diff mbox series

[net-next,v5,1/6] posix-clock: introduce posix_clock_context concept

Message ID 992c76f8570de9e0549c4d2446d17cae0a959b77.1696804243.git.reibax@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ptp: Support for multiple filtered timestamp event queue readers | expand

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Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1375 this patch: 1375
netdev/cc_maintainers success CCed 3 of 3 maintainers
netdev/build_clang success Errors and warnings before: 1388 this patch: 1388
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1400 this patch: 1400
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Xabier Marquiegui Oct. 8, 2023, 10:49 p.m. UTC 
Add the necessary structure to support custom private-data per
posix-clock user.

The previous implementation of posix-clock assumed all file open
instances need access to the same clock structure on private_data.

The need for individual data structures per file open instance has been
identified when developing support for multiple timestamp event queue
users for ptp_clock.

This patch introduces a generic posix_clock_context data structure as a
solution to that, and similar problems.

Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
---
v3:
  - fix spelling on commit message
v2: https://lore.kernel.org/netdev/35e1e4f96e8ad58b4ee6a7fd46424f4cd6294353.1696511486.git.reibax@gmail.com/
  - split from previous patch that combined more changes
  - rename posix_clock_user to posix_clock_context
  - remove unnecessary flush_users clock operation
  - remove unnecessary tests
v1: https://lore.kernel.org/netdev/20230928133544.3642650-3-reibax@gmail.com/
---
 drivers/ptp/ptp_chardev.c   | 21 +++++++++++++--------
 drivers/ptp/ptp_private.h   | 16 +++++++++-------
 include/linux/posix-clock.h | 22 ++++++++++++++--------
 kernel/time/posix-clock.c   | 36 +++++++++++++++++++++++++++---------
 4 files changed, 63 insertions(+), 32 deletions(-)

Comments

Richard Cochran Oct. 9, 2023, 2:04 a.m. UTC | #1 
On Mon, Oct 09, 2023 at 12:49:16AM +0200, Xabier Marquiegui wrote:

> -int ptp_open(struct posix_clock *pc, fmode_t fmode)
> +int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
>  {
>  	return 0;
>  }

You are changing the functional interface, as needed, but I wonder
whether drivers/ptp/ptp_chardev.c is the only driver that implements
open/read/ioctl.

Did you audit the callers of posix_clock_register(), or maybe do a
`make allyesconfig` ?

Thanks,
Richard
Thomas Gleixner Oct. 9, 2023, 2:52 p.m. UTC | #2 
On Mon, Oct 09 2023 at 00:49, Xabier Marquiegui wrote:

> Add the necessary structure to support custom private-data per
> posix-clock user.
>
> The previous implementation of posix-clock assumed all file open
> instances need access to the same clock structure on private_data.
>
> The need for individual data structures per file open instance has been
> identified when developing support for multiple timestamp event queue
> users for ptp_clock.
>
> This patch introduces a generic posix_clock_context data structure as a

"This patch .."

We already know that this is a patch.

https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes

>  
> +struct posix_clock_context {
> +	struct posix_clock *clk;
> +	void *private_clkdata;
> +};

https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#struct-declarations-and-initializers

Thanks,

        tglx
Xabier Marquiegui Oct. 11, 2023, 10:30 p.m. UTC | #3 
Richard Cochran said:
> You are changing the functional interface, as needed, but I wonder
> whether drivers/ptp/ptp_chardev.c is the only driver that implements
> open/read/ioctl.
> 
> Did you audit the callers of posix_clock_register(), or maybe do a
> `make allyesconfig` ?

