[PATCH v2 1/8] PCI: endpoint: Add dstate change notifier support

[PATCH v2 1/8] PCI: endpoint: Add dstate change notifier support

[Krishna chaitanya chundru]

Add support to notify the EPF device about the D-state change event
from the EPC device.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 Documentation/PCI/endpoint/pci-endpoint.rst |  5 +++++
 drivers/pci/endpoint/pci-epc-core.c         | 27 +++++++++++++++++++++++++++
 include/linux/pci-epc.h                     |  1 +
 include/linux/pci-epf.h                     |  1 +
 4 files changed, 34 insertions(+)

diff --git a/Documentation/PCI/endpoint/pci-endpoint.rst b/Documentation/PCI/endpoint/pci-endpoint.rst
index 4f5622a..0538cdc 100644
--- a/Documentation/PCI/endpoint/pci-endpoint.rst
+++ b/Documentation/PCI/endpoint/pci-endpoint.rst
@@ -78,6 +78,11 @@ by the PCI controller driver.
    Cleanup the pci_epc_mem structure allocated during pci_epc_mem_init().
 
 
+* pci_epc_dstate_change()
+
+   In order to notify all the function devices that the EPC device has
+   changed its D-state.
+
 EPC APIs for the PCI Endpoint Function Driver
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index 6c54fa5..cad360f 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -785,6 +785,33 @@ void pci_epc_bme_notify(struct pci_epc *epc)
 EXPORT_SYMBOL_GPL(pci_epc_bme_notify);
 
 /**
+ * pci_epc_dstate_change() - Notify the EPF device that EPC device D-state
+ *			has changed
+ * @epc: the EPC device which has change in D-state
+ * @state: the changed D-state
+ *
+ * Invoke to Notify the EPF device that the EPC device has D-state has
+ * changed.
+ */
+void pci_epc_dstate_change(struct pci_epc *epc, pci_power_t state)
+{
+	struct pci_epf *epf;
+
+	if (!epc || IS_ERR(epc))
+		return;
+
+	mutex_lock(&epc->list_lock);
+	list_for_each_entry(epf, &epc->pci_epf, list) {
+		mutex_lock(&epf->lock);
+		if (epf->event_ops && epf->event_ops->dstate_change)
+			epf->event_ops->dstate_change(epf, state);
+		mutex_unlock(&epf->lock);
+	}
+	mutex_unlock(&epc->list_lock);
+}
+EXPORT_SYMBOL_GPL(pci_epc_dstate_change);
+
+/**
  * pci_epc_destroy() - destroy the EPC device
  * @epc: the EPC device that has to be destroyed
  *
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 5cb6940..26a1108 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -251,4 +251,5 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
 				     phys_addr_t *phys_addr, size_t size);
 void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
 			   void __iomem *virt_addr, size_t size);
+void pci_epc_dstate_change(struct pci_epc *epc, pci_power_t state);
 #endif /* __LINUX_PCI_EPC_H */
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 4b52807..1d3c2a2 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -79,6 +79,7 @@ struct pci_epc_event_ops {
 	int (*link_up)(struct pci_epf *epf);
 	int (*link_down)(struct pci_epf *epf);
 	int (*bme)(struct pci_epf *epf);
+	int (*dstate_change)(struct pci_epf *epf, pci_power_t state);
 };
 
 /**
-- 
2.7.4

[PATCH v2 4/8] PCI: endpoint: Add wakeup host API to EPC core

[Krishna chaitanya chundru]

Endpoint cannot send any data/MSI when the D-state is in
D3cold or D3hot. Endpoint needs to bring the host back to D0
to send any kind of data.

Endpoint can toggle wake signal when the D-state is in D3cold and vaux is
not supplied or can send inband PME.

