From patchwork Wed Sep 25 16:37:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Huth X-Patchwork-Id: 11161129 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D7874112B for ; Wed, 25 Sep 2019 16:38:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0AFF21D7C for ; Wed, 25 Sep 2019 16:38:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2505123AbfIYQi0 (ORCPT ); Wed, 25 Sep 2019 12:38:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55268 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502032AbfIYQiZ (ORCPT ); Wed, 25 Sep 2019 12:38:25 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 497C5307D985; Wed, 25 Sep 2019 16:38:25 +0000 (UTC) Received: from thuth.com (ovpn-116-109.ams2.redhat.com [10.36.116.109]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7D29760BF1; Wed, 25 Sep 2019 16:38:21 +0000 (UTC) From: Thomas Huth To: kvm@vger.kernel.org, Paolo Bonzini , =?utf-8?b?UmFk?= =?utf-8?b?aW0gS3LEjW3DocWZ?= Cc: David Hildenbrand , Janosch Frank Subject: [kvm-unit-tests PULL 11/17] s390x: Use interrupts in SCLP and add locking Date: Wed, 25 Sep 2019 18:37:08 +0200 Message-Id: <20190925163714.27519-12-thuth@redhat.com> In-Reply-To: <20190925163714.27519-1-thuth@redhat.com> References: <20190925163714.27519-1-thuth@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Wed, 25 Sep 2019 16:38:25 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Janosch Frank We need to properly implement interrupt handling for SCLP, because on z/VM and LPAR SCLP calls are not synchronous! Also with smp CPUs have to compete for sclp. Let's add some locking, so they execute sclp calls in an orderly fashion and don't compete for the data buffer. Signed-off-by: Janosch Frank Reviewed-by: Thomas Huth Message-Id: <20190920080356.1948-2-frankja@linux.ibm.com> Acked-by: David Hildenbrand Signed-off-by: Thomas Huth --- lib/s390x/asm/interrupt.h | 2 ++ lib/s390x/interrupt.c | 12 +++++++-- lib/s390x/sclp-console.c | 2 ++ lib/s390x/sclp.c | 55 +++++++++++++++++++++++++++++++++++++-- lib/s390x/sclp.h | 3 +++ 5 files changed, 70 insertions(+), 4 deletions(-) diff --git a/lib/s390x/asm/interrupt.h b/lib/s390x/asm/interrupt.h index 013709f..f485e96 100644 --- a/lib/s390x/asm/interrupt.h +++ b/lib/s390x/asm/interrupt.h @@ -11,6 +11,8 @@ #define _ASMS390X_IRQ_H_ #include +#define EXT_IRQ_SERVICE_SIG 0x2401 + void handle_pgm_int(void); void handle_ext_int(void); void handle_mcck_int(void); diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c index cf0a794..7832711 100644 --- a/lib/s390x/interrupt.c +++ b/lib/s390x/interrupt.c @@ -12,6 +12,7 @@ #include #include #include +#include static bool pgm_int_expected; static struct lowcore *lc; @@ -107,8 +108,15 @@ void handle_pgm_int(void) void handle_ext_int(void) { - report_abort("Unexpected external call interrupt: at %#lx", - lc->ext_old_psw.addr); + if (lc->ext_int_code != EXT_IRQ_SERVICE_SIG) { + report_abort("Unexpected external call interrupt: at %#lx", + lc->ext_old_psw.addr); + } else { + lc->ext_old_psw.mask &= ~PSW_MASK_EXT; + lc->sw_int_cr0 &= ~(1UL << 9); + sclp_handle_ext(); + lc->ext_int_code = 0; + } } void handle_mcck_int(void) diff --git a/lib/s390x/sclp-console.c b/lib/s390x/sclp-console.c index bc01f41..a5ef45f 100644 --- a/lib/s390x/sclp-console.c +++ b/lib/s390x/sclp-console.c @@ -17,6 +17,7 @@ static void sclp_set_write_mask(void) { WriteEventMask *sccb = (void *)_sccb; + sclp_mark_busy(); sccb->h.length = sizeof(WriteEventMask); sccb->mask_length = sizeof(unsigned int); sccb->receive_mask = SCLP_EVENT_MASK_MSG_ASCII; @@ -37,6 +38,7 @@ void sclp_print(const char *str) int len = strlen(str); WriteEventData *sccb = (void *)_sccb; + sclp_mark_busy(); sccb->h.length = sizeof(WriteEventData) + len; sccb->h.function_code = SCLP_FC_NORMAL_WRITE; sccb->ebh.length = sizeof(EventBufferHeader) + len; diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c index b60f7a4..56fca0c 100644 --- a/lib/s390x/sclp.c +++ b/lib/s390x/sclp.c @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include "sclp.h" #include #include @@ -25,6 +27,8 @@ static uint64_t max_ram_size; static uint64_t ram_size; char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096))); +static volatile bool sclp_busy; +static struct spinlock sclp_lock; static void mem_init(phys_addr_t mem_end) { @@ -41,17 +45,62 @@ static void mem_init(phys_addr_t mem_end) page_alloc_ops_enable(); } +static void sclp_setup_int(void) +{ + uint64_t mask; + + ctl_set_bit(0, 9); + + mask = extract_psw_mask(); + mask |= PSW_MASK_EXT; + load_psw_mask(mask); +} + +void sclp_handle_ext(void) +{ + ctl_clear_bit(0, 9); + spin_lock(&sclp_lock); + sclp_busy = false; + spin_unlock(&sclp_lock); +} + +void sclp_wait_busy(void) +{ + while (sclp_busy) + mb(); +} + +void sclp_mark_busy(void) +{ + /* + * With multiple CPUs we might need to wait for another CPU's + * request before grabbing the busy indication. + */ + while (true) { + sclp_wait_busy(); + spin_lock(&sclp_lock); + if (!sclp_busy) { + sclp_busy = true; + spin_unlock(&sclp_lock); + return; + } + spin_unlock(&sclp_lock); + } +} + static void sclp_read_scp_info(ReadInfo *ri, int length) { unsigned int commands[] = { SCLP_CMDW_READ_SCP_INFO_FORCED, SCLP_CMDW_READ_SCP_INFO }; - int i; + int i, cc; for (i = 0; i < ARRAY_SIZE(commands); i++) { + sclp_mark_busy(); memset(&ri->h, 0, sizeof(ri->h)); ri->h.length = length; - if (sclp_service_call(commands[i], ri)) + cc = sclp_service_call(commands[i], ri); + if (cc) break; if (ri->h.response_code == SCLP_RC_NORMAL_READ_COMPLETION) return; @@ -66,12 +115,14 @@ int sclp_service_call(unsigned int command, void *sccb) { int cc; + sclp_setup_int(); asm volatile( " .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */ " ipm %0\n" " srl %0,28" : "=&d" (cc) : "d" (command), "a" (__pa(sccb)) : "cc", "memory"); + sclp_wait_busy(); if (cc == 3) return -1; if (cc == 2) diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h index 583c4e5..63cf609 100644 --- a/lib/s390x/sclp.h +++ b/lib/s390x/sclp.h @@ -213,6 +213,9 @@ typedef struct ReadEventData { } __attribute__((packed)) ReadEventData; extern char _sccb[]; +void sclp_handle_ext(void); +void sclp_wait_busy(void); +void sclp_mark_busy(void); void sclp_console_setup(void); void sclp_print(const char *str); int sclp_service_call(unsigned int command, void *sccb);