* [PATCH] debugfs: add helper function to create device related seq_file
@ 2014-10-11 16:01 Arend van Spriel
2014-10-11 16:09 ` Arend van Spriel
2014-10-11 20:17 ` Greg Kroah-Hartman
0 siblings, 2 replies; 6+ messages in thread
From: Arend van Spriel @ 2014-10-11 16:01 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: linux-kernel, Arend van Spriel
This patch adds a helper function that simplifies adding a
sequence file for device drivers. The calling device driver
needs to provide a read function and a device pointer. The
field struct seq_file::private will reference the device
pointer upon call to the read function so the driver can
obtain his data from it and do its seq_printf() calls.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
---
fs/debugfs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/debugfs.h | 16 ++++++++++++++-
2 files changed, 69 insertions(+), 1 deletion(-)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 76c08c2..088b3fc 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -22,6 +22,7 @@
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/atomic.h>
+#include <linux/device.h>
static ssize_t default_read_file(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
@@ -761,3 +762,56 @@ struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
EXPORT_SYMBOL_GPL(debugfs_create_regset32);
#endif /* CONFIG_HAS_IOMEM */
+
+struct debugfs_devm_entry {
+ int (*read)(struct seq_file *seq, void *data);
+ struct device *dev;
+};
+
+static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
+{
+ struct debugfs_devm_entry *entry = inode->i_private;
+
+ return single_open(f, entry->read, entry->dev);
+}
+
+static const struct file_operations debugfs_devm_entry_ops = {
+ .owner = THIS_MODULE,
+ .open = debugfs_devm_entry_open,
+ .release = single_release,
+ .read = seq_read,
+ .llseek = seq_lseek
+};
+
+/**
+ * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
+ *
+ * @dev: device related to this debugfs file.
+ * @name: name of the debugfs file.
+ * @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
+ * file will be created in the root of the debugfs filesystem.
+ * @read_fn: function pointer called to print the seq_file content.
+ */
+struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
+ struct dentry *parent,
+ int (*read_fn)(struct seq_file *s,
+ void *data))
+{
+ struct debugfs_devm_entry *entry;
+
+ if (IS_ERR(parent))
+ return ERR_PTR(-ENOENT);
+
+ entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return ERR_PTR(-ENOMEM);
+
+ entry->read = read_fn;
+ entry->dev = dev;
+
+ return debugfs_create_file(name, S_IRUGO, parent, entry,
+ &debugfs_devm_entry_ops);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);
+
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 4d0b4d1..f8c0db4 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -99,13 +99,18 @@ struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
struct dentry *parent,
u32 *array, u32 elements);
+struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
+ struct dentry *parent,
+ int (*read_fn)(struct seq_file *s,
+ void *data));
+
bool debugfs_initialized(void);
#else
#include <linux/err.h>
-/*
+/*
* We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
* so users have a chance to detect if there was a real error or not. We don't
* want to duplicate the design decision mistakes of procfs and devfs again.
@@ -251,6 +256,15 @@ static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t
return ERR_PTR(-ENODEV);
}
+static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
+ const char *name,
+ struct dentry *parent,
+ int (*read_fn)(struct seq_file *s,
+ void *data))
+{
+ return ERR_PTR(-ENODEV);
+}
+
#endif
#endif
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] debugfs: add helper function to create device related seq_file
2014-10-11 16:01 [PATCH] debugfs: add helper function to create device related seq_file Arend van Spriel
@ 2014-10-11 16:09 ` Arend van Spriel
2014-10-11 20:17 ` Greg Kroah-Hartman
2014-10-11 20:17 ` Greg Kroah-Hartman
1 sibling, 1 reply; 6+ messages in thread
From: Arend van Spriel @ 2014-10-11 16:09 UTC (permalink / raw)
To: Arend van Spriel; +Cc: Greg Kroah-Hartman, linux-kernel
On 10/11/14 18:01, Arend van Spriel wrote:
> This patch adds a helper function that simplifies adding a
> sequence file for device drivers. The calling device driver
> needs to provide a read function and a device pointer. The
> field struct seq_file::private will reference the device
> pointer upon call to the read function so the driver can
> obtain his data from it and do its seq_printf() calls.
