diff mbox series

drm/i915: convert i915_active.count from atomic_t to refcount_t

Message ID Y6d0EDmyqJILVoRw@qemulion (mailing list archive)
State New, archived
Headers show
Series drm/i915: convert i915_active.count from atomic_t to refcount_t | expand

Commit Message

Deepak R Varma Dec. 24, 2022, 9:50 p.m. UTC 
The refcount_* APIs are designed to address known issues with the
atomic_t APIs for reference counting. They provide following distinct
advantages:
   - protect the reference counters from overflow/underflow
   - avoid use-after-free errors
   - provide improved memory ordering guarantee schemes
   - neater and safer.
Hence, convert the atomic_t count member variable and associated
atomic_*() API calls to equivalent refcount_t type and refcount_*() API
calls.

This patch proposal address the following warnings generated by
the atomic_as_refcounter.cocci coccinelle script
	atomic_add_unless

Signed-off-by: Deepak R Varma <drv@mailo.com>
---
Please note: Proposed changes are compile tested only.

 drivers/gpu/drm/i915/i915_active.c       | 24 +++++++++++++-----------
 drivers/gpu/drm/i915/i915_active.h       |  6 +++---
 drivers/gpu/drm/i915/i915_active_types.h |  4 ++--
 3 files changed, 18 insertions(+), 16 deletions(-)

--
2.34.1

Comments

kernel test robot Dec. 25, 2022, 1:42 a.m. UTC | #1 
Hi Deepak,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on drm-intel/for-linux-next-fixes linus/master v6.1 next-20221220]
[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/Deepak-R-Varma/drm-i915-convert-i915_active-count-from-atomic_t-to-refcount_t/20221225-055105
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
patch link:    https://lore.kernel.org/r/Y6d0EDmyqJILVoRw%40qemulion
patch subject: [PATCH] drm/i915: convert i915_active.count from atomic_t to refcount_t
config: x86_64-allyesconfig
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/04a191f9a3d0f02bbd37735a47401bc92d685234
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Deepak-R-Varma/drm-i915-convert-i915_active-count-from-atomic_t-to-refcount_t/20221225-055105
        git checkout 04a191f9a3d0f02bbd37735a47401bc92d685234
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 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 >>):

