[v3,1/4] i915: Move list_count() to list.h for broader use

Message ID 20221122153516.52577-1-andriy.shevchenko@linux.intel.com
State New
Headers
Series [v3,1/4] i915: Move list_count() to list.h for broader use |

Commit Message

Andy Shevchenko Nov. 22, 2022, 3:35 p.m. UTC
  Some of the existing users, and definitely will be new ones, want to
count existing nodes in the list. Provide a generic API for that by
moving code from i915 to list.h.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
---
v3: added tag (Jani), changed to be static inline (Mike)
v2: dropped the duplicate code in i915 (LKP)
 drivers/gpu/drm/i915/gt/intel_engine_cs.c | 13 +------------
 include/linux/list.h                      | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 12 deletions(-)
  

Comments

Andy Shevchenko Nov. 22, 2022, 3:43 p.m. UTC | #1
On Tue, Nov 22, 2022 at 05:35:13PM +0200, Andy Shevchenko wrote:
> Some of the existing users, and definitely will be new ones, want to
> count existing nodes in the list. Provide a generic API for that by
> moving code from i915 to list.h.

Sorry for the noise, forgot to squash one part, so it get's not compilable.
  
kernel test robot Nov. 22, 2022, 6:13 p.m. UTC | #2
Hi Andy,

I love your patch! Yet something to improve:

[auto build test ERROR on usb/usb-testing]
[also build test ERROR on usb/usb-next usb/usb-linus drm-intel/for-linux-next drm-intel/for-linux-next-fixes linus/master v6.1-rc6 next-20221122]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/i915-Move-list_count-to-list-h-for-broader-use/20221122-233657
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20221122153516.52577-1-andriy.shevchenko%40linux.intel.com
patch subject: [PATCH v3 1/4] i915: Move list_count() to list.h for broader use
config: um-i386_defconfig
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/3d217ef769536f160f5c20224aeb0f9070bdfdcf
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andy-Shevchenko/i915-Move-list_count-to-list-h-for-broader-use/20221122-233657
        git checkout 3d217ef769536f160f5c20224aeb0f9070bdfdcf
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=um SUBARCH=i386 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   ld: fs/isofs/inode.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/isofs/namei.o:include/linux/list.h:663: first defined here
   ld: fs/isofs/dir.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/isofs/namei.o:include/linux/list.h:663: first defined here
   ld: fs/isofs/util.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/isofs/namei.o:include/linux/list.h:663: first defined here
   ld: fs/isofs/rock.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/isofs/namei.o:include/linux/list.h:663: first defined here
   ld: fs/isofs/export.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/isofs/namei.o:include/linux/list.h:663: first defined here
   ld: fs/isofs/joliet.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/isofs/namei.o:include/linux/list.h:663: first defined here
--
   ld: fs/autofs/inode.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/autofs/init.o:include/linux/list.h:663: first defined here
   ld: fs/autofs/root.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/autofs/init.o:include/linux/list.h:663: first defined here
   ld: fs/autofs/symlink.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/autofs/init.o:include/linux/list.h:663: first defined here
   ld: fs/autofs/waitq.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/autofs/init.o:include/linux/list.h:663: first defined here
   ld: fs/autofs/expire.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/autofs/init.o:include/linux/list.h:663: first defined here
   ld: fs/autofs/dev-ioctl.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; fs/autofs/init.o:include/linux/list.h:663: first defined here
--
   ld: block/bfq-wf2q.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; block/bfq-iosched.o:include/linux/list.h:663: first defined here
   ld: block/bfq-cgroup.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; block/bfq-iosched.o:include/linux/list.h:663: first defined here


