Re: [PATCH 04/13] iommu/arm-smmu: Clean up bus_set_iommu()

2022-04-21 Thread Will Deacon 
On Wed, Apr 20, 2022 at 05:05:03PM +0100, Robin Murphy wrote:
> On 2022-04-19 15:40, Will Deacon wrote:
> > On Thu, Apr 14, 2022 at 01:42:33PM +0100, Robin Murphy wrote:
> > > Stop calling bus_set_iommu() since it's now unnecessary. With device
> > > probes now replayed for every IOMMU instance registration, the whole
> > > sorry ordering workaround for legacy DT bindings goes too, hooray!
> > 
> > Ha, I hope you tested this!
> 
> Oh alright then, since it's you... :)
> 
> I've hacked up a Juno DT with the old bindings, and (after needing a while
> to remember that they're fundamentally incompatible with disable_bypass),
> can confirm that with my whole dev branch including this series applied, it
> boots and creates IOMMU groups as expected. I then made the mistake of
> trying without the branch to check whether the squawks from
> iommu_setup_dma_ops() were new or not, and... well... plain rc3 doesn't even
> boot on the same setup - it's somehow blowing up in the failure cleanup path
> of iommu_bus_init(), apparently calling iommu_release_device() on something
> where dev->iommu->iommu_dev is NULL, for reasons that are far from clear and
> I'm not sure I can really be bothered to debug further... :/

Great, so your series is a fix!

Will
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Re: [PATCH 04/13] iommu/arm-smmu: Clean up bus_set_iommu()

2022-04-20 Thread Robin Murphy 

On 2022-04-19 15:40, Will Deacon wrote:

On Thu, Apr 14, 2022 at 01:42:33PM +0100, Robin Murphy wrote:

Stop calling bus_set_iommu() since it's now unnecessary. With device
probes now replayed for every IOMMU instance registration, the whole
sorry ordering workaround for legacy DT bindings goes too, hooray!


Ha, I hope you tested this!


Oh alright then, since it's you... :)

I've hacked up a Juno DT with the old bindings, and (after needing a 
while to remember that they're fundamentally incompatible with 
disable_bypass), can confirm that with my whole dev branch including 
this series applied, it boots and creates IOMMU groups as expected. I 
then made the mistake of trying without the branch to check whether the 
squawks from iommu_setup_dma_ops() were new or not, and... well... plain 
rc3 doesn't even boot on the same setup - it's somehow blowing up in the 
failure cleanup path of iommu_bus_init(), apparently calling 
iommu_release_device() on something where dev->iommu->iommu_dev is NULL, 
for reasons that are far from clear and I'm not sure I can really be 
bothered to debug further... :/


Cheers,
Robin.


Signed-off-by: Robin Murphy 
---
  drivers/iommu/arm/arm-smmu/arm-smmu.c | 84 +--
  1 file changed, 2 insertions(+), 82 deletions(-)


Assuming it works,

Acked-by: Will Deacon 

Will

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Re: [PATCH 04/13] iommu/arm-smmu: Clean up bus_set_iommu()

2022-04-19 Thread Will Deacon 
On Thu, Apr 14, 2022 at 01:42:33PM +0100, Robin Murphy wrote:
> Stop calling bus_set_iommu() since it's now unnecessary. With device
> probes now replayed for every IOMMU instance registration, the whole
> sorry ordering workaround for legacy DT bindings goes too, hooray!

Ha, I hope you tested this!

> Signed-off-by: Robin Murphy 
> ---
>  drivers/iommu/arm/arm-smmu/arm-smmu.c | 84 +--
>  1 file changed, 2 insertions(+), 82 deletions(-)

Assuming it works,

Acked-by: Will Deacon 

Will
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[PATCH 04/13] iommu/arm-smmu: Clean up bus_set_iommu()

2022-04-14 Thread Robin Murphy 
Stop calling bus_set_iommu() since it's now unnecessary. With device
probes now replayed for every IOMMU instance registration, the whole
sorry ordering workaround for legacy DT bindings goes too, hooray!