To support this adding wake up host to epc core.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
---
 Documentation/PCI/endpoint/pci-endpoint.rst |  6 ++++++
 drivers/pci/endpoint/pci-epc-core.c         | 31 +++++++++++++++++++++++++++++
 include/linux/pci-epc.h                     | 11 ++++++++++
 3 files changed, 48 insertions(+)

diff --git a/Documentation/PCI/endpoint/pci-endpoint.rst b/Documentation/PCI/endpoint/pci-endpoint.rst
index 0538cdc..186ce3b 100644
--- a/Documentation/PCI/endpoint/pci-endpoint.rst
+++ b/Documentation/PCI/endpoint/pci-endpoint.rst
@@ -53,6 +53,7 @@ by the PCI controller driver.
 	 * raise_irq: ops to raise a legacy, MSI or MSI-X interrupt
 	 * start: ops to start the PCI link
 	 * stop: ops to stop the PCI link
+	 * wakeup_host: ops to wake host
 
    The PCI controller driver can then create a new EPC device by invoking
    devm_pci_epc_create()/pci_epc_create().
@@ -122,6 +123,11 @@ by the PCI endpoint function driver.
    The PCI endpoint function driver should use pci_epc_mem_free_addr() to
    free the memory space allocated using pci_epc_mem_alloc_addr().
 