vim +663 include/linux/list.h

   557	
   558	/**
   559	 * list_next_entry - get the next element in list
   560	 * @pos:	the type * to cursor
   561	 * @member:	the name of the list_head within the struct.
   562	 */
   563	#define list_next_entry(pos, member) \
   564		list_entry((pos)->member.next, typeof(*(pos)), member)
   565	
   566	/**
   567	 * list_next_entry_circular - get the next element in list
   568	 * @pos:	the type * to cursor.
   569	 * @head:	the list head to take the element from.
   570	 * @member:	the name of the list_head within the struct.
   571	 *
   572	 * Wraparound if pos is the last element (return the first element).
   573	 * Note, that list is expected to be not empty.
   574	 */
   575	#define list_next_entry_circular(pos, head, member) \
   576		(list_is_last(&(pos)->member, head) ? \
   577		list_first_entry(head, typeof(*(pos)), member) : list_next_entry(pos, member))
   578	
   579	/**
   580	 * list_prev_entry - get the prev element in list
   581	 * @pos:	the type * to cursor
   582	 * @member:	the name of the list_head within the struct.
   583	 */
   584	#define list_prev_entry(pos, member) \
   585		list_entry((pos)->member.prev, typeof(*(pos)), member)
   586	
   587	/**
   588	 * list_prev_entry_circular - get the prev element in list
   589	 * @pos:	the type * to cursor.
   590	 * @head:	the list head to take the element from.
   591	 * @member:	the name of the list_head within the struct.
   592	 *
   593	 * Wraparound if pos is the first element (return the last element).
   594	 * Note, that list is expected to be not empty.
   595	 */
   596	#define list_prev_entry_circular(pos, head, member) \
   597		(list_is_first(&(pos)->member, head) ? \
   598		list_last_entry(head, typeof(*(pos)), member) : list_prev_entry(pos, member))
   599	
   600	/**
   601	 * list_for_each	-	iterate over a list
   602	 * @pos:	the &struct list_head to use as a loop cursor.
   603	 * @head:	the head for your list.
   604	 */
   605	#define list_for_each(pos, head) \
   606		for (pos = (head)->next; !list_is_head(pos, (head)); pos = pos->next)
   607	
   608	/**
   609	 * list_for_each_rcu - Iterate over a list in an RCU-safe fashion
   610	 * @pos:	the &struct list_head to use as a loop cursor.
   611	 * @head:	the head for your list.
   612	 */
   613	#define list_for_each_rcu(pos, head)		  \
   614		for (pos = rcu_dereference((head)->next); \
   615		     !list_is_head(pos, (head)); \
   616		     pos = rcu_dereference(pos->next))
   617	
   618	/**
   619	 * list_for_each_continue - continue iteration over a list
   620	 * @pos:	the &struct list_head to use as a loop cursor.
   621	 * @head:	the head for your list.
   622	 *
   623	 * Continue to iterate over a list, continuing after the current position.
   624	 */
   625	#define list_for_each_continue(pos, head) \
   626		for (pos = pos->next; !list_is_head(pos, (head)); pos = pos->next)
   627	
   628	/**
   629	 * list_for_each_prev	-	iterate over a list backwards
   630	 * @pos:	the &struct list_head to use as a loop cursor.
   631	 * @head:	the head for your list.
   632	 */
   633	#define list_for_each_prev(pos, head) \
   634		for (pos = (head)->prev; !list_is_head(pos, (head)); pos = pos->prev)
   635	
   636	/**
   637	 * list_for_each_safe - iterate over a list safe against removal of list entry
   638	 * @pos:	the &struct list_head to use as a loop cursor.
   639	 * @n:		another &struct list_head to use as temporary storage
   640	 * @head:	the head for your list.
   641	 */
   642	#define list_for_each_safe(pos, n, head) \
   643		for (pos = (head)->next, n = pos->next; \
   644		     !list_is_head(pos, (head)); \
   645		     pos = n, n = pos->next)
   646	
   647	/**
   648	 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
   649	 * @pos:	the &struct list_head to use as a loop cursor.
   650	 * @n:		another &struct list_head to use as temporary storage
   651	 * @head:	the head for your list.
   652	 */
   653	#define list_for_each_prev_safe(pos, n, head) \
   654		for (pos = (head)->prev, n = pos->prev; \
   655		     !list_is_head(pos, (head)); \
   656		     pos = n, n = pos->prev)
   657	
   658	/**
   659	 * list_count - count nodes in the list
   660	 * @head:	the head for your list.
   661	 */
   662	size_t list_count(struct list_head *head)
 > 663	{
   664		struct list_head *pos;
   665		size_t count = 0;
   666	
   667		list_for_each(pos, head)
   668			count++;
   669	
   670		return count;
   671	}
   672
  
