2017-07-13 18:21:22

by Tai Nguyen

[permalink] [raw]
Subject: [PATCH] perf: xgene: Remove unnecessary managed resources cleanup

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 <[email protected]> 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 <[email protected]>
---
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