[v3,08/10] iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev

Message ID 20210420082751.1829-9-shameerali.kolothum.thodi@huawei.com
State New
Headers show
Series
  • ACPI/IORT: Support for IORT RMR node
Related show

Commit Message

Shameerali Kolothum Thodi April 20, 2021, 8:27 a.m.
Get RMR regions associated with a dev reserved so that there is
a unity mapping for them in SMMU.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29 +++++++++++++++++++++
 1 file changed, 29 insertions(+)

-- 
2.17.1

Comments

Robin Murphy May 7, 2021, 10:01 a.m. | #1
On 2021-04-20 09:27, Shameer Kolothum wrote:
> Get RMR regions associated with a dev reserved so that there is

> a unity mapping for them in SMMU.

> 

> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

> ---

>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29 +++++++++++++++++++++

>   1 file changed, 29 insertions(+)

> 

> 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 14e9c7034c04..8bacedf7bb34 100644

> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

> @@ -2531,6 +2531,34 @@ static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)

>   	return iommu_fwspec_add_ids(dev, args->args, 1);

>   }

>   

> +static bool arm_smmu_dev_has_rmr(struct arm_smmu_master *master,

> +				 struct iommu_rmr *e)

> +{

> +	int i;

> +

> +	for (i = 0; i < master->num_sids; i++) {

> +		if (e->sid == master->sids[i])

> +			return true;

> +	}

> +

> +	return false;

> +}

> +

> +static void arm_smmu_rmr_get_resv_regions(struct device *dev,

> +					  struct list_head *head)

> +{

> +	struct arm_smmu_master *master = dev_iommu_priv_get(dev);

> +	struct arm_smmu_device *smmu = master->smmu;

> +	struct iommu_rmr *rmr;

> +

> +	list_for_each_entry(rmr, &smmu->rmr_list, list) {

> +		if (!arm_smmu_dev_has_rmr(master, rmr))

> +			continue;

> +

> +		iommu_dma_get_rmr_resv_regions(dev, rmr, head);

> +	}

> +}

> +


TBH I wouldn't have thought we need a driver-specific hook for this, or 
is it too painful to correlate fwspec->iommu_fwnode back to the relevant 
IORT node generically?

Robin.

>   static void arm_smmu_get_resv_regions(struct device *dev,

>   				      struct list_head *head)

>   {

> @@ -2545,6 +2573,7 @@ static void arm_smmu_get_resv_regions(struct device *dev,

>   	list_add_tail(&region->list, head);

>   

>   	iommu_dma_get_resv_regions(dev, head);

> +	arm_smmu_rmr_get_resv_regions(dev, head);

>   }

>   

>   static bool arm_smmu_dev_has_feature(struct device *dev,

>
Shameerali Kolothum Thodi May 10, 2021, 9:19 a.m. | #2
Hi Robin,

> -----Original Message-----

> From: Robin Murphy [mailto:robin.murphy@arm.com]

> Sent: 07 May 2021 11:02

> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;

> linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org;

> iommu@lists.linux-foundation.org

> Cc: Linuxarm <linuxarm@huawei.com>; lorenzo.pieralisi@arm.com;

> joro@8bytes.org; wanghuiqiang <wanghuiqiang@huawei.com>; Guohanjun

> (Hanjun Guo) <guohanjun@huawei.com>; steven.price@arm.com;

> Sami.Mujawar@arm.com; jon@solid-run.com; eric.auger@redhat.com

> Subject: Re: [PATCH v3 08/10] iommu/arm-smmu-v3: Reserve any RMR regions

> associated with a dev

> 

> On 2021-04-20 09:27, Shameer Kolothum wrote:

> > Get RMR regions associated with a dev reserved so that there is

> > a unity mapping for them in SMMU.

> >

> > Signed-off-by: Shameer Kolothum

> <shameerali.kolothum.thodi@huawei.com>

> > ---

> >   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29

> +++++++++++++++++++++

> >   1 file changed, 29 insertions(+)

> >

> > 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 14e9c7034c04..8bacedf7bb34 100644

> > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

> > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

> > @@ -2531,6 +2531,34 @@ static int arm_smmu_of_xlate(struct device *dev,

> struct of_phandle_args *args)

> >   	return iommu_fwspec_add_ids(dev, args->args, 1);

> >   }

> >

> > +static bool arm_smmu_dev_has_rmr(struct arm_smmu_master *master,

> > +				 struct iommu_rmr *e)

> > +{

> > +	int i;

> > +

> > +	for (i = 0; i < master->num_sids; i++) {

> > +		if (e->sid == master->sids[i])

> > +			return true;

> > +	}

> > +

> > +	return false;

> > +}

> > +

> > +static void arm_smmu_rmr_get_resv_regions(struct device *dev,

> > +					  struct list_head *head)

> > +{

> > +	struct arm_smmu_master *master = dev_iommu_priv_get(dev);

> > +	struct arm_smmu_device *smmu = master->smmu;

> > +	struct iommu_rmr *rmr;

> > +

> > +	list_for_each_entry(rmr, &smmu->rmr_list, list) {

> > +		if (!arm_smmu_dev_has_rmr(master, rmr))

> > +			continue;

> > +

> > +		iommu_dma_get_rmr_resv_regions(dev, rmr, head);

> > +	}

> > +}

> > +

> 

> TBH I wouldn't have thought we need a driver-specific hook for this, or

> is it too painful to correlate fwspec->iommu_fwnode back to the relevant

> IORT node generically?