kernel test robot Nov. 22, 2022, 6:43 p.m. UTC | #3
Hi Andy,

I love your patch! Yet something to improve:

[auto build test ERROR on usb/usb-testing]
[also build test ERROR on usb/usb-next usb/usb-linus drm-intel/for-linux-next drm-intel/for-linux-next-fixes linus/master v6.1-rc6 next-20221122]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/i915-Move-list_count-to-list-h-for-broader-use/20221122-233657
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20221122153516.52577-1-andriy.shevchenko%40linux.intel.com
patch subject: [PATCH v3 1/4] i915: Move list_count() to list.h for broader use
config: s390-defconfig
compiler: s390-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/3d217ef769536f160f5c20224aeb0f9070bdfdcf
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andy-Shevchenko/i915-Move-list_count-to-list-h-for-broader-use/20221122-233657
        git checkout 3d217ef769536f160f5c20224aeb0f9070bdfdcf
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 prepare

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   scripts/genksyms/parse.y: warning: 9 shift/reduce conflicts [-Wconflicts-sr]
   scripts/genksyms/parse.y: warning: 5 reduce/reduce conflicts [-Wconflicts-rr]
   scripts/genksyms/parse.y: note: rerun with option '-Wcounterexamples' to generate conflict counterexamples
   In file included from include/linux/preempt.h:11,
                    from include/linux/percpu.h:6,
                    from include/linux/context_tracking_state.h:5,
                    from include/linux/hardirq.h:5,
                    from include/linux/kvm_host.h:7,
                    from arch/s390/kernel/asm-offsets.c:11:
   include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   In file included from include/linux/preempt.h:11,
                    from arch/s390/include/asm/timex.h:13,
                    from arch/s390/kernel/vdso64/getcpu.c:6:
   include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from arch/s390/include/asm/syscall.h:13,
                    from arch/s390/include/asm/vdso/gettimeofday.h:9,
                    from include/vdso/datapage.h:137,
                    from arch/s390/kernel/vdso64/../../../../lib/vdso/gettimeofday.c:5,
                    from arch/s390/kernel/vdso64/vdso64_generic.c:2:
   include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   s390-linux-ld: arch/s390/kernel/vdso64/getcpu.o: in function `list_count':
>> include/linux/list.h:663: multiple definition of `list_count'; arch/s390/kernel/vdso64/vdso64_generic.o:include/linux/list.h:663: first defined here
   make[2]: *** [arch/s390/kernel/vdso64/Makefile:50: arch/s390/kernel/vdso64/vdso64.so.dbg] Error 1
   make[2]: Target 'include/generated/vdso64-offsets.h' not remade because of errors.
   make[1]: *** [arch/s390/Makefile:159: vdso_prepare] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:231: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.


