[PATCH AUTOSEL 6.2 03/18] iommu/arm-smmu-qcom: Limit the SMR groups to 128

[PATCH AUTOSEL 6.2 03/18] iommu/arm-smmu-qcom: Limit the SMR groups to 128

[Sasha Levin]

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

[ Upstream commit 12261134732689b7e30c59db9978f81230965181 ]

Some platforms support more than 128 stream matching groups than what is
defined by the ARM SMMU architecture specification. But due to some unknown
reasons, those additional groups don't exhibit the same behavior as the
architecture supported ones.

For instance, the additional groups will not detect the quirky behavior of
some firmware versions intercepting writes to S2CR register, thus skipping
the quirk implemented in the driver and causing boot crash.

So let's limit the groups to 128 for now until the issue with those groups
are fixed and issue a notice to users in that case.

Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20230327080029.11584-1-manivannan.sadhasivam@linaro.org
[will: Reworded the comment slightly]
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index 91d404deb1155..f43499869e381 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -266,12 +266,26 @@ static int qcom_smmu_init_context(struct arm_smmu_domain *smmu_domain,
 
 static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu)
 {
-	unsigned int last_s2cr = ARM_SMMU_GR0_S2CR(smmu->num_mapping_groups - 1);
 	struct qcom_smmu *qsmmu = to_qcom_smmu(smmu);
+	unsigned int last_s2cr;
 	u32 reg;
 	u32 smr;
 	int i;
 
+	/*
+	 * Some platforms support more than the Arm SMMU architected maximum of
+	 * 128 stream matching groups. For unknown reasons, the additional
+	 * groups don't exhibit the same behavior as the architected registers,
+	 * so limit the groups to 128 until the behavior is fixed for the other
+	 * groups.
+	 */
+	if (smmu->num_mapping_groups > 128) {
+		dev_notice(smmu->dev, "\tLimiting the stream matching groups to 128\n");
+		smmu->num_mapping_groups = 128;
+	}
+
+	last_s2cr = ARM_SMMU_GR0_S2CR(smmu->num_mapping_groups - 1);
+
 	/*
 	 * With some firmware versions writes to S2CR of type FAULT are
 	 * ignored, and writing BYPASS will end up written as FAULT in the
-- 
2.39.2

[PATCH AUTOSEL 6.2 11/18] iommu/arm-smmu-v3: Acknowledge pri/event queue overflow if any

[Sasha Levin]

From: Tomas Krcka <krckatom@amazon.de>

[ Upstream commit 67ea0b7ce41844eae7c10bb04dfe66a23318c224 ]

When an overflow occurs in the PRI queue, the SMMU toggles the overflow
flag in the PROD register. To exit the overflow condition, the PRI thread
is supposed to acknowledge it by toggling this flag in the CONS register.
Unacknowledged overflow causes the queue to stop adding anything new.

Currently, the priq thread always writes the CONS register back to the
SMMU after clearing the queue.

The writeback is not necessary if the OVFLG in the PROD register has not
been changed, no overflow has occured.

This commit checks the difference of the overflow flag between CONS and
PROD register. If it's different, toggles the OVACKFLG flag in the CONS
register and write it to the SMMU.

The situation is similar for the event queue.
The acknowledge register is also toggled after clearing the event
queue but never propagated to the hardware. This would only be done the
next time when executing evtq thread.

Unacknowledged event queue overflow doesn't affect the event
queue, because the SMMU still adds elements to that queue when the
overflow condition is active.
But it feel nicer to keep SMMU in sync when possible, so use the same
way here as well.

Signed-off-by: Tomas Krcka <krckatom@amazon.de>
Link: https://lore.kernel.org/r/20230329123420.34641-1-tomas.krcka@gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index f2425b0f0cd62..7614739ea2c1b 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -152,6 +152,18 @@ static void queue_inc_cons(struct arm_smmu_ll_queue *q)
 	q->cons = Q_OVF(q->cons) | Q_WRP(q, cons) | Q_IDX(q, cons);
 }
 
+static void queue_sync_cons_ovf(struct arm_smmu_queue *q)
+{
+	struct arm_smmu_ll_queue *llq = &q->llq;
+
+	if (likely(Q_OVF(llq->prod) == Q_OVF(llq->cons)))
+		return;
+
+	llq->cons = Q_OVF(llq->prod) | Q_WRP(llq, llq->cons) |
+		      Q_IDX(llq, llq->cons);
+	queue_sync_cons_out(q);
+}
+
 static int queue_sync_prod_in(struct arm_smmu_queue *q)
 {
 	u32 prod;
@@ -1577,8 +1589,7 @@ static irqreturn_t arm_smmu_evtq_thread(int irq, void *dev)
 	} while (!queue_empty(llq));
 