Maybe should have made this RFC first. Anyways, it is intended for 3.19,
although I don't mind if it would end up in 3.18 :-p
Regards,
Arend
> Signed-off-by: Arend van Spriel<arend@broadcom.com>
> ---
> fs/debugfs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/debugfs.h | 16 ++++++++++++++-
> 2 files changed, 69 insertions(+), 1 deletion(-)
>
> diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
> index 76c08c2..088b3fc 100644
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -22,6 +22,7 @@
> #include<linux/io.h>
> #include<linux/slab.h>
> #include<linux/atomic.h>
> +#include<linux/device.h>
>
> static ssize_t default_read_file(struct file *file, char __user *buf,
> size_t count, loff_t *ppos)
> @@ -761,3 +762,56 @@ struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
> EXPORT_SYMBOL_GPL(debugfs_create_regset32);
>
> #endif /* CONFIG_HAS_IOMEM */
> +
> +struct debugfs_devm_entry {
> + int (*read)(struct seq_file *seq, void *data);
> + struct device *dev;
> +};
> +
> +static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
> +{
> + struct debugfs_devm_entry *entry = inode->i_private;
> +
> + return single_open(f, entry->read, entry->dev);
> +}
> +
> +static const struct file_operations debugfs_devm_entry_ops = {
> + .owner = THIS_MODULE,
> + .open = debugfs_devm_entry_open,
> + .release = single_release,
> + .read = seq_read,
> + .llseek = seq_lseek
> +};
> +
> +/**
> + * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
> + *
> + * @dev: device related to this debugfs file.
> + * @name: name of the debugfs file.
> + * @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
> + * file will be created in the root of the debugfs filesystem.
> + * @read_fn: function pointer called to print the seq_file content.
> + */
> +struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
> + struct dentry *parent,
> + int (*read_fn)(struct seq_file *s,
> + void *data))
> +{
> + struct debugfs_devm_entry *entry;
> +
> + if (IS_ERR(parent))
> + return ERR_PTR(-ENOENT);
> +
> + entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
> + if (!entry)
> + return ERR_PTR(-ENOMEM);
> +
> + entry->read = read_fn;
> + entry->dev = dev;
> +
> + return debugfs_create_file(name, S_IRUGO, parent, entry,
> + &debugfs_devm_entry_ops);
> +}
> +EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);
> +
> diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
> index 4d0b4d1..f8c0db4 100644
> --- a/include/linux/debugfs.h
> +++ b/include/linux/debugfs.h
> @@ -99,13 +99,18 @@ struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
> struct dentry *parent,
> u32 *array, u32 elements);
>
> +struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
> + struct dentry *parent,
> + int (*read_fn)(struct seq_file *s,
> + void *data));
> +
> bool debugfs_initialized(void);
>
> #else
>
> #include<linux/err.h>
>
> -/*
> +/*
> * We do not return NULL from these functions if CONFIG_DEBUG_FS is not enabled
> * so users have a chance to detect if there was a real error or not. We don't
> * want to duplicate the design decision mistakes of procfs and devfs again.
> @@ -251,6 +256,15 @@ static inline struct dentry *debugfs_create_u32_array(const char *name, umode_t
> return ERR_PTR(-ENODEV);
> }
>
> +static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
> + const char *name,
> + struct dentry *parent,
> + int (*read_fn)(struct seq_file *s,
> + void *data))
> +{
> + return ERR_PTR(-ENODEV);
> +}
> +
> #endif
>
> #endif
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] debugfs: add helper function to create device related seq_file
2014-10-11 16:09 ` Arend van Spriel
@ 2014-10-11 20:17 ` Greg Kroah-Hartman
0 siblings, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2014-10-11 20:17 UTC (permalink / raw)
To: Arend van Spriel; +Cc: linux-kernel
On Sat, Oct 11, 2014 at 06:09:47PM +0200, Arend van Spriel wrote:
> On 10/11/14 18:01, Arend van Spriel wrote:
> >This patch adds a helper function that simplifies adding a
> >sequence file for device drivers. The calling device driver
> >needs to provide a read function and a device pointer. The
> >field struct seq_file::private will reference the device
> >pointer upon call to the read function so the driver can
> >obtain his data from it and do its seq_printf() calls.
>
> Maybe should have made this RFC first. Anyways, it is intended for 3.19,
> although I don't mind if it would end up in 3.18 :-p
It's too late for 3.18, sorry.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] debugfs: add helper function to create device related seq_file
2014-10-11 16:01 [PATCH] debugfs: add helper function to create device related seq_file Arend van Spriel
2014-10-11 16:09 ` Arend van Spriel
@ 2014-10-11 20:17 ` Greg Kroah-Hartman
2014-10-12 8:13 ` Arend van Spriel
1 sibling, 1 reply; 6+ messages in thread
From: Greg Kroah-Hartman @ 2014-10-11 20:17 UTC (permalink / raw)
To: Arend van Spriel; +Cc: linux-kernel
On Sat, Oct 11, 2014 at 06:01:55PM +0200, Arend van Spriel wrote:
> This patch adds a helper function that simplifies adding a
> sequence file for device drivers. The calling device driver
> needs to provide a read function and a device pointer. The
> field struct seq_file::private will reference the device
> pointer upon call to the read function so the driver can
> obtain his data from it and do its seq_printf() calls.
