From patchwork Thu Apr 30 14:34:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Philippe Brucker X-Patchwork-Id: 11520453 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 99CFA139A for ; Thu, 30 Apr 2020 14:40:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 828F220774 for ; Thu, 30 Apr 2020 14:40:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="MCxsvKs9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727025AbgD3OkX (ORCPT ); Thu, 30 Apr 2020 10:40:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1727077AbgD3OkW (ORCPT ); Thu, 30 Apr 2020 10:40:22 -0400 Received: from mail-wr1-x442.google.com (mail-wr1-x442.google.com [IPv6:2a00:1450:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33941C035495 for ; Thu, 30 Apr 2020 07:40:22 -0700 (PDT) Received: by mail-wr1-x442.google.com with SMTP id e16so2101001wra.7 for ; Thu, 30 Apr 2020 07:40:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=q1hatq5aHJx0R9t8uwCtyn8RhcKvbal/ky2u44TDT94=; b=MCxsvKs90x61N1oHzFrmVtQMdyghKsGyTHvvdPRwSEBey9Uq7axJbJ07O8bAxBIe5n CEZB46onPbKWAF0h+5dud8ZtxQdd65J9fyVAQTwzYTUDkfVTAeFzxYI6HxgJosS3vYe1 Msx6igRoBSv8E+/+bnophcNGlT84MJ4AtufsoNBtgnzsiSlx8Npu+a8mYBFYIVoJZ/aw Lb10HHaDmfBzmOhPJoysfpSLSp+khb9XGFd9xyiWbeAktOvrUDYTbiN1JmCrG+RB5qJH pZneZseQkQCxH45G6HtCd7hcoqmHh06Mb0PWkAV0Fzk8yecal8e3zAuw2AgM3oIpTe91 MooA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=q1hatq5aHJx0R9t8uwCtyn8RhcKvbal/ky2u44TDT94=; b=L/STw57txQ0s3IHKsYphwqSO6V+G204om7jR9oI9HmKICIdonBraSK5lw8qwU+AjEy EGQlBJam5NuU+3V3haTGz/88FSqOXehfIg12uTRCA9wBEc/HytSSFKxq7EPmRfje1zur jAJN65KfNpzIRf2+NZM/cWWm2PND583FA4Nrzz0lqUbOIkxMjo+T0ea33rjrdRaF4wMO krkYlTNdrIpB4RYShuGRKaFBNPFfaqTw3hH+8e+kMue1OuxqQyQEoESJdwTU3nloHZC+ 6ifMpsjj8unsfLd1Rlfy8jtBQRZp7NHemMEWvRJRQAhozQ27OBr2hZ2ILrUSaN+6M4yz H4+g== X-Gm-Message-State: AGi0PuZ3JrVSWc3kOG3UE1vuijxTApUuTcxMwYwZblGH/cnUYuqOT9gA cmA/QreYjKCzqde6zH5emOh8bw== X-Google-Smtp-Source: APiQypKmA3hmCuHCbQ57+52GKfslTBCMUy7QnU27YXVTt1gy0M70oLF4dUSLPGv+PyNWWYWlo+FzKQ== X-Received: by 2002:a5d:62cc:: with SMTP id o12mr4212778wrv.75.1588257620897; Thu, 30 Apr 2020 07:40:20 -0700 (PDT) Received: from localhost.localdomain ([2001:171b:226e:c200:c43b:ef78:d083:b355]) by smtp.gmail.com with ESMTPSA id n2sm4153286wrt.33.2020.04.30.07.40.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Apr 2020 07:40:19 -0700 (PDT) From: Jean-Philippe Brucker To: iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, linux-mm@kvack.org Cc: joro@8bytes.org, catalin.marinas@arm.com, will@kernel.org, robin.murphy@arm.com, kevin.tian@intel.com, baolu.lu@linux.intel.com, Jonathan.Cameron@huawei.com, jacob.jun.pan@linux.intel.com, christian.koenig@amd.com, felix.kuehling@amd.com, zhangfei.gao@linaro.org, jgg@ziepe.ca, xuzaibo@huawei.com, fenghua.yu@intel.com, hch@infradead.org, Jean-Philippe Brucker Subject: [PATCH v6 03/25] iommu/sva: Add PASID helpers Date: Thu, 30 Apr 2020 16:34:02 +0200 Message-Id: <20200430143424.2787566-4-jean-philippe@linaro.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200430143424.2787566-1-jean-philippe@linaro.org> References: <20200430143424.2787566-1-jean-philippe@linaro.org> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Let IOMMU drivers allocate a single PASID per mm. Store the mm in the IOASID set to allow refcounting and searching mm by PASID, when handling an I/O page fault. Signed-off-by: Jean-Philippe Brucker --- drivers/iommu/Kconfig | 5 +++ drivers/iommu/Makefile | 1 + drivers/iommu/iommu-sva.h | 15 +++++++ drivers/iommu/iommu-sva.c | 85 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 106 insertions(+) create mode 100644 drivers/iommu/iommu-sva.h