Re: [RESEND PATCH v17 2/5] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device

On Thu, Nov 22, 2018 at 05:32:24PM +0530, Vivek Gautam wrote:

Hi Will,

On Wed, Nov 21, 2018 at 11:09 PM Will Deacon [off-list ref] wrote:

quoted

On Fri, Nov 16, 2018 at 04:54:27PM +0530, Vivek Gautam wrote:

quoted

From: Sricharan R <redacted>

The smmu device probe/remove and add/remove master device callbacks
gets called when the smmu is not linked to its master, that is without
the context of the master device. So calling runtime apis in those places
separately.
Global locks are also initialized before enabling runtime pm as the
runtime_resume() calls device_reset() which does tlb_sync_global()
that ultimately requires locks to be initialized.

Signed-off-by: Sricharan R <redacted>
[vivek: Cleanup pm runtime calls]
Signed-off-by: Vivek Gautam <redacted>
Reviewed-by: Tomasz Figa <redacted>
Tested-by: Srinivas Kandagatla <redacted>
Reviewed-by: Robin Murphy <redacted>
---
 drivers/iommu/arm-smmu.c | 101 ++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 91 insertions(+), 10 deletions(-)

Given that you're doing the get/put in the TLBI ops unconditionally:

quoted

 static void arm_smmu_flush_iotlb_all(struct iommu_domain *domain)
 {
      struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+     struct arm_smmu_device *smmu = smmu_domain->smmu;

-     if (smmu_domain->tlb_ops)
+     if (smmu_domain->tlb_ops) {
+             arm_smmu_rpm_get(smmu);
              smmu_domain->tlb_ops->tlb_flush_all(smmu_domain);
+             arm_smmu_rpm_put(smmu);
+     }
 }

 static void arm_smmu_iotlb_sync(struct iommu_domain *domain)
 {
      struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+     struct arm_smmu_device *smmu = smmu_domain->smmu;

-     if (smmu_domain->tlb_ops)
+     if (smmu_domain->tlb_ops) {
+             arm_smmu_rpm_get(smmu);
              smmu_domain->tlb_ops->tlb_sync(smmu_domain);
+             arm_smmu_rpm_put(smmu);
+     }

Why do you need them around the map/unmap calls as well?

We still have .tlb_add_flush path?

Ok, so we could add the ops around that as well. Right now, we've got
the runtime pm hooks crossing two parts of the API.

Will