Re: [EXT] Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On Thu, Apr 23, 2020 at 09:56:54AM +, Makarand Pawagi wrote: [...] > > > At a first glance, looks like this could very well fix the ACPI > > > scenario, but I have some unclarities on the approach: > > > * are we going to rely in DT and ACPI generic layers even if these > > > devices are not published / enumerated through DT or ACPI tables? > > > > Assuming you mean the DPRC devices rather than the MC itself, then yes; in > > that > > sense it's exactly the same as how we treat dynamically-discovered PCI > > devices. > > > > > * the firmware manages and provides discrete streamids for the > > > devices it exposes so there's no translation involved. There's no > > > requestor_id / input_id involved but it seems that we would still > > > do some kind of translation relying for this on the DT/ACPI functions. > > > > Wrong - last time I looked, what that firmware actually manages are > > *ICIDs* for the devices, not SMMU Stream IDs or GIC Device IDs; what DT/ACPI > > specifies is a translation from ICID to Stream ID/Device ID. The ICID is > > very much > > the requester/input ID for that translation. Yes, in practice the > > "translation" is > > effectively always a trivial identity mapping, but conceptually it most > > definitely > > exists. Yes, the subtlety is incredibly easy to overlook because it's > > basically > > drawing a distinction between one end of some wires vs. the other end, but > > it > > matters. > > > > (and of course "trivial 1:1 translation" isn't even true in the case of SMMU > > Stream ID values, since IIRC they are really composed of 5 different > > inputs, only > > one of which is (part of) the incoming ICID) > > > > > * MC firmware has its own stream_id (e.g. on some chips 0x4000, > > > others 0xf00, so outside the range of stream_ids used for the mc devices) > > > while for the devices on this bus, MC allocates stream_ids from a > > > range (e.g. 0x17 - 0x3f). Is it possible to describe this in the IORT > > > table? > > > > If it represents a unique ICID allocated to the MC itself, then sure, it > > simply goes > > through the mapping like anything else. Just like a PCI host bridge owns > > requester ID 0:0.0 and thus whatever Stream ID/Device ID that might map to. > > > > If (for the sake of argument, because AIUI everything is an ICID in this > > particular > > case) it's some hard-wired thing that exists in Stream ID/Device ID space > > only, > > then it's a little trickier, but still in scope. In DT we have a lovely > > distinction > > between between "originating from the node" and "translated through the > > node", e.g. "msi-parent" vs. > > "msi-map"; IORT is not quite as clear-cut, but there are at least a few > > options. If > > the valid input ID space is smaller than 32 bits, then the "Named Component > > as > > bridge" binding could simply define special out-of-range values to > > represent IDs > > originating from the bridge itself, such that the NC driver knows what to > > do and > > from IORT's point of view everything is just a normal mapping. Alternatively > > there's already the example of SMMUv3 where we can have a mix of the normal > > mappings from Stream ID to Device ID for the upstream masters plus a single > > mapping for the SMMU's own Device ID - admittedly that depends on the > > additional SMMUv3-specific Device ID Mapping Index property, but if > > necessary > > it might be workable to have a de-facto interface for NCs that only > > considers > > single mappings when configuring the NC itself, and only considers normal > > mappings when configuring its children. Or maybe define a new mapping flag > > or > > NC property if there's a real need to specify such a situation > > unambiguously at > > the IORT level. > > > > > * Regarding the of_map_rid() use you mentioned, I was planning to > > > decouple the mc bus from the DT layer by dropping the use of > > > of_map_rid(), see patch 4. > > > I briefly glanced over the iort code and spotted this static function: > > > iort_iommu_xlate(). Wouldn't it also help, of course after making it > > > public? > > > > I won't speak for Lorenzo or claim we've agreed on an approach at all (not > > least > > because in all honesty we haven't really discussed it beyond these various > > email > > threads), but FWIW my vision is that ultimately the DT/ACPI code would > > expose > > a *_dma_configure() interface that takes an optional input ID, or (perhaps > > more > > likely) an explicit pair of interfaces for "configure this regular device" > > and > > "configure this device based on this 'host' device and this ID", and it > > becomes > > the bus code's responsibility to pass the right device(s) and deal with > > multiple IDs > > (i.e. for starters all the PCI alias stuff goes back to the PCI code where > > it really > > should be, rather than having multiple copies of magic PCI awareness deep > > down in DT/ACPI code). > > > > Robin. > > Hi Lorenzo, Robin,
RE: [EXT] Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
> -Original Message-
> From: Robin Murphy
> Sent: Wednesday, April 15, 2020 11:02 PM
> To: Laurentiu Tudor ; Lorenzo Pieralisi
>
> Cc: linux-ker...@vger.kernel.org; iommu@lists.linux-foundation.org; linux-arm-
> ker...@lists.infradead.org; linux-a...@vger.kernel.org;
> ard.biesheu...@linaro.org; Ioana Ciornei ; Diana
> Madalina Craciun (OSS) ; m...@kernel.org;
> j...@solid-run.com; Pankaj Bansal ; Makarand
> Pawagi ; Calvin Johnson
> ; Varun Sethi ; Cristi Sovaiala
> ; stuart.yo...@arm.com; jeremy.lin...@arm.com;
> j...@8bytes.org; t...@linutronix.de; ja...@lakedaemon.net
> Subject: [EXT] Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure
> implementation
>
> Caution: EXT Email
>
> On 2020-04-15 4:44 pm, Laurentiu Tudor wrote:
> >
> >
> > On 4/14/2020 5:32 PM, Lorenzo Pieralisi wrote:
> >> On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
> >>> Hi Lorenzo,
> >>>
> >>> On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
> >>>> On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com
> wrote:
> >>>>> From: Laurentiu Tudor
> >>>>>
> >>>>> The devices on this bus are not discovered by way of device tree
> >>>>> but by queries to the firmware. It makes little sense to trick the
> >>>>> generic of layer into thinking that these devices are of related
> >>>>> so that we can get our dma configuration. Instead of doing that,
> >>>>> add our custom dma configuration implementation.
