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

From: kernel test robot
Date: Fri Nov 13 2020 - 00:06:22 EST

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 <lkp@xxxxxxxxx>


"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

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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