Re: [PATCH 2/2] devm-helpers: Add resource managed version of debugfs directory create function
From: Dave Jiang
Date: Thu Feb 22 2024 - 12:24:14 EST
On 2/22/24 7:58 AM, Marek Behún wrote:
> A few drivers register a devm action to remove a debugfs directory,
> implementing a one-liner function that calls debufs_remove_recursive().
> Help drivers avoid this repeated implementations by adding managed
> version of debugfs directory create function.
>
> Use the new function devm_debugfs_create_dir() in the following
> drivers:
> drivers/crypto/caam/ctrl.c
> drivers/gpu/drm/bridge/ti-sn65dsi86.c
> drivers/hwmon/hp-wmi-sensors.c
> drivers/hwmon/mr75203.c
> drivers/hwmon/pmbus/pmbus_core.c
>
> Also use the action function devm_debugfs_dir_recursive_drop() in
> drivers
> drivers/cxl/mem.c
> drivers/gpio/gpio-mockup.c
>
> Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
> ---
> drivers/crypto/caam/ctrl.c | 16 +++------
> drivers/cxl/mem.c | 9 ++---
> drivers/gpio/gpio-mockup.c | 11 ++----
> drivers/gpu/drm/bridge/ti-sn65dsi86.c | 13 ++------
> drivers/hwmon/hp-wmi-sensors.c | 15 ++-------
> drivers/hwmon/mr75203.c | 15 +++------
> drivers/hwmon/pmbus/pmbus_core.c | 16 +++------
> include/linux/devm-helpers.h | 48 +++++++++++++++++++++++++++
> 8 files changed, 72 insertions(+), 71 deletions(-)
>
> diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
> index bdf367f3f679..ea3ed9a17f1a 100644
> --- a/drivers/crypto/caam/ctrl.c
> +++ b/drivers/crypto/caam/ctrl.c
> @@ -7,6 +7,7 @@
> */
>
> #include <linux/device.h>
> +#include <linux/devm-helpers.h>
> #include <linux/of_address.h>
> #include <linux/of_irq.h>
> #include <linux/platform_device.h>
> @@ -604,11 +605,6 @@ static int init_clocks(struct device *dev, const struct caam_imx_data *data)
> return devm_add_action_or_reset(dev, disable_clocks, ctrlpriv);
> }
>
> -static void caam_remove_debugfs(void *root)
> -{
> - debugfs_remove_recursive(root);
> -}
> -
> #ifdef CONFIG_FSL_MC_BUS
> static bool check_version(struct fsl_mc_version *mc_version, u32 major,
> u32 minor, u32 revision)
> @@ -1058,13 +1054,9 @@ static int caam_probe(struct platform_device *pdev)
> ctrlpriv->era = caam_get_era(perfmon);
> ctrlpriv->domain = iommu_get_domain_for_dev(dev);
>
> - dfs_root = debugfs_create_dir(dev_name(dev), NULL);
> - if (IS_ENABLED(CONFIG_DEBUG_FS)) {
> - ret = devm_add_action_or_reset(dev, caam_remove_debugfs,
> - dfs_root);
> - if (ret)
> - return ret;
> - }
> + dfs_root = devm_debugfs_create_dir(dev, dev_name(dev), NULL);
> + if (IS_ERR(dfs_root))
> + return PTR_ERR(dfs_root);
>
> caam_debugfs_init(ctrlpriv, perfmon, dfs_root);
>
> diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> index c5c9d8e0d88d..4b38514887a4 100644
> --- a/drivers/cxl/mem.c
> +++ b/drivers/cxl/mem.c
> @@ -2,6 +2,7 @@
> /* Copyright(c) 2022 Intel Corporation. All rights reserved. */
> #include <linux/debugfs.h>
> #include <linux/device.h>
> +#include <linux/devm-helpers.h>
> #include <linux/module.h>
> #include <linux/pci.h>
>
> @@ -30,11 +31,6 @@ static void enable_suspend(void *data)
> cxl_mem_active_dec();
> }
>
> -static void remove_debugfs(void *dentry)
> -{
> - debugfs_remove_recursive(dentry);
> -}
> -
> static int cxl_mem_dpa_show(struct seq_file *file, void *data)
> {
> struct device *dev = file->private;
> @@ -138,7 +134,8 @@ static int cxl_mem_probe(struct device *dev)
> debugfs_create_file("clear_poison", 0200, dentry, cxlmd,