> >>>>>
> >>>>> Signed-off-by: Laurentiu Tudor
> >>>>> ---
> >>>>> drivers/bus/fsl-mc/fsl-mc-bus.c | 31
> ++-
> >>>>> 1 file changed, 30 insertions(+), 1 deletion(-)
> >>>>>
> >>>>> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
> >>>>> b/drivers/bus/fsl-mc/fsl-mc-bus.c index 36eb25f82c8e..eafaa0e0b906
> >>>>> 100644
> >>>>> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> >>>>> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> >>>>> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device
> *dev, struct kobj_uevent_env *env)
> >>>>> static int fsl_mc_dma_configure(struct device *dev)
> >>>>> {
> >>>>> struct device *dma_dev = dev;
> >>>>> + struct iommu_fwspec *fwspec;
> >>>>> + const struct iommu_ops *iommu_ops; struct fsl_mc_device *mc_dev
> >>>>> + = to_fsl_mc_device(dev); int ret;
> >>>>> + u32 icid;
> >>>>>
> >>>>> while (dev_is_fsl_mc(dma_dev))
> >>>>> dma_dev = dma_dev->parent;
> >>>>>
> >>>>> - return of_dma_configure(dev, dma_dev->of_node, 0);
> >>>>> + fwspec = dev_iommu_fwspec_get(dma_dev); if (!fwspec)
> >>>>> + return -ENODEV;
> >>>>> + iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
> >>>>> + if (!iommu_ops)
> >>>>> + return -ENODEV;
> >>>>> +
> >>>>> + ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
> >>>>> + if (ret)
> >>>>> + return ret;
> >>>>> +
> >>>>> + icid = mc_dev->icid;
> >>>>> + ret = iommu_fwspec_add_ids(dev, , 1);
> >>>>
> >>>> I see. So with this patch we would use the MC named component only
> >>>> to retrieve the iommu_ops
> >>>
> >>> Right. I'd also add that the implementation tries to follow the
> >>> existing standard .dma_configure implementations, e.g.
> >>> of_dma_configure + of_iommu_configure. I'd also note that similarly
> >>> to the ACPI case, this MC FW device is probed as a platform device
> >>> in the DT scenario, binding here [1].
> >>> A similar approach is used for the retrieval of the msi irq domain,
> >>> see following patch.
> >>>
> >>>> - the streamid are injected directly here bypassing OF/IORT bindings
> translations altogether.
> >>>
> >>> Actually I've submitted a v2 [2] that calls into .of_xlate() to
> >>> allow the smmu driver to do some processing on the raw streamid
> >>> coming from the firmware. I have not yet tested this with ACPI but
> >>> expect it to work, however, it's de
Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On 4/15/2020 7:04 PM, Lorenzo Pieralisi wrote:
> On Wed, Apr 15, 2020 at 06:44:37PM +0300, Laurentiu Tudor wrote:
>>
>>
>> On 4/14/2020 5:32 PM, Lorenzo Pieralisi wrote:
>>> On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
Hi Lorenzo,
On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
> On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
>> From: Laurentiu Tudor
>>
>> The devices on this bus are not discovered by way of device tree
>> but by queries to the firmware. It makes little sense to trick the
>> generic of layer into thinking that these devices are of related so
>> that we can get our dma configuration. Instead of doing that, add
>> our custom dma configuration implementation.
>>
>> Signed-off-by: Laurentiu Tudor
>> ---
>> drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++-
>> 1 file changed, 30 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
>> b/drivers/bus/fsl-mc/fsl-mc-bus.c
>> index 36eb25f82c8e..eafaa0e0b906 100644
>> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
>> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
>> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev,
>> struct kobj_uevent_env *env)
>> static int fsl_mc_dma_configure(struct device *dev)
>> {
>> struct device *dma_dev = dev;
>> +struct iommu_fwspec *fwspec;
>> +const struct iommu_ops *iommu_ops;
>> +struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
>> +int ret;
>> +u32 icid;
>>
>> while (dev_is_fsl_mc(dma_dev))
>> dma_dev = dma_dev->parent;
>>
>> -return of_dma_configure(dev, dma_dev->of_node, 0);
>> +fwspec = dev_iommu_fwspec_get(dma_dev);
>> +if (!fwspec)
>> +return -ENODEV;
>> +iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
>> +if (!iommu_ops)
>> +return -ENODEV;
>> +
>> +ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
>> +if (ret)
>> +return ret;
>> +
>> +icid = mc_dev->icid;
>> +ret = iommu_fwspec_add_ids(dev, , 1);
>
> I see. So with this patch we would use the MC named component only to
> retrieve the iommu_ops
Right. I'd also add that the implementation tries to follow the existing
standard .dma_configure implementations, e.g. of_dma_configure +
of_iommu_configure. I'd also note that similarly to the ACPI case, this
MC FW device is probed as a platform device in the DT scenario, binding
here [1].
