From cdf7efe4b02aa93813db0bf1ca596ad298ab6b06 Mon Sep 17 00:00:00 2001 From: Murali Nalajala Date: Wed, 14 Aug 2024 15:32:44 -0700 Subject: [PATCH] firmware: qcom: scm: Mark get_wq_ctx() as atomic call commit 9960085a3a82c58d3323c1c20b991db6045063b0 upstream. Currently get_wq_ctx() is wrongly configured as a standard call. When two SMC calls are in sleep and one SMC wakes up, it calls get_wq_ctx() to resume the corresponding sleeping thread. But if get_wq_ctx() is interrupted, goes to sleep and another SMC call is waiting to be allocated a waitq context, it leads to a deadlock. To avoid this get_wq_ctx() must be an atomic call and can't be a standard SMC call. Hence mark get_wq_ctx() as a fast call. Fixes: 6bf325992236 ("firmware: qcom: scm: Add wait-queue handling logic") Cc: stable@vger.kernel.org Signed-off-by: Murali Nalajala Signed-off-by: Unnathi Chalicheemala Reviewed-by: Elliot Berman Link: https://lore.kernel.org/r/20240814223244.40081-1-quic_uchalich@quicinc.com Signed-off-by: Bjorn Andersson Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/qcom_scm-smc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/qcom_scm-smc.c b/drivers/firmware/qcom_scm-smc.c index 16cf88acfa8e..0a2a2c794d0e 100644 --- a/drivers/firmware/qcom_scm-smc.c +++ b/drivers/firmware/qcom_scm-smc.c @@ -71,7 +71,7 @@ int scm_get_wq_ctx(u32 *wq_ctx, u32 *flags, u32 *more_pending) struct arm_smccc_res get_wq_res; struct arm_smccc_args get_wq_ctx = {0}; - get_wq_ctx.args[0] = ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, + get_wq_ctx.args[0] = ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_64, ARM_SMCCC_OWNER_SIP, SCM_SMC_FNID(QCOM_SCM_SVC_WAITQ, QCOM_SCM_WAITQ_GET_WQ_CTX));