> &cxl_poison_clear_fops);
>
> - rc = devm_add_action_or_reset(dev, remove_debugfs, dentry);
> + rc = devm_add_action_or_reset(dev, devm_debugfs_dir_recursive_drop,
> + dentry);
This is probably the better fix for cxl:
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 3b64fb1b9ed0..3258427af032 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -57,7 +57,6 @@ int cxl_send_cmd(struct cxl_memdev *cxlmd, struct cxl_send_command __user *s);
void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
resource_size_t length);
-struct dentry *cxl_debugfs_create_dir(const char *dir);
int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
enum cxl_decoder_mode mode);
int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size);
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 27166a411705..5c2db4791b8b 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -1402,7 +1402,7 @@ void __init cxl_mbox_init(void)
{
struct dentry *mbox_debugfs;
- mbox_debugfs = cxl_debugfs_create_dir("mbox");
+ mbox_debugfs = debugfs_create_dir("mbox", NULL);
debugfs_create_bool("raw_allow_all", 0600, mbox_debugfs,
&cxl_raw_allow_all);
}
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index e59d9d37aa65..82c6a1c6aff4 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -10,6 +10,7 @@
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/node.h>
+#include <linux/devm-helpers.h>
#include <cxlmem.h>
#include <cxlpci.h>
#include <cxl.h>
@@ -2207,13 +2208,7 @@ struct bus_type cxl_bus_type = {
};
EXPORT_SYMBOL_NS_GPL(cxl_bus_type, CXL);
-static struct dentry *cxl_debugfs;
-
-struct dentry *cxl_debugfs_create_dir(const char *dir)
-{
- return debugfs_create_dir(dir, cxl_debugfs);
-}
-EXPORT_SYMBOL_NS_GPL(cxl_debugfs_create_dir, CXL);
+struct dentry *cxl_debugfs;
static __init int cxl_core_init(void)
{
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index b6017c0c57b4..ca8399b24955 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -880,6 +880,8 @@ void cxl_switch_parse_cdat(struct cxl_port *port);
int cxl_endpoint_get_perf_coordinates(struct cxl_port *port,
struct access_coordinate *coord);
+extern struct dentry *cxl_debugfs;
+
/*
* Unit test builds overrides this to __weak, find the 'strong' version
* of these symbols in tools/testing/cxl/.
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 5303d6942b88..b6f13ba87927 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -859,6 +859,5 @@ struct cxl_hdm {
};
struct seq_file;
-struct dentry *cxl_debugfs_create_dir(const char *dir);
void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds);
#endif /* __CXL_MEM_H__ */
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index c5c9d8e0d88d..494abe7a54c5 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -4,6 +4,7 @@
#include <linux/device.h>
#include <linux/module.h>
#include <linux/pci.h>
+#include <linux/devm-helpers.h>
#include "cxlmem.h"
#include "cxlpci.h"
@@ -30,11 +31,6 @@ static void enable_suspend(void *data)
cxl_mem_active_dec();
}
-static void remove_debugfs(void *dentry)
-{
- debugfs_remove_recursive(dentry);
-}
-
static int cxl_mem_dpa_show(struct seq_file *file, void *data)
{
struct device *dev = file->private;
@@ -128,7 +124,10 @@ static int cxl_mem_probe(struct device *dev)
if (work_pending(&cxlmd->detach_work))
return -EBUSY;
- dentry = cxl_debugfs_create_dir(dev_name(dev));
+ dentry = devm_debugfs_create_dir(dev, dev_name(dev), NULL);