vim +663 include/linux/list.h

   557	
   558	/**
   559	 * list_next_entry - get the next element in list
   560	 * @pos:	the type * to cursor
   561	 * @member:	the name of the list_head within the struct.
   562	 */
   563	#define list_next_entry(pos, member) \
   564		list_entry((pos)->member.next, typeof(*(pos)), member)
   565	
   566	/**
   567	 * list_next_entry_circular - get the next element in list
   568	 * @pos:	the type * to cursor.
   569	 * @head:	the list head to take the element from.
   570	 * @member:	the name of the list_head within the struct.
   571	 *
   572	 * Wraparound if pos is the last element (return the first element).
   573	 * Note, that list is expected to be not empty.
   574	 */
   575	#define list_next_entry_circular(pos, head, member) \
   576		(list_is_last(&(pos)->member, head) ? \
   577		list_first_entry(head, typeof(*(pos)), member) : list_next_entry(pos, member))
   578	
   579	/**
   580	 * list_prev_entry - get the prev element in list
   581	 * @pos:	the type * to cursor
   582	 * @member:	the name of the list_head within the struct.
   583	 */
   584	#define list_prev_entry(pos, member) \
   585		list_entry((pos)->member.prev, typeof(*(pos)), member)
   586	
   587	/**
   588	 * list_prev_entry_circular - get the prev element in list
   589	 * @pos:	the type * to cursor.
   590	 * @head:	the list head to take the element from.
   591	 * @member:	the name of the list_head within the struct.
   592	 *
   593	 * Wraparound if pos is the first element (return the last element).
   594	 * Note, that list is expected to be not empty.
   595	 */
   596	#define list_prev_entry_circular(pos, head, member) \
   597		(list_is_first(&(pos)->member, head) ? \
   598		list_last_entry(head, typeof(*(pos)), member) : list_prev_entry(pos, member))
   599	
   600	/**
   601	 * list_for_each	-	iterate over a list
   602	 * @pos:	the &struct list_head to use as a loop cursor.
   603	 * @head:	the head for your list.
   604	 */
   605	#define list_for_each(pos, head) \
   606		for (pos = (head)->next; !list_is_head(pos, (head)); pos = pos->next)
   607	
   608	/**
   609	 * list_for_each_rcu - Iterate over a list in an RCU-safe fashion
   610	 * @pos:	the &struct list_head to use as a loop cursor.
   611	 * @head:	the head for your list.
   612	 */
   613	#define list_for_each_rcu(pos, head)		  \
   614		for (pos = rcu_dereference((head)->next); \
   615		     !list_is_head(pos, (head)); \
   616		     pos = rcu_dereference(pos->next))
   617	
   618	/**
   619	 * list_for_each_continue - continue iteration over a list
   620	 * @pos:	the &struct list_head to use as a loop cursor.
   621	 * @head:	the head for your list.
   622	 *
   623	 * Continue to iterate over a list, continuing after the current position.
   624	 */
   625	#define list_for_each_continue(pos, head) \
   626		for (pos = pos->next; !list_is_head(pos, (head)); pos = pos->next)
   627	
   628	/**
   629	 * list_for_each_prev	-	iterate over a list backwards
   630	 * @pos:	the &struct list_head to use as a loop cursor.
   631	 * @head:	the head for your list.
   632	 */
   633	#define list_for_each_prev(pos, head) \
   634		for (pos = (head)->prev; !list_is_head(pos, (head)); pos = pos->prev)
   635	
   636	/**
   637	 * list_for_each_safe - iterate over a list safe against removal of list entry
   638	 * @pos:	the &struct list_head to use as a loop cursor.
   639	 * @n:		another &struct list_head to use as temporary storage
   640	 * @head:	the head for your list.
   641	 */
   642	#define list_for_each_safe(pos, n, head) \
   643		for (pos = (head)->next, n = pos->next; \
   644		     !list_is_head(pos, (head)); \
   645		     pos = n, n = pos->next)
   646	
   647	/**
   648	 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
   649	 * @pos:	the &struct list_head to use as a loop cursor.
   650	 * @n:		another &struct list_head to use as temporary storage
   651	 * @head:	the head for your list.
   652	 */
   653	#define list_for_each_prev_safe(pos, n, head) \
   654		for (pos = (head)->prev, n = pos->prev; \
   655		     !list_is_head(pos, (head)); \
   656		     pos = n, n = pos->prev)
   657	
   658	/**
   659	 * list_count - count nodes in the list
   660	 * @head:	the head for your list.
   661	 */
   662	size_t list_count(struct list_head *head)
 > 663	{
   664		struct list_head *pos;
   665		size_t count = 0;
   666	
   667		list_for_each(pos, head)
   668			count++;
   669	
   670		return count;
   671	}
   672
  
kernel test robot Nov. 23, 2022, 10:02 a.m. UTC | #4
Hi Andy,

I love your patch! Perhaps something to improve:

[auto build test WARNING on usb/usb-testing]
[also build test WARNING on usb/usb-next usb/usb-linus drm-intel/for-linux-next drm-intel/for-linux-next-fixes linus/master v6.1-rc6 next-20221122]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Andy-Shevchenko/i915-Move-list_count-to-list-h-for-broader-use/20221122-233657
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
patch link:    https://lore.kernel.org/r/20221122153516.52577-1-andriy.shevchenko%40linux.intel.com
patch subject: [PATCH v3 1/4] i915: Move list_count() to list.h for broader use
config: m68k-allyesconfig
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/3d217ef769536f160f5c20224aeb0f9070bdfdcf
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andy-Shevchenko/i915-Move-list_count-to-list-h-for-broader-use/20221122-233657
        git checkout 3d217ef769536f160f5c20224aeb0f9070bdfdcf
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k prepare

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from arch/m68k/kernel/asm-offsets.c:15:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
--
   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from arch/m68k/kernel/ptrace.c:14:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/ptrace.c:275:16: warning: no previous prototype for 'syscall_trace_enter' [-Wmissing-prototypes]
     275 | asmlinkage int syscall_trace_enter(void)
         |                ^~~~~~~~~~~~~~~~~~~
   arch/m68k/kernel/ptrace.c:284:17: warning: no previous prototype for 'syscall_trace_leave' [-Wmissing-prototypes]
     284 | asmlinkage void syscall_trace_leave(void)
         |                 ^~~~~~~~~~~~~~~~~~~
--
   In file included from include/linux/preempt.h:11,
                    from include/linux/spinlock.h:56,
                    from include/linux/mmzone.h:8,
                    from include/linux/gfp.h:7,
                    from include/linux/mm.h:7,
                    from arch/m68k/kernel/setup_mm.c:13,
                    from arch/m68k/kernel/setup.c:3:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/setup_mm.c:507:6: warning: no previous prototype for 'check_bugs' [-Wmissing-prototypes]
     507 | void check_bugs(void)
         |      ^~~~~~~~~~
--
   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from arch/m68k/kernel/signal.c:31:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/signal.c:756:18: warning: no previous prototype for 'do_sigreturn' [-Wmissing-prototypes]
     756 | asmlinkage void *do_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
         |                  ^~~~~~~~~~~~
   arch/m68k/kernel/signal.c:783:18: warning: no previous prototype for 'do_rt_sigreturn' [-Wmissing-prototypes]
     783 | asmlinkage void *do_rt_sigreturn(struct pt_regs *regs, struct switch_stack *sw)
         |                  ^~~~~~~~~~~~~~~
   arch/m68k/kernel/signal.c:1106:6: warning: no previous prototype for 'do_notify_resume' [-Wmissing-prototypes]
    1106 | void do_notify_resume(struct pt_regs *regs)
         |      ^~~~~~~~~~~~~~~~
--
   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from arch/m68k/kernel/sys_m68k.c:12:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/sys_m68k.c:40:17: warning: no previous prototype for 'sys_mmap2' [-Wmissing-prototypes]
      40 | asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
         |                 ^~~~~~~~~
   arch/m68k/kernel/sys_m68k.c:378:1: warning: no previous prototype for 'sys_cacheflush' [-Wmissing-prototypes]
     378 | sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
         | ^~~~~~~~~~~~~~
   arch/m68k/kernel/sys_m68k.c:463:1: warning: no previous prototype for 'sys_atomic_cmpxchg_32' [-Wmissing-prototypes]
     463 | sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
         | ^~~~~~~~~~~~~~~~~~~~~
   arch/m68k/kernel/sys_m68k.c:562:16: warning: no previous prototype for 'sys_getpagesize' [-Wmissing-prototypes]
     562 | asmlinkage int sys_getpagesize(void)
         |                ^~~~~~~~~~~~~~~
   arch/m68k/kernel/sys_m68k.c:567:26: warning: no previous prototype for 'sys_get_thread_area' [-Wmissing-prototypes]
     567 | asmlinkage unsigned long sys_get_thread_area(void)
         |                          ^~~~~~~~~~~~~~~~~~~
   arch/m68k/kernel/sys_m68k.c:572:16: warning: no previous prototype for 'sys_set_thread_area' [-Wmissing-prototypes]
     572 | asmlinkage int sys_set_thread_area(unsigned long tp)
         |                ^~~~~~~~~~~~~~~~~~~
