Subject: Re: [PATCH 3/3] powerpc: rewrite atomics to use ARCH_ATOMIC

From: kernel test robot <[email-masked]>
Date: Fri, 13 Nov 2020 13:05:01 +0800

Hi Nicholas,

I love your patch! Perhaps something to improve:

[auto build test WARNING on powerpc/next]
[also build test WARNING on asm-generic/master linus/master v5.10-rc3 next-20201112]
[cannot apply to scottwood/next]
[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]

url:    https://github.com/0day-ci/linux/commits/Nicholas-Piggin/powerpc-convert-to-use-ARCH_ATOMIC/20201111-190941
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc64-randconfig-s031-20201111 (attached as .config)
compiler: powerpc-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-107-gaf3512a6-dirty
        # https://github.com/0day-ci/linux/commit/9e1bec8fe216b0745c647e52c40d1f0033fb4efd
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Nicholas-Piggin/powerpc-convert-to-use-ARCH_ATOMIC/20201111-190941
        git checkout 9e1bec8fe216b0745c647e52c40d1f0033fb4efd
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=powerpc64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <[email-masked]>

"sparse warnings: (new ones prefixed by >>)"
>> drivers/gpu/drm/drm_lock.c:75:24: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:75:24: sparse:     expected void *ptr
>> drivers/gpu/drm/drm_lock.c:75:24: sparse:     got unsigned int volatile *__ai_ptr
>> drivers/gpu/drm/drm_lock.c:75:24: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:75:24: sparse:     expected void *ptr
>> drivers/gpu/drm/drm_lock.c:75:24: sparse:     got unsigned int volatile *__ai_ptr
   drivers/gpu/drm/drm_lock.c:118:24: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:118:24: sparse:     expected void *ptr
   drivers/gpu/drm/drm_lock.c:118:24: sparse:     got unsigned int volatile *__ai_ptr
   drivers/gpu/drm/drm_lock.c:118:24: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:118:24: sparse:     expected void *ptr
   drivers/gpu/drm/drm_lock.c:118:24: sparse:     got unsigned int volatile *__ai_ptr
   drivers/gpu/drm/drm_lock.c:141:24: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:141:24: sparse:     expected void *ptr
   drivers/gpu/drm/drm_lock.c:141:24: sparse:     got unsigned int volatile *__ai_ptr
   drivers/gpu/drm/drm_lock.c:141:24: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:141:24: sparse:     expected void *ptr
   drivers/gpu/drm/drm_lock.c:141:24: sparse:     got unsigned int volatile *__ai_ptr
   drivers/gpu/drm/drm_lock.c:319:40: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:319:40: sparse:     expected void *ptr
   drivers/gpu/drm/drm_lock.c:319:40: sparse:     got unsigned int volatile *__ai_ptr
   drivers/gpu/drm/drm_lock.c:319:40: sparse: sparse: incorrect type in argument 1 (different modifiers) @@     expected void *ptr @@     got unsigned int volatile *__ai_ptr @@
   drivers/gpu/drm/drm_lock.c:319:40: sparse:     expected void *ptr
   drivers/gpu/drm/drm_lock.c:319:40: sparse:     got unsigned int volatile *__ai_ptr