+* pci_epc_wakeup_host()
+
+   The PCI endpoint function driver should use pci_epc_wakeup_host() to wake
+   host.
+
 Other EPC APIs
 ~~~~~~~~~~~~~~
 
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index cad360f..23599b8 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -167,6 +167,37 @@ const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 EXPORT_SYMBOL_GPL(pci_epc_get_features);
 
 /**
+ * pci_epc_wakeup_host() - Wakeup the host
+ * @epc: the EPC device which has to wake the host
+ * @func_no: the physical endpoint function number in the EPC device
+ * @vfunc_no: the virtual endpoint function number in the physical function
+ * @type: specify the type of wakeup: WAKEUP_FROM_D3COLD, WAKEUP_FROM_D3HOT
+ *
+ * Invoke to wakeup host
+ */
+int pci_epc_wakeup_host(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+			enum pci_epc_wakeup_host_type type)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
+		return -EINVAL;
+
+	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
+		return -EINVAL;
+
+	if (!epc->ops->wakeup_host)
+		return 0;
+
+	mutex_lock(&epc->lock);
+	ret = epc->ops->wakeup_host(epc, func_no, vfunc_no, type);
+	mutex_unlock(&epc->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epc_wakeup_host);
+
+/**
  * pci_epc_stop() - stop the PCI link
  * @epc: the link of the EPC device that has to be stopped
  *
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 26a1108..2323a10 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -26,6 +26,12 @@ enum pci_epc_irq_type {
 	PCI_EPC_IRQ_MSIX,
 };
 
+enum pci_epc_wakeup_host_type {
+	PCI_WAKEUP_UNKNOWN,
+	PCI_WAKEUP_SEND_PME,
+	PCI_WAKEUP_TOGGLE_WAKE,
+};
+
 static inline const char *
 pci_epc_interface_string(enum pci_epc_interface_type type)
 {
@@ -59,6 +65,7 @@ pci_epc_interface_string(enum pci_epc_interface_type type)
  * @start: ops to start the PCI link
  * @stop: ops to stop the PCI link
  * @get_features: ops to get the features supported by the EPC
+ * @wakeup_host: ops to wakeup the host
  * @owner: the module owner containing the ops
  */
 struct pci_epc_ops {
@@ -88,6 +95,8 @@ struct pci_epc_ops {
 	void	(*stop)(struct pci_epc *epc);
 	const struct pci_epc_features* (*get_features)(struct pci_epc *epc,
 						       u8 func_no, u8 vfunc_no);
+	int	(*wakeup_host)(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+				enum pci_epc_wakeup_host_type type);
 	struct module *owner;
 };
 
@@ -234,6 +243,8 @@ int pci_epc_start(struct pci_epc *epc);
 void pci_epc_stop(struct pci_epc *epc);
 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
 						    u8 func_no, u8 vfunc_no);
+int pci_epc_wakeup_host(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
+					enum pci_epc_wakeup_host_type type);
 enum pci_barno
 pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features);
 enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
-- 
2.7.4

Re: [PATCH v2 1/8] PCI: endpoint: Add dstate change notifier support

[Manivannan Sadhasivam]

On Fri, Jun 30, 2023 at 04:22:04PM +0530, Krishna chaitanya chundru wrote:
> Add support to notify the EPF device about the D-state change event
> from the EPC device.
> 
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  Documentation/PCI/endpoint/pci-endpoint.rst |  5 +++++
>  drivers/pci/endpoint/pci-epc-core.c         | 27 +++++++++++++++++++++++++++
>  include/linux/pci-epc.h                     |  1 +
>  include/linux/pci-epf.h                     |  1 +
>  4 files changed, 34 insertions(+)
> 
> diff --git a/Documentation/PCI/endpoint/pci-endpoint.rst b/Documentation/PCI/endpoint/pci-endpoint.rst
> index 4f5622a..0538cdc 100644
> --- a/Documentation/PCI/endpoint/pci-endpoint.rst
> +++ b/Documentation/PCI/endpoint/pci-endpoint.rst
> @@ -78,6 +78,11 @@ by the PCI controller driver.
>     Cleanup the pci_epc_mem structure allocated during pci_epc_mem_init().
>  
>  
> +* pci_epc_dstate_change()
> +
> +   In order to notify all the function devices that the EPC device has
> +   changed its D-state.
> +
>  EPC APIs for the PCI Endpoint Function Driver
