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

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 <[email protected]>
---
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



2023-07-07 06:20:26

by Manivannan Sadhasivam

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

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 <[email protected]>
> ---
> 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

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


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 <[email protected]>
>> ---
>> 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
>>