[PATCH v4 4/4] firmware: qcom: scm: introduce qcom_scm_bw class for bandwidth management

[Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>]

Define DEFINE_CLASS(qcom_scm_bw) that calls qcom_scm_bw_enable() on
construction and automatically calls qcom_scm_bw_disable() at scope exit
*if* the enable succeeded.

This allows us to convert all call sites to using
CLASS(qcom_scm_bw, bw)() instead of the manual enable/check/disable
pattern and to remove the associated goto labels in cleanup path.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/firmware/qcom/qcom_scm.c | 67 ++++++++++++++++------------------------
 1 file changed, 27 insertions(+), 40 deletions(-)

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 28fb80a8496fe9a613228d4fe3acab9de2637634..73f8868c7bffa2a7149110c8b201d5e3c5c3c807 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -244,6 +244,9 @@ static void qcom_scm_bw_disable(void)
 	mutex_unlock(&__scm->scm_bw_lock);
 }
 
+DEFINE_CLASS(qcom_scm_bw_guard, int, if (!_T) qcom_scm_bw_disable(),
+	     qcom_scm_bw_enable(), void)
+
 enum qcom_scm_convention qcom_scm_convention = SMC_CONVENTION_UNKNOWN;
 static DEFINE_SPINLOCK(scm_query_lock);
 
@@ -594,14 +597,13 @@ static int __qcom_scm_pas_init_image(struct device *dev, u32 pas_id,
 	if (clk_guard)
 		return clk_guard;
 
-	ret = qcom_scm_bw_enable();
-	if (ret)
-		return ret;
+	CLASS(qcom_scm_bw_guard, bw_guard)();
+	if (bw_guard)
+		return bw_guard;
 
 	desc.args[1] = mdata_phys;
 
 	ret = qcom_scm_call(dev, &desc, res);
-	qcom_scm_bw_disable();
 
 	return ret;
 }
@@ -701,12 +703,11 @@ static int qcom_scm_pas_mem_setup(struct device *dev, u32 pas_id,
 	if (clk_guard)
 		return clk_guard;
 
-	ret = qcom_scm_bw_enable();
-	if (ret)
-		return ret;
+	CLASS(qcom_scm_bw_guard, bw_guard)();
+	if (bw_guard)
+		return bw_guard;
 
 	ret = qcom_scm_call(dev, &desc, &res);
-	qcom_scm_bw_disable();
 
 	return ret ? : res.result[0];
 }
@@ -770,15 +771,14 @@ static void *qcom_scm_pas_get_rsc_table(struct device *dev,
 	struct resource_table empty_rsc = {};
 	size_t size = SZ_16K;
 	void *tbl_ptr;
-	int ret;
 
 	CLASS(qcom_scm_clk_guard, clk_guard)();
 	if (clk_guard)
 		return ERR_PTR(clk_guard);
 
-	ret = qcom_scm_bw_enable();
-	if (ret)
-		return ERR_PTR(ret);
+	CLASS(qcom_scm_bw_guard, bw_guard)();
+	if (bw_guard)
+		return ERR_PTR(bw_guard);
 
 	/*
 	 * TrustZone can not accept buffer as NULL value as argument hence,
@@ -793,10 +793,8 @@ static void *qcom_scm_pas_get_rsc_table(struct device *dev,
 	void *input_rt_tzm __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool,
 								  input_rt_size,
 								  GFP_KERNEL);
-	if (!input_rt_tzm) {
-		ret = -ENOMEM;
-		goto disable_scm_bw;
-	}
+	if (!input_rt_tzm)
+		return ERR_PTR(-ENOMEM);
 
 	memcpy(input_rt_tzm, input_rt, input_rt_size);
 
@@ -811,31 +809,22 @@ static void *qcom_scm_pas_get_rsc_table(struct device *dev,
 							     input_rt_size,
 							     &size);
 	}
-	if (IS_ERR(output_rt_tzm)) {
-		ret = PTR_ERR(output_rt_tzm);
-		goto disable_scm_bw;
-	}
+	if (IS_ERR(output_rt_tzm))
+		return output_rt_tzm;
 
 	*output_rt_size = size;
 
 	/* A zero-sized table means that TrustZone has no resource table. */
-	if (!size) {
-		tbl_ptr = NULL;
-		goto disable_scm_bw;
-	}
+	if (!size)
+		return NULL;
 
 	tbl_ptr = kmemdup(output_rt_tzm, size, GFP_KERNEL);
-	if (!tbl_ptr) {
-		ret = -ENOMEM;
-		goto disable_scm_bw;
-	}
+	if (!tbl_ptr)
+		return ERR_PTR(-ENOMEM);
 
 	*output_rt_size = size;
 
-disable_scm_bw:
-	qcom_scm_bw_disable();
-
-	return ret ? ERR_PTR(ret) : tbl_ptr;
+	return tbl_ptr;
 }
 
 static int qcom_scm_pas_auth_and_reset(struct device *dev, u32 pas_id)
@@ -854,12 +843,11 @@ static int qcom_scm_pas_auth_and_reset(struct device *dev, u32 pas_id)
 	if (clk_guard)
 		return clk_guard;
 
-	ret = qcom_scm_bw_enable();
-	if (ret)
-		return ret;
+	CLASS(qcom_scm_bw_guard, bw_guard)();
+	if (bw_guard)
+		return bw_guard;
 
 	ret = qcom_scm_call(dev, &desc, &res);
-	qcom_scm_bw_disable();
 
 	return ret ? : res.result[0];
 }
@@ -927,12 +915,11 @@ static int qcom_scm_pas_shutdown(struct device *dev, u32 pas_id)
 	if (clk_guard)
 		return clk_guard;
 
-	ret = qcom_scm_bw_enable();
-	if (ret)
-		return ret;
+	CLASS(qcom_scm_bw_guard, bw_guard)();
+	if (bw_guard)
+		return bw_guard;
 
 	ret = qcom_scm_call(dev, &desc, &res);
-	qcom_scm_bw_disable();
 
 	return ret ? : res.result[0];
 }

-- 
2.47.3