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>  
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index 6c54fa5..cad360f 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -785,6 +785,33 @@ void pci_epc_bme_notify(struct pci_epc *epc)
>  EXPORT_SYMBOL_GPL(pci_epc_bme_notify);
>  
>  /**
> + * pci_epc_dstate_change() - Notify the EPF device that EPC device D-state
> + *			has changed
> + * @epc: the EPC device which has change in D-state
> + * @state: the changed D-state
> + *
> + * Invoke to Notify the EPF device that the EPC device has D-state has
> + * changed.
> + */
> +void pci_epc_dstate_change(struct pci_epc *epc, pci_power_t state)

How about "pci_epc_dstate_notity()"?

Rest looks good.

- Mani

> +{
> +	struct pci_epf *epf;
> +
> +	if (!epc || IS_ERR(epc))
> +		return;
> +
> +	mutex_lock(&epc->list_lock);
> +	list_for_each_entry(epf, &epc->pci_epf, list) {
> +		mutex_lock(&epf->lock);
> +		if (epf->event_ops && epf->event_ops->dstate_change)
> +			epf->event_ops->dstate_change(epf, state);
> +		mutex_unlock(&epf->lock);
> +	}
> +	mutex_unlock(&epc->list_lock);
> +}
> +EXPORT_SYMBOL_GPL(pci_epc_dstate_change);
> +
> +/**
>   * pci_epc_destroy() - destroy the EPC device
>   * @epc: the EPC device that has to be destroyed
>   *
> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> index 5cb6940..26a1108 100644
> --- a/include/linux/pci-epc.h
> +++ b/include/linux/pci-epc.h
> @@ -251,4 +251,5 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
>  				     phys_addr_t *phys_addr, size_t size);
>  void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
>  			   void __iomem *virt_addr, size_t size);
> +void pci_epc_dstate_change(struct pci_epc *epc, pci_power_t state);
>  #endif /* __LINUX_PCI_EPC_H */
> diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
> index 4b52807..1d3c2a2 100644
> --- a/include/linux/pci-epf.h
> +++ b/include/linux/pci-epf.h
> @@ -79,6 +79,7 @@ struct pci_epc_event_ops {
>  	int (*link_up)(struct pci_epf *epf);
>  	int (*link_down)(struct pci_epf *epf);
>  	int (*bme)(struct pci_epf *epf);
> +	int (*dstate_change)(struct pci_epf *epf, pci_power_t state);
>  };
>  
>  /**
> -- 
> 2.7.4
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v2 4/8] PCI: endpoint: Add wakeup host API to EPC core

[Manivannan Sadhasivam]

On Fri, Jun 30, 2023 at 04:22:07PM +0530, Krishna chaitanya chundru wrote:
> Endpoint cannot send any data/MSI when the D-state is in
> D3cold or D3hot. Endpoint needs to bring the host back to D0

Endpoint needs to wake up the host to bring the D-state to D0

> to send any kind of data.
> 
> Endpoint can toggle wake signal when the D-state is in D3cold and vaux is
> not supplied or can send inband PME.
> 
> To support this adding wake up host to epc core.
> 

"add wakeup_host() callback to the EPC core".


> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  Documentation/PCI/endpoint/pci-endpoint.rst |  6 ++++++
>  drivers/pci/endpoint/pci-epc-core.c         | 31 +++++++++++++++++++++++++++++
>  include/linux/pci-epc.h                     | 11 ++++++++++
>  3 files changed, 48 insertions(+)
> 
> diff --git a/Documentation/PCI/endpoint/pci-endpoint.rst b/Documentation/PCI/endpoint/pci-endpoint.rst
> index 0538cdc..186ce3b 100644
> --- a/Documentation/PCI/endpoint/pci-endpoint.rst
> +++ b/Documentation/PCI/endpoint/pci-endpoint.rst
> @@ -53,6 +53,7 @@ by the PCI controller driver.
>  	 * raise_irq: ops to raise a legacy, MSI or MSI-X interrupt
>  	 * start: ops to start the PCI link
>  	 * stop: ops to stop the PCI link
> +	 * wakeup_host: ops to wake host

wakeup

>  
>     The PCI controller driver can then create a new EPC device by invoking
>     devm_pci_epc_create()/pci_epc_create().
> @@ -122,6 +123,11 @@ by the PCI endpoint function driver.
>     The PCI endpoint function driver should use pci_epc_mem_free_addr() to
>     free the memory space allocated using pci_epc_mem_alloc_addr().
>  
> +* pci_epc_wakeup_host()
> +
