diff mbox series

[PATCHv2,2/2] iommu/arm-smmu-qcom: Move the adreno smmu specific impl earlier

Message ID c607d71eb0fe507c8b83cc0ea9b393777f22149a.1614332994.git.saiprakash.ranjan@codeaurora.org
State Superseded
Headers show
Series iommu/arm-smmu-qcom: Add SC7280 support | expand

Commit Message

Sai Prakash Ranjan Feb. 26, 2021, 9:55 a.m. UTC
Adreno(GPU) SMMU and APSS(Application Processor SubSystem) SMMU
both implement "arm,mmu-500" in some QTI SoCs and to run through
adreno smmu specific implementation such as enabling split pagetables
support, we need to match the "qcom,adreno-smmu" compatible first
before apss smmu or else we will be running apps smmu implementation
for adreno smmu and the additional features for adreno smmu is never
set. For ex: we have "qcom,sc7280-smmu-500" compatible for both apps
and adreno smmu implementing "arm,mmu-500", so the adreno smmu
implementation is never reached because the current sequence checks
for apps smmu compatible(qcom,sc7280-smmu-500) first and runs that
specific impl and we never reach adreno smmu specific implementation.

Suggested-by: Akhil P Oommen <akhilpo@codeaurora.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Comments

Bjorn Andersson April 19, 2021, 2:38 p.m. UTC | #1
On Fri 26 Feb 03:55 CST 2021, Sai Prakash Ranjan wrote:

> Adreno(GPU) SMMU and APSS(Application Processor SubSystem) SMMU

> both implement "arm,mmu-500" in some QTI SoCs and to run through

> adreno smmu specific implementation such as enabling split pagetables

> support, we need to match the "qcom,adreno-smmu" compatible first

> before apss smmu or else we will be running apps smmu implementation

> for adreno smmu and the additional features for adreno smmu is never

> set. For ex: we have "qcom,sc7280-smmu-500" compatible for both apps

> and adreno smmu implementing "arm,mmu-500", so the adreno smmu

> implementation is never reached because the current sequence checks

> for apps smmu compatible(qcom,sc7280-smmu-500) first and runs that

> specific impl and we never reach adreno smmu specific implementation.

> 

> Suggested-by: Akhil P Oommen <akhilpo@codeaurora.org>

> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>


Sorry for taking my time thinking about this.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>


Regards,
Bjorn

> ---

>  drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 12 +++++++++---

>  1 file changed, 9 insertions(+), 3 deletions(-)

> 

> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c

> index bea3ee0dabc2..03f048aebb80 100644

> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c

> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c

> @@ -345,11 +345,17 @@ struct arm_smmu_device *qcom_smmu_impl_init(struct arm_smmu_device *smmu)

>  {

>  	const struct device_node *np = smmu->dev->of_node;

>  

> -	if (of_match_node(qcom_smmu_impl_of_match, np))

> -		return qcom_smmu_create(smmu, &qcom_smmu_impl);

> -

> +	/*

> +	 * Do not change this order of implementation, i.e., first adreno

> +	 * smmu impl and then apss smmu since we can have both implementing

> +	 * arm,mmu-500 in which case we will miss setting adreno smmu specific

> +	 * features if the order is changed.

> +	 */

>  	if (of_device_is_compatible(np, "qcom,adreno-smmu"))

>  		return qcom_smmu_create(smmu, &qcom_adreno_smmu_impl);

>  

> +	if (of_match_node(qcom_smmu_impl_of_match, np))

> +		return qcom_smmu_create(smmu, &qcom_smmu_impl);

> +

>  	return smmu;

>  }

> -- 

> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member

> of Code Aurora Forum, hosted by The Linux Foundation

>
Sai Prakash Ranjan April 20, 2021, 6:06 a.m. UTC | #2
On 2021-04-19 20:08, Bjorn Andersson wrote:
> On Fri 26 Feb 03:55 CST 2021, Sai Prakash Ranjan wrote:

> 

>> Adreno(GPU) SMMU and APSS(Application Processor SubSystem) SMMU

>> both implement "arm,mmu-500" in some QTI SoCs and to run through

>> adreno smmu specific implementation such as enabling split pagetables

>> support, we need to match the "qcom,adreno-smmu" compatible first

>> before apss smmu or else we will be running apps smmu implementation

>> for adreno smmu and the additional features for adreno smmu is never

>> set. For ex: we have "qcom,sc7280-smmu-500" compatible for both apps

>> and adreno smmu implementing "arm,mmu-500", so the adreno smmu

>> implementation is never reached because the current sequence checks

>> for apps smmu compatible(qcom,sc7280-smmu-500) first and runs that

>> specific impl and we never reach adreno smmu specific implementation.

>> 

>> Suggested-by: Akhil P Oommen <akhilpo@codeaurora.org>

>> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>

> 

> Sorry for taking my time thinking about this.

> 

> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> 


No worries, thanks Bjorn.

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a 
member
of Code Aurora Forum, hosted by The Linux Foundation
diff mbox series

Patch

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index bea3ee0dabc2..03f048aebb80 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -345,11 +345,17 @@  struct arm_smmu_device *qcom_smmu_impl_init(struct arm_smmu_device *smmu)
 {
 	const struct device_node *np = smmu->dev->of_node;
 
-	if (of_match_node(qcom_smmu_impl_of_match, np))
-		return qcom_smmu_create(smmu, &qcom_smmu_impl);
-
+	/*
+	 * Do not change this order of implementation, i.e., first adreno
+	 * smmu impl and then apss smmu since we can have both implementing
+	 * arm,mmu-500 in which case we will miss setting adreno smmu specific
+	 * features if the order is changed.
+	 */
 	if (of_device_is_compatible(np, "qcom,adreno-smmu"))
 		return qcom_smmu_create(smmu, &qcom_adreno_smmu_impl);
 
+	if (of_match_node(qcom_smmu_impl_of_match, np))
+		return qcom_smmu_create(smmu, &qcom_smmu_impl);
+
 	return smmu;
 }