99 lines
3.4 KiB
Diff
99 lines
3.4 KiB
Diff
From 04e1b16dbb3abd8aa6be8c80b2f9944ca3b323e8 Mon Sep 17 00:00:00 2001
|
|
From: Laura Abbott <labbott@redhat.com>
|
|
Date: Mon, 20 May 2019 22:21:02 -0400
|
|
Subject: [PATCH] iommu/arm-smmu: workaround DMA mode issues
|
|
|
|
Message-id: <20190520222102.19488-1-labbott@redhat.com>
|
|
Patchwork-id: 259215
|
|
O-Subject: [ARK INTERNAL PATCH] iommu/arm-smmu: workaround DMA mode issues
|
|
Bugzilla:
|
|
RH-Acked-by: Mark Langsdorf <mlangsdo@redhat.com>
|
|
RH-Acked-by: Mark Salter <msalter@redhat.com>
|
|
|
|
From: Mark Salter <msalter@redhat.com>
|
|
|
|
Rebased for v5.2-rc1
|
|
|
|
Bugzilla: 1652259
|
|
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=19244562
|
|
Upstream status: RHEL only.
|
|
|
|
rhel8 commit 65feb1ed0ec9a088a63a90d46c0f7563ac96ad0f
|
|
Author: Mark Salter <msalter@redhat.com>
|
|
Date: Wed Nov 21 17:15:59 2018 +0100
|
|
|
|
[iommu] iommu/arm-smmu: workaround DMA mode issues
|
|
|
|
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1624077
|
|
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=18112820
|
|
Testing: Verified iommu.passthrough=1 no longer needed on gigabyte platforms.
|
|
Upstream Status: RHEL-only
|
|
|
|
In RHEL_ALT 7.5 we carried a RHEL-only patch which forced the arm smmuv2
|
|
into bypass mode due to performance issues on CN88xx. This was intended
|
|
to be a temporary hack until the issues were resolved. Another vendor
|
|
had issues with the iommu in bypass mode so we reverted the RHEL-only
|
|
patch so that iommu is in DMA mode by default (upstream default).
|
|
|
|
It turns on that there are remaining SMMU DMA mode issues on Gigabyte
|
|
platformws with CN88xx cpus. The problem manifests itself by pcie
|
|
card drivers failing to initialize the cards when SMMU is in DMA mode.
|
|
The root cause has not been determined yet, but looks likely to be
|
|
a hw or firmware issue. This patch forces bypass mode for Gigabyte
|
|
platforms. CN88xx isn't officially supported in RHEL but we have a
|
|
lot of them being used internally for testing, so I think we want
|
|
this to support that use case in RHEL8.
|
|
|
|
Signed-off-by: Mark Salter <msalter@redhat.com>
|
|
Signed-off-by: Herton R. Krzesinski <herton@redhat.com>
|
|
|
|
Acked-by: Mark Salter <msalter@redhat.com>
|
|
Acked-by: Donald Dutile <ddutile@redhat.com>
|
|
|
|
Upstream Status: RHEL only
|
|
Signed-off-by: Laura Abbott <labbott@redhat.com>
|
|
---
|
|
drivers/iommu/iommu.c | 22 ++++++++++++++++++++++
|
|
1 file changed, 22 insertions(+)
|
|
|
|
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
|
|
index 2b471419e26c..83c8d9845aed 100644
|
|
--- a/drivers/iommu/iommu.c
|
|
+++ b/drivers/iommu/iommu.c
|
|
@@ -7,6 +7,7 @@
|
|
#define pr_fmt(fmt) "iommu: " fmt
|
|
|
|
#include <linux/device.h>
|
|
+#include <linux/dmi.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/bug.h>
|
|
#include <linux/types.h>
|
|
@@ -2658,3 +2659,24 @@ int iommu_sva_get_pasid(struct iommu_sva *handle)
|
|
return ops->sva_get_pasid(handle);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iommu_sva_get_pasid);
|
|
+
|
|
+#ifdef CONFIG_ARM64
|
|
+static int __init iommu_quirks(void)
|
|
+{
|
|
+ const char *vendor, *name;
|
|
+
|
|
+ vendor = dmi_get_system_info(DMI_SYS_VENDOR);
|
|
+ name = dmi_get_system_info(DMI_PRODUCT_NAME);
|
|
+
|
|
+ if (vendor &&
|
|
+ (strncmp(vendor, "GIGABYTE", 8) == 0 && name &&
|
|
+ (strncmp(name, "R120", 4) == 0 ||
|
|
+ strncmp(name, "R270", 4) == 0))) {
|
|
+ pr_warn("Gigabyte %s detected, force iommu passthrough mode", name);
|
|
+ iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
|
|
+ }
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+arch_initcall(iommu_quirks);
|
|
+#endif
|
|
--
|
|
2.26.2
|
|
|