On Tue, Mar 14, 2023 at 07:11:34PM +0800, Huisong Li wrote:
> Currently, PCC driver doesn't support the processing of platform
> notification for type 4 PCC subspaces.
>
> According to ACPI specification, if platform sends a notification
> to OSPM, it must clear the command complete bit and trigger platform
> interrupt. OSPM needs to check whether the command complete bit is
> cleared, clear platform interrupt, process command, and then set the
> command complete and ring doorbell to the Platform.
>
> Let us stash the value of the pcc type and use the same while processing
> the interrupt of the channel. We also need to set the command complete
> bit and ring doorbell in the interrupt handler for the type 4 channel to
> complete the communication flow after processing the notification from
> the Platform.
>
> Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx>
> ---
> drivers/mailbox/pcc.c | 50 +++++++++++++++++++++++++++++++++++--------
> 1 file changed, 41 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
> index 105d46c9801b..a0a87c480d8b 100644
> --- a/drivers/mailbox/pcc.c
> +++ b/drivers/mailbox/pcc.c
> @@ -91,6 +91,7 @@ struct pcc_chan_reg {
> * @cmd_update: PCC register bundle for the command complete update register
> * @error: PCC register bundle for the error status register
> * @plat_irq: platform interrupt
> + * @type: PCC subspace type
> */
> struct pcc_chan_info {
> struct pcc_mbox_chan chan;
> @@ -100,12 +101,15 @@ struct pcc_chan_info {
> struct pcc_chan_reg cmd_update;
> struct pcc_chan_reg error;
> int plat_irq;
> + u8 type;
> };
>
> #define to_pcc_chan_info(c) container_of(c, struct pcc_chan_info, chan)
> static struct pcc_chan_info *chan_info;
> static int pcc_chan_count;
>
> +static int pcc_send_data(struct mbox_chan *chan, void *data);
> +
> /*
> * PCC can be used with perf critical drivers such as CPPC
> * So it makes sense to locally cache the virtual address and
> @@ -221,6 +225,34 @@ static int pcc_map_interrupt(u32 interrupt, u32 flags)
> return acpi_register_gsi(NULL, interrupt, trigger, polarity);
> }
>
> +static bool pcc_mbox_cmd_complete_check(struct pcc_chan_info *pchan)
> +{
> + u64 val;
> + int ret;
> +
> + ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
> + if (ret)
> + return false;
> +
> + if (!pchan->cmd_complete.gas)
> + return true;
> +
> + /*
> + * Judge if the channel respond the interrupt based on the value of
> + * command complete.
> + */
> + val &= pchan->cmd_complete.status_mask;
[super nit] Would prefer an blank line here.
--
Regards,
Sudeep