   In file included from drivers/gpu/drm/i915/i915_active.c:1152:
   drivers/gpu/drm/i915/selftests/i915_active.c: In function '__live_active_setup':
>> drivers/gpu/drm/i915/selftests/i915_active.c:128:25: error: passing argument 1 of 'atomic_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
     128 |         if (atomic_read(&active->base.count) != count) {
         |                         ^~~~~~~~~~~~~~~~~~~
         |                         |
         |                         refcount_t * {aka struct refcount_struct *}
   In file included from include/linux/atomic.h:82,
                    from include/linux/cpumask.h:13,
                    from arch/x86/include/asm/cpumask.h:5,
                    from arch/x86/include/asm/msr.h:11,
                    from arch/x86/include/asm/processor.h:22,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:60,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:56,
                    from include/linux/debugobjects.h:6,
                    from drivers/gpu/drm/i915/i915_active.c:7:
   include/linux/atomic/atomic-instrumented.h:25:29: note: expected 'const atomic_t *' but argument is of type 'refcount_t *' {aka 'struct refcount_struct *'}
      25 | atomic_read(const atomic_t *v)
         |             ~~~~~~~~~~~~~~~~^
   In file included from include/linux/kernel.h:29,
                    from arch/x86/include/asm/percpu.h:27,
                    from arch/x86/include/asm/preempt.h:6,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:56,
                    from include/linux/debugobjects.h:6,
                    from drivers/gpu/drm/i915/i915_active.c:7:
   drivers/gpu/drm/i915/selftests/i915_active.c:130:36: error: passing argument 1 of 'atomic_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
     130 |                        atomic_read(&active->base.count), count);
         |                                    ^~~~~~~~~~~~~~~~~~~
         |                                    |
         |                                    refcount_t * {aka struct refcount_struct *}
   include/linux/printk.h:429:33: note: in definition of macro 'printk_index_wrap'
     429 |                 _p_func(_fmt, ##__VA_ARGS__);                           \
         |                                 ^~~~~~~~~~~
   include/linux/printk.h:500:9: note: in expansion of macro 'printk'
     500 |         printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
         |         ^~~~~~
   drivers/gpu/drm/i915/selftests/i915_active.c:129:17: note: in expansion of macro 'pr_err'
     129 |                 pr_err("i915_active not tracking all requests, found %d, expected %d\n",
         |                 ^~~~~~
   In file included from include/linux/atomic.h:82,
                    from include/linux/cpumask.h:13,
                    from arch/x86/include/asm/cpumask.h:5,
                    from arch/x86/include/asm/msr.h:11,
                    from arch/x86/include/asm/processor.h:22,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:60,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:56,
                    from include/linux/debugobjects.h:6,
                    from drivers/gpu/drm/i915/i915_active.c:7:
   include/linux/atomic/atomic-instrumented.h:25:29: note: expected 'const atomic_t *' but argument is of type 'refcount_t *' {aka 'struct refcount_struct *'}
      25 | atomic_read(const atomic_t *v)
         |             ~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/i915/i915_active.c:1152:
   drivers/gpu/drm/i915/selftests/i915_active.c: In function 'i915_active_print':
   drivers/gpu/drm/i915/selftests/i915_active.c:282:52: error: passing argument 1 of 'atomic_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
     282 |         drm_printf(m, "\tcount: %d\n", atomic_read(&ref->count));
         |                                                    ^~~~~~~~~~~
         |                                                    |
         |                                                    refcount_t * {aka struct refcount_struct *}
   In file included from include/linux/atomic.h:82,
                    from include/linux/cpumask.h:13,
                    from arch/x86/include/asm/cpumask.h:5,
                    from arch/x86/include/asm/msr.h:11,
                    from arch/x86/include/asm/processor.h:22,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:60,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:56,
                    from include/linux/debugobjects.h:6,
                    from drivers/gpu/drm/i915/i915_active.c:7:
   include/linux/atomic/atomic-instrumented.h:25:29: note: expected 'const atomic_t *' but argument is of type 'refcount_t *' {aka 'struct refcount_struct *'}
      25 | atomic_read(const atomic_t *v)
         |             ~~~~~~~~~~~~~~~~^
   In file included from drivers/gpu/drm/i915/i915_active.c:1152:
   drivers/gpu/drm/i915/selftests/i915_active.c: In function 'active_flush':
>> drivers/gpu/drm/i915/selftests/i915_active.c:327:20: error: passing argument 1 of 'atomic_dec' from incompatible pointer type [-Werror=incompatible-pointer-types]
     327 |         atomic_dec(&ref->count);
         |                    ^~~~~~~~~~~
         |                    |
         |                    refcount_t * {aka struct refcount_struct *}
   In file included from include/linux/atomic.h:82,
                    from include/linux/cpumask.h:13,
                    from arch/x86/include/asm/cpumask.h:5,
                    from arch/x86/include/asm/msr.h:11,
                    from arch/x86/include/asm/processor.h:22,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:60,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:56,
                    from include/linux/debugobjects.h:6,
                    from drivers/gpu/drm/i915/i915_active.c:7:
   include/linux/atomic/atomic-instrumented.h:255:22: note: expected 'atomic_t *' but argument is of type 'refcount_t *' {aka 'struct refcount_struct *'}
     255 | atomic_dec(atomic_t *v)
         |            ~~~~~~~~~~^
   cc1: all warnings being treated as errors


