diff mbox series

[v4,3/9] PCI: epf-mhi: Add support for handling D-state notify from EPC

Message ID 1689232218-28265-4-git-send-email-quic_krichai@quicinc.com
State New
Headers show
Series PCI: EPC: Add support to wake up host from D3 states | expand

Commit Message

Krishna Chaitanya Chundru July 13, 2023, 7:10 a.m. UTC
Add support for handling D-state notify for MHI EPF.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 drivers/pci/endpoint/functions/pci-epf-mhi.c | 11 +++++++++++
 include/linux/mhi_ep.h                       |  3 +++
 2 files changed, 14 insertions(+)

Comments

Manivannan Sadhasivam July 28, 2023, 4:09 a.m. UTC | #1
On Thu, Jul 13, 2023 at 12:40:12PM +0530, Krishna chaitanya chundru wrote:
> Add support for handling D-state notify for MHI EPF.
> 
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  drivers/pci/endpoint/functions/pci-epf-mhi.c | 11 +++++++++++
>  include/linux/mhi_ep.h                       |  3 +++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> index 9c1f5a1..ee91bfc 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> @@ -339,6 +339,16 @@ static int pci_epf_mhi_bme(struct pci_epf *epf)
>  	return 0;
>  }
>  
> +static int pci_epf_mhi_dstate_notify(struct pci_epf *epf, pci_power_t state)
> +{
> +	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
> +	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
> +
> +	mhi_cntrl->dstate = state;

Where is this variable being used? Also, don't we need any locking?

- Mani

> +
> +	return 0;
> +}
> +
>  static int pci_epf_mhi_bind(struct pci_epf *epf)
>  {
>  	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
> @@ -394,6 +404,7 @@ static struct pci_epc_event_ops pci_epf_mhi_event_ops = {
>  	.link_up = pci_epf_mhi_link_up,
>  	.link_down = pci_epf_mhi_link_down,
>  	.bme = pci_epf_mhi_bme,
> +	.dstate_notify = pci_epf_mhi_dstate_notify,
>  };
>  
>  static int pci_epf_mhi_probe(struct pci_epf *epf,
> diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
> index f198a8a..c3a0685 100644
> --- a/include/linux/mhi_ep.h
> +++ b/include/linux/mhi_ep.h
> @@ -8,6 +8,7 @@
>  
>  #include <linux/dma-direction.h>
>  #include <linux/mhi.h>
> +#include <linux/pci.h>
>  
>  #define MHI_EP_DEFAULT_MTU 0x8000
>  
> @@ -139,6 +140,8 @@ struct mhi_ep_cntrl {
>  
>  	enum mhi_state mhi_state;
>  
> +	pci_power_t dstate;
> +
>  	u32 max_chan;
>  	u32 mru;
>  	u32 event_rings;
> -- 
> 2.7.4
>
Krishna Chaitanya Chundru July 31, 2023, 5:35 a.m. UTC | #2
On 7/28/2023 9:39 AM, Manivannan Sadhasivam wrote:
> On Thu, Jul 13, 2023 at 12:40:12PM +0530, Krishna chaitanya chundru wrote:
>> Add support for handling D-state notify for MHI EPF.
>>
>> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
>> ---
>>   drivers/pci/endpoint/functions/pci-epf-mhi.c | 11 +++++++++++
>>   include/linux/mhi_ep.h                       |  3 +++
>>   2 files changed, 14 insertions(+)
>>
>> diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
>> index 9c1f5a1..ee91bfc 100644
>> --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
>> +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
>> @@ -339,6 +339,16 @@ static int pci_epf_mhi_bme(struct pci_epf *epf)
>>   	return 0;
>>   }
>>   
>> +static int pci_epf_mhi_dstate_notify(struct pci_epf *epf, pci_power_t state)
>> +{
>> +	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
>> +	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
>> +
>> +	mhi_cntrl->dstate = state;
> Where is this variable being used? Also, don't we need any locking?
>
> - Mani

we are using this variable in wakeup host op which is introduced on 
patch [PATCH v4 8/9] PCI: epf-mhi: Add wakeup host op

I will add lock in my next series.