Yes, I have been searching for other drivers using that call, but I haven't
found any. I have also run compilations with allyesconfig in a couple of
build machines, and have seen no errors thrown by the compiler.
diff mbox series

Patch

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 362bf756e6b7..0ba3e7064df2 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -101,14 +101,16 @@  int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
 	return 0;
 }
 
-int ptp_open(struct posix_clock *pc, fmode_t fmode)
+int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 {
 	return 0;
 }
 
-long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
+long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
+	       unsigned long arg)
 {
-	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct ptp_sys_offset_extended *extoff = NULL;
 	struct ptp_sys_offset_precise precise_offset;
 	struct system_device_crosststamp xtstamp;
@@ -432,9 +434,11 @@  long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 	return err;
 }
 
-__poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
+__poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
+		  poll_table *wait)
 {
-	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 
 	poll_wait(fp, &ptp->tsev_wq, wait);
 
@@ -443,10 +447,11 @@  __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 
 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 
-ssize_t ptp_read(struct posix_clock *pc,
-		 uint rdflags, char __user *buf, size_t cnt)
+ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
+		 char __user *buf, size_t cnt)
 {
-	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue = &ptp->tsevq;
 	struct ptp_extts_event *event;
 	unsigned long flags;
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 75f58fc468a7..a3110c85f694 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -117,16 +117,18 @@  extern struct class *ptp_class;
 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
 		    enum ptp_pin_function func, unsigned int chan);
 
-long ptp_ioctl(struct posix_clock *pc,
-	       unsigned int cmd, unsigned long arg);
+long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
+	       unsigned long arg);
 
-int ptp_open(struct posix_clock *pc, fmode_t fmode);
+int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode);
 
-ssize_t ptp_read(struct posix_clock *pc,
-		 uint flags, char __user *buf, size_t cnt);
+int ptp_release(struct posix_clock_context *pccontext);
 
-__poll_t ptp_poll(struct posix_clock *pc,
-	      struct file *fp, poll_table *wait);
+ssize_t ptp_read(struct posix_clock_context *pccontext, uint flags, char __user *buf,
+		 size_t cnt);
+
+__poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
+		  poll_table *wait);
 
 /*
  * see ptp_sysfs.c
diff --git a/include/linux/posix-clock.h b/include/linux/posix-clock.h
index 468328b1e1dd..d7c6f126575f 100644
--- a/include/linux/posix-clock.h
+++ b/include/linux/posix-clock.h
@@ -14,6 +14,7 @@ 
 #include <linux/rwsem.h>
 
 struct posix_clock;
+struct posix_clock_context;
 
 /**
  * struct posix_clock_operations - functional interface to the clock
@@ -50,18 +51,18 @@  struct posix_clock_operations {
 	/*
 	 * Optional character device methods:
 	 */
-	long    (*ioctl)   (struct posix_clock *pc,
-			    unsigned int cmd, unsigned long arg);
+	long (*ioctl)(struct posix_clock_context *pccontext, unsigned int cmd,
+		      unsigned long arg);
 
-	int     (*open)    (struct posix_clock *pc, fmode_t f_mode);
+	int (*open)(struct posix_clock_context *pccontext, fmode_t f_mode);
 
-	__poll_t (*poll)   (struct posix_clock *pc,
-			    struct file *file, poll_table *wait);
+	__poll_t (*poll)(struct posix_clock_context *pccontext, struct file *file,
+			 poll_table *wait);
 
-	int     (*release) (struct posix_clock *pc);
+	int (*release)(struct posix_clock_context *pccontext);
 
-	ssize_t (*read)    (struct posix_clock *pc,
-			    uint flags, char __user *buf, size_t cnt);
+	ssize_t (*read)(struct posix_clock_context *pccontext, uint flags,
+			char __user *buf, size_t cnt);
 };
 
 /**
@@ -90,6 +91,11 @@  struct posix_clock {
 	bool zombie;
 };
 
+struct posix_clock_context {
+	struct posix_clock *clk;
+	void *private_clkdata;
+};
+
 /**
  * posix_clock_register() - register a new clock
  * @clk:   Pointer to the clock. Caller must provide 'ops' field
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c
index 77c0c2370b6d..9de66bbbb3d1 100644
--- a/kernel/time/posix-clock.c
+++ b/kernel/time/posix-clock.c
@@ -19,7 +19,8 @@ 
  */
 static struct posix_clock *get_posix_clock(struct file *fp)
 {
-	struct posix_clock *clk = fp->private_data;
+	struct posix_clock_context *pccontext = fp->private_data;
+	struct posix_clock *clk = pccontext->clk;
 
 	down_read(&clk->rwsem);
 