vim +/atomic_read +128 drivers/gpu/drm/i915/selftests/i915_active.c

5361db1a33c7e2 Chris Wilson    2019-06-21   76  
5361db1a33c7e2 Chris Wilson    2019-06-21   77  static struct live_active *
5361db1a33c7e2 Chris Wilson    2019-06-21   78  __live_active_setup(struct drm_i915_private *i915)
64d6c500a38434 Chris Wilson    2019-02-05   79  {
64d6c500a38434 Chris Wilson    2019-02-05   80  	struct intel_engine_cs *engine;
64d6c500a38434 Chris Wilson    2019-02-05   81  	struct i915_sw_fence *submit;
5361db1a33c7e2 Chris Wilson    2019-06-21   82  	struct live_active *active;
64d6c500a38434 Chris Wilson    2019-02-05   83  	unsigned int count = 0;
64d6c500a38434 Chris Wilson    2019-02-05   84  	int err = 0;
64d6c500a38434 Chris Wilson    2019-02-05   85  
5361db1a33c7e2 Chris Wilson    2019-06-21   86  	active = __live_alloc(i915);
5361db1a33c7e2 Chris Wilson    2019-06-21   87  	if (!active)
5361db1a33c7e2 Chris Wilson    2019-06-21   88  		return ERR_PTR(-ENOMEM);
64d6c500a38434 Chris Wilson    2019-02-05   89  
5361db1a33c7e2 Chris Wilson    2019-06-21   90  	submit = heap_fence_create(GFP_KERNEL);
5361db1a33c7e2 Chris Wilson    2019-06-21   91  	if (!submit) {
5361db1a33c7e2 Chris Wilson    2019-06-21   92  		kfree(active);
5361db1a33c7e2 Chris Wilson    2019-06-21   93  		return ERR_PTR(-ENOMEM);
5361db1a33c7e2 Chris Wilson    2019-06-21   94  	}
64d6c500a38434 Chris Wilson    2019-02-05   95  
12c255b5dad115 Chris Wilson    2019-06-21   96  	err = i915_active_acquire(&active->base);
12c255b5dad115 Chris Wilson    2019-06-21   97  	if (err)
64d6c500a38434 Chris Wilson    2019-02-05   98  		goto out;
64d6c500a38434 Chris Wilson    2019-02-05   99  
928da10c0ca2ae Chris Wilson    2019-10-21  100  	for_each_uabi_engine(engine, i915) {
64d6c500a38434 Chris Wilson    2019-02-05  101  		struct i915_request *rq;
64d6c500a38434 Chris Wilson    2019-02-05  102  
de5825beae9a0a Chris Wilson    2019-11-25  103  		rq = intel_engine_create_kernel_request(engine);
64d6c500a38434 Chris Wilson    2019-02-05  104  		if (IS_ERR(rq)) {
64d6c500a38434 Chris Wilson    2019-02-05  105  			err = PTR_ERR(rq);
64d6c500a38434 Chris Wilson    2019-02-05  106  			break;
64d6c500a38434 Chris Wilson    2019-02-05  107  		}
64d6c500a38434 Chris Wilson    2019-02-05  108  
64d6c500a38434 Chris Wilson    2019-02-05  109  		err = i915_sw_fence_await_sw_fence_gfp(&rq->submit,
64d6c500a38434 Chris Wilson    2019-02-05  110  						       submit,
64d6c500a38434 Chris Wilson    2019-02-05  111  						       GFP_KERNEL);
64d6c500a38434 Chris Wilson    2019-02-05  112  		if (err >= 0)
d19d71fc2b15bf Chris Wilson    2019-09-19  113  			err = i915_active_add_request(&active->base, rq);
64d6c500a38434 Chris Wilson    2019-02-05  114  		i915_request_add(rq);
64d6c500a38434 Chris Wilson    2019-02-05  115  		if (err) {
64d6c500a38434 Chris Wilson    2019-02-05  116  			pr_err("Failed to track active ref!\n");
64d6c500a38434 Chris Wilson    2019-02-05  117  			break;
64d6c500a38434 Chris Wilson    2019-02-05  118  		}
64d6c500a38434 Chris Wilson    2019-02-05  119  
64d6c500a38434 Chris Wilson    2019-02-05  120  		count++;
64d6c500a38434 Chris Wilson    2019-02-05  121  	}
64d6c500a38434 Chris Wilson    2019-02-05  122  
64d6c500a38434 Chris Wilson    2019-02-05  123  	i915_active_release(&active->base);
