Currently, the return from the smc call assumes the completion of
the scmi request. However this may not be true in virtual platforms
that are using hvc doorbell.
This change adds a Kconfig to enable the polling for the request
completion.
Signed-off-by: Nikunj Kela <quic_nkela@xxxxxxxxxxx>
---
drivers/firmware/arm_scmi/Kconfig | 14 ++++++++++++++
drivers/firmware/arm_scmi/smc.c | 15 ++++++++++++++-
2 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index ea0f5083ac47..771d60f8319f 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig
@@ -125,6 +125,20 @@ config ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE
in atomic context too, at the price of using a number of busy-waiting
primitives all over instead. If unsure say N.
+config ARM_SCMI_TRANSPORT_SMC_POLL_COMPLETION
+ bool "Enable polling support for SCMI SMC transport"
+ depends on ARM_SCMI_TRANSPORT_SMC
+ help
+ Enable completion polling support for SCMI SMC based transport.
+
+ If you want the SCMI SMC based transport to poll for the completion,
+ answer Y.
+ Enabling completion polling might be desired in the absence of the a2p
+ irq when the return from smc/hvc call doesn't indicate the completion
+ of the SCMI requests. This might be useful for instances used in
+ virtual platforms.
+ If unsure say N.
+
config ARM_SCMI_TRANSPORT_VIRTIO
bool "SCMI transport based on VirtIO"
depends on VIRTIO=y || VIRTIO=ARM_SCMI_PROTOCOL
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index c193516a254d..0a0b7e401159 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -250,6 +250,16 @@ static void smc_mark_txdone(struct scmi_chan_info *cinfo, int ret,
smc_channel_lock_release(scmi_info);
}
+#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC_POLL_COMPLETION
+static bool
+smc_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
+{
+ struct scmi_smc *scmi_info = cinfo->transport_info;
+
+ return shmem_poll_done(scmi_info->shmem, xfer);
+}
+#endif
+
static const struct scmi_transport_ops scmi_smc_ops = {
.chan_available = smc_chan_available,
.chan_setup = smc_chan_setup,
@@ -257,6 +267,9 @@ static const struct scmi_transport_ops scmi_smc_ops = {
.send_message = smc_send_message,
.mark_txdone = smc_mark_txdone,
.fetch_response = smc_fetch_response,
+#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC_POLL_COMPLETION
+ .poll_done = smc_poll_done,
+#endif
};
const struct scmi_desc scmi_smc_desc = {
@@ -272,6 +285,6 @@ const struct scmi_desc scmi_smc_desc = {
* for the issued command will be immmediately ready to be fetched
* from the shared memory area.
*/
- .sync_cmds_completed_on_ret = true,
+ .sync_cmds_completed_on_ret = !IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_POLL_COMPLETION),
.atomic_enabled = IS_ENABLED(CONFIG_ARM_SCMI_TRANSPORT_SMC_ATOMIC_ENABLE),
};
--
2.17.1