> +   The PCI endpoint function driver should use pci_epc_wakeup_host() to wake

wakeup

> +   host.
> +
>  Other EPC APIs
>  ~~~~~~~~~~~~~~
>  
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index cad360f..23599b8 100644
> --- a/drivers/pci/endpoint/pci-epc-core.c
> +++ b/drivers/pci/endpoint/pci-epc-core.c
> @@ -167,6 +167,37 @@ const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
>  EXPORT_SYMBOL_GPL(pci_epc_get_features);
>  
>  /**
> + * pci_epc_wakeup_host() - Wakeup the host
> + * @epc: the EPC device which has to wake the host

wakeup

> + * @func_no: the physical endpoint function number in the EPC device
> + * @vfunc_no: the virtual endpoint function number in the physical function
> + * @type: specify the type of wakeup: WAKEUP_FROM_D3COLD, WAKEUP_FROM_D3HOT
> + *
> + * Invoke to wakeup host
> + */
> +int pci_epc_wakeup_host(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
> +			enum pci_epc_wakeup_host_type type)

Why can't you use a bool?

- Mani

> +{
> +	int ret;
> +
> +	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
> +		return -EINVAL;
> +
> +	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
> +		return -EINVAL;
> +
> +	if (!epc->ops->wakeup_host)
> +		return 0;
> +
> +	mutex_lock(&epc->lock);
> +	ret = epc->ops->wakeup_host(epc, func_no, vfunc_no, type);
> +	mutex_unlock(&epc->lock);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(pci_epc_wakeup_host);
> +
> +/**
>   * pci_epc_stop() - stop the PCI link
>   * @epc: the link of the EPC device that has to be stopped
>   *
> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
> index 26a1108..2323a10 100644
> --- a/include/linux/pci-epc.h
> +++ b/include/linux/pci-epc.h
> @@ -26,6 +26,12 @@ enum pci_epc_irq_type {
>  	PCI_EPC_IRQ_MSIX,
>  };
>  
> +enum pci_epc_wakeup_host_type {
> +	PCI_WAKEUP_UNKNOWN,
> +	PCI_WAKEUP_SEND_PME,
> +	PCI_WAKEUP_TOGGLE_WAKE,
> +};
> +
>  static inline const char *
>  pci_epc_interface_string(enum pci_epc_interface_type type)
>  {
> @@ -59,6 +65,7 @@ pci_epc_interface_string(enum pci_epc_interface_type type)
>   * @start: ops to start the PCI link
>   * @stop: ops to stop the PCI link
>   * @get_features: ops to get the features supported by the EPC
> + * @wakeup_host: ops to wakeup the host
>   * @owner: the module owner containing the ops
>   */
>  struct pci_epc_ops {
> @@ -88,6 +95,8 @@ struct pci_epc_ops {
>  	void	(*stop)(struct pci_epc *epc);
>  	const struct pci_epc_features* (*get_features)(struct pci_epc *epc,
>  						       u8 func_no, u8 vfunc_no);
> +	int	(*wakeup_host)(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
> +				enum pci_epc_wakeup_host_type type);
>  	struct module *owner;
>  };
>  
> @@ -234,6 +243,8 @@ int pci_epc_start(struct pci_epc *epc);
>  void pci_epc_stop(struct pci_epc *epc);
>  const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
>  						    u8 func_no, u8 vfunc_no);
> +int pci_epc_wakeup_host(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
> +					enum pci_epc_wakeup_host_type type);
>  enum pci_barno
>  pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features);
>  enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
> -- 
> 2.7.4
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v2 1/8] PCI: endpoint: Add dstate change notifier support

[Krishna Chaitanya Chundru]

On 7/7/2023 11:14 AM, Manivannan Sadhasivam wrote:
> On Fri, Jun 30, 2023 at 04:22:04PM +0530, Krishna chaitanya chundru wrote:
>> Add support to notify the EPF device about the D-state change event
>> from the EPC device.
>>
>> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
>> ---
>>   Documentation/PCI/endpoint/pci-endpoint.rst |  5 +++++
>>   drivers/pci/endpoint/pci-epc-core.c         | 27 +++++++++++++++++++++++++++
>>   include/linux/pci-epc.h                     |  1 +
>>   include/linux/pci-epf.h                     |  1 +
>>   4 files changed, 34 insertions(+)
>>
>> diff --git a/Documentation/PCI/endpoint/pci-endpoint.rst b/Documentation/PCI/endpoint/pci-endpoint.rst
>> index 4f5622a..0538cdc 100644
