From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: iommu@lists.linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>,
Joerg Roedel <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alex Williamson <alex.williamson@redhat.com>,
Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
Raj Ashok <ashok.raj@intel.com>,
Jean Delvare <khali@linux-fr.org>,
"Christoph Hellwig" <hch@infradead.org>,
"Lu Baolu" <baolu.lu@linux.intel.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH v5 12/23] iommu: add a timeout parameter for prq response
Date: Fri, 11 May 2018 13:54:04 -0700 [thread overview]
Message-ID: <1526072055-86990-13-git-send-email-jacob.jun.pan@linux.intel.com> (raw)
In-Reply-To: <1526072055-86990-1-git-send-email-jacob.jun.pan@linux.intel.com>
When an IO page request is processed outside IOMMU subsystem, response can be
delayed or lost. Add a tunable setup parameter such that user can chooose
the timeout for IOMMU to track pending page requests.
This timeout mechanism is a basic safty net which can be implemented in conjunction
with credit based or device level page response exception handling.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
Documentation/admin-guide/kernel-parameters.txt | 8 +++++++
drivers/iommu/iommu.c | 28 +++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 11fc28e..5c1e836 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1718,6 +1718,14 @@
1 - Bypass the IOMMU for DMA.
unset - Use IOMMU translation for DMA.
+ iommu.prq_timeout=
+ Timeout in seconds to wait for page response
+ of a pending page request.
+ Format: <integer>
+ Default: 10
+ 0 - no timeout tracking
+ 1 to 100 - allowed range
+
io7= [HW] IO7 for Marvel based alpha systems
See comment before marvel_specify_io7 in
arch/alpha/kernel/core_marvel.c.
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 784e019..3a49b96 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -37,6 +37,18 @@
static struct kset *iommu_group_kset;
static DEFINE_IDA(iommu_group_ida);
static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA;
+/*
+ * Timeout to wait for page response of a pending page request. This is
+ * intended as a basic safty net in case a pending page request is not
+ * responded for an exceptionally long time. Device may also implement
+ * its own protection mechanism against this exception.
+ * Units are in jiffies with a range between 1 - 100 seconds equivalent.
+ * Default to 10 seconds.
+ * Setting 0 means no timeout tracking.
+ */
+#define IOMMU_PAGE_RESPONSE_MAX_TIMEOUT (HZ * 100)
+#define IOMMU_PAGE_RESPONSE_DEF_TIMEOUT (HZ * 10)
+static unsigned long prq_timeout = IOMMU_PAGE_RESPONSE_DEF_TIMEOUT;
struct iommu_callback_data {
const struct iommu_ops *ops;
@@ -125,6 +137,22 @@ static int __init iommu_set_def_domain_type(char *str)
}
early_param("iommu.passthrough", iommu_set_def_domain_type);
+static int __init iommu_set_prq_timeout(char *str)
+{
+ unsigned long timeout;
+
+ if (!str)
+ return -EINVAL;
+ timeout = simple_strtoul(str, NULL, 0);
+ timeout = timeout * HZ;
+ if (timeout > IOMMU_PAGE_RESPONSE_MAX_TIMEOUT)
+ return -EINVAL;
+ prq_timeout = timeout;
+
+ return 0;
+}
+early_param("iommu.prq_timeout", iommu_set_prq_timeout);
+
static ssize_t iommu_group_attr_show(struct kobject *kobj,
struct attribute *__attr, char *buf)
{
--
2.7.4
next prev parent reply other threads:[~2018-05-11 20:54 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-11 20:53 [PATCH v5 00/23] IOMMU and VT-d driver support for Shared Virtual Address (SVA) Jacob Pan
2018-05-11 20:53 ` [PATCH v5 01/23] iommu: introduce bind_pasid_table API function Jacob Pan
2018-08-23 16:34 ` Auger Eric
2018-08-24 12:47 ` Liu, Yi L
2018-08-24 13:20 ` Auger Eric
2018-08-28 17:04 ` Jacob Pan
