrapper for the SET PREFIX and STORE PREFIX instructions, and > use it instead of using inline assembly. > > Signed-off-by: Claudio Imbrenda > Reviewed-by: Thomas Huth > --- > lib/s390x/asm/arch_def.h | 13 +++++++++++++ > s390x/intercept.c | 23 ++++++++--------------- > 2 files changed, 21 insertions(+), 15 deletions(-) > > diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h > index 1a5e3c6..15a4d49 100644 > --- a/lib/s390x/asm/arch_def.h > +++ b/lib/s390x/asm/arch_def.h > @@ -284,4 +284,17 @@ static inline int servc(uint32_t command, unsigned long sccb) > return cc; > } > > +static inline void set_prefix(uint32_t new_prefix) > +{ > + asm volatile(" spx %0" : : "Q" (new_prefix) : "memory"); > +} > + > +static inline uint32_t get_prefix(void) > +{ > + uint32_t current_prefix; > + > + asm volatile(" stpx %0" : "=Q" (current_prefix)); > + return current_prefix; > +} > + > #endif > diff --git a/s390x/intercept.c b/s390x/intercept.c > index 3696e33..cd96121 100644 > --- a/s390x/intercept.c > +++ b/s390x/intercept.c > @@ -26,13 +26,10 @@ static void test_stpx(void) > uint32_t new_prefix = (uint32_t)(intptr_t)pagebuf; > > /* Can we successfully change the prefix? */ > - asm volatile ( > - " stpx %0\n" > - " spx %2\n" > - " stpx %1\n" > - " spx %0\n" > - : "+Q"(old_prefix), "+Q"(tst_prefix) > - : "Q"(new_prefix)); > + old_prefix = get_prefix(); > + set_prefix(new_prefix); > + tst_prefix = get_prefix(); > + set_prefix(old_prefix); > report(old_prefix == 0 && tst_prefix == new_prefix, "store prefix"); > > expect_pgm_int(); > @@ -63,14 +60,10 @@ static void test_spx(void) > * some facility bits there ... at least some of them should be > * set in our buffer afterwards. > */ > - asm volatile ( > - " stpx %0\n" > - " spx %1\n" > - " stfl 0\n" > - " spx %0\n" > - : "+Q"(old_prefix) > - : "Q"(new_prefix) > - : "memory"); > + old_prefix = get_prefix(); > + set_prefix(new_prefix); > + asm volatile(" stfl 0" : : : "memory"); > + set_prefix(old_prefix); > report(pagebuf[GEN_LC_STFL] != 0, "stfl to new prefix"); > > expect_pgm_int(); > Besides the comments from Janosch, looks good to me. -- Thanks, David / dhildenb