remoteproc: qcom_q6v5_pas: Add hwspinlock bust on stop

When remoteproc goes down unexpectedly this results in a state where any
acquired hwspinlocks will remain locked possibly resulting in deadlock.
In order to ensure all locks are freed we include a call to
qcom_smem_bust_hwspin_lock_by_host() during remoteproc shutdown.

For qcom_q6v5_pas remoteprocs, each remoteproc has an assigned smem
host_id. Remoteproc can pass this id to smem to try and bust the lock on
remoteproc stop.

This edge case only occurs with q6v5_pas watchdog crashes. The error
fatal case has handling to clear the hwspinlock before the error fatal
interrupt is triggered.
Signed-off-by: Richard Maina <quic_rmaina@quicinc.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Chris Lew <quic_clew@quicinc.com>
Link: https://lore.kernel.org/r/20240529-hwspinlock-bust-v3-4-c8b924ffa5a2@quicinc.comSigned-off-by: Bjorn Andersson <andersson@kernel.org>

drivers/remoteproc/qcom_q6v5_pas.c

@@ -52,6 +52,7 @@ struct adsp_data {
 	const char *ssr_name;
 	const char *sysmon_name;
 	int ssctl_id;
+	unsigned int smem_host_id;
 
 	int region_assign_idx;
 	int region_assign_count;
@@ -81,6 +82,7 @@ struct qcom_adsp {
 	int lite_pas_id;
 	unsigned int minidump_id;
 	int crash_reason_smem;
+	unsigned int smem_host_id;
 	bool decrypt_shutdown;
 	const char *info_name;
 
@@ -399,6 +401,9 @@ static int adsp_stop(struct rproc *rproc)
 	if (handover)
 		qcom_pas_handover(&adsp->q6v5);
 
+	if (adsp->smem_host_id)
+		ret = qcom_smem_bust_hwspin_lock_by_host(adsp->smem_host_id);
+
 	return ret;
 }
 
@@ -727,6 +732,7 @@ static int adsp_probe(struct platform_device *pdev)
 	adsp->pas_id = desc->pas_id;
 	adsp->lite_pas_id = desc->lite_pas_id;
 	adsp->info_name = desc->sysmon_name;
+	adsp->smem_host_id = desc->smem_host_id;
 	adsp->decrypt_shutdown = desc->decrypt_shutdown;
 	adsp->region_assign_idx = desc->region_assign_idx;
 	adsp->region_assign_count = min_t(int, MAX_ASSIGN_COUNT, desc->region_assign_count);
@@ -1196,6 +1202,7 @@ static const struct adsp_data sm8550_adsp_resource = {
 	.ssr_name = "lpass",
 	.sysmon_name = "adsp",
 	.ssctl_id = 0x14,
+	.smem_host_id = 2,
 };
 
 static const struct adsp_data sm8550_cdsp_resource = {
@@ -1216,6 +1223,7 @@ static const struct adsp_data sm8550_cdsp_resource = {
 	.ssr_name = "cdsp",
 	.sysmon_name = "cdsp",
 	.ssctl_id = 0x17,
+	.smem_host_id = 5,
 };
 
 static const struct adsp_data sm8550_mpss_resource = {
@@ -1236,6 +1244,7 @@ static const struct adsp_data sm8550_mpss_resource = {
 	.ssr_name = "mpss",
 	.sysmon_name = "modem",
 	.ssctl_id = 0x12,
+	.smem_host_id = 1,
 	.region_assign_idx = 2,
 	.region_assign_count = 1,
 	.region_assign_vmid = QCOM_SCM_VMID_MSS_MSA,
@@ -1275,6 +1284,7 @@ static const struct adsp_data sm8650_cdsp_resource = {
 	.ssr_name = "cdsp",
 	.sysmon_name = "cdsp",
 	.ssctl_id = 0x17,
+	.smem_host_id = 5,
 	.region_assign_idx = 2,
 	.region_assign_count = 1,
 	.region_assign_shared = true,
@@ -1299,6 +1309,7 @@ static const struct adsp_data sm8650_mpss_resource = {
 	.ssr_name = "mpss",
 	.sysmon_name = "modem",
 	.ssctl_id = 0x12,
+	.smem_host_id = 1,
 	.region_assign_idx = 2,
 	.region_assign_count = 3,
 	.region_assign_vmid = QCOM_SCM_VMID_MSS_MSA,