A similar approach is used for the retrieval of the msi irq domain, see
following patch.
> - the streamid are injected directly here bypassing OF/IORT bindings
> translations altogether.
Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
the smmu driver to do some processing on the raw streamid coming from
the firmware. I have not yet tested this with ACPI but expect it to
work, however, it's debatable how valid is this approach in the context
of ACPI.
>>>
>>> Actually, what I think you need is of_map_rid() (and an IORT
>>> equivalent, that I am going to write - generalizing iort_msi_map_rid()).
>>>
>>> Would that be enough to enable IORT "normal" mappings in the MC bus
>>> named components ?
>>>
>>
>> At a first glance, looks like this could very well fix the ACPI
>> scenario, but I have some unclarities on the approach:
>> * are we going to rely in DT and ACPI generic layers even if these
>> devices are not published / enumerated through DT or ACPI tables?
>> * the firmware manages and provides discrete streamids for the devices
>> it exposes so there's no translation involved. There's no
>>requestor_id / input_id involved but it seems that we would still do
>> some kind of translation relying for this on the DT/ACPI functions.
>> * MC firmware has its own stream_id (e.g. on some chips 0x4000, others
>> 0xf00, so outside the range of stream_ids used for the mc devices)
>>while for the devices on this bus, MC allocates stream_ids from a
>> range (e.g. 0x17 - 0x3f). Is it possible to describe this in the IORT table?
>> * Regarding the of_map_rid() use you mentioned, I was planning to
>> decouple the mc bus from the DT layer by dropping the use of
>> of_map_rid(), see patch 4.
>> I briefly glanced over the iort code and spotted this static function:
>> iort_iommu_xlate(). Wouldn't it also help, of course after making it public?
>
> Guys I have lost you honestly. I don't understand what you really need
> to do with DT and ACPI here. Are they needed to describe what you need
> or not ? If the MC dma configure function does not need any DT/ACPI
> bindings that's fine by me, I don't
RE: [EXT] Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
> -Original Message-
> From: Lorenzo Pieralisi
> Sent: Tuesday, April 14, 2020 8:02 PM
> To: Laurentiu Tudor
> Cc: linux-ker...@vger.kernel.org; iommu@lists.linux-foundation.org; linux-arm-
> ker...@lists.infradead.org; linux-a...@vger.kernel.org;
> robin.mur...@arm.com; ard.biesheu...@linaro.org; Ioana Ciornei
> ; Diana Madalina Craciun (OSS)
> ; m...@kernel.org; j...@solid-run.com; Pankaj
> Bansal ; Makarand Pawagi
> ; Calvin Johnson ;
> Varun Sethi ; Cristi Sovaiala ;
> stuart.yo...@arm.com; jeremy.lin...@arm.com; j...@8bytes.org;
> t...@linutronix.de; ja...@lakedaemon.net
> Subject: [EXT] Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure
> implementation
>
> Caution: EXT Email
>
> On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
> > Hi Lorenzo,
> >
> > On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
> > > On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
> > >> From: Laurentiu Tudor
> > >>
> > >> The devices on this bus are not discovered by way of device tree
> > >> but by queries to the firmware. It makes little sense to trick the
> > >> generic of layer into thinking that these devices are of related so
> > >> that we can get our dma configuration. Instead of doing that, add
> > >> our custom dma configuration implementation.
> > >>
> > >> Signed-off-by: Laurentiu Tudor
> > >> ---
> > >> drivers/bus/fsl-mc/fsl-mc-bus.c | 31
> > >> ++-
> > >> 1 file changed, 30 insertions(+), 1 deletion(-)
> > >>
> > >> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
> > >> b/drivers/bus/fsl-mc/fsl-mc-bus.c index 36eb25f82c8e..eafaa0e0b906
> > >> 100644
> > >> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> > >> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> > >> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device
> > >> *dev, struct kobj_uevent_env *env) static int
> > >> fsl_mc_dma_configure(struct device *dev) {
> > >>struct device *dma_dev = dev;
> > >> + struct iommu_fwspec *fwspec;
> > >> + const struct iommu_ops *iommu_ops; struct fsl_mc_device *mc_dev
> > >> + = to_fsl_mc_device(dev); int ret;
> > >> + u32 icid;
> > >>
> > >>while (dev_is_fsl_mc(dma_dev))
> > >>dma_dev = dma_dev->parent;
> > >>
> > >> - return of_dma_configure(dev, dma_dev->of_node, 0);
> > >> + fwspec = dev_iommu_fwspec_get(dma_dev); if (!fwspec)
> > >> + return -ENODEV;
> > >> + iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
> > >> + if (!iommu_ops)
> > >> + return -ENODEV;
> > >> +
> > >> + ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
> > >> + if (ret)
> > >> + return ret;
> > >> +
> > >> + icid = mc_dev->icid;
> > >> + ret = iommu_fwspec_add_ids(dev, , 1);
> > >
> > > I see. So with this patch we would use the MC named component only
> > > to retrieve the iommu_ops
> >
> > Right. I'd also add that the implementation tries to follow the
> > existing standard .dma_configure implementations, e.g.
