On Thu, Jul 13, 2023 at 12:40:14PM +0530, Krishna chaitanya chundru wrote:
> Endpoint cannot send any data/MSI when the D-state is in
> D3cold or D3hot. Endpoint needs to wake up the host to
> bring the D-state to D0.
>
> 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 add wakeup_host() callback to the EPC core.
>
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
> ---
> 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 3a54713..eb79b77 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 wakeup 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 wakeup
> + host.
> +
> Other EPC APIs
> ~~~~~~~~~~~~~~
>
> diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
> index ea76baf..b419eff 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 wakeup 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
> + */
> +bool 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 false;
> +
> + if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
> + return false;
> +
> + if (!epc->ops->wakeup_host)
> + return true;
> +
> + 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..d262179 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,
I think I asked you to get rid of these enums and use a bool. I don't see any
new wakeup mechanism going to be added to the spec. So using enums for just 2
options looks overkill to me.
If you defer, please discuss it here.
- Mani
> +};
> +
> 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);
> + bool (*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);
> +bool 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
>
--
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