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From: Jean-Philippe Brucker <jean-philippe@linaro.org>
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: fenghua.yu@intel.com, kevin.tian@intel.com, jgg@ziepe.ca,
	catalin.marinas@arm.com, robin.murphy@arm.com, hch@infradead.org,
	zhangfei.gao@linaro.org,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	felix.kuehling@amd.com, will@kernel.org,
	christian.koenig@amd.com
Subject: [PATCH v7 03/24] iommu/sva: Add PASID helpers
Date: Tue, 19 May 2020 19:54:41 +0200	[thread overview]
Message-ID: <20200519175502.2504091-4-jean-philippe@linaro.org> (raw)
In-Reply-To: <20200519175502.2504091-1-jean-philippe@linaro.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 <jean-philippe@linaro.org>
---
 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 2ab07ce17abb..d9fa5b410015 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 9f33fdb3bb05..40c800dd4e3e 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 000000000000..78f806fcacbe
--- /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 <linux/ioasid.h>
+#include <linux/mm_types.h>
+
+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 000000000000..442644a1ade0
--- /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 <linux/mutex.h>
+#include <linux/sched/mm.h>
+
+#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_put(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);
-- 
2.26.2

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  parent reply	other threads:[~2020-05-19 18:01 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-19 17:54 [PATCH v7 00/24] iommu: Shared Virtual Addressing for SMMUv3 Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 01/24] mm: Add a PASID field to mm_struct Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 02/24] iommu/ioasid: Add ioasid references Jean-Philippe Brucker
2020-05-20  2:31   ` Lu Baolu
2020-05-19 17:54 ` Jean-Philippe Brucker [this message]
2020-05-20  2:41   ` [PATCH v7 03/24] iommu/sva: Add PASID helpers Lu Baolu
2020-05-19 17:54 ` [PATCH v7 04/24] iommu: Add a page fault handler Jean-Philippe Brucker
2020-05-20  6:42   ` Lu Baolu
2020-11-11 13:57     ` Jean-Philippe Brucker
2020-11-11 23:11       ` Lu Baolu
2020-05-29  9:18   ` Xiang Zheng
2020-11-11 13:57     ` Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 05/24] arm64: mm: Add asid_gen_match() helper Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 06/24] arm64: mm: Pin down ASIDs for sharing mm with devices Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 07/24] iommu/io-pgtable-arm: Move some definitions to a header Jean-Philippe Brucker
2020-05-21 14:16   ` Will Deacon
2020-05-19 17:54 ` [PATCH v7 08/24] iommu/arm-smmu-v3: Manage ASIDs with xarray Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 09/24] arm64: cpufeature: Export symbol read_sanitised_ftr_reg() Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 10/24] iommu/arm-smmu-v3: Share process page tables Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 11/24] iommu/arm-smmu-v3: Seize private ASID Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 12/24] iommu/arm-smmu-v3: Add support for VHE Jean-Philippe Brucker
2020-05-21 14:16   ` Will Deacon
2020-05-19 17:54 ` [PATCH v7 13/24] iommu/arm-smmu-v3: Enable broadcast TLB maintenance Jean-Philippe Brucker
2020-05-21 14:17   ` Will Deacon
2020-05-21 14:38     ` Marc Zyngier
2020-05-22 10:17       ` Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 14/24] iommu/arm-smmu-v3: Add SVA feature checking Jean-Philippe Brucker
2020-05-21 14:17   ` Will Deacon
2020-05-19 17:54 ` [PATCH v7 15/24] iommu/arm-smmu-v3: Add SVA device feature Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 16/24] iommu/arm-smmu-v3: Implement iommu_sva_bind/unbind() Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 17/24] iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 18/24] iommu/arm-smmu-v3: Add support for Hardware Translation Table Update Jean-Philippe Brucker
2020-05-21 11:12   ` Will Deacon
2020-05-27  3:00   ` Xiang Zheng
2020-05-27  8:41     ` Jean-Philippe Brucker
2020-08-28  9:28   ` Zenghui Yu
2020-09-16 14:11     ` Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 19/24] iommu/arm-smmu-v3: Maintain a SID->device structure Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 20/24] dt-bindings: document stall property for IOMMU masters Jean-Philippe Brucker
2020-05-19 17:54 ` [PATCH v7 21/24] iommu/arm-smmu-v3: Add stall support for platform devices Jean-Philippe Brucker
2020-06-01 12:42   ` Shameerali Kolothum Thodi
2020-06-02  9:38     ` Jean-Philippe Brucker
2020-06-02 10:31       ` Shameerali Kolothum Thodi
2020-06-02 11:46         ` Jean-Philippe Brucker
2020-06-02 12:12           ` Shameerali Kolothum Thodi
2020-06-03  7:38             ` Jean-Philippe Brucker
2020-05-19 17:55 ` [PATCH v7 22/24] PCI/ATS: Add PRI stubs Jean-Philippe Brucker
2020-05-19 17:55 ` [PATCH v7 23/24] PCI/ATS: Export PRI functions Jean-Philippe Brucker
2020-05-19 17:55 ` [PATCH v7 24/24] iommu/arm-smmu-v3: Add support for PRI Jean-Philippe Brucker
2020-05-21 10:35 ` [PATCH v7 00/24] iommu: Shared Virtual Addressing for SMMUv3 Will Deacon
2020-05-21 14:17   ` Will Deacon

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