> > of_dma_configure + of_iommu_configure. I'd also note that similarly to
> > the ACPI case, this MC FW device is probed as a platform device in the
> > DT scenario, binding here [1].
> > A similar approach is used for the retrieval of the msi irq domain,
> > see following patch.
> >
> > > - the streamid are injected directly here bypassing OF/IORT bindings
> translations altogether.
> >
> > Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
> > the smmu driver to do some processing on the raw streamid coming from
> > the firmware. I have not yet tested this with ACPI but expect it to
> > work, however, it's debatable how valid is this approach in the
> > context of ACPI.
>
> Actually, what I think you need is of_map_rid() (and an IORT equivalent, that
> I
> am going to write - generalizing iort_msi_map_rid()).
>
That would help.
> Would that be enough to enable IORT "normal" mappings in the MC bus named
> components ?
>
But still the question remain unanswered that how we are going to represent MC?
As Platform device with single ID mapping flag?
> Thanks,
> Lorenzo
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Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On 2020-04-15 4:44 pm, Laurentiu Tudor wrote:
On 4/14/2020 5:32 PM, Lorenzo Pieralisi wrote:
On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
Hi Lorenzo,
On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
From: Laurentiu Tudor
The devices on this bus are not discovered by way of device tree
but by queries to the firmware. It makes little sense to trick the
generic of layer into thinking that these devices are of related so
that we can get our dma configuration. Instead of doing that, add
our custom dma configuration implementation.
Signed-off-by: Laurentiu Tudor
---
drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 36eb25f82c8e..eafaa0e0b906 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev, struct
kobj_uevent_env *env)
static int fsl_mc_dma_configure(struct device *dev)
{
struct device *dma_dev = dev;
+ struct iommu_fwspec *fwspec;
+ const struct iommu_ops *iommu_ops;
+ struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+ int ret;
+ u32 icid;
while (dev_is_fsl_mc(dma_dev))
dma_dev = dma_dev->parent;
- return of_dma_configure(dev, dma_dev->of_node, 0);
+ fwspec = dev_iommu_fwspec_get(dma_dev);
+ if (!fwspec)
+ return -ENODEV;
+ iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
+ if (!iommu_ops)
+ return -ENODEV;
+
+ ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
+ if (ret)
+ return ret;
+
+ icid = mc_dev->icid;
+ ret = iommu_fwspec_add_ids(dev, , 1);
I see. So with this patch we would use the MC named component only to
retrieve the iommu_ops
Right. I'd also add that the implementation tries to follow the existing
standard .dma_configure implementations, e.g. of_dma_configure +
of_iommu_configure. I'd also note that similarly to the ACPI case, this
MC FW device is probed as a platform device in the DT scenario, binding
here [1].
A similar approach is used for the retrieval of the msi irq domain, see
following patch.
- the streamid are injected directly here bypassing OF/IORT bindings
translations altogether.
Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
the smmu driver to do some processing on the raw streamid coming from
the firmware. I have not yet tested this with ACPI but expect it to
work, however, it's debatable how valid is this approach in the context
of ACPI.
Actually, what I think you need is of_map_rid() (and an IORT
equivalent, that I am going to write - generalizing iort_msi_map_rid()).
Would that be enough to enable IORT "normal" mappings in the MC bus
named components ?
At a first glance, looks like this could very well fix the ACPI
scenario, but I have some unclarities on the approach:
* are we going to rely in DT and ACPI generic layers even if these
devices are not published / enumerated through DT or ACPI tables?
Assuming you mean the DPRC devices rather than the MC itself, then yes;
in that sense it's exactly the same as how we treat
dynamically-discovered PCI devices.
* the firmware manages and provides discrete streamids for the devices
it exposes so there's no translation involved. There's no
requestor_id / input_id involved but it seems that we would still do
some kind of translation relying for this on the DT/ACPI functions.
Wrong - last time I looked, what that firmware actually manages are
*ICIDs* for the devices, not SMMU Stream IDs or GIC Device IDs; what
DT/ACPI specifies is a translation from ICID to Stream ID/Device ID. The
ICID is very much the requester/input ID for that translation. Yes, in
practice the "translation" is effectively always a trivial identity
mapping, but conceptually it most definitely exists. Yes, the subtlety
is incredibly easy to overlook because it's basically drawing a
distinction between one end of some wires vs. the other end, but it matters.
(and of course "trivial 1:1 translation" isn't even true in the case of
SMMU Stream ID values, since IIRC they are really composed of 5
different inputs, only one of which is (part of) the incoming ICID)
* MC firmware has its own stream_id (e.g. on some chips 0x4000, others
0xf00, so outside the range of stream_ids used for the mc devices)
while for the devices on this bus, MC allocates stream_ids from a
range (e.g. 0x17 - 0x3f). Is it possible to describe this in the IORT table?
