firmware: qcom: scm: Fix __scm and waitq completion variable initialization

[ Upstream commit 2e4955167e ]

It is possible qcom_scm_is_available() gives wrong indication that
if __scm is initialized while __scm->dev is not and similar issue
is also possible with __scm->waitq_comp.

Fix this appropriately by the use of release barrier and read barrier
that will make sure if __scm is initialized so, is all of its field
variable.

Fixes: d0f6fa7ba2 ("firmware: qcom: scm: Convert SCM to platform driver")
Fixes: 6bf3259922 ("firmware: qcom: scm: Add wait-queue handling logic")
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Link: https://lore.kernel.org/r/1711034642-22860-4-git-send-email-quic_mojha@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Mukesh Ojha 2024-03-21 20:54:02 +05:30 committed by Greg Kroah-Hartman
parent 8fc7934635
commit 0cac39347f
1 changed files with 5 additions and 5 deletions

View File

@ -1333,7 +1333,7 @@ static int qcom_scm_find_dload_address(struct device *dev, u64 *addr)
*/
bool qcom_scm_is_available(void)
{
return !!__scm;
return !!READ_ONCE(__scm);
}
EXPORT_SYMBOL_GPL(qcom_scm_is_available);
@ -1414,10 +1414,12 @@ static int qcom_scm_probe(struct platform_device *pdev)
if (!scm)
return -ENOMEM;
scm->dev = &pdev->dev;
ret = qcom_scm_find_dload_address(&pdev->dev, &scm->dload_mode_addr);
if (ret < 0)
return ret;
init_completion(&scm->waitq_comp);
mutex_init(&scm->scm_bw_lock);
scm->path = devm_of_icc_get(&pdev->dev, NULL);
@ -1449,10 +1451,8 @@ static int qcom_scm_probe(struct platform_device *pdev)
if (ret)
return ret;
__scm = scm;
__scm->dev = &pdev->dev;
init_completion(&__scm->waitq_comp);
/* Let all above stores be available after this */
smp_store_release(&__scm, scm);
irq = platform_get_irq_optional(pdev, 0);
if (irq < 0) {