[PATCH] perf: xgene: Remove unnecessary managed resources cleanup

[Tai Nguyen]

Managed resources in the driver should be automatically cleaned up on
driver detach. It's unnecessary to manually free/unmmap these resources.
One of the manual cleanup causes static checkers to complain.
The bug is reported by Dan Carpenter <dan.carpenter@xxxxxxxxxx> in [1]

[1] https://www.spinics.net/lists/arm-kernel/msg593012.html

This patch gets rid of all the unnecessary manual cleanup and properly
unregister all the registered PMU devices by the driver on driver detach.

Signed-off-by: Tai Nguyen <ttnguyen@xxxxxxx>
---
 drivers/perf/xgene_pmu.c | 74 ++++++++++++++----------------------------------
 1 file changed, 22 insertions(+), 52 deletions(-)

diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
index e841282..eb23311 100644
--- a/drivers/perf/xgene_pmu.c
+++ b/drivers/perf/xgene_pmu.c
@@ -1147,7 +1147,6 @@ static int xgene_init_perf(struct xgene_pmu_dev *pmu_dev, char *name)
 {
 	struct device *dev = xgene_pmu->dev;
 	struct xgene_pmu_dev *pmu;
-	int rc;
 
 	pmu = devm_kzalloc(dev, sizeof(*pmu), GFP_KERNEL);
 	if (!pmu)
@@ -1159,7 +1158,7 @@ static int xgene_init_perf(struct xgene_pmu_dev *pmu_dev, char *name)
 	switch (pmu->inf->type) {
 	case PMU_TYPE_L3C:
 		if (!(xgene_pmu->l3c_active_mask & pmu->inf->enable_mask))
-			goto dev_err;
+			return -ENODEV;
 		if (xgene_pmu->version == PCP_PMU_V3)
 			pmu->attr_groups = l3c_pmu_v3_attr_groups;
 		else
@@ -1177,7 +1176,7 @@ static int xgene_init_perf(struct xgene_pmu_dev *pmu_dev, char *name)
 		break;
 	case PMU_TYPE_MCB:
 		if (!(xgene_pmu->mcb_active_mask & pmu->inf->enable_mask))
-			goto dev_err;
+			return -ENODEV;
 		if (xgene_pmu->version == PCP_PMU_V3)
 			pmu->attr_groups = mcb_pmu_v3_attr_groups;
 		else
@@ -1185,7 +1184,7 @@ static int xgene_init_perf(struct xgene_pmu_dev *pmu_dev, char *name)
 		break;
 	case PMU_TYPE_MC:
 		if (!(xgene_pmu->mc_active_mask & pmu->inf->enable_mask))
-			goto dev_err;
+			return -ENODEV;
 		if (xgene_pmu->version == PCP_PMU_V3)
 			pmu->attr_groups = mc_pmu_v3_attr_groups;
 		else
@@ -1195,19 +1194,14 @@ static int xgene_init_perf(struct xgene_pmu_dev *pmu_dev, char *name)
 		return -EINVAL;
 	}
 
-	rc = xgene_init_perf(pmu, ctx->name);
-	if (rc) {
+	if (xgene_init_perf(pmu, ctx->name)) {
 		dev_err(dev, "%s PMU: Failed to init perf driver\n", ctx->name);
-		goto dev_err;
+		return -ENODEV;
 	}
 
 	dev_info(dev, "%s PMU registered\n", ctx->name);
 
-	return rc;
-
-dev_err:
-	devm_kfree(dev, pmu);
-	return -ENODEV;
+	return 0;
 }
 
 static void _xgene_pmu_isr(int irq, struct xgene_pmu_dev *pmu_dev)
@@ -1515,13 +1509,13 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
 	acpi_dev_free_resource_list(&resource_list);
 	if (rc < 0) {
 		dev_err(dev, "PMU type %d: No resource address found\n", type);
-		goto err;
+		return NULL;
 	}
 
 	dev_csr = devm_ioremap_resource(dev, &res);
 	if (IS_ERR(dev_csr)) {
 		dev_err(dev, "PMU type %d: Fail to map resource\n", type);
-		goto err;
+		return NULL;
 	}
 
 	/* A PMU device node without enable-bit-index is always enabled */
@@ -1535,7 +1529,7 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
 	ctx->name = xgene_pmu_dev_name(dev, type, enable_bit);
 	if (!ctx->name) {
 		dev_err(dev, "PMU type %d: Fail to get device name\n", type);
-		goto err;
+		return NULL;
 	}
 	inf = &ctx->inf;
 	inf->type = type;
@@ -1543,9 +1537,6 @@ xgene_pmu_dev_ctx *acpi_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
 	inf->enable_mask = 1 << enable_bit;
 
 	return ctx;
-err:
-	devm_kfree(dev, ctx);
-	return NULL;
 }
 
 static const struct acpi_device_id xgene_pmu_acpi_type_match[] = {
@@ -1663,20 +1654,20 @@ xgene_pmu_dev_ctx *fdt_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
 	void __iomem *dev_csr;
 	struct resource res;
 	int enable_bit;
-	int rc;
 