vim +75 drivers/gpu/drm/drm_lock.c

4ac5ec40ec70022 Daniel Vetter     2010-08-23  48  
bd50d4a2168370b Benjamin Gaignard 2020-03-06  49  /*
1a75a222f5ca106 Daniel Vetter     2016-06-14  50   * Take the heavyweight lock.
1a75a222f5ca106 Daniel Vetter     2016-06-14  51   *
1a75a222f5ca106 Daniel Vetter     2016-06-14  52   * \param lock lock pointer.
1a75a222f5ca106 Daniel Vetter     2016-06-14  53   * \param context locking context.
1a75a222f5ca106 Daniel Vetter     2016-06-14  54   * \return one if the lock is held, or zero otherwise.
1a75a222f5ca106 Daniel Vetter     2016-06-14  55   *
1a75a222f5ca106 Daniel Vetter     2016-06-14  56   * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction.
1a75a222f5ca106 Daniel Vetter     2016-06-14  57   */
1a75a222f5ca106 Daniel Vetter     2016-06-14  58  static
1a75a222f5ca106 Daniel Vetter     2016-06-14  59  int drm_lock_take(struct drm_lock_data *lock_data,
1a75a222f5ca106 Daniel Vetter     2016-06-14  60  		  unsigned int context)
1a75a222f5ca106 Daniel Vetter     2016-06-14  61  {
1a75a222f5ca106 Daniel Vetter     2016-06-14  62  	unsigned int old, new, prev;
1a75a222f5ca106 Daniel Vetter     2016-06-14  63  	volatile unsigned int *lock = &lock_data->hw_lock->lock;
1a75a222f5ca106 Daniel Vetter     2016-06-14  64  
1a75a222f5ca106 Daniel Vetter     2016-06-14  65  	spin_lock_bh(&lock_data->spinlock);
1a75a222f5ca106 Daniel Vetter     2016-06-14  66  	do {
1a75a222f5ca106 Daniel Vetter     2016-06-14  67  		old = *lock;
1a75a222f5ca106 Daniel Vetter     2016-06-14  68  		if (old & _DRM_LOCK_HELD)
1a75a222f5ca106 Daniel Vetter     2016-06-14  69  			new = old | _DRM_LOCK_CONT;
1a75a222f5ca106 Daniel Vetter     2016-06-14  70  		else {
1a75a222f5ca106 Daniel Vetter     2016-06-14  71  			new = context | _DRM_LOCK_HELD |
1a75a222f5ca106 Daniel Vetter     2016-06-14  72  				((lock_data->user_waiters + lock_data->kernel_waiters > 1) ?
1a75a222f5ca106 Daniel Vetter     2016-06-14  73  				 _DRM_LOCK_CONT : 0);
1a75a222f5ca106 Daniel Vetter     2016-06-14  74  		}
1a75a222f5ca106 Daniel Vetter     2016-06-14 @75  		prev = cmpxchg(lock, old, new);
1a75a222f5ca106 Daniel Vetter     2016-06-14  76  	} while (prev != old);
1a75a222f5ca106 Daniel Vetter     2016-06-14  77  	spin_unlock_bh(&lock_data->spinlock);
1a75a222f5ca106 Daniel Vetter     2016-06-14  78  
1a75a222f5ca106 Daniel Vetter     2016-06-14  79  	if (_DRM_LOCKING_CONTEXT(old) == context) {
1a75a222f5ca106 Daniel Vetter     2016-06-14  80  		if (old & _DRM_LOCK_HELD) {
1a75a222f5ca106 Daniel Vetter     2016-06-14  81  			if (context != DRM_KERNEL_CONTEXT) {
1a75a222f5ca106 Daniel Vetter     2016-06-14  82  				DRM_ERROR("%d holds heavyweight lock\n",
1a75a222f5ca106 Daniel Vetter     2016-06-14  83  					  context);
1a75a222f5ca106 Daniel Vetter     2016-06-14  84  			}
1a75a222f5ca106 Daniel Vetter     2016-06-14  85  			return 0;
1a75a222f5ca106 Daniel Vetter     2016-06-14  86  		}
1a75a222f5ca106 Daniel Vetter     2016-06-14  87  	}
1a75a222f5ca106 Daniel Vetter     2016-06-14  88  
1a75a222f5ca106 Daniel Vetter     2016-06-14  89  	if ((_DRM_LOCKING_CONTEXT(new)) == context && (new & _DRM_LOCK_HELD)) {
1a75a222f5ca106 Daniel Vetter     2016-06-14  90  		/* Have lock */
1a75a222f5ca106 Daniel Vetter     2016-06-14  91  		return 1;
1a75a222f5ca106 Daniel Vetter     2016-06-14  92  	}
1a75a222f5ca106 Daniel Vetter     2016-06-14  93  	return 0;
1a75a222f5ca106 Daniel Vetter     2016-06-14  94  }
1a75a222f5ca106 Daniel Vetter     2016-06-14  95  

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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email-masked]