If it represents a unique ICID allocated to the MC itself, then sure, it
simply goes through the mapping like anything else. Just like a PCI host
bridge owns requester ID 0:0.0 and thus whatever Stream ID/Device ID
that
Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On Wed, Apr 15, 2020 at 06:44:37PM +0300, Laurentiu Tudor wrote:
>
>
> On 4/14/2020 5:32 PM, Lorenzo Pieralisi wrote:
> > On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
> >> Hi Lorenzo,
> >>
> >> On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
> >>> On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
> From: Laurentiu Tudor
>
> The devices on this bus are not discovered by way of device tree
> but by queries to the firmware. It makes little sense to trick the
> generic of layer into thinking that these devices are of related so
> that we can get our dma configuration. Instead of doing that, add
> our custom dma configuration implementation.
>
> Signed-off-by: Laurentiu Tudor
> ---
> drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++-
> 1 file changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
> b/drivers/bus/fsl-mc/fsl-mc-bus.c
> index 36eb25f82c8e..eafaa0e0b906 100644
> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev,
> struct kobj_uevent_env *env)
> static int fsl_mc_dma_configure(struct device *dev)
> {
> struct device *dma_dev = dev;
> +struct iommu_fwspec *fwspec;
> +const struct iommu_ops *iommu_ops;
> +struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
> +int ret;
> +u32 icid;
>
> while (dev_is_fsl_mc(dma_dev))
> dma_dev = dma_dev->parent;
>
> -return of_dma_configure(dev, dma_dev->of_node, 0);
> +fwspec = dev_iommu_fwspec_get(dma_dev);
> +if (!fwspec)
> +return -ENODEV;
> +iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
> +if (!iommu_ops)
> +return -ENODEV;
> +
> +ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
> +if (ret)
> +return ret;
> +
> +icid = mc_dev->icid;
> +ret = iommu_fwspec_add_ids(dev, , 1);
> >>>
> >>> I see. So with this patch we would use the MC named component only to
> >>> retrieve the iommu_ops
> >>
> >> Right. I'd also add that the implementation tries to follow the existing
> >> standard .dma_configure implementations, e.g. of_dma_configure +
> >> of_iommu_configure. I'd also note that similarly to the ACPI case, this
> >> MC FW device is probed as a platform device in the DT scenario, binding
> >> here [1].
> >> A similar approach is used for the retrieval of the msi irq domain, see
> >> following patch.
> >>
> >>> - the streamid are injected directly here bypassing OF/IORT bindings
> >>> translations altogether.
> >>
> >> Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
> >> the smmu driver to do some processing on the raw streamid coming from
> >> the firmware. I have not yet tested this with ACPI but expect it to
> >> work, however, it's debatable how valid is this approach in the context
> >> of ACPI.
> >
> > Actually, what I think you need is of_map_rid() (and an IORT
> > equivalent, that I am going to write - generalizing iort_msi_map_rid()).
> >
> > Would that be enough to enable IORT "normal" mappings in the MC bus
> > named components ?
> >
>
> At a first glance, looks like this could very well fix the ACPI
> scenario, but I have some unclarities on the approach:
> * are we going to rely in DT and ACPI generic layers even if these
> devices are not published / enumerated through DT or ACPI tables?
> * the firmware manages and provides discrete streamids for the devices
> it exposes so there's no translation involved. There's no
>requestor_id / input_id involved but it seems that we would still do
> some kind of translation relying for this on the DT/ACPI functions.
> * MC firmware has its own stream_id (e.g. on some chips 0x4000, others
> 0xf00, so outside the range of stream_ids used for the mc devices)
>while for the devices on this bus, MC allocates stream_ids from a
> range (e.g. 0x17 - 0x3f). Is it possible to describe this in the IORT table?
> * Regarding the of_map_rid() use you mentioned, I was planning to
> decouple the mc bus from the DT layer by dropping the use of
> of_map_rid(), see patch 4.
> I briefly glanced over the iort code and spotted this static function:
> iort_iommu_xlate(). Wouldn't it also help, of course after making it public?
Guys I have lost you honestly. I don't understand what you really need
to do with DT and ACPI here. Are they needed to describe what you need
or not ? If the MC dma configure function does not need any DT/ACPI
bindings that's fine by me, I don't understand though why you are still
asking how to represent MC in ACPI then, what
Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On 4/14/2020 5:32 PM, Lorenzo Pieralisi wrote:
> On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
>> Hi Lorenzo,
>>
>> On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
>>> On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
From: Laurentiu Tudor
The devices on this bus are not discovered by way of device tree
but by queries to the firmware. It makes little sense to trick the
generic of layer into thinking that these devices are of related so
that we can get our dma configuration. Instead of doing that, add
our custom dma configuration implementation.
