Invoke rpmh_flush for non OSI targets

Currently rpmh ctrlr dirty flag is set for all cases regardless of data is really changed or not. Add changes to update dirty flag when data is changed to newer values.

Also move dirty flag updates to happen from within cache_lock and remove unnecessary INIT_LIST_HEAD() call and a default case from switch.

Fixes 600513dfeef3 ("drivers: qcom: rpmh: cache sleep/wake state requests")

Signed-off-by Maulik Shah <[email protected]>

Reviewed-by Srinivas Rao L <[email protected]>

---
 drivers/soc/qcom/rpmh.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

drivers/soc/qcom/rpmh.c +0 -0

index eb0ded0..3f5d9eb 100644

drivers/soc/qcom/rpmh.c +14 -11

        list_add_tail(&req->list, &ctrlr->cache);
 
 existing:
        switch (state) {
        case RPMH_ACTIVE_ONLY_STATE:
-               if (req->sleep_val != UINT_MAX)
+               if (req->sleep_val != UINT_MAX) {
                        req->wake_val = cmd->data;
+                       ctrlr->dirty = true;
+               }
                break;
        case RPMH_WAKE_ONLY_STATE:
-               req->wake_val = cmd->data;
+               if (req->wake_val != cmd->data) {
+                       req->wake_val = cmd->data;
+                       ctrlr->dirty = true;
+               }
                break;
        case RPMH_SLEEP_STATE:
-               req->sleep_val = cmd->data;
-               break;
-       default:
+               if (req->sleep_val != cmd->data) {
+                       req->sleep_val = cmd->data;
+                       ctrlr->dirty = true;
+               }
                break;
        }
 
-       ctrlr->dirty = true;
 unlock:
        spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 

@@ -287,6 +291,7 @@ static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req)
 
        spin_lock_irqsave(&ctrlr->cache_lock, flags);
        list_add_tail(&req->list, &ctrlr->batch_cache);
+       ctrlr->dirty = true;
        spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 }
 

@@ -323,6 +328,7 @@ static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
        list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
                kfree(req);
        INIT_LIST_HEAD(&ctrlr->batch_cache);
+       ctrlr->dirty = true;
        spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 }
 

@@ -456,13 +462,9 @@ static int send_single(struct rpmh_ctrlr *ctrlr, enum rpmh_state state,
 int rpmh_flush(struct rpmh_ctrlr *ctrlr)
 {
        struct cache_req *p;
+       unsigned long flags;
        int ret;
 
-       if (!ctrlr->dirty) {
-               pr_debug("Skipping flush, TCS has latest data.\n");
-               return 0;
-       }
-
        /* First flush the cached batch requests */
        ret = flush_batch(ctrlr);
        if (ret)

Quoted 19 lines · Maulik Shah

Currently rpmh ctrlr dirty flag is set for all cases regardless of data is really changed or not. Add changes to update dirty flag when data is changed to newer values.

Also move dirty flag updates to happen from within cache_lock and remove unnecessary INIT_LIST_HEAD() call and a default case from switch.

Fixes 600513dfeef3 ("drivers: qcom: rpmh: cache sleep/wake state requests")

Signed-off-by Maulik Shah <[email protected]>

Reviewed-by Srinivas Rao L <[email protected]>

---
  drivers/soc/qcom/rpmh.c | 29 ++++++++++++++++-------------
  1 file changed, 16 insertions(+), 13 deletions(-)

drivers/soc/qcom/rpmh.c +0 -0

index eb0ded0..3f5d9eb 100644

drivers/soc/qcom/rpmh.c static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr, · line 136

Quoted 4 lines

drivers/soc/qcom/rpmh.c +0 -1

@@ -133,26 +133,30 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr,
 
         req->addr = cmd->addr;
         req->sleep_val = req->wake_val = UINT_MAX;
-       INIT_LIST_HEAD(&req->list);

Thanks!

Quoted 65 lines

drivers/soc/qcom/rpmh.c +14 -11

         list_add_tail(&req->list, &ctrlr->cache);
 
  existing:
         switch (state) {
         case RPMH_ACTIVE_ONLY_STATE:
-               if (req->sleep_val != UINT_MAX)
+               if (req->sleep_val != UINT_MAX) {
                         req->wake_val = cmd->data;
+                       ctrlr->dirty = true;
+               }
                 break;
         case RPMH_WAKE_ONLY_STATE:
-               req->wake_val = cmd->data;
+               if (req->wake_val != cmd->data) {
+                       req->wake_val = cmd->data;
+                       ctrlr->dirty = true;
+               }
                 break;
         case RPMH_SLEEP_STATE:
-               req->sleep_val = cmd->data;
-               break;
-       default:
+               if (req->sleep_val != cmd->data) {
+                       req->sleep_val = cmd->data;
+                       ctrlr->dirty = true;
+               }
                 break;
         }
 
-       ctrlr->dirty = true;
  unlock:
         spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
 

@@ -287,6 +291,7 @@ static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req)
 
         spin_lock_irqsave(&ctrlr->cache_lock, flags);
         list_add_tail(&req->list, &ctrlr->batch_cache);
+       ctrlr->dirty = true;
         spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
  }
 

@@ -323,6 +328,7 @@ static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
         list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
                 kfree(req);
         INIT_LIST_HEAD(&ctrlr->batch_cache);
+       ctrlr->dirty = true;
         spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
  }
 

@@ -456,13 +462,9 @@ static int send_single(struct rpmh_ctrlr *ctrlr, enum rpmh_state state,
  int rpmh_flush(struct rpmh_ctrlr *ctrlr)
  {
         struct cache_req *p;
+       unsigned long flags;
         int ret;
 
-       if (!ctrlr->dirty) {
-               pr_debug("Skipping flush, TCS has latest data.\n");
-               return 0;
-       }
-
         /* First flush the cached batch requests */
         ret = flush_batch(ctrlr);
         if (ret)

drivers/soc/qcom/rpmh.c int rpmh_flush(struct rpmh_ctrlr *ctrlr) · line 495

Quoted 6 lines

drivers/soc/qcom/rpmh.c +2 -0

@@ -488,7 +490,9 @@ int rpmh_flush(struct rpmh_ctrlr *ctrlr)
                         return ret;
         }
 
+       spin_lock_irqsave(&ctrlr->cache_lock, flags);
         ctrlr->dirty = false;
+       spin_unlock_irqrestore(&ctrlr->cache_lock, flags);

You're acquiring a lock around an operation that's already inherently atomic, which is not right. If the comment earlier in this function is still correct that "Nobody else should be calling this function other than system PM, hence we can run without locks", then you can simply remove this hunk and the part moving ->dirty = true into invalidate_batch.

However, if rpmh_flush() can now be called in a scenario where pre-emption is enabled or multiple cores are alive, then ctrlr->cache is no longer adequately protected. You'd need to add a lock acquire/release around the list iteration above, and fix up the comment.
-Evan