Re: [PATCH v2 1/2] mailbox: pcc: Add support for platform notification handling

From: lihuisong (C)
Date: Mon Mar 27 2023 - 08:25:12 EST



在 2023/3/27 19:30, Sudeep Holla 写道:
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.

Yeah, it would be better if there is an blank line here.
Is it necessary to send v3 for this?