>
> Signed-off-by: Arend van Spriel <arend@broadcom.com>
> ---
> fs/debugfs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/debugfs.h | 16 ++++++++++++++-
> 2 files changed, 69 insertions(+), 1 deletion(-)
Do you have some kernel code pending that needs this change? Or can
existing users be moved to it, saving them code?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] debugfs: add helper function to create device related seq_file
2014-10-11 20:17 ` Greg Kroah-Hartman
@ 2014-10-12 8:13 ` Arend van Spriel
2014-10-19 13:57 ` Arend van Spriel
0 siblings, 1 reply; 6+ messages in thread
From: Arend van Spriel @ 2014-10-12 8:13 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: linux-kernel
On 11-10-14 22:17, Greg Kroah-Hartman wrote:
> On Sat, Oct 11, 2014 at 06:01:55PM +0200, Arend van Spriel wrote:
>> This patch adds a helper function that simplifies adding a
>> sequence file for device drivers. The calling device driver
>> needs to provide a read function and a device pointer. The
>> field struct seq_file::private will reference the device
>> pointer upon call to the read function so the driver can
>> obtain his data from it and do its seq_printf() calls.
>>
>> Signed-off-by: Arend van Spriel <arend@broadcom.com>
>> ---
>> fs/debugfs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
>> include/linux/debugfs.h | 16 ++++++++++++++-
>> 2 files changed, 69 insertions(+), 1 deletion(-)
>
> Do you have some kernel code pending that needs this change? Or can
> existing users be moved to it, saving them code?
Yes and maybe. I made a similar change in our brcm80211 drivers, but
figured it may be useful for other device drivers. So when this gets in
the kernel I want to align the brcm80211 drivers. I will also have a
quick look at the wireless drivers and get some metrics about code savings.
Regards,
Arend
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] debugfs: add helper function to create device related seq_file
2014-10-12 8:13 ` Arend van Spriel
@ 2014-10-19 13:57 ` Arend van Spriel
0 siblings, 0 replies; 6+ messages in thread
From: Arend van Spriel @ 2014-10-19 13:57 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: linux-kernel
On 12-10-14 10:13, Arend van Spriel wrote:
> On 11-10-14 22:17, Greg Kroah-Hartman wrote:
>> On Sat, Oct 11, 2014 at 06:01:55PM +0200, Arend van Spriel wrote:
>>> This patch adds a helper function that simplifies adding a
>>> sequence file for device drivers. The calling device driver
>>> needs to provide a read function and a device pointer. The
>>> field struct seq_file::private will reference the device
>>> pointer upon call to the read function so the driver can
>>> obtain his data from it and do its seq_printf() calls.
>>>
>>> Signed-off-by: Arend van Spriel <arend@broadcom.com>
>>> ---
>>> fs/debugfs/file.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
>>> include/linux/debugfs.h | 16 ++++++++++++++-
>>> 2 files changed, 69 insertions(+), 1 deletion(-)
>>
>> Do you have some kernel code pending that needs this change? Or can
>> existing users be moved to it, saving them code?
>
> Yes and maybe. I made a similar change in our brcm80211 drivers, but
> figured it may be useful for other device drivers. So when this gets in
> the kernel I want to align the brcm80211 drivers. I will also have a
> quick look at the wireless drivers and get some metrics about code savings.
Hi, Greg
Killed a bit of time between lpc sessions in dusseldorf. I picked the
ath9k wireless driver as a test case. I made the changes in two steps.
First step was changing to use seq_file api and second step made use of
the helper function:
original seq_file helper
logstat - 173+/255- 32+/96-
ath9k.o 115968 113224 111024 (.text size)
I am considering to make an attempt at capturing the transition in a
SmPL script so it can be applied to other drivers as well. Have to do a
bit of self-study for that ;-)
Regards,
Arend
^ permalink raw reply [flat|nested] 6+ messages in thread
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2014-10-11 16:01 [PATCH] debugfs: add helper function to create device related seq_file Arend van Spriel
2014-10-11 16:09 ` Arend van Spriel
2014-10-11 20:17 ` Greg Kroah-Hartman
2014-10-11 20:17 ` Greg Kroah-Hartman
2014-10-12 8:13 ` Arend van Spriel
2014-10-19 13:57 ` Arend van Spriel
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