linux-kernel - [PATCH v14 6/6] soc: qcom: rpmh-rsc: Allow using free WAKE TCS for active request

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Date:   Thu, 26 Mar 2020 23:07:50 +0530
From:   Maulik Shah <mkshah@...eaurora.org>
To:     swboyd@...omium.org, evgreen@...omium.org, dianders@...omium.org,
        bjorn.andersson@...aro.org
Cc:     linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        agross@...nel.org, mka@...omium.org, rnayak@...eaurora.org,
        ilina@...eaurora.org, lsrao@...eaurora.org,
        Maulik Shah <mkshah@...eaurora.org>
Subject: [PATCH v14 6/6] soc: qcom: rpmh-rsc: Allow using free WAKE TCS for active request

When there are more than one WAKE TCS available and there is no dedicated
ACTIVE TCS available, invalidating all WAKE TCSes and waiting for current
transfer to complete in first WAKE TCS blocks using another free WAKE TCS
to complete current request.

Remove rpmh_rsc_invalidate() to happen from tcs_write() when WAKE TCSes
is re-purposed to be used for Active mode. Clear only currently used
WAKE TCS's register configuration.

Mark the caches as dirty so next time when rpmh_flush() is invoked it
can invalidate and program cached sleep and wake sets again.

Fixes: 2de4b8d33eab (drivers: qcom: rpmh-rsc: allow active requests from wake TCS)
Signed-off-by: Maulik Shah <mkshah@...eaurora.org>
---
 drivers/soc/qcom/rpmh-rsc.c | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index 8fa70b4..c0513af 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -154,8 +154,9 @@ int rpmh_rsc_invalidate(struct rsc_drv *drv)
 static struct tcs_group *get_tcs_for_msg(struct rsc_drv *drv,
 					 const struct tcs_request *msg)
 {
-	int type, ret;
+	int type;
 	struct tcs_group *tcs;
+	unsigned long flags;
 
 	switch (msg->state) {
 	case RPMH_ACTIVE_ONLY_STATE:
@@ -175,18 +176,18 @@ static struct tcs_group *get_tcs_for_msg(struct rsc_drv *drv,
 	 * If we are making an active request on a RSC that does not have a
 	 * dedicated TCS for active state use, then re-purpose a wake TCS to
 	 * send active votes.
-	 * NOTE: The driver must be aware that this RSC does not have a
-	 * dedicated AMC, and therefore would invalidate the sleep and wake
-	 * TCSes before making an active state request.
+	 *
+	 * NOTE: Mark caches as dirty here since existing data in wake TCS will
+	 * be lost. rpmh_flush() will processed for dirty caches to restore
+	 * data.
 	 */
 	tcs = get_tcs_of_type(drv, type);
 	if (msg->state == RPMH_ACTIVE_ONLY_STATE && !tcs->num_tcs) {
 		tcs = get_tcs_of_type(drv, WAKE_TCS);
-		if (tcs->num_tcs) {
-			ret = rpmh_rsc_invalidate(drv);
-			if (ret)
-				return ERR_PTR(ret);
-		}
+
+		spin_lock_irqsave(&drv->client.cache_lock, flags);
+		drv->client.dirty = true;
+		spin_unlock_irqrestore(&drv->client.cache_lock, flags);
 	}
 
 	return tcs;
@@ -412,8 +413,16 @@ static int tcs_write(struct rsc_drv *drv, const struct tcs_request *msg)
 
 	tcs->req[tcs_id - tcs->offset] = msg;
 	set_bit(tcs_id, drv->tcs_in_use);
-	if (msg->state == RPMH_ACTIVE_ONLY_STATE && tcs->type != ACTIVE_TCS)
+	if (msg->state == RPMH_ACTIVE_ONLY_STATE && tcs->type != ACTIVE_TCS) {
+		/*
+		 * Clear previously programmed WAKE commands in selected
+		 * repurposed TCS to avoid triggering them. tcs->slots will be
+		 * cleaned from rpmh_flush() by invoking rpmh_rsc_invalidate()
+		 */
+		write_tcs_reg_sync(drv, RSC_DRV_CMD_ENABLE, tcs_id, 0);
+		write_tcs_reg_sync(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, 0);
 		enable_tcs_irq(drv, tcs_id, true);
+	}
 	spin_unlock(&drv->lock);
 
 	__tcs_buffer_write(drv, tcs_id, 0, msg);
-- 
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