From patchwork Thu Jun 20 04:12:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alastair D'Silva X-Patchwork-Id: 1119112 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 45TpPM5jjmz9s9y for ; Thu, 20 Jun 2019 14:14:47 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=au1.ibm.com Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 45TpPM4gDTzDqwN for ; Thu, 20 Jun 2019 14:14:47 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=au1.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=alastair@au1.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=au1.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 45TpMW6vLSzDqpd for ; Thu, 20 Jun 2019 14:13:11 +1000 (AEST) Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x5K4CNeO084846 for ; Thu, 20 Jun 2019 00:13:08 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0a-001b2d01.pphosted.com with ESMTP id 2t80n7cbry-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 20 Jun 2019 00:13:07 -0400 Received: from localhost by e06smtp01.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, 20 Jun 2019 05:13:01 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x5K4D0PO51970296 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 20 Jun 2019 04:13:00 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A58AC4C04E; Thu, 20 Jun 2019 04:13:00 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1342E4C044; Thu, 20 Jun 2019 04:13:00 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 20 Jun 2019 04:13:00 +0000 (GMT) Received: from adsilva.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id AECBFA011C; Thu, 20 Jun 2019 14:12:57 +1000 (AEST) From: "Alastair D'Silva" To: alastair@d-silva.org Subject: [PATCH v2] ocxl: Allow contexts to be attached with a NULL mm Date: Thu, 20 Jun 2019 14:12:01 +1000 X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19062004-4275-0000-0000-00000343F20B X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19062004-4276-0000-0000-000038541FDE Message-Id: <20190620041203.12274-1-alastair@au1.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-06-20_03:, , 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=502 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906200032 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Donnellan , Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Nicholas Piggin , Masahiro Yamada , Paul Mackerras , Suraj Jitindar Singh , Frederic Barrat , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Thomas Gleixner Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Alastair D'Silva If an OpenCAPI context is to be used directly by a kernel driver, there may not be a suitable mm to use. The patch makes the mm parameter to ocxl_context_attach optional. Signed-off-by: Alastair D'Silva Acked-by: Nicholas Piggin Acked-by: Frederic Barrat Acked-by: Andrew Donnellan --- arch/powerpc/mm/book3s64/radix_tlb.c | 5 +++++ drivers/misc/ocxl/context.c | 9 ++++++--- drivers/misc/ocxl/link.c | 28 ++++++++++++++++++++++++---- 3 files changed, 35 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c index bb9835681315..ce8a77fae6a7 100644 --- a/arch/powerpc/mm/book3s64/radix_tlb.c +++ b/arch/powerpc/mm/book3s64/radix_tlb.c @@ -666,6 +666,11 @@ EXPORT_SYMBOL(radix__flush_tlb_page); #define radix__flush_all_mm radix__local_flush_all_mm #endif /* CONFIG_SMP */ +/* + * If kernel TLBIs ever become local rather than global, then + * drivers/misc/ocxl/link.c:ocxl_link_add_pe will need some work, as it + * assumes kernel TLBIs are global. + */ void radix__flush_tlb_kernel_range(unsigned long start, unsigned long end) { _tlbie_pid(0, RIC_FLUSH_ALL); diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c index bab9c9364184..994563a078eb 100644 --- a/drivers/misc/ocxl/context.c +++ b/drivers/misc/ocxl/context.c @@ -69,6 +69,7 @@ static void xsl_fault_error(void *data, u64 addr, u64 dsisr) int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) { int rc; + unsigned long pidr = 0; // Locks both status & tidr mutex_lock(&ctx->status_mutex); @@ -77,9 +78,11 @@ int ocxl_context_attach(struct ocxl_context *ctx, u64 amr, struct mm_struct *mm) goto out; } - rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, - mm->context.id, ctx->tidr, amr, mm, - xsl_fault_error, ctx); + if (mm) + pidr = mm->context.id; + + rc = ocxl_link_add_pe(ctx->afu->fn->link, ctx->pasid, pidr, ctx->tidr, + amr, mm, xsl_fault_error, ctx); if (rc) goto out; diff --git a/drivers/misc/ocxl/link.c b/drivers/misc/ocxl/link.c index cce5b0d64505..58d111afd9f6 100644 --- a/drivers/misc/ocxl/link.c +++ b/drivers/misc/ocxl/link.c @@ -224,6 +224,17 @@ static irqreturn_t xsl_fault_handler(int irq, void *data) ack_irq(spa, ADDRESS_ERROR); return IRQ_HANDLED; } + + if (!pe_data->mm) { + /* + * translation fault from a kernel context - an OpenCAPI + * device tried to access a bad kernel address + */ + rcu_read_unlock(); + pr_warn("Unresolved OpenCAPI xsl fault in kernel context\n"); + ack_irq(spa, ADDRESS_ERROR); + return IRQ_HANDLED; + } WARN_ON(pe_data->mm->context.id != pid); if (mmget_not_zero(pe_data->mm)) { @@ -523,7 +534,13 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, pe->amr = cpu_to_be64(amr); pe->software_state = cpu_to_be32(SPA_PE_VALID); - mm_context_add_copro(mm); + /* + * For user contexts, register a copro so that TLBIs are seen + * by the nest MMU. If we have a kernel context, TLBIs are + * already global. + */ + if (mm) + mm_context_add_copro(mm); /* * Barrier is to make sure PE is visible in the SPA before it * is used by the device. It also helps with the global TLBI @@ -546,7 +563,8 @@ int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr, * have a reference on mm_users. Incrementing mm_count solves * the problem. */ - mmgrab(mm); + if (mm) + mmgrab(mm); trace_ocxl_context_add(current->pid, spa->spa_mem, pasid, pidr, tidr); unlock: mutex_unlock(&spa->spa_lock); @@ -652,8 +670,10 @@ int ocxl_link_remove_pe(void *link_handle, int pasid) if (!pe_data) { WARN(1, "Couldn't find pe data when removing PE\n"); } else { - mm_context_remove_copro(pe_data->mm); - mmdrop(pe_data->mm); + if (pe_data->mm) { + mm_context_remove_copro(pe_data->mm); + mmdrop(pe_data->mm); + } kfree_rcu(pe_data, rcu); } unlock: