[PATCH V2 3/4] drivers: qcom: rpmh: switch over from spinlock irq variants

From: Lina Iyer
Date: Mon Jul 22 2019 - 17:54:08 EST


From: "Raju P.L.S.S.S.N" <rplsssn@xxxxxxxxxxxxxx>

Switch over from using _irqsave/_irqrestore variants since we no longer
race with a lock from the interrupt handler. While we are at it, rename
the cache_lock to just lock to allow use of the lock to synchronize
controller access.

Signed-off-by: Raju P.L.S.S.S.N <rplsssn@xxxxxxxxxxxxxx>
Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
---
drivers/soc/qcom/rpmh-internal.h | 4 ++--
drivers/soc/qcom/rpmh-rsc.c | 2 +-
drivers/soc/qcom/rpmh.c | 21 ++++++++-------------
3 files changed, 11 insertions(+), 16 deletions(-)

diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h
index 969d5030860e..93d59db435bb 100644
--- a/drivers/soc/qcom/rpmh-internal.h
+++ b/drivers/soc/qcom/rpmh-internal.h
@@ -67,13 +67,13 @@ struct rpmh_request {
* struct rpmh_ctrlr: our representation of the controller
*
* @cache: the list of cached requests
- * @cache_lock: synchronize access to the cache data
+ * @lock: synchronize access to the controller data
* @dirty: was the cache updated since flush
* @batch_cache: Cache sleep and wake requests sent as batch
*/
struct rpmh_ctrlr {
struct list_head cache;
- spinlock_t cache_lock;
+ spinlock_t lock;
bool dirty;
struct list_head batch_cache;
};
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index 694ba881624e..add5e84751c9 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -656,7 +656,7 @@ static int rpmh_rsc_probe(struct platform_device *pdev)
/* Enable the active TCS to send requests immediately */
write_tcs_reg(drv, RSC_DRV_IRQ_ENABLE, 0, drv->tcs[ACTIVE_TCS].mask);

- spin_lock_init(&drv->client.cache_lock);
+ spin_lock_init(&drv->client.lock);
INIT_LIST_HEAD(&drv->client.cache);
INIT_LIST_HEAD(&drv->client.batch_cache);

diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index 035091fd44b8..d6fb254a4b57 100644
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -118,9 +118,8 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr,
struct tcs_cmd *cmd)
{
struct cache_req *req;
- unsigned long flags;

- spin_lock_irqsave(&ctrlr->cache_lock, flags);
+ spin_lock(&ctrlr->lock);
req = __find_req(ctrlr, cmd->addr);
if (req)
goto existing;
@@ -154,7 +153,7 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr,

ctrlr->dirty = true;
unlock:
- spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
+ spin_unlock(&ctrlr->lock);

return req;
}
@@ -283,23 +282,20 @@ EXPORT_SYMBOL(rpmh_write);

static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req)
{
- unsigned long flags;
-
- spin_lock_irqsave(&ctrlr->cache_lock, flags);
+ spin_lock(&ctrlr->lock);
list_add_tail(&req->list, &ctrlr->batch_cache);
- spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
+ spin_unlock(&ctrlr->lock);
}

static int flush_batch(struct rpmh_ctrlr *ctrlr)
{
struct batch_cache_req *req;
const struct rpmh_request *rpm_msg;
- unsigned long flags;
int ret = 0;
int i;

/* Send Sleep/Wake requests to the controller, expect no response */
- spin_lock_irqsave(&ctrlr->cache_lock, flags);
+ spin_lock(&ctrlr->lock);
list_for_each_entry(req, &ctrlr->batch_cache, list) {
for (i = 0; i < req->count; i++) {
rpm_msg = req->rpm_msgs + i;
@@ -309,7 +305,7 @@ static int flush_batch(struct rpmh_ctrlr *ctrlr)
break;
}
}
- spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
+ spin_unlock(&ctrlr->lock);

return ret;
}
@@ -317,13 +313,12 @@ static int flush_batch(struct rpmh_ctrlr *ctrlr)
static void invalidate_batch(struct rpmh_ctrlr *ctrlr)
{
struct batch_cache_req *req, *tmp;
- unsigned long flags;

- spin_lock_irqsave(&ctrlr->cache_lock, flags);
+ spin_lock(&ctrlr->lock);
list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list)
kfree(req);
INIT_LIST_HEAD(&ctrlr->batch_cache);
- spin_unlock_irqrestore(&ctrlr->cache_lock, flags);
+ spin_unlock(&ctrlr->lock);
}

/**
--
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