From a quick look, I think I could get rid of the above with something like below,

------8<----
+static bool iommu_dma_dev_has_rmr(struct iommu_fwspec *fwspec,
+                                 struct iommu_rmr *e)
+{
+       int i;
+
+       for (i = 0; i < fwspec->num_ids; i++) {
+                if (e->sid == fwspec->ids[i])
+                        return true;
+        }
+
+        return false;
+}
+
+
+void iommu_dma_get_rmr_resv_regions(struct device *dev, struct list_head *list)
+{
+       struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+       struct list_head rmr_list;
+       struct iommu_rmr *rmr;
+
+       INIT_LIST_HEAD(&rmr_list);
+       if (iommu_dma_get_rmrs(fwspec->iommu_fwnode, &rmr_list))
+               return;
        ...
+       list_for_each_entry(rmr, &rmr_list, list) {
+     
+       if (!iommu_dma_dev_has_rmr(fwspec, rmr)
+           continue;
+          ... 
+               region = iommu_alloc_resv_region(rmr->base_address,
+                                                rmr->length, prot,
+                                                type);
         ...
+       }
+}
 /**
  * iommu_dma_get_resv_regions - Reserved region driver helper
  * @dev: Device from iommu_get_resv_regions()
@@ -188,10 +242,11 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
        if (!is_of_node(dev_iommu_fwspec_get(dev)->iommu_fwnode))
                iort_iommu_msi_get_resv_regions(dev, list);
 
+       iommu_dma_get_rmr_resv_regions(dev, list);
 }

----8<----

But looking at the SMMUv2 code, the fwspec->ids is MASK:SID, so I am not
sure the RMR sid can be compared directly to fwspec->ids above. Right? Or
is there a better way here?

Thanks,
Shameer


> 

> >   static void arm_smmu_get_resv_regions(struct device *dev,

> >   				      struct list_head *head)

> >   {

> > @@ -2545,6 +2573,7 @@ static void arm_smmu_get_resv_regions(struct

> device *dev,

> >   	list_add_tail(&region->list, head);

> >

> >   	iommu_dma_get_resv_regions(dev, head);

> > +	arm_smmu_rmr_get_resv_regions(dev, head);

> >   }

> >

> >   static bool arm_smmu_dev_has_feature(struct device *dev,

> >
Robin Murphy May 10, 2021, 2:22 p.m. | #3
On 2021-05-10 10:19, Shameerali Kolothum Thodi wrote:
> Hi Robin,

> 

>> -----Original Message-----

>> From: Robin Murphy [mailto:robin.murphy@arm.com]

>> Sent: 07 May 2021 11:02

>> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;

>> linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org;

>> iommu@lists.linux-foundation.org

>> Cc: Linuxarm <linuxarm@huawei.com>; lorenzo.pieralisi@arm.com;

>> joro@8bytes.org; wanghuiqiang <wanghuiqiang@huawei.com>; Guohanjun

>> (Hanjun Guo) <guohanjun@huawei.com>; steven.price@arm.com;

>> Sami.Mujawar@arm.com; jon@solid-run.com; eric.auger@redhat.com

>> Subject: Re: [PATCH v3 08/10] iommu/arm-smmu-v3: Reserve any RMR regions

>> associated with a dev

>>

>> On 2021-04-20 09:27, Shameer Kolothum wrote:

>>> Get RMR regions associated with a dev reserved so that there is

>>> a unity mapping for them in SMMU.

>>>

>>> Signed-off-by: Shameer Kolothum

>> <shameerali.kolothum.thodi@huawei.com>

>>> ---

>>>    drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 29

>> +++++++++++++++++++++

>>>    1 file changed, 29 insertions(+)

>>>

>>> 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 14e9c7034c04..8bacedf7bb34 100644

>>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

>>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

>>> @@ -2531,6 +2531,34 @@ static int arm_smmu_of_xlate(struct device *dev,

>> struct of_phandle_args *args)

>>>    	return iommu_fwspec_add_ids(dev, args->args, 1);

>>>    }

>>>

>>> +static bool arm_smmu_dev_has_rmr(struct arm_smmu_master *master,

>>> +				 struct iommu_rmr *e)

>>> +{

>>> +	int i;

>>> +

>>> +	for (i = 0; i < master->num_sids; i++) {

>>> +		if (e->sid == master->sids[i])

>>> +			return true;

>>> +	}

>>> +

>>> +	return false;

>>> +}

>>> +

>>> +static void arm_smmu_rmr_get_resv_regions(struct device *dev,

>>> +					  struct list_head *head)

>>> +{

>>> +	struct arm_smmu_master *master = dev_iommu_priv_get(dev);

>>> +	struct arm_smmu_device *smmu = master->smmu;

>>> +	struct iommu_rmr *rmr;

>>> +

>>> +	list_for_each_entry(rmr, &smmu->rmr_list, list) {

>>> +		if (!arm_smmu_dev_has_rmr(master, rmr))

>>> +			continue;

>>> +

>>> +		iommu_dma_get_rmr_resv_regions(dev, rmr, head);

>>> +	}

>>> +}

>>> +

>>

>> TBH I wouldn't have thought we need a driver-specific hook for this, or

>> is it too painful to correlate fwspec->iommu_fwnode back to the relevant

>> IORT node generically?