>> --- a/Documentation/PCI/endpoint/pci-endpoint.rst
>> +++ b/Documentation/PCI/endpoint/pci-endpoint.rst
>> @@ -78,6 +78,11 @@ by the PCI controller driver.
>>      Cleanup the pci_epc_mem structure allocated during pci_epc_mem_init().
>>   
>>   
>> +* pci_epc_dstate_change()
>> +
>> +   In order to notify all the function devices that the EPC device has
>> +   changed its D-state.
>> +
>>   EPC APIs for the PCI Endpoint Function Driver
>>   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>   
>> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
>> index 6c54fa5..cad360f 100644
>> --- a/drivers/pci/endpoint/pci-epc-core.c
>> +++ b/drivers/pci/endpoint/pci-epc-core.c
>> @@ -785,6 +785,33 @@ void pci_epc_bme_notify(struct pci_epc *epc)
>>   EXPORT_SYMBOL_GPL(pci_epc_bme_notify);
>>   
>>   /**
>> + * pci_epc_dstate_change() - Notify the EPF device that EPC device D-state
>> + *			has changed
>> + * @epc: the EPC device which has change in D-state
>> + * @state: the changed D-state
>> + *
>> + * Invoke to Notify the EPF device that the EPC device has D-state has
>> + * changed.
>> + */
>> +void pci_epc_dstate_change(struct pci_epc *epc, pci_power_t state)
> How about "pci_epc_dstate_notity()"?
>
> Rest looks good.
>
> - Mani

sure I will change to pci_epc_dstate_notity

-KC

>
>> +{
>> +	struct pci_epf *epf;
>> +
>> +	if (!epc || IS_ERR(epc))
>> +		return;
>> +
>> +	mutex_lock(&epc->list_lock);
>> +	list_for_each_entry(epf, &epc->pci_epf, list) {
>> +		mutex_lock(&epf->lock);
>> +		if (epf->event_ops && epf->event_ops->dstate_change)
>> +			epf->event_ops->dstate_change(epf, state);
>> +		mutex_unlock(&epf->lock);
>> +	}
>> +	mutex_unlock(&epc->list_lock);
>> +}
>> +EXPORT_SYMBOL_GPL(pci_epc_dstate_change);
>> +
>> +/**
>>    * pci_epc_destroy() - destroy the EPC device
>>    * @epc: the EPC device that has to be destroyed
>>    *
>> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
>> index 5cb6940..26a1108 100644
>> --- a/include/linux/pci-epc.h
>> +++ b/include/linux/pci-epc.h
>> @@ -251,4 +251,5 @@ void __iomem *pci_epc_mem_alloc_addr(struct pci_epc *epc,
>>   				     phys_addr_t *phys_addr, size_t size);
>>   void pci_epc_mem_free_addr(struct pci_epc *epc, phys_addr_t phys_addr,
>>   			   void __iomem *virt_addr, size_t size);
>> +void pci_epc_dstate_change(struct pci_epc *epc, pci_power_t state);
>>   #endif /* __LINUX_PCI_EPC_H */
>> diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
>> index 4b52807..1d3c2a2 100644
>> --- a/include/linux/pci-epf.h
>> +++ b/include/linux/pci-epf.h
>> @@ -79,6 +79,7 @@ struct pci_epc_event_ops {
>>   	int (*link_up)(struct pci_epf *epf);
>>   	int (*link_down)(struct pci_epf *epf);
>>   	int (*bme)(struct pci_epf *epf);
>> +	int (*dstate_change)(struct pci_epf *epf, pci_power_t state);
>>   };
>>   
>>   /**
>> -- 
>> 2.7.4
>>

Re: [PATCH v2 4/8] PCI: endpoint: Add wakeup host API to EPC core

[Krishna Chaitanya Chundru]

On 7/7/2023 11:34 AM, Manivannan Sadhasivam wrote:
> On Fri, Jun 30, 2023 at 04:22:07PM +0530, Krishna chaitanya chundru wrote:
>> Endpoint cannot send any data/MSI when the D-state is in
>> D3cold or D3hot. Endpoint needs to bring the host back to D0
> Endpoint needs to wake up the host to bring the D-state to D0
>
>> to send any kind of data.
>>
>> Endpoint can toggle wake signal when the D-state is in D3cold and vaux is
>> not supplied or can send inband PME.
>>
>> To support this adding wake up host to epc core.
>>
> "add wakeup_host() callback to the EPC core".
>
>
>> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
>> ---
>>   Documentation/PCI/endpoint/pci-endpoint.rst |  6 ++++++
>>   drivers/pci/endpoint/pci-epc-core.c         | 31 +++++++++++++++++++++++++++++
>>   include/linux/pci-epc.h                     | 11 ++++++++++
>>   3 files changed, 48 insertions(+)
>>
>> diff --git a/Documentation/PCI/endpoint/pci-endpoint.rst b/Documentation/PCI/endpoint/pci-endpoint.rst
>> index 0538cdc..186ce3b 100644
>> --- a/Documentation/PCI/endpoint/pci-endpoint.rst
>> +++ b/Documentation/PCI/endpoint/pci-endpoint.rst