create mode 100644 drivers/iommu/iommu-sva.c diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 58b4a4dbfc78b..5327ec663dea1 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -102,6 +102,11 @@ config IOMMU_DMA select IRQ_MSI_IOMMU select NEED_SG_DMA_LENGTH +# Shared Virtual Addressing library +config IOMMU_SVA + bool + select IOASID + config FSL_PAMU bool "Freescale IOMMU support" depends on PCI diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 9f33fdb3bb051..40c800dd4e3ef 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -37,3 +37,4 @@ obj-$(CONFIG_S390_IOMMU) += s390-iommu.o obj-$(CONFIG_QCOM_IOMMU) += qcom_iommu.o obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o +obj-$(CONFIG_IOMMU_SVA) += iommu-sva.o diff --git a/drivers/iommu/iommu-sva.h b/drivers/iommu/iommu-sva.h new file mode 100644 index 0000000000000..78f806fcacbe3 --- /dev/null +++ b/drivers/iommu/iommu-sva.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * SVA library for IOMMU drivers + */ +#ifndef _IOMMU_SVA_H +#define _IOMMU_SVA_H + +#include +#include + +int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max); +void iommu_sva_free_pasid(struct mm_struct *mm); +struct mm_struct *iommu_sva_find(ioasid_t pasid); + +#endif /* _IOMMU_SVA_H */ diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c new file mode 100644 index 0000000000000..3e07b71bde918 --- /dev/null +++ b/drivers/iommu/iommu-sva.c @@ -0,0 +1,85 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helpers for IOMMU drivers implementing SVA + */ +#include +#include + +#include "iommu-sva.h" + +static DEFINE_MUTEX(iommu_sva_lock); +static DECLARE_IOASID_SET(shared_pasid); + +/** + * iommu_sva_alloc_pasid - Allocate a PASID for the mm + * @mm: the mm + * @min: minimum PASID value (inclusive) + * @max: maximum PASID value (inclusive) + * + * Try to allocate a PASID for this mm, or take a reference to the existing one + * provided it fits within the [min, max] range. On success the PASID is + * available in mm->pasid, and must be released with iommu_sva_free_pasid(). + * + * Returns 0 on success and < 0 on error. + */ +int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) +{ + int ret = 0; + ioasid_t pasid; + + if (min == INVALID_IOASID || max == INVALID_IOASID || + min == 0 || max < min) + return -EINVAL; + + mutex_lock(&iommu_sva_lock); + if (mm->pasid) { + if (mm->pasid >= min && mm->pasid <= max) + ioasid_get(mm->pasid); + else + ret = -EOVERFLOW; + } else { + pasid = ioasid_alloc(&shared_pasid, min, max, mm); + if (pasid == INVALID_IOASID) + ret = -ENOMEM; + else + mm->pasid = pasid; + } + mutex_unlock(&iommu_sva_lock); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid); + +/** + * iommu_sva_free_pasid - Release the mm's PASID + * @mm: the mm. + * + * Drop one reference to a PASID allocated with iommu_sva_alloc_pasid() + */ +void iommu_sva_free_pasid(struct mm_struct *mm) +{ + mutex_lock(&iommu_sva_lock); + if (ioasid_free(mm->pasid)) + mm->pasid = 0; + mutex_unlock(&iommu_sva_lock); +} +EXPORT_SYMBOL_GPL(iommu_sva_free_pasid); + +/* ioasid wants a void * argument */ +static bool __mmget_not_zero(void *mm) +{ + return mmget_not_zero(mm); +} + +/** + * iommu_sva_find() - Find mm associated to the given PASID + * @pasid: Process Address Space ID assigned to the mm + * + * On success a reference to the mm is taken, and must be released with mmput(). + * + * Returns the mm corresponding to this PASID, or an error if not found. + */ +struct mm_struct *iommu_sva_find(ioasid_t pasid) +{ + return ioasid_find(&shared_pasid, pasid, __mmget_not_zero); +} +EXPORT_SYMBOL_GPL(iommu_sva_find);