274cbf20fd108f Chris Wilson    2019-10-04  124  	if (READ_ONCE(active->retired) && count) {
64d6c500a38434 Chris Wilson    2019-02-05  125  		pr_err("i915_active retired before submission!\n");
64d6c500a38434 Chris Wilson    2019-02-05  126  		err = -EINVAL;
64d6c500a38434 Chris Wilson    2019-02-05  127  	}
12c255b5dad115 Chris Wilson    2019-06-21 @128  	if (atomic_read(&active->base.count) != count) {
64d6c500a38434 Chris Wilson    2019-02-05  129  		pr_err("i915_active not tracking all requests, found %d, expected %d\n",
12c255b5dad115 Chris Wilson    2019-06-21  130  		       atomic_read(&active->base.count), count);
64d6c500a38434 Chris Wilson    2019-02-05  131  		err = -EINVAL;
64d6c500a38434 Chris Wilson    2019-02-05  132  	}
64d6c500a38434 Chris Wilson    2019-02-05  133  
64d6c500a38434 Chris Wilson    2019-02-05  134  out:
64d6c500a38434 Chris Wilson    2019-02-05  135  	i915_sw_fence_commit(submit);
64d6c500a38434 Chris Wilson    2019-02-05  136  	heap_fence_put(submit);
12c255b5dad115 Chris Wilson    2019-06-21  137  	if (err) {
12c255b5dad115 Chris Wilson    2019-06-21  138  		__live_put(active);
12c255b5dad115 Chris Wilson    2019-06-21  139  		active = ERR_PTR(err);
12c255b5dad115 Chris Wilson    2019-06-21  140  	}
64d6c500a38434 Chris Wilson    2019-02-05  141  
12c255b5dad115 Chris Wilson    2019-06-21  142  	return active;
64d6c500a38434 Chris Wilson    2019-02-05  143  }
64d6c500a38434 Chris Wilson    2019-02-05  144  
64d6c500a38434 Chris Wilson    2019-02-05  145  static int live_active_wait(void *arg)
64d6c500a38434 Chris Wilson    2019-02-05  146  {
64d6c500a38434 Chris Wilson    2019-02-05  147  	struct drm_i915_private *i915 = arg;
5361db1a33c7e2 Chris Wilson    2019-06-21  148  	struct live_active *active;
5361db1a33c7e2 Chris Wilson    2019-06-21  149  	int err = 0;
64d6c500a38434 Chris Wilson    2019-02-05  150  
64d6c500a38434 Chris Wilson    2019-02-05  151  	/* Check that we get a callback when requests retire upon waiting */
64d6c500a38434 Chris Wilson    2019-02-05  152  
5361db1a33c7e2 Chris Wilson    2019-06-21  153  	active = __live_active_setup(i915);
b1e3177bd1d8f4 Chris Wilson    2019-10-04  154  	if (IS_ERR(active))
b1e3177bd1d8f4 Chris Wilson    2019-10-04  155  		return PTR_ERR(active);
64d6c500a38434 Chris Wilson    2019-02-05  156  
d75a92a8146793 Chris Wilson    2020-03-27  157  	__i915_active_wait(&active->base, TASK_UNINTERRUPTIBLE);
274cbf20fd108f Chris Wilson    2019-10-04  158  	if (!READ_ONCE(active->retired)) {
5de34ed13787c4 Chris Wilson    2019-12-10  159  		struct drm_printer p = drm_err_printer(__func__);
5de34ed13787c4 Chris Wilson    2019-12-10  160  
64d6c500a38434 Chris Wilson    2019-02-05  161  		pr_err("i915_active not retired after waiting!\n");
5de34ed13787c4 Chris Wilson    2019-12-10  162  		i915_active_print(&active->base, &p);
5de34ed13787c4 Chris Wilson    2019-12-10  163  
64d6c500a38434 Chris Wilson    2019-02-05  164  		err = -EINVAL;
64d6c500a38434 Chris Wilson    2019-02-05  165  	}
64d6c500a38434 Chris Wilson    2019-02-05  166  
12c255b5dad115 Chris Wilson    2019-06-21  167  	__live_put(active);
5361db1a33c7e2 Chris Wilson    2019-06-21  168  
7e8057626640cf Chris Wilson    2019-10-04  169  	if (igt_flush_test(i915))
64d6c500a38434 Chris Wilson    2019-02-05  170  		err = -EIO;
5361db1a33c7e2 Chris Wilson    2019-06-21  171  
64d6c500a38434 Chris