From patchwork Thu Aug 29 12:14:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Janosch Frank X-Patchwork-Id: 11121267 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 682D214DE for ; Thu, 29 Aug 2019 12:15:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46DDE22CF5 for ; Thu, 29 Aug 2019 12:15:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727565AbfH2MP0 (ORCPT ); Thu, 29 Aug 2019 08:15:26 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:25300 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727176AbfH2MPZ (ORCPT ); Thu, 29 Aug 2019 08:15:25 -0400 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x7TC744q076301 for ; Thu, 29 Aug 2019 08:15:25 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2upd9vavuy-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 29 Aug 2019 08:15:23 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 29 Aug 2019 13:15:18 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x7TCFHMD41615832 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Aug 2019 12:15:17 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A0D2B5205F; Thu, 29 Aug 2019 12:15:17 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.55.105]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 610285204E; Thu, 29 Aug 2019 12:15:16 +0000 (GMT) From: Janosch Frank To: kvm@vger.kernel.org Cc: linux-s390@vger.kernel.org, david@redhat.com, thuth@redhat.com Subject: [kvm-unit-tests PATCH 1/6] s390x: Use interrupts in SCLP and add locking Date: Thu, 29 Aug 2019 14:14:54 +0200 X-Mailer: git-send-email 2.17.0 In-Reply-To: <20190829121459.1708-1-frankja@linux.ibm.com> References: <20190829121459.1708-1-frankja@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19082912-0020-0000-0000-000003653F41 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19082912-0021-0000-0000-000021BA977E Message-Id: <20190829121459.1708-2-frankja@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-29_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908290135 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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 --- lib/s390x/asm/interrupt.h | 2 ++ lib/s390x/interrupt.c | 12 +++++++-- lib/s390x/sclp-console.c | 2 ++ lib/s390x/sclp.c | 54 +++++++++++++++++++++++++++++++++++++-- lib/s390x/sclp.h | 3 +++ 5 files changed, 69 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..257eb02 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 +45,61 @@ 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. + */ +retry_wait: + sclp_wait_busy(); + spin_lock(&sclp_lock); + if (sclp_busy) { + spin_unlock(&sclp_lock); + goto retry_wait; + } + sclp_busy = true; + 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 +114,14 @@ 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);