+ if (IS_ERR(dentry))
+ return PTR_ERR(dentry);
+
debugfs_create_devm_seqfile(dev, "dpamem", dentry, cxl_mem_dpa_show);
if (test_bit(CXL_POISON_ENABLED_INJECT, mds->poison.enabled_cmds))
@@ -138,10 +137,6 @@ static int cxl_mem_probe(struct device *dev)
debugfs_create_file("clear_poison", 0200, dentry, cxlmd,
&cxl_poison_clear_fops);
- rc = devm_add_action_or_reset(dev, remove_debugfs, dentry);
- if (rc)
- return rc;
-
rc = devm_cxl_enumerate_ports(cxlmd);
if (rc)
return rc;
> if (rc)
> return rc;
>
> diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
> index 455eecf6380e..adbe0fe09490 100644
> --- a/drivers/gpio/gpio-mockup.c
> +++ b/drivers/gpio/gpio-mockup.c
> @@ -12,6 +12,7 @@
> #include <linux/cleanup.h>
> #include <linux/debugfs.h>
> #include <linux/device.h>
> +#include <linux/devm-helpers.h>
> #include <linux/gpio/driver.h>
> #include <linux/interrupt.h>
> #include <linux/irq.h>
> @@ -390,13 +391,6 @@ static void gpio_mockup_debugfs_setup(struct device *dev,
> }
> }
>
> -static void gpio_mockup_debugfs_cleanup(void *data)
> -{
> - struct gpio_mockup_chip *chip = data;
> -
> - debugfs_remove_recursive(chip->dbg_dir);
> -}
> -
> static void gpio_mockup_dispose_mappings(void *data)
> {
> struct gpio_mockup_chip *chip = data;
> @@ -480,7 +474,8 @@ static int gpio_mockup_probe(struct platform_device *pdev)
>
> gpio_mockup_debugfs_setup(dev, chip);
>
> - return devm_add_action_or_reset(dev, gpio_mockup_debugfs_cleanup, chip);
> + return devm_add_action_or_reset(dev, devm_debugfs_dir_recursive_drop,
> + chip->dbg_dir);
> }
>
> static const struct of_device_id gpio_mockup_of_match[] = {
> diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> index 62cc3893dca5..ad0ed2459394 100644
> --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c
> @@ -10,6 +10,7 @@
> #include <linux/bits.h>
> #include <linux/clk.h>
> #include <linux/debugfs.h>
> +#include <linux/devm-helpers.h>
> #include <linux/gpio/consumer.h>
> #include <linux/gpio/driver.h>
> #include <linux/i2c.h>
> @@ -427,18 +428,12 @@ static int status_show(struct seq_file *s, void *data)
>
> DEFINE_SHOW_ATTRIBUTE(status);
>
> -static void ti_sn65dsi86_debugfs_remove(void *data)
> -{
> - debugfs_remove_recursive(data);
> -}
> -
> static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
> {
> struct device *dev = pdata->dev;
> struct dentry *debugfs;
> - int ret;
>
> - debugfs = debugfs_create_dir(dev_name(dev), NULL);
> + debugfs = devm_debugfs_create_dir(dev, dev_name(dev), NULL);
>
> /*
> * We might get an error back if debugfs wasn't enabled in the kernel
> @@ -447,10 +442,6 @@ static void ti_sn65dsi86_debugfs_init(struct ti_sn65dsi86 *pdata)
> if (IS_ERR_OR_NULL(debugfs))
> return;
>
> - ret = devm_add_action_or_reset(dev, ti_sn65dsi86_debugfs_remove, debugfs);
> - if (ret)
> - return;
> -
> debugfs_create_file("status", 0600, debugfs, pdata, &status_fops);
> }
>
> diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
> index b5325d0e72b9..2a7c33763ce8 100644
> --- a/drivers/hwmon/hp-wmi-sensors.c
> +++ b/drivers/hwmon/hp-wmi-sensors.c
> @@ -23,6 +23,7 @@
>
> #include <linux/acpi.h>
> #include <linux/debugfs.h>
> +#include <linux/devm-helpers.h>
> #include <linux/hwmon.h>
> #include <linux/jiffies.h>
> #include <linux/mutex.h>
> @@ -1304,12 +1305,6 @@ static int current_reading_show(struct seq_file *seqf, void *ignored)
> }
> DEFINE_SHOW_ATTRIBUTE(current_reading);