- KC

>
>> +
>> +	return 0;
>> +}
>> +
>>   static int pci_epf_mhi_bind(struct pci_epf *epf)
>>   {
>>   	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
>> @@ -394,6 +404,7 @@ static struct pci_epc_event_ops pci_epf_mhi_event_ops = {
>>   	.link_up = pci_epf_mhi_link_up,
>>   	.link_down = pci_epf_mhi_link_down,
>>   	.bme = pci_epf_mhi_bme,
>> +	.dstate_notify = pci_epf_mhi_dstate_notify,
>>   };
>>   
>>   static int pci_epf_mhi_probe(struct pci_epf *epf,
>> diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
>> index f198a8a..c3a0685 100644
>> --- a/include/linux/mhi_ep.h
>> +++ b/include/linux/mhi_ep.h
>> @@ -8,6 +8,7 @@
>>   
>>   #include <linux/dma-direction.h>
>>   #include <linux/mhi.h>
>> +#include <linux/pci.h>
>>   
>>   #define MHI_EP_DEFAULT_MTU 0x8000
>>   
>> @@ -139,6 +140,8 @@ struct mhi_ep_cntrl {
>>   
>>   	enum mhi_state mhi_state;
>>   
>> +	pci_power_t dstate;
>> +
>>   	u32 max_chan;
>>   	u32 mru;
>>   	u32 event_rings;
>> -- 
>> 2.7.4
>>
Krishna Chaitanya Chundru Aug. 1, 2023, 5:01 a.m. UTC | #3
On 7/31/2023 11:05 AM, Krishna Chaitanya Chundru wrote:
>
> On 7/28/2023 9:39 AM, Manivannan Sadhasivam wrote:
>> On Thu, Jul 13, 2023 at 12:40:12PM +0530, Krishna chaitanya chundru 
>> wrote:
>>> Add support for handling D-state notify for MHI EPF.
>>>
>>> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
>>> ---
>>>   drivers/pci/endpoint/functions/pci-epf-mhi.c | 11 +++++++++++
>>>   include/linux/mhi_ep.h                       |  3 +++
>>>   2 files changed, 14 insertions(+)
>>>
>>> diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c 
>>> b/drivers/pci/endpoint/functions/pci-epf-mhi.c
>>> index 9c1f5a1..ee91bfc 100644
>>> --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
>>> +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
>>> @@ -339,6 +339,16 @@ static int pci_epf_mhi_bme(struct pci_epf *epf)
>>>       return 0;
>>>   }
>>>   +static int pci_epf_mhi_dstate_notify(struct pci_epf *epf, 
>>> pci_power_t state)
>>> +{
>>> +    struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
>>> +    struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
>>> +
>>> +    mhi_cntrl->dstate = state;
>> Where is this variable being used? Also, don't we need any locking?
>>
>> - Mani
>
> we are using this variable in wakeup host op which is introduced on 
> patch [PATCH v4 8/9] PCI: epf-mhi: Add wakeup host op
>
> I will add lock in my next series.
>
> - KC

Mani, as this is being called from IRQ context do we need to add any 
lock here.

- KC

>
>>
>>> +
>>> +    return 0;
>>> +}
>>> +
>>>   static int pci_epf_mhi_bind(struct pci_epf *epf)
>>>   {
>>>       struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
>>> @@ -394,6 +404,7 @@ static struct pci_epc_event_ops 
>>> pci_epf_mhi_event_ops = {
>>>       .link_up = pci_epf_mhi_link_up,
>>>       .link_down = pci_epf_mhi_link_down,
>>>       .bme = pci_epf_mhi_bme,
>>> +    .dstate_notify = pci_epf_mhi_dstate_notify,
>>>   };
>>>     static int pci_epf_mhi_probe(struct pci_epf *epf,
>>> diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
>>> index f198a8a..c3a0685 100644
>>> --- a/include/linux/mhi_ep.h
>>> +++ b/include/linux/mhi_ep.h
>>> @@ -8,6 +8,7 @@
>>>     #include <linux/dma-direction.h>
>>>   #include <linux/mhi.h>
>>> +#include <linux/pci.h>
>>>     #define MHI_EP_DEFAULT_MTU 0x8000
>>>   @@ -139,6 +140,8 @@ struct mhi_ep_cntrl {
>>>         enum mhi_state mhi_state;
>>>   +    pci_power_t dstate;
>>> +
>>>       u32 max_chan;
>>>       u32 mru;
>>>       u32 event_rings;
>>> -- 
>>> 2.7.4
>>>
>
Manivannan Sadhasivam Aug. 1, 2023, 5:21 p.m. UTC | #4
On Tue, Aug 01, 2023 at 10:31:42AM +0530, Krishna Chaitanya Chundru wrote:
> 
> On 7/31/2023 11:05 AM, Krishna Chaitanya Chundru wrote:
> > 
> > On 7/28/2023 9:39 AM, Manivannan Sadhasivam wrote:
> > > On Thu, Jul 13, 2023 at 12:40:12PM +0530, Krishna chaitanya chundru
> > > wrote:
> > > > Add support for handling D-state notify for MHI EPF.
> > > > 
> > > > Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> > > > ---
> > > >   drivers/pci/endpoint/functions/pci-epf-mhi.c | 11 +++++++++++
> > > >   include/linux/mhi_ep.h                       |  3 +++
> > > >   2 files changed, 14 insertions(+)
> > > > 
> > > > diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> > > > b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> > > > index 9c1f5a1..ee91bfc 100644
> > > > --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> > > > +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> > > > @@ -339,6 +339,16 @@ static int pci_epf_mhi_bme(struct pci_epf *epf)
> > > >       return 0;
> > > >   }
> > > >   +static int pci_epf_mhi_dstate_notify(struct pci_epf *epf,
> > > > pci_power_t state)
> > > > +{
> > > > +    struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
> > > > +    struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
> > > > +
> > > > +    mhi_cntrl->dstate = state;
> > > Where is this variable being used? Also, don't we need any locking?
> > > 
> > > - Mani
> > 
> > we are using this variable in wakeup host op which is introduced on
> > patch [PATCH v4 8/9] PCI: epf-mhi: Add wakeup host op
> > 
> > I will add lock in my next series.
> > 
> > - KC
> 
> Mani, as this is being called from IRQ context do we need to add any lock
> here.
> 