 	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
 		return NULL;
-	rc = of_address_to_resource(np, 0, &res);
-	if (rc < 0) {
+
+	if (of_address_to_resource(np, 0, &res) < 0) {
 		dev_err(dev, "PMU type %d: No resource address found\n", type);
-		goto err;
+		return NULL;
 	}
+
 	dev_csr = devm_ioremap_resource(dev, &res);
 	if (IS_ERR(dev_csr)) {
 		dev_err(dev, "PMU type %d: Fail to map resource\n", type);
-		goto err;
+		return NULL;
 	}
 
 	/* A PMU device node without enable-bit-index is always enabled */
@@ -1686,17 +1677,15 @@ xgene_pmu_dev_ctx *fdt_get_pmu_hw_inf(struct xgene_pmu *xgene_pmu,
 	ctx->name = xgene_pmu_dev_name(dev, type, enable_bit);
 	if (!ctx->name) {
 		dev_err(dev, "PMU type %d: Fail to get device name\n", type);
-		goto err;
+		return NULL;
 	}
+
 	inf = &ctx->inf;
 	inf->type = type;
 	inf->csr = dev_csr;
 	inf->enable_mask = 1 << enable_bit;
 
 	return ctx;
-err:
-	devm_kfree(dev, ctx);
-	return NULL;
 }
 
 static int fdt_pmu_probe_pmu_dev(struct xgene_pmu *xgene_pmu,
@@ -1868,22 +1857,20 @@ static int xgene_pmu_probe(struct platform_device *pdev)
 	xgene_pmu->pcppmu_csr = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(xgene_pmu->pcppmu_csr)) {
 		dev_err(&pdev->dev, "ioremap failed for PCP PMU resource\n");
-		rc = PTR_ERR(xgene_pmu->pcppmu_csr);
-		goto err;
+		return PTR_ERR(xgene_pmu->pcppmu_csr);
 	}
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		dev_err(&pdev->dev, "No IRQ resource\n");
-		rc = -EINVAL;
-		goto err;
+		return -EINVAL;
 	}
 	rc = devm_request_irq(&pdev->dev, irq, xgene_pmu_isr,
 				IRQF_NOBALANCING | IRQF_NO_THREAD,
 				dev_name(&pdev->dev), xgene_pmu);
 	if (rc) {
 		dev_err(&pdev->dev, "Could not request IRQ %d\n", irq);
-		goto err;
+		return rc;
 	}
 
 	raw_spin_lock_init(&xgene_pmu->lock);
@@ -1903,42 +1890,29 @@ static int xgene_pmu_probe(struct platform_device *pdev)
 	rc = irq_set_affinity(irq, &xgene_pmu->cpu);
 	if (rc) {
 		dev_err(&pdev->dev, "Failed to set interrupt affinity!\n");
-		goto err;
+		return rc;
 	}
 
 	/* Walk through the tree for all PMU perf devices */
 	rc = xgene_pmu_probe_pmu_dev(xgene_pmu, pdev);
 	if (rc) {
 		dev_err(&pdev->dev, "No PMU perf devices found!\n");
-		goto err;
+		return rc;
 	}
 
 	/* Enable interrupt */
 	xgene_pmu->ops->unmask_int(xgene_pmu);
 
 	return 0;
-
-err:
-	if (xgene_pmu->pcppmu_csr)
-		devm_iounmap(&pdev->dev, xgene_pmu->pcppmu_csr);
-	devm_kfree(&pdev->dev, xgene_pmu);
-
-	return rc;
 }
 
 static void
 xgene_pmu_dev_cleanup(struct xgene_pmu *xgene_pmu, struct list_head *pmus)
 {
 	struct xgene_pmu_dev_ctx *ctx;
-	struct device *dev = xgene_pmu->dev;
-	struct xgene_pmu_dev *pmu_dev;
 
 	list_for_each_entry(ctx, pmus, next) {
-		pmu_dev = ctx->pmu_dev;
-		if (pmu_dev->inf->csr)
-			devm_iounmap(dev, pmu_dev->inf->csr);
-		devm_kfree(dev, ctx);
-		devm_kfree(dev, pmu_dev);
+		perf_pmu_unregister(&ctx->pmu_dev->pmu);
 	}
 }
 
@@ -1951,10 +1925,6 @@ static int xgene_pmu_remove(struct platform_device *pdev)
 	xgene_pmu_dev_cleanup(xgene_pmu, &xgene_pmu->mcbpmus);
 	xgene_pmu_dev_cleanup(xgene_pmu, &xgene_pmu->mcpmus);
 
-	if (xgene_pmu->pcppmu_csr)
-		devm_iounmap(&pdev->dev, xgene_pmu->pcppmu_csr);
-	devm_kfree(&pdev->dev, xgene_pmu);
-
 	return 0;
 }
 
-- 
1.9.1