>
> -/* hp_wmi_devm_debugfs_remove - devm callback for debugfs cleanup */
> -static void hp_wmi_devm_debugfs_remove(void *res)
> -{
> - debugfs_remove_recursive(res);
> -}
> -
> /* hp_wmi_debugfs_init - create and populate debugfs directory tree */
> static void hp_wmi_debugfs_init(struct device *dev, struct hp_wmi_info *info,
> struct hp_wmi_platform_events *pevents,
> @@ -1320,21 +1315,15 @@ static void hp_wmi_debugfs_init(struct device *dev, struct hp_wmi_info *info,
> struct dentry *debugfs;
> struct dentry *entries;
> struct dentry *dir;
> - int err;
> u8 i;
>
> /* dev_name() gives a not-very-friendly GUID for WMI devices. */
> scnprintf(buf, sizeof(buf), "hp-wmi-sensors-%u", dev->id);
>
> - debugfs = debugfs_create_dir(buf, NULL);
> + debugfs = devm_debugfs_create_dir(dev, buf, NULL);
> if (IS_ERR(debugfs))
> return;
>
> - err = devm_add_action_or_reset(dev, hp_wmi_devm_debugfs_remove,
> - debugfs);
> - if (err)
> - return;
> -
> entries = debugfs_create_dir("sensor", debugfs);
>
> for (i = 0; i < icount; i++, info++) {
> diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
> index 50a8b9c3f94d..50f348fca108 100644
> --- a/drivers/hwmon/mr75203.c
> +++ b/drivers/hwmon/mr75203.c
> @@ -10,6 +10,7 @@
> #include <linux/bits.h>
> #include <linux/clk.h>
> #include <linux/debugfs.h>
> +#include <linux/devm-helpers.h>
> #include <linux/hwmon.h>
> #include <linux/kstrtox.h>
> #include <linux/module.h>
> @@ -216,17 +217,11 @@ static const struct file_operations pvt_ts_coeff_j_fops = {
> .llseek = default_llseek,
> };
>
> -static void devm_pvt_ts_dbgfs_remove(void *data)
> -{
> - struct pvt_device *pvt = (struct pvt_device *)data;
> -
> - debugfs_remove_recursive(pvt->dbgfs_dir);
> - pvt->dbgfs_dir = NULL;
> -}
> -
> static int pvt_ts_dbgfs_create(struct pvt_device *pvt, struct device *dev)
> {
> - pvt->dbgfs_dir = debugfs_create_dir(dev_name(dev), NULL);
> + pvt->dbgfs_dir = devm_debugfs_create_dir(dev, dev_name(dev), NULL);
> + if (IS_ERR(pvt->dbgfs_dir))
> + return PTR_ERR(pvt->dbgfs_dir);
>
> debugfs_create_u32("ts_coeff_h", 0644, pvt->dbgfs_dir,
> &pvt->ts_coeff.h);
> @@ -237,7 +232,7 @@ static int pvt_ts_dbgfs_create(struct pvt_device *pvt, struct device *dev)
> debugfs_create_file("ts_coeff_j", 0644, pvt->dbgfs_dir, pvt,
> &pvt_ts_coeff_j_fops);
>
> - return devm_add_action_or_reset(dev, devm_pvt_ts_dbgfs_remove, pvt);
> + return 0;
> }
>
> static umode_t pvt_is_visible(const void *data, enum hwmon_sensor_types type,
> diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> index 1363d9f89181..e0f956a21125 100644
> --- a/drivers/hwmon/pmbus/pmbus_core.c
> +++ b/drivers/hwmon/pmbus/pmbus_core.c
> @@ -7,6 +7,7 @@
> */
>
> #include <linux/debugfs.h>
> +#include <linux/devm-helpers.h>
> #include <linux/kernel.h>
> #include <linux/math64.h>
> #include <linux/module.h>
> @@ -3336,13 +3337,6 @@ static const struct file_operations pmbus_debugfs_ops_mfr = {
> .open = simple_open,
> };
>
> -static void pmbus_remove_debugfs(void *data)
> -{
> - struct dentry *entry = data;
> -
> - debugfs_remove_recursive(entry);
> -}
> -
> static int pmbus_init_debugfs(struct i2c_client *client,
> struct pmbus_data *data)
> {
> @@ -3357,8 +3351,9 @@ static int pmbus_init_debugfs(struct i2c_client *client,
> * Create the debugfs directory for this device. Use the hwmon device
> * name to avoid conflicts (hwmon numbers are globally unique).