Signed-off-by: Robin Murphy 
---
 drivers/iommu/arm/arm-smmu/arm-smmu.c | 84 +--
 1 file changed, 2 insertions(+), 82 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c 
b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 52bd42d80b4f..34cab56b9c6d 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -37,7 +37,6 @@
 #include 
 #include 
 
-#include 
 #include 
 
 #include "arm-smmu.h"
@@ -93,8 +92,6 @@ static struct platform_driver arm_smmu_driver;
 static struct iommu_ops arm_smmu_ops;
 
 #ifdef CONFIG_ARM_SMMU_LEGACY_DT_BINDINGS
-static int arm_smmu_bus_init(struct iommu_ops *ops);
-
 static struct device_node *dev_get_dev_node(struct device *dev)
 {
if (dev_is_pci(dev)) {
@@ -180,20 +177,6 @@ static int arm_smmu_register_legacy_master(struct device 
*dev,
kfree(sids);
return err;
 }
-
-/*
- * With the legacy DT binding in play, we have no guarantees about
- * probe order, but then we're also not doing default domains, so we can
- * delay setting bus ops until we're sure every possible SMMU is ready,
- * and that way ensure that no probe_device() calls get missed.
- */
-static int arm_smmu_legacy_bus_init(void)
-{
-   if (using_legacy_binding)
-   return arm_smmu_bus_init(&arm_smmu_ops);
-   return 0;
-}
-device_initcall_sync(arm_smmu_legacy_bus_init);
 #else
 static int arm_smmu_register_legacy_master(struct device *dev,
   struct arm_smmu_device **smmu)
@@ -2022,52 +2005,6 @@ static int arm_smmu_device_dt_probe(struct 
arm_smmu_device *smmu,
return 0;
 }
 
-static int arm_smmu_bus_init(struct iommu_ops *ops)
-{
-   int err;
-
-   /* Oh, for a proper bus abstraction */
-   if (!iommu_present(&platform_bus_type)) {
-   err = bus_set_iommu(&platform_bus_type, ops);
-   if (err)
-   return err;
-   }
-#ifdef CONFIG_ARM_AMBA
-   if (!iommu_present(&amba_bustype)) {
-   err = bus_set_iommu(&amba_bustype, ops);
-   if (err)
-   goto err_reset_platform_ops;
-   }
-#endif
-#ifdef CONFIG_PCI
-   if (!iommu_present(&pci_bus_type)) {
-   err = bus_set_iommu(&pci_bus_type, ops);
-   if (err)
-   goto err_reset_amba_ops;
-   }
-#endif
-#ifdef CONFIG_FSL_MC_BUS
-   if (!iommu_present(&fsl_mc_bus_type)) {
-   err = bus_set_iommu(&fsl_mc_bus_type, ops);
-   if (err)
-   goto err_reset_pci_ops;
-   }
-#endif
-   return 0;
-
-err_reset_pci_ops: __maybe_unused;
-#ifdef CONFIG_PCI
-   bus_set_iommu(&pci_bus_type, NULL);
-#endif
-err_reset_amba_ops: __maybe_unused;
-#ifdef CONFIG_ARM_AMBA
-   bus_set_iommu(&amba_bustype, NULL);
-#endif
-err_reset_platform_ops: __maybe_unused;
-   bus_set_iommu(&platform_bus_type, NULL);
-   return err;
-}
-
 static int arm_smmu_device_probe(struct platform_device *pdev)
 {
struct resource *res;
@@ -2185,7 +2122,8 @@ static int arm_smmu_device_probe(struct platform_device 
*pdev)
err = iommu_device_register(&smmu->iommu, &arm_smmu_ops, dev);
if (err) {
dev_err(dev, "Failed to register iommu\n");
-   goto err_sysfs_remove;
+   iommu_device_sysfs_remove(&smmu->iommu);
+   return err;
}
 
platform_set_drvdata(pdev, smmu);
@@ -2203,24 +2141,7 @@ static int arm_smmu_device_probe(struct platform_device 
*pdev)
pm_runtime_enable(dev);
}
 
-   /*
-* For ACPI and generic DT bindings, an SMMU will be probed before
-* any device which might need it, so we want the bus ops in place
-* ready to handle default domain setup as soon as any SMMU exists.
-*/
-   if (!using_legacy_binding) {
-   err = arm_smmu_bus_init(&arm_smmu_ops);
-   if (err)
-   goto err_unregister_device;
-   }
-
return 0;
-
-err_unregister_device:
-   iommu_device_unregister(&smmu->iommu);
-err_sysfs_remove:
-   iommu_device_sysfs_remove(&smmu->iommu);
-   return err;
 }
 
 static int arm_smmu_device_remove(struct platform_device *pdev)
@@ -2233,7 +2154,6 @@ static int arm_smmu_device_remove(struct platform_device 
*pdev)
if (!bitmap_empty(smmu->context_map, ARM_SMMU_MAX_CBS))
dev_notice(&pdev->dev, "disabling translation\n");
 
-   arm_smmu_bus_init(NULL);
iommu_device_unregister(&smmu->iommu);
iommu_device_sysfs_remove(&smmu->iommu);
 
-- 
2.28.0.dirty

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