Signed-off-by: Laurentiu Tudor
---
drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
b/drivers/bus/fsl-mc/fsl-mc-bus.c
index 36eb25f82c8e..eafaa0e0b906 100644
--- a/drivers/bus/fsl-mc/fsl-mc-bus.c
+++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
@@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev,
struct kobj_uevent_env *env)
static int fsl_mc_dma_configure(struct device *dev)
{
struct device *dma_dev = dev;
+ struct iommu_fwspec *fwspec;
+ const struct iommu_ops *iommu_ops;
+ struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
+ int ret;
+ u32 icid;
while (dev_is_fsl_mc(dma_dev))
dma_dev = dma_dev->parent;
- return of_dma_configure(dev, dma_dev->of_node, 0);
+ fwspec = dev_iommu_fwspec_get(dma_dev);
+ if (!fwspec)
+ return -ENODEV;
+ iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
+ if (!iommu_ops)
+ return -ENODEV;
+
+ ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
+ if (ret)
+ return ret;
+
+ icid = mc_dev->icid;
+ ret = iommu_fwspec_add_ids(dev, , 1);
>>>
>>> I see. So with this patch we would use the MC named component only to
>>> retrieve the iommu_ops
>>
>> Right. I'd also add that the implementation tries to follow the existing
>> standard .dma_configure implementations, e.g. of_dma_configure +
>> of_iommu_configure. I'd also note that similarly to the ACPI case, this
>> MC FW device is probed as a platform device in the DT scenario, binding
>> here [1].
>> A similar approach is used for the retrieval of the msi irq domain, see
>> following patch.
>>
>>> - the streamid are injected directly here bypassing OF/IORT bindings
>>> translations altogether.
>>
>> Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
>> the smmu driver to do some processing on the raw streamid coming from
>> the firmware. I have not yet tested this with ACPI but expect it to
>> work, however, it's debatable how valid is this approach in the context
>> of ACPI.
>
> Actually, what I think you need is of_map_rid() (and an IORT
> equivalent, that I am going to write - generalizing iort_msi_map_rid()).
>
> Would that be enough to enable IORT "normal" mappings in the MC bus
> named components ?
>
At a first glance, looks like this could very well fix the ACPI
scenario, but I have some unclarities on the approach:
* are we going to rely in DT and ACPI generic layers even if these
devices are not published / enumerated through DT or ACPI tables?
* the firmware manages and provides discrete streamids for the devices
it exposes so there's no translation involved. There's no
requestor_id / input_id involved but it seems that we would still do
some kind of translation relying for this on the DT/ACPI functions.
* MC firmware has its own stream_id (e.g. on some chips 0x4000, others
0xf00, so outside the range of stream_ids used for the mc devices)
while for the devices on this bus, MC allocates stream_ids from a
range (e.g. 0x17 - 0x3f). Is it possible to describe this in the IORT table?
* Regarding the of_map_rid() use you mentioned, I was planning to
decouple the mc bus from the DT layer by dropping the use of
of_map_rid(), see patch 4.
I briefly glanced over the iort code and spotted this static function:
iort_iommu_xlate(). Wouldn't it also help, of course after making it public?
---
Thanks & Best Regards, Laurentiu
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Re: [EXT] Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On Wed, Apr 15, 2020 at 05:42:03AM +, Makarand Pawagi wrote:
>
>
> > -Original Message-
> > From: Lorenzo Pieralisi
> > Sent: Tuesday, April 14, 2020 8:02 PM
> > To: Laurentiu Tudor
> > Cc: linux-ker...@vger.kernel.org; iommu@lists.linux-foundation.org;
> > linux-arm-
> > ker...@lists.infradead.org; linux-a...@vger.kernel.org;
> > robin.mur...@arm.com; ard.biesheu...@linaro.org; Ioana Ciornei
> > ; Diana Madalina Craciun (OSS)
> > ; m...@kernel.org; j...@solid-run.com; Pankaj
> > Bansal ; Makarand Pawagi
> > ; Calvin Johnson ;
> > Varun Sethi ; Cristi Sovaiala ;
> > stuart.yo...@arm.com; jeremy.lin...@arm.com; j...@8bytes.org;
> > t...@linutronix.de; ja...@lakedaemon.net
> > Subject: [EXT] Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure
> > implementation
> >
> > Caution: EXT Email
> >
> > On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
> > > Hi Lorenzo,
> > >
> > > On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
> > > > On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
> > > >> From: Laurentiu Tudor
> > > >>
> > > >> The devices on this bus are not discovered by way of device tree
> > > >> but by queries to the firmware. It makes little sense to trick the
> > > >> generic of layer into thinking that these devices are of related so
> > > >> that we can get our dma configuration. Instead of doing that, add
> > > >> our custom dma configuration implementation.
> > > >>
> > > >> Signed-off-by: Laurentiu Tudor
> > > >> ---
> > > >> drivers/bus/fsl-mc/fsl-mc-bus.c | 31
> > > >> ++-
> > > >> 1 file changed, 30 insertions(+), 1 deletion(-)
> > > >>
> > > >> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
> > > >> b/drivers/bus/fsl-mc/fsl-mc-bus.c index 36eb25f82c8e..eafaa0e0b906
> > > >> 100644
> > > >> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> > > >> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> > > >> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device
> > > >> *dev, struct kobj_uevent_env *env) static int
> > > >> fsl_mc_dma_configure(struct device *dev) {
> > > >>struct device *dma_dev = dev;
> > > >> + struct iommu_fwspec *fwspec;
> > > >> + const struct iommu_ops *iommu_ops; struct fsl_mc_device *mc_dev
> > > >> + = to_fsl_mc_device(dev); int ret;
> > > >> + u32 icid;
> > > >>
> > > >>while (dev_is_fsl_mc(dma_dev))
> > > >>dma_dev = dma_dev->parent;
> > > >>
> > > >> - return of_dma_configure(dev, dma_dev->of_node, 0);
> > > >> + fwspec = dev_iommu_fwspec_get(dma_dev); if (!fwspec)
> > > >> + return -ENODEV;
> > > >> + iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
> > > >> + if (!iommu_ops)
> > > >> + return -ENODEV;
> > > >> +
> > > >> + ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
> > > >> + if (ret)
> > > >> + return ret;
> > > >> +
> > > >> + icid = mc_dev->icid;
> > > >> + ret = iommu_fwspec_add_ids(dev, , 1);
> > > >
> > > > I see. So with this patch we would use the MC named component only
> > > > to retrieve the iommu_ops
> > >
> > > Right. I'd also add that the implementation tries to follow the
> > > existing standard .dma_configure implementations, e.g.