   arch/m68k/kernel/sys_m68k.c:578:16: warning: no previous prototype for 'sys_atomic_barrier' [-Wmissing-prototypes]
     578 | asmlinkage int sys_atomic_barrier(void)
         |                ^~~~~~~~~~~~~~~~~~
--
   In file included from include/linux/module.h:12,
                    from arch/m68k/kernel/time.c:16:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/time.c:154:13: warning: no previous prototype for 'time_init' [-Wmissing-prototypes]
     154 | void __init time_init(void)
         |             ^~~~~~~~~
--
   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from arch/m68k/kernel/traps.c:21:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/traps.c:752:17: warning: no previous prototype for 'buserr_c' [-Wmissing-prototypes]
     752 | asmlinkage void buserr_c(struct frame *fp)
         |                 ^~~~~~~~
   arch/m68k/kernel/traps.c:966:6: warning: no previous prototype for 'bad_super_trap' [-Wmissing-prototypes]
     966 | void bad_super_trap (struct frame *fp)
         |      ^~~~~~~~~~~~~~
   arch/m68k/kernel/traps.c:1138:17: warning: no previous prototype for 'set_esp0' [-Wmissing-prototypes]
    1138 | asmlinkage void set_esp0(unsigned long ssp)
         |                 ^~~~~~~~
   arch/m68k/kernel/traps.c:1147:17: warning: no previous prototype for 'fpsp040_die' [-Wmissing-prototypes]
    1147 | asmlinkage void fpsp040_die(void)
         |                 ^~~~~~~~~~~
   arch/m68k/kernel/traps.c:1153:17: warning: no previous prototype for 'fpemu_signal' [-Wmissing-prototypes]
    1153 | asmlinkage void fpemu_signal(int signal, int code, void *addr)
         |                 ^~~~~~~~~~~~
--
   In file included from include/linux/module.h:12,
                    from arch/m68k/kernel/ints.c:9:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/ints.c:57:13: warning: no previous prototype for 'init_IRQ' [-Wmissing-prototypes]
      57 | void __init init_IRQ(void)
         |             ^~~~~~~~
   arch/m68k/kernel/ints.c:165:17: warning: no previous prototype for 'handle_badint' [-Wmissing-prototypes]
     165 | asmlinkage void handle_badint(struct pt_regs *regs)
         |                 ^~~~~~~~~~~~~
--
   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from arch/m68k/kernel/vectors.c:20:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/vectors.c:51:13: warning: no previous prototype for 'base_trap_init' [-Wmissing-prototypes]
      51 | void __init base_trap_init(void)
         |             ^~~~~~~~~~~~~~
   arch/m68k/kernel/vectors.c:74:13: warning: no previous prototype for 'trap_init' [-Wmissing-prototypes]
      74 | void __init trap_init (void)
         |             ^~~~~~~~~
--
   In file included from include/linux/rculist.h:10,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from include/linux/sched/task_stack.h:9,
                    from include/linux/elfcore.h:7,
                    from include/linux/crash_core.h:6,
                    from include/linux/kexec.h:18,
                    from arch/m68k/kernel/machine_kexec.c:6:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/machine_kexec.c:26:6: warning: no previous prototype for 'machine_shutdown' [-Wmissing-prototypes]
      26 | void machine_shutdown(void)
         |      ^~~~~~~~~~~~~~~~
   arch/m68k/kernel/machine_kexec.c:30:6: warning: no previous prototype for 'machine_crash_shutdown' [-Wmissing-prototypes]
      30 | void machine_crash_shutdown(struct pt_regs *regs)
         |      ^~~~~~~~~~~~~~~~~~~~~~
--
   In file included from include/linux/module.h:12,
                    from arch/m68k/kernel/process.c:15:
>> include/linux/list.h:662:8: warning: no previous prototype for 'list_count' [-Wmissing-prototypes]
     662 | size_t list_count(struct list_head *head)
         |        ^~~~~~~~~~
   arch/m68k/kernel/process.c:114:16: warning: no previous prototype for 'm68k_clone' [-Wmissing-prototypes]
     114 | asmlinkage int m68k_clone(struct pt_regs *regs)
         |                ^~~~~~~~~~
   arch/m68k/kernel/process.c:135:16: warning: no previous prototype for 'm68k_clone3' [-Wmissing-prototypes]
     135 | asmlinkage int m68k_clone3(struct pt_regs *regs)
         |                ^~~~~~~~~~~
   arch/m68k/kernel/process.c:216:5: warning: no previous prototype for 'dump_fpu' [-Wmissing-prototypes]
     216 | int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
         |     ^~~~~~~~
..