@@ -39,6 +40,7 @@  static void put_posix_clock(struct posix_clock *clk)
 static ssize_t posix_clock_read(struct file *fp, char __user *buf,
 				size_t count, loff_t *ppos)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	int err = -EINVAL;
 
@@ -46,7 +48,7 @@  static ssize_t posix_clock_read(struct file *fp, char __user *buf,
 		return -ENODEV;
 
 	if (clk->ops.read)
-		err = clk->ops.read(clk, fp->f_flags, buf, count);
+		err = clk->ops.read(pccontext, fp->f_flags, buf, count);
 
 	put_posix_clock(clk);
 
@@ -55,6 +57,7 @@  static ssize_t posix_clock_read(struct file *fp, char __user *buf,
 
 static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	__poll_t result = 0;
 
@@ -62,7 +65,7 @@  static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
 		return EPOLLERR;
 
 	if (clk->ops.poll)
-		result = clk->ops.poll(clk, fp, wait);
+		result = clk->ops.poll(pccontext, fp, wait);
 
 	put_posix_clock(clk);
 
@@ -72,6 +75,7 @@  static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
 static long posix_clock_ioctl(struct file *fp,
 			      unsigned int cmd, unsigned long arg)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	int err = -ENOTTY;
 
@@ -79,7 +83,7 @@  static long posix_clock_ioctl(struct file *fp,
 		return -ENODEV;
 
 	if (clk->ops.ioctl)
-		err = clk->ops.ioctl(clk, cmd, arg);
+		err = clk->ops.ioctl(pccontext, cmd, arg);
 
 	put_posix_clock(clk);
 
@@ -90,6 +94,7 @@  static long posix_clock_ioctl(struct file *fp,
 static long posix_clock_compat_ioctl(struct file *fp,
 				     unsigned int cmd, unsigned long arg)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	int err = -ENOTTY;
 
@@ -97,7 +102,7 @@  static long posix_clock_compat_ioctl(struct file *fp,
 		return -ENODEV;
 
 	if (clk->ops.ioctl)
-		err = clk->ops.ioctl(clk, cmd, arg);
+		err = clk->ops.ioctl(pccontext, cmd, arg);
 
 	put_posix_clock(clk);
 
@@ -110,6 +115,7 @@  static int posix_clock_open(struct inode *inode, struct file *fp)
 	int err;
 	struct posix_clock *clk =
 		container_of(inode->i_cdev, struct posix_clock, cdev);
+	struct posix_clock_context *pccontext;
 
 	down_read(&clk->rwsem);
 
@@ -117,14 +123,20 @@  static int posix_clock_open(struct inode *inode, struct file *fp)
 		err = -ENODEV;
 		goto out;
 	}
+	pccontext = kzalloc(sizeof(*pccontext), GFP_KERNEL);
+	if (!pccontext) {
+		err = -ENOMEM;
+		goto out;
+	}
+	pccontext->clk = clk;
+	fp->private_data = pccontext;
 	if (clk->ops.open)
-		err = clk->ops.open(clk, fp->f_mode);
+		err = clk->ops.open(pccontext, fp->f_mode);
 	else
 		err = 0;
 
 	if (!err) {
 		get_device(clk->dev);
-		fp->private_data = clk;
 	}
 out:
 	up_read(&clk->rwsem);
@@ -133,14 +145,20 @@  static int posix_clock_open(struct inode *inode, struct file *fp)
 
 static int posix_clock_release(struct inode *inode, struct file *fp)
 {
-	struct posix_clock *clk = fp->private_data;
+	struct posix_clock_context *pccontext = fp->private_data;
+	struct posix_clock *clk;
 	int err = 0;
 
+	if (!pccontext)
+		return -ENODEV;
+	clk = pccontext->clk;
+
 	if (clk->ops.release)
-		err = clk->ops.release(clk);
+		err = clk->ops.release(pccontext);
 
 	put_device(clk->dev);
 
+	kfree(pccontext);
 	fp->private_data = NULL;
 
 	return err;