> > > of_dma_configure + of_iommu_configure. I'd also note that similarly to
> > > the ACPI case, this MC FW device is probed as a platform device in the
> > > DT scenario, binding here [1].
> > > A similar approach is used for the retrieval of the msi irq domain,
> > > see following patch.
> > >
> > > > - the streamid are injected directly here bypassing OF/IORT bindings
> > translations altogether.
> > >
> > > Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
> > > the smmu driver to do some processing on the raw streamid coming from
> > > the firmware. I have not yet tested this with ACPI but expect it to
> > > work, however, it's debatable how valid is this approach in the
> > > context of ACPI.
> >
> > Actually, what I think you need is of_map_rid() (and an IORT equivalent,
> > that I
> > am going to write - generalizing iort_msi_map_rid()).
> >
>
> That would help.
>
> > Would that be enough to enable IORT "normal" mappings in the MC bus named
> > components ?
> >
>
> But still the question remain unanswered that how we are going to represent
> MC? As Platform device with single ID mapping flag?
No, "normal" mappings, that's what I wrote above and it is not a
platform device it is a named component in ACPI/IORT terms.
Thanks,
Lorenzo
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Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On Wed, Mar 25, 2020 at 06:48:55PM +0200, Laurentiu Tudor wrote:
> Hi Lorenzo,
>
> On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
> > On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
> >> From: Laurentiu Tudor
> >>
> >> The devices on this bus are not discovered by way of device tree
> >> but by queries to the firmware. It makes little sense to trick the
> >> generic of layer into thinking that these devices are of related so
> >> that we can get our dma configuration. Instead of doing that, add
> >> our custom dma configuration implementation.
> >>
> >> Signed-off-by: Laurentiu Tudor
> >> ---
> >> drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++-
> >> 1 file changed, 30 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
> >> b/drivers/bus/fsl-mc/fsl-mc-bus.c
> >> index 36eb25f82c8e..eafaa0e0b906 100644
> >> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> >> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> >> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev,
> >> struct kobj_uevent_env *env)
> >> static int fsl_mc_dma_configure(struct device *dev)
> >> {
> >>struct device *dma_dev = dev;
> >> + struct iommu_fwspec *fwspec;
> >> + const struct iommu_ops *iommu_ops;
> >> + struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
> >> + int ret;
> >> + u32 icid;
> >>
> >>while (dev_is_fsl_mc(dma_dev))
> >>dma_dev = dma_dev->parent;
> >>
> >> - return of_dma_configure(dev, dma_dev->of_node, 0);
> >> + fwspec = dev_iommu_fwspec_get(dma_dev);
> >> + if (!fwspec)
> >> + return -ENODEV;
> >> + iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
> >> + if (!iommu_ops)
> >> + return -ENODEV;
> >> +
> >> + ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
> >> + if (ret)
> >> + return ret;
> >> +
> >> + icid = mc_dev->icid;
> >> + ret = iommu_fwspec_add_ids(dev, , 1);
> >
> > I see. So with this patch we would use the MC named component only to
> > retrieve the iommu_ops
>
> Right. I'd also add that the implementation tries to follow the existing
> standard .dma_configure implementations, e.g. of_dma_configure +
> of_iommu_configure. I'd also note that similarly to the ACPI case, this
> MC FW device is probed as a platform device in the DT scenario, binding
> here [1].
> A similar approach is used for the retrieval of the msi irq domain, see
> following patch.
>
> > - the streamid are injected directly here bypassing OF/IORT bindings
> > translations altogether.
>
> Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
> the smmu driver to do some processing on the raw streamid coming from
> the firmware. I have not yet tested this with ACPI but expect it to
> work, however, it's debatable how valid is this approach in the context
> of ACPI.
Actually, what I think you need is of_map_rid() (and an IORT
equivalent, that I am going to write - generalizing iort_msi_map_rid()).
Would that be enough to enable IORT "normal" mappings in the MC bus
named components ?
Thanks,
Lorenzo
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Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
Hi Lorenzo,
On 3/25/2020 2:51 PM, Lorenzo Pieralisi wrote:
> On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
>> From: Laurentiu Tudor
>>
>> The devices on this bus are not discovered by way of device tree
>> but by queries to the firmware. It makes little sense to trick the
>> generic of layer into thinking that these devices are of related so
>> that we can get our dma configuration. Instead of doing that, add
>> our custom dma configuration implementation.