2018-08-24 15:00 ` Auger Eric
2018-08-28 5:14 ` Jacob Pan
2018-08-28 8:34 ` Auger Eric
2018-08-28 16:36 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 02/23] iommu/vt-d: move device_domain_info to header Jacob Pan
2018-05-11 20:53 ` [PATCH v5 03/23] iommu/vt-d: add a flag for pasid table bound status Jacob Pan
2018-05-13 7:33 ` Lu Baolu
2018-05-14 18:51 ` Jacob Pan
2018-05-13 8:01 ` Lu Baolu
2018-05-14 18:52 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 04/23] iommu/vt-d: add bind_pasid_table function Jacob Pan
2018-05-13 9:29 ` Lu Baolu
2018-05-14 20:22 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 05/23] iommu: introduce iommu invalidate API function Jacob Pan
2018-05-11 20:53 ` [PATCH v5 06/23] iommu/vt-d: add definitions for PFSID Jacob Pan
2018-05-14 1:36 ` Lu Baolu
2018-05-14 20:30 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 07/23] iommu/vt-d: fix dev iotlb pfsid use Jacob Pan
2018-05-14 1:52 ` Lu Baolu
2018-05-14 20:38 ` Jacob Pan
2018-05-11 20:54 ` [PATCH v5 08/23] iommu/vt-d: support flushing more translation cache types Jacob Pan
2018-05-14 2:18 ` Lu Baolu
2018-05-14 20:46 ` Jacob Pan
2018-05-17 8:44 ` kbuild test robot
2018-05-11 20:54 ` [PATCH v5 09/23] iommu/vt-d: add svm/sva invalidate function Jacob Pan
2018-05-14 3:35 ` Lu Baolu
2018-05-14 20:49 ` Jacob Pan
2018-05-11 20:54 ` [PATCH v5 10/23] iommu: introduce device fault data Jacob Pan
2018-09-21 10:07 ` Auger Eric
2018-09-21 17:05 ` Jacob Pan
2018-09-26 10:20 ` Auger Eric
2018-05-11 20:54 ` [PATCH v5 11/23] driver core: add per device iommu param Jacob Pan
2018-05-14 5:27 ` Lu Baolu
2018-05-14 20:52 ` Jacob Pan
2018-05-11 20:54 ` Jacob Pan [this message]
2018-05-11 20:54 ` [PATCH v5 13/23] iommu: introduce device fault report API Jacob Pan
2018-05-14 6:01 ` Lu Baolu
2018-05-14 20:55 ` Jacob Pan
2018-05-15 6:52 ` Lu Baolu
2018-05-17 11:41 ` Liu, Yi L
2018-05-17 15:59 ` Jacob Pan
2018-05-17 23:22 ` Liu, Yi L
2018-05-21 23:03 ` Jacob Pan
2018-09-06 9:25 ` Auger Eric
2018-09-06 12:42 ` Jean-Philippe Brucker
2018-09-06 13:14 ` Auger Eric
2018-09-06 17:06 ` Jean-Philippe Brucker
2018-09-07 7:11 ` Auger Eric
2018-09-07 11:23 ` Jean-Philippe Brucker
2018-09-14 13:24 ` Auger Eric
2018-09-17 16:57 ` Jacob Pan
2018-09-25 14:58 ` Jean-Philippe Brucker
2018-09-25 22:17 ` Jacob Pan
2018-09-26 10:14 ` Jean-Philippe Brucker
2018-05-11 20:54 ` [PATCH v5 14/23] iommu: introduce page response function Jacob Pan
2018-05-14 6:39 ` Lu Baolu
2018-05-29 16:13 ` Jacob Pan
2018-09-10 14:52 ` Auger Eric
2018-09-10 17:50 ` Jacob Pan
2018-09-10 19:06 ` Auger Eric
2018-05-11 20:54 ` [PATCH v5 15/23] iommu: handle page response timeout Jacob Pan
2018-05-14 7:43 ` Lu Baolu
2018-05-29 16:20 ` Jacob Pan
2018-05-30 7:46 ` Lu Baolu
2018-05-11 20:54 ` [PATCH v5 16/23] iommu/config: add build dependency for dmar Jacob Pan
2018-05-11 20:54 ` [PATCH v5 17/23] iommu/vt-d: report non-recoverable faults to device Jacob Pan
2018-05-14 8:17 ` Lu Baolu
2018-05-29 17:33 ` Jacob Pan
2018-05-11 20:54 ` [PATCH v5 18/23] iommu/intel-svm: report device page request Jacob Pan
2018-05-11 20:54 ` [PATCH v5 19/23] iommu/intel-svm: replace dev ops with fault report API Jacob Pan
2018-05-11 20:54 ` [PATCH v5 20/23] iommu/intel-svm: do not flush iotlb for viommu Jacob Pan
2018-05-11 20:54 ` [PATCH v5 21/23] iommu/vt-d: add intel iommu page response function Jacob Pan
2018-05-11 20:54 ` [PATCH v5 22/23] trace/iommu: add sva trace events Jacob Pan
2018-05-11 20:54 ` [PATCH v5 23/23] iommu: use sva invalidate and device fault trace event Jacob Pan
2018-05-29 15:54 ` [PATCH v5 00/23] IOMMU and VT-d driver support for Shared Virtual Address (SVA) Jacob Pan
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