> */
> - data->debugfs = debugfs_create_dir(dev_name(data->hwmon_dev),
> - pmbus_debugfs_dir);
> + data->debugfs = devm_debugfs_create_dir(data->dev,
> + dev_name(data->hwmon_dev),
> + pmbus_debugfs_dir);
> if (IS_ERR_OR_NULL(data->debugfs)) {
> data->debugfs = NULL;
> return -ENODEV;
> @@ -3542,8 +3537,7 @@ static int pmbus_init_debugfs(struct i2c_client *client,
> }
> }
>
> - return devm_add_action_or_reset(data->dev,
> - pmbus_remove_debugfs, data->debugfs);
> + return 0;
> }
> #else
> static int pmbus_init_debugfs(struct i2c_client *client,
> diff --git a/include/linux/devm-helpers.h b/include/linux/devm-helpers.h
> index 70640fb96117..39d743175ec4 100644
> --- a/include/linux/devm-helpers.h
> +++ b/include/linux/devm-helpers.h
> @@ -23,6 +23,7 @@
> * already ran.
> */
>
> +#include <linux/debugfs.h>
> #include <linux/device.h>
> #include <linux/kconfig.h>
> #include <linux/mutex.h>
> @@ -108,4 +109,51 @@ static inline int devm_mutex_init(struct device *dev, struct mutex *lock)
> return 0;
> }
>
> +static inline void devm_debugfs_dir_recursive_drop(void *res)
> +{
> + debugfs_remove_recursive(res);
> +}
> +
> +/**
> + * devm_debugfs_create_dir - Resource managed debugfs directory creation
> + * @dev: Device which lifetime the directory is bound to
> + * @name: a pointer to a string containing the name of the directory to
> + * create
> + * @parent: a pointer to the parent dentry for this file. This should be a
> + * directory dentry if set. If this parameter is NULL, then the
> + * directory will be created in the root of the debugfs filesystem.
> + *
> + * Create a debugfs directory which is automatically recursively removed when
> + * the driver is detached. A few drivers create debugfs directories which they
> + * want removed before driver is detached.
> + * devm_debugfs_create_dir() can be used to omit the explicit
> + * debugfs_remove_recursive() call when driver is detached.
> + */
> +static inline struct dentry *
> +devm_debugfs_create_dir(struct device *dev, const char *name,
> + struct dentry *parent)
> +{
> + struct dentry *dentry;
> +
> + dentry = debugfs_create_dir(name, parent);
> + if (IS_ERR(dentry))
> + return dentry;
> +
> + /*
> + * debugfs_remove_recursive() is an empty function if CONFIG_DEBUG_FS is
> + * disabled. No need to register an action in that case.
> + */
> + if (IS_ENABLED(CONFIG_DEBUG_FS)) {
> + int err;
> +
> + err = devm_add_action_or_reset(dev,
> + devm_debugfs_dir_recursive_drop,
> + dentry);
> + if (err < 0)
> + return ERR_PTR(err);
> + }
> +
> + return dentry;
> +}
> +
> #endif