>>
>> Signed-off-by: Laurentiu Tudor
>> ---
>> drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++-
>> 1 file changed, 30 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c
>> b/drivers/bus/fsl-mc/fsl-mc-bus.c
>> index 36eb25f82c8e..eafaa0e0b906 100644
>> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
>> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
>> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev,
>> struct kobj_uevent_env *env)
>> static int fsl_mc_dma_configure(struct device *dev)
>> {
>> struct device *dma_dev = dev;
>> +struct iommu_fwspec *fwspec;
>> +const struct iommu_ops *iommu_ops;
>> +struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
>> +int ret;
>> +u32 icid;
>>
>> while (dev_is_fsl_mc(dma_dev))
>> dma_dev = dma_dev->parent;
>>
>> -return of_dma_configure(dev, dma_dev->of_node, 0);
>> +fwspec = dev_iommu_fwspec_get(dma_dev);
>> +if (!fwspec)
>> +return -ENODEV;
>> +iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
>> +if (!iommu_ops)
>> +return -ENODEV;
>> +
>> +ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
>> +if (ret)
>> +return ret;
>> +
>> +icid = mc_dev->icid;
>> +ret = iommu_fwspec_add_ids(dev, , 1);
>
> I see. So with this patch we would use the MC named component only to
> retrieve the iommu_ops
Right. I'd also add that the implementation tries to follow the existing
standard .dma_configure implementations, e.g. of_dma_configure +
of_iommu_configure. I'd also note that similarly to the ACPI case, this
MC FW device is probed as a platform device in the DT scenario, binding
here [1].
A similar approach is used for the retrieval of the msi irq domain, see
following patch.
> - the streamid are injected directly here bypassing OF/IORT bindings
> translations altogether.
Actually I've submitted a v2 [2] that calls into .of_xlate() to allow
the smmu driver to do some processing on the raw streamid coming from
the firmware. I have not yet tested this with ACPI but expect it to
work, however, it's debatable how valid is this approach in the context
of ACPI.
> Am I reading this code correctly ?
Yes. Thanks for taking the time.
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/misc/fsl,qoriq-mc.txt
[2] https://www.spinics.net/lists/arm-kernel/msg794757.html
---
Best Regards, Laurentiu
>
>> +if (ret)
>> +return ret;
>> +
>> +if (!device_iommu_mapped(dev)) {
>> +ret = iommu_probe_device(dev);
>> +if (ret)
>> +return ret;
>> +}
>> +
>> +arch_setup_dma_ops(dev, 0, *dma_dev->dma_mask + 1, iommu_ops, true);
>> +
>> +return 0;
>> }
>>
>> static ssize_t modalias_show(struct device *dev, struct device_attribute
>> *attr,
>> --
>> 2.17.1
>>
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Re: [RFC PATCH 1/4] bus: fsl-mc: add custom .dma_configure implementation
On Thu, Feb 27, 2020 at 12:05:39PM +0200, laurentiu.tu...@nxp.com wrote:
> From: Laurentiu Tudor
>
> The devices on this bus are not discovered by way of device tree
> but by queries to the firmware. It makes little sense to trick the
> generic of layer into thinking that these devices are of related so
> that we can get our dma configuration. Instead of doing that, add
> our custom dma configuration implementation.
>
> Signed-off-by: Laurentiu Tudor
> ---
> drivers/bus/fsl-mc/fsl-mc-bus.c | 31 ++-
> 1 file changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c
> index 36eb25f82c8e..eafaa0e0b906 100644
> --- a/drivers/bus/fsl-mc/fsl-mc-bus.c
> +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c
> @@ -132,11 +132,40 @@ static int fsl_mc_bus_uevent(struct device *dev, struct
> kobj_uevent_env *env)
> static int fsl_mc_dma_configure(struct device *dev)
> {
> struct device *dma_dev = dev;
> + struct iommu_fwspec *fwspec;
> + const struct iommu_ops *iommu_ops;
> + struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
> + int ret;
> + u32 icid;
>
> while (dev_is_fsl_mc(dma_dev))
> dma_dev = dma_dev->parent;
>
> - return of_dma_configure(dev, dma_dev->of_node, 0);
> + fwspec = dev_iommu_fwspec_get(dma_dev);
> + if (!fwspec)
> + return -ENODEV;
> + iommu_ops = iommu_ops_from_fwnode(fwspec->iommu_fwnode);
> + if (!iommu_ops)
> + return -ENODEV;
> +
> + ret = iommu_fwspec_init(dev, fwspec->iommu_fwnode, iommu_ops);
> + if (ret)
> + return ret;
> +
> + icid = mc_dev->icid;
> + ret = iommu_fwspec_add_ids(dev, , 1);
I see. So with this patch we would use the MC named component only to
retrieve the iommu_ops - the streamid are injected directly here
bypassing OF/IORT bindings translations altogether. Am I reading this
code correctly ?
Thanks,
Lorenzo
> + if (ret)
> + return ret;
> +
> + if (!device_iommu_mapped(dev)) {
> + ret = iommu_probe_device(dev);
> + if (ret)
> + return ret;
> + }
> +
> + arch_setup_dma_ops(dev, 0, *dma_dev->dma_mask + 1, iommu_ops, true);
> +
> + return 0;
> }
>
> static ssize_t modalias_show(struct device *dev, struct device_attribute
> *attr,
> --
> 2.17.1
>
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