[PATCH AUTOSEL 4.9 043/107] iommu/amd: Fix amd_iommu=force_isolation

[PATCH AUTOSEL 4.9 043/107] iommu/amd: Fix amd_iommu=force_isolation

[Sasha Levin]

From: Yu Zhao <yuzhao@google.com>

[ Upstream commit c12b08ebbe16f0d3a96a116d86709b04c1ee8e74 ]

The parameter is still there but it's ignored. We need to check its
value before deciding to go into passthrough mode for AMD IOMMU v2
capable device.

We occasionally use this parameter to force v2 capable device into
translation mode to debug memory corruption that we suspect is
caused by DMA writes.

To address the following comment from Joerg Roedel on the first
version, v2 capability of device is completely ignored.
> This breaks the iommu_v2 use-case, as it needs a direct mapping for the
> devices that support it.

And from Documentation/admin-guide/kernel-parameters.txt:
  This option does not override iommu=pt

Fixes: aafd8ba0ca74 ("iommu/amd: Implement add_device and remove_device")

Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/amd_iommu.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index bba1b9f2f782..e984418ffa2a 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -464,7 +464,14 @@ static int iommu_init_device(struct device *dev)
 
 	dev_data->alias = get_alias(dev);
 
-	if (dev_is_pci(dev) && pci_iommuv2_capable(to_pci_dev(dev))) {
+	/*
+	 * By default we use passthrough mode for IOMMUv2 capable device.
+	 * But if amd_iommu=force_isolation is set (e.g. to debug DMA to
+	 * invalid address), we ignore the capability for the device so
+	 * it'll be forced to go into translation mode.
+	 */
+	if ((iommu_pass_through || !amd_iommu_force_isolation) &&
+	    dev_is_pci(dev) && pci_iommuv2_capable(to_pci_dev(dev))) {
 		struct amd_iommu *iommu;
 
 		iommu = amd_iommu_rlookup_table[dev_data->devid];
-- 
2.19.1

[PATCH AUTOSEL 4.9 048/107] iommu/arm-smmu: Add support for qcom, smmu-v2 variant

[Sasha Levin]

From: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>

[ Upstream commit 89cddc563743cb1e0068867ac97013b2a5bf86aa ]

qcom,smmu-v2 is an arm,smmu-v2 implementation with specific
clock and power requirements.
On msm8996, multiple cores, viz. mdss, video, etc. use this
smmu. On sdm845, this smmu is used with gpu.
Add bindings for the same.

Signed-off-by: Vivek Gautam <vivek.gautam-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Reviewed-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Reviewed-by: Tomasz Figa <tfiga-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Reviewed-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Sasha Levin <sashal-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/iommu/arm-smmu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 5a9a4416f467..f7ecb30a0bac 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -297,6 +297,7 @@ enum arm_smmu_implementation {
 	GENERIC_SMMU,
 	ARM_MMU500,
 	CAVIUM_SMMUV2,
+	QCOM_SMMUV2,
 };
 
 struct arm_smmu_s2cr {
@@ -1894,6 +1895,7 @@ ARM_SMMU_MATCH_DATA(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU);
 ARM_SMMU_MATCH_DATA(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU);
 ARM_SMMU_MATCH_DATA(arm_mmu500, ARM_SMMU_V2, ARM_MMU500);
 ARM_SMMU_MATCH_DATA(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2);
+ARM_SMMU_MATCH_DATA(qcom_smmuv2, ARM_SMMU_V2, QCOM_SMMUV2);
 
 static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,smmu-v1", .data = &smmu_generic_v1 },
@@ -1902,6 +1904,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,mmu-401", .data = &arm_mmu401 },
 	{ .compatible = "arm,mmu-500", .data = &arm_mmu500 },
 	{ .compatible = "cavium,smmu-v2", .data = &cavium_smmuv2 },
+	{ .compatible = "qcom,smmu-v2", .data = &qcom_smmuv2 },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
-- 
2.19.1

[PATCH AUTOSEL 4.9 049/107] iommu/arm-smmu-v3: Use explicit mb() when moving cons pointer

[Sasha Levin]

From: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>

[ Upstream commit a868e8530441286342f90c1fd9c5f24de3aa2880 ]

After removing an entry from a queue (e.g. reading an event in
arm_smmu_evtq_thread()) it is necessary to advance the MMIO consumer
pointer to free the queue slot back to the SMMU. A memory barrier is
required here so that all reads targetting the queue entry have
completed before the consumer pointer is updated.

The implementation of queue_inc_cons() relies on a writel() to complete
the previous reads, but this is incorrect because writel() is only
guaranteed to complete prior writes. This patch replaces the call to
writel() with an mb(); writel_relaxed() sequence, which gives us the
read->write ordering which we require.

Cc: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Sasha Levin <sashal-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/iommu/arm-smmu-v3.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index ff4be1174ff0..7bd98585d78d 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -697,7 +697,13 @@ static void queue_inc_cons(struct arm_smmu_queue *q)
 	u32 cons = (Q_WRP(q, q->cons) | Q_IDX(q, q->cons)) + 1;
 
 	q->cons = Q_OVF(q, q->cons) | Q_WRP(q, cons) | Q_IDX(q, cons);
-	writel(q->cons, q->cons_reg);
+
+	/*
+	 * Ensure that all CPU accesses (reads and writes) to the queue
+	 * are complete before we update the cons pointer.
+	 */
+	mb();
+	writel_relaxed(q->cons, q->cons_reg);
 }
 
 static int queue_sync_prod(struct arm_smmu_queue *q)
-- 
2.19.1