>> @@ -53,6 +53,7 @@ by the PCI controller driver.
>>   	 * raise_irq: ops to raise a legacy, MSI or MSI-X interrupt
>>   	 * start: ops to start the PCI link
>>   	 * stop: ops to stop the PCI link
>> +	 * wakeup_host: ops to wake host
> wakeup
>
>>   
>>      The PCI controller driver can then create a new EPC device by invoking
>>      devm_pci_epc_create()/pci_epc_create().
>> @@ -122,6 +123,11 @@ by the PCI endpoint function driver.
>>      The PCI endpoint function driver should use pci_epc_mem_free_addr() to
>>      free the memory space allocated using pci_epc_mem_alloc_addr().
>>   
>> +* pci_epc_wakeup_host()
>> +
>> +   The PCI endpoint function driver should use pci_epc_wakeup_host() to wake
> wakeup
>
>> +   host.
>> +
>>   Other EPC APIs
>>   ~~~~~~~~~~~~~~
>>   
>> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
>> index cad360f..23599b8 100644
>> --- a/drivers/pci/endpoint/pci-epc-core.c
>> +++ b/drivers/pci/endpoint/pci-epc-core.c
>> @@ -167,6 +167,37 @@ const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
>>   EXPORT_SYMBOL_GPL(pci_epc_get_features);
>>   
>>   /**
>> + * pci_epc_wakeup_host() - Wakeup the host
>> + * @epc: the EPC device which has to wake the host
> wakeup
>
>> + * @func_no: the physical endpoint function number in the EPC device
>> + * @vfunc_no: the virtual endpoint function number in the physical function
>> + * @type: specify the type of wakeup: WAKEUP_FROM_D3COLD, WAKEUP_FROM_D3HOT
>> + *
>> + * Invoke to wakeup host
>> + */
>> +int pci_epc_wakeup_host(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
>> +			enum pci_epc_wakeup_host_type type)
> Why can't you use a bool?
>
> - Mani

Sure I will change it to bool as suggested.

- KC

>
>> +{
>> +	int ret;
>> +
>> +	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
>> +		return -EINVAL;
>> +
>> +	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
>> +		return -EINVAL;
>> +
>> +	if (!epc->ops->wakeup_host)
>> +		return 0;
>> +
>> +	mutex_lock(&epc->lock);
>> +	ret = epc->ops->wakeup_host(epc, func_no, vfunc_no, type);
>> +	mutex_unlock(&epc->lock);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(pci_epc_wakeup_host);
>> +
>> +/**
>>    * pci_epc_stop() - stop the PCI link
>>    * @epc: the link of the EPC device that has to be stopped
>>    *
>> diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
>> index 26a1108..2323a10 100644
>> --- a/include/linux/pci-epc.h
>> +++ b/include/linux/pci-epc.h
>> @@ -26,6 +26,12 @@ enum pci_epc_irq_type {
>>   	PCI_EPC_IRQ_MSIX,
>>   };
>>   
>> +enum pci_epc_wakeup_host_type {
>> +	PCI_WAKEUP_UNKNOWN,
>> +	PCI_WAKEUP_SEND_PME,
>> +	PCI_WAKEUP_TOGGLE_WAKE,
>> +};
>> +
>>   static inline const char *
>>   pci_epc_interface_string(enum pci_epc_interface_type type)
>>   {
>> @@ -59,6 +65,7 @@ pci_epc_interface_string(enum pci_epc_interface_type type)
>>    * @start: ops to start the PCI link
>>    * @stop: ops to stop the PCI link
>>    * @get_features: ops to get the features supported by the EPC
>> + * @wakeup_host: ops to wakeup the host
>>    * @owner: the module owner containing the ops
>>    */
>>   struct pci_epc_ops {
>> @@ -88,6 +95,8 @@ struct pci_epc_ops {
>>   	void	(*stop)(struct pci_epc *epc);
>>   	const struct pci_epc_features* (*get_features)(struct pci_epc *epc,
>>   						       u8 func_no, u8 vfunc_no);
>> +	int	(*wakeup_host)(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
>> +				enum pci_epc_wakeup_host_type type);
>>   	struct module *owner;
>>   };
>>   
>> @@ -234,6 +243,8 @@ int pci_epc_start(struct pci_epc *epc);
>>   void pci_epc_stop(struct pci_epc *epc);
>>   const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
>>   						    u8 func_no, u8 vfunc_no);
>> +int pci_epc_wakeup_host(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
>> +					enum pci_epc_wakeup_host_type type);
>>   enum pci_barno
>>   pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features);
>>   enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
>> -- 
>> 2.7.4
>>