> 

>  From a quick look, I think I could get rid of the above with something like below,

> 

> ------8<----

> +static bool iommu_dma_dev_has_rmr(struct iommu_fwspec *fwspec,

> +                                 struct iommu_rmr *e)

> +{

> +       int i;

> +

> +       for (i = 0; i < fwspec->num_ids; i++) {

> +                if (e->sid == fwspec->ids[i])

> +                        return true;

> +        }

> +

> +        return false;

> +}

> +

> +

> +void iommu_dma_get_rmr_resv_regions(struct device *dev, struct list_head *list)

> +{

> +       struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);

> +       struct list_head rmr_list;

> +       struct iommu_rmr *rmr;

> +

> +       INIT_LIST_HEAD(&rmr_list);

> +       if (iommu_dma_get_rmrs(fwspec->iommu_fwnode, &rmr_list))

> +               return;

>          ...

> +       list_for_each_entry(rmr, &rmr_list, list) {

> +

> +       if (!iommu_dma_dev_has_rmr(fwspec, rmr)

> +           continue;

> +          ...

> +               region = iommu_alloc_resv_region(rmr->base_address,

> +                                                rmr->length, prot,

> +                                                type);

>           ...

> +       }

> +}

>   /**

>    * iommu_dma_get_resv_regions - Reserved region driver helper

>    * @dev: Device from iommu_get_resv_regions()

> @@ -188,10 +242,11 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)

>          if (!is_of_node(dev_iommu_fwspec_get(dev)->iommu_fwnode))

>                  iort_iommu_msi_get_resv_regions(dev, list);

>   

> +       iommu_dma_get_rmr_resv_regions(dev, list);

>   }

> 

> ----8<----

> 

> But looking at the SMMUv2 code, the fwspec->ids is MASK:SID, so I am not

> sure the RMR sid can be compared directly to fwspec->ids above. Right? Or

> is there a better way here?


Ah, but consider how the IDs got there in the first place ;)

A mask will never be set on ACPI systems, since IORT (intentionally) 
only caters for straightforward mappings rather than arbitrary 
complexity, so the assumption of fwspec ID == SID is already baked in by 
virtue of arm_smmu_iort_xlate(). The IORT code is free to assume its own 
behaviour!

Robin.

> 

> Thanks,

> Shameer

> 

> 

>>

>>>    static void arm_smmu_get_resv_regions(struct device *dev,

>>>    				      struct list_head *head)

>>>    {

>>> @@ -2545,6 +2573,7 @@ static void arm_smmu_get_resv_regions(struct

>> device *dev,

>>>    	list_add_tail(&region->list, head);

>>>

>>>    	iommu_dma_get_resv_regions(dev, head);

>>> +	arm_smmu_rmr_get_resv_regions(dev, head);

>>>    }

>>>

>>>    static bool arm_smmu_dev_has_feature(struct device *dev,

>>>

Patch

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 14e9c7034c04..8bacedf7bb34 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2531,6 +2531,34 @@  static int arm_smmu_of_xlate(struct device *dev, struct of_phandle_args *args)
 	return iommu_fwspec_add_ids(dev, args->args, 1);
 }
 
+static bool arm_smmu_dev_has_rmr(struct arm_smmu_master *master,
+				 struct iommu_rmr *e)
+{
+	int i;
+
+	for (i = 0; i < master->num_sids; i++) {
+		if (e->sid == master->sids[i])
+			return true;
+	}
+
+	return false;
+}
+
+static void arm_smmu_rmr_get_resv_regions(struct device *dev,
+					  struct list_head *head)
+{
+	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
+	struct arm_smmu_device *smmu = master->smmu;
+	struct iommu_rmr *rmr;
+
+	list_for_each_entry(rmr, &smmu->rmr_list, list) {
+		if (!arm_smmu_dev_has_rmr(master, rmr))
+			continue;
+
+		iommu_dma_get_rmr_resv_regions(dev, rmr, head);
+	}
+}
+
 static void arm_smmu_get_resv_regions(struct device *dev,
 				      struct list_head *head)
 {
@@ -2545,6 +2573,7 @@  static void arm_smmu_get_resv_regions(struct device *dev,
 	list_add_tail(&region->list, head);
 
 	iommu_dma_get_resv_regions(dev, head);
+	arm_smmu_rmr_get_resv_regions(dev, head);
 }
 
 static bool arm_smmu_dev_has_feature(struct device *dev,