 	/* Sync our overflow flag, as we believe we're up to speed */
-	llq->cons = Q_OVF(llq->prod) | Q_WRP(llq, llq->cons) |
-		    Q_IDX(llq, llq->cons);
+	queue_sync_cons_ovf(q);
 	return IRQ_HANDLED;
 }
 
@@ -1636,9 +1647,7 @@ static irqreturn_t arm_smmu_priq_thread(int irq, void *dev)
 	} while (!queue_empty(llq));
 
 	/* Sync our overflow flag, as we believe we're up to speed */
-	llq->cons = Q_OVF(llq->prod) | Q_WRP(llq, llq->cons) |
-		      Q_IDX(llq, llq->cons);
-	queue_sync_cons_out(q);
+	queue_sync_cons_ovf(q);
 	return IRQ_HANDLED;
 }
 
-- 
2.39.2

[PATCH AUTOSEL 6.2 12/18] iommu/arm-smmu: Drop if with an always false condition

[Sasha Levin]

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

[ Upstream commit a2972cb89935160bfe515b15d28a77694723ac06 ]

The remove and shutdown callback are only called after probe completed
successfully. In this case platform_set_drvdata() was called with a
non-NULL argument and so smmu is never NULL. Other functions in this
driver also don't check for smmu being non-NULL before using it.

Also note that returning an error code from a remove callback doesn't
result in the device staying bound. It's still removed and devm allocated
resources are freed (among others *smmu and the register mapping). So
after an early exit to iommu device stayed around and using it probably
oopses.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20230321084125.337021-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/arm/arm-smmu/arm-smmu.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 2ff7a72cf3772..f4a36533ae478 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -2195,9 +2195,6 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev)
 {
 	struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
 
-	if (!smmu)
-		return;
-
 	if (!bitmap_empty(smmu->context_map, ARM_SMMU_MAX_CBS))
 		dev_notice(&pdev->dev, "disabling translation\n");
 
@@ -2218,9 +2215,6 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 {
 	struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
 
-	if (!smmu)
-		return -ENODEV;
-
 	iommu_device_unregister(&smmu->iommu);
 	iommu_device_sysfs_remove(&smmu->iommu);
 
-- 
2.39.2

[PATCH AUTOSEL 6.2 13/18] iommu/sprd: Release dma buffer to avoid memory leak

[Sasha Levin]

From: Chunyan Zhang <chunyan.zhang@unisoc.com>

[ Upstream commit 9afea57384d4ae7b2034593eac7fa76c7122762a ]

When attaching to a domain, the driver would alloc a DMA buffer which
is used to store address mapping table, and it need to be released
when the IOMMU domain is freed.

Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20230331033124.864691-2-zhang.lyra@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/sprd-iommu.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c
index 219bfa11f7f48..ef450cfcd5d78 100644
--- a/drivers/iommu/sprd-iommu.c
+++ b/drivers/iommu/sprd-iommu.c
@@ -151,13 +151,6 @@ static struct iommu_domain *sprd_iommu_domain_alloc(unsigned int domain_type)
 	return &dom->domain;
 }
 
-static void sprd_iommu_domain_free(struct iommu_domain *domain)
-{
-	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
-
-	kfree(dom);
-}
-
 static void sprd_iommu_first_vpn(struct sprd_iommu_domain *dom)
 {
 	struct sprd_iommu_device *sdev = dom->sdev;
@@ -230,6 +223,28 @@ static void sprd_iommu_hw_en(struct sprd_iommu_device *sdev, bool en)
 	sprd_iommu_update_bits(sdev, reg_cfg, mask, 0, val);
 }
 
+static void sprd_iommu_cleanup(struct sprd_iommu_domain *dom)
+{
+	size_t pgt_size;
+
+	/* Nothing need to do if the domain hasn't been attached */
+	if (!dom->sdev)
+		return;
+
+	pgt_size = sprd_iommu_pgt_size(&dom->domain);
+	dma_free_coherent(dom->sdev->dev, pgt_size, dom->pgt_va, dom->pgt_pa);
+	dom->sdev = NULL;
+	sprd_iommu_hw_en(dom->sdev, false);
+}
+
+static void sprd_iommu_domain_free(struct iommu_domain *domain)
+{
+	struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+
+	sprd_iommu_cleanup(dom);
+	kfree(dom);
+}
+
 static int sprd_iommu_attach_device(struct iommu_domain *domain,
 				    struct device *dev)
 {
-- 
2.39.2