Notifiers are invoked in process context. And here, the context doesn't matter
as either way you need locking to prevent concurrent access to dstate variable.

But I think it is safe to ignore lock for now provided that wakeup_host callback
is only called while MHI is in M3 state. Even if dstate changes while processing
wakeup_host, it won't affect the behavior.

- Mani

> - KC
> 
> > 
> > > 
> > > > +
> > > > +    return 0;
> > > > +}
> > > > +
> > > >   static int pci_epf_mhi_bind(struct pci_epf *epf)
> > > >   {
> > > >       struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
> > > > @@ -394,6 +404,7 @@ static struct pci_epc_event_ops
> > > > pci_epf_mhi_event_ops = {
> > > >       .link_up = pci_epf_mhi_link_up,
> > > >       .link_down = pci_epf_mhi_link_down,
> > > >       .bme = pci_epf_mhi_bme,
> > > > +    .dstate_notify = pci_epf_mhi_dstate_notify,
> > > >   };
> > > >     static int pci_epf_mhi_probe(struct pci_epf *epf,
> > > > diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
> > > > index f198a8a..c3a0685 100644
> > > > --- a/include/linux/mhi_ep.h
> > > > +++ b/include/linux/mhi_ep.h
> > > > @@ -8,6 +8,7 @@
> > > >     #include <linux/dma-direction.h>
> > > >   #include <linux/mhi.h>
> > > > +#include <linux/pci.h>
> > > >     #define MHI_EP_DEFAULT_MTU 0x8000
> > > >   @@ -139,6 +140,8 @@ struct mhi_ep_cntrl {
> > > >         enum mhi_state mhi_state;
> > > >   +    pci_power_t dstate;
> > > > +
> > > >       u32 max_chan;
> > > >       u32 mru;
> > > >       u32 event_rings;
> > > > -- 
> > > > 2.7.4
> > > > 
> >
diff mbox series

Patch

diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
index 9c1f5a1..ee91bfc 100644
--- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
+++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
@@ -339,6 +339,16 @@  static int pci_epf_mhi_bme(struct pci_epf *epf)
 	return 0;
 }
 
+static int pci_epf_mhi_dstate_notify(struct pci_epf *epf, pci_power_t state)
+{
+	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
+	struct mhi_ep_cntrl *mhi_cntrl = &epf_mhi->mhi_cntrl;
+
+	mhi_cntrl->dstate = state;
+
+	return 0;
+}
+
 static int pci_epf_mhi_bind(struct pci_epf *epf)
 {
 	struct pci_epf_mhi *epf_mhi = epf_get_drvdata(epf);
@@ -394,6 +404,7 @@  static struct pci_epc_event_ops pci_epf_mhi_event_ops = {
 	.link_up = pci_epf_mhi_link_up,
 	.link_down = pci_epf_mhi_link_down,
 	.bme = pci_epf_mhi_bme,
+	.dstate_notify = pci_epf_mhi_dstate_notify,
 };
 
 static int pci_epf_mhi_probe(struct pci_epf *epf,
diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
index f198a8a..c3a0685 100644
--- a/include/linux/mhi_ep.h
+++ b/include/linux/mhi_ep.h
@@ -8,6 +8,7 @@ 
 
 #include <linux/dma-direction.h>
 #include <linux/mhi.h>
+#include <linux/pci.h>
 
 #define MHI_EP_DEFAULT_MTU 0x8000
 
@@ -139,6 +140,8 @@  struct mhi_ep_cntrl {
 
 	enum mhi_state mhi_state;
 
+	pci_power_t dstate;
+
 	u32 max_chan;
 	u32 mru;
 	u32 event_rings;