vim +/list_count +662 include/linux/list.h

   557	
   558	/**
   559	 * list_next_entry - get the next element in list
   560	 * @pos:	the type * to cursor
   561	 * @member:	the name of the list_head within the struct.
   562	 */
   563	#define list_next_entry(pos, member) \
   564		list_entry((pos)->member.next, typeof(*(pos)), member)
   565	
   566	/**
   567	 * list_next_entry_circular - get the next element in list
   568	 * @pos:	the type * to cursor.
   569	 * @head:	the list head to take the element from.
   570	 * @member:	the name of the list_head within the struct.
   571	 *
   572	 * Wraparound if pos is the last element (return the first element).
   573	 * Note, that list is expected to be not empty.
   574	 */
   575	#define list_next_entry_circular(pos, head, member) \
   576		(list_is_last(&(pos)->member, head) ? \
   577		list_first_entry(head, typeof(*(pos)), member) : list_next_entry(pos, member))
   578	
   579	/**
   580	 * list_prev_entry - get the prev element in list
   581	 * @pos:	the type * to cursor
   582	 * @member:	the name of the list_head within the struct.
   583	 */
   584	#define list_prev_entry(pos, member) \
   585		list_entry((pos)->member.prev, typeof(*(pos)), member)
   586	
   587	/**
   588	 * list_prev_entry_circular - get the prev element in list
   589	 * @pos:	the type * to cursor.
   590	 * @head:	the list head to take the element from.
   591	 * @member:	the name of the list_head within the struct.
   592	 *
   593	 * Wraparound if pos is the first element (return the last element).
   594	 * Note, that list is expected to be not empty.
   595	 */
   596	#define list_prev_entry_circular(pos, head, member) \
   597		(list_is_first(&(pos)->member, head) ? \
   598		list_last_entry(head, typeof(*(pos)), member) : list_prev_entry(pos, member))
   599	
   600	/**
   601	 * list_for_each	-	iterate over a list
   602	 * @pos:	the &struct list_head to use as a loop cursor.
   603	 * @head:	the head for your list.
   604	 */
   605	#define list_for_each(pos, head) \
   606		for (pos = (head)->next; !list_is_head(pos, (head)); pos = pos->next)
   607	
   608	/**
   609	 * list_for_each_rcu - Iterate over a list in an RCU-safe fashion
   610	 * @pos:	the &struct list_head to use as a loop cursor.
   611	 * @head:	the head for your list.
   612	 */
   613	#define list_for_each_rcu(pos, head)		  \
   614		for (pos = rcu_dereference((head)->next); \
   615		     !list_is_head(pos, (head)); \
   616		     pos = rcu_dereference(pos->next))
   617	
   618	/**
   619	 * list_for_each_continue - continue iteration over a list
   620	 * @pos:	the &struct list_head to use as a loop cursor.
   621	 * @head:	the head for your list.
   622	 *
   623	 * Continue to iterate over a list, continuing after the current position.
   624	 */
   625	#define list_for_each_continue(pos, head) \
   626		for (pos = pos->next; !list_is_head(pos, (head)); pos = pos->next)
   627	
   628	/**
   629	 * list_for_each_prev	-	iterate over a list backwards
   630	 * @pos:	the &struct list_head to use as a loop cursor.
   631	 * @head:	the head for your list.
   632	 */
   633	#define list_for_each_prev(pos, head) \
   634		for (pos = (head)->prev; !list_is_head(pos, (head)); pos = pos->prev)
   635	
   636	/**
   637	 * list_for_each_safe - iterate over a list safe against removal of list entry
   638	 * @pos:	the &struct list_head to use as a loop cursor.
   639	 * @n:		another &struct list_head to use as temporary storage
   640	 * @head:	the head for your list.
   641	 */
   642	#define list_for_each_safe(pos, n, head) \
   643		for (pos = (head)->next, n = pos->next; \
   644		     !list_is_head(pos, (head)); \
   645		     pos = n, n = pos->next)
   646	
   647	/**
   648	 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry
   649	 * @pos:	the &struct list_head to use as a loop cursor.
   650	 * @n:		another &struct list_head to use as temporary storage
   651	 * @head:	the head for your list.
   652	 */
   653	#define list_for_each_prev_safe(pos, n, head) \
   654		for (pos = (head)->prev, n = pos->prev; \
   655		     !list_is_head(pos, (head)); \
   656		     pos = n, n = pos->prev)
   657	
   658	/**
   659	 * list_count - count nodes in the list
   660	 * @head:	the head for your list.
   661	 */
 > 662	size_t list_count(struct list_head *head)
   663	{
   664		struct list_head *pos;
   665		size_t count = 0;
   666	
   667		list_for_each(pos, head)
   668			count++;
   669	
   670		return count;
   671	}
   672
  

Patch

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 6ae8b07cfaa1..b5d474be564d 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -2085,17 +2085,6 @@  static void print_request_ring(struct drm_printer *m, struct i915_request *rq)
 	}
 }
 
-static unsigned long list_count(struct list_head *list)
-{
-	struct list_head *pos;
-	unsigned long count = 0;
-
-	list_for_each(pos, list)
-		count++;
-
-	return count;
-}
-
 static unsigned long read_ul(void *p, size_t x)
 {
 	return *(unsigned long *)(p + x);
@@ -2270,7 +2259,7 @@  void intel_engine_dump(struct intel_engine_cs *engine,
 	spin_lock_irqsave(&engine->sched_engine->lock, flags);
 	engine_dump_active_requests(engine, m);
 
-	drm_printf(m, "\tOn hold?: %lu\n",
+	drm_printf(m, "\tOn hold?: %zu\n",
 		   list_count(&engine->sched_engine->hold));
 	spin_unlock_irqrestore(&engine->sched_engine->lock, flags);
 
diff --git a/include/linux/list.h b/include/linux/list.h
index 61762054b4be..65aab596ae33 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -655,6 +655,21 @@  static inline void list_splice_tail_init(struct list_head *list,
 	     !list_is_head(pos, (head)); \
 	     pos = n, n = pos->prev)
 
+/**
+ * list_count - count nodes in the list
+ * @head:	the head for your list.
+ */
+size_t list_count(struct list_head *head)
+{
+	struct list_head *pos;
+	size_t count = 0;
+
+	list_for_each(pos, head)
+		count++;
+
+	return count;
+}
+
 /**
  * list_entry_is_head - test if the entry points to the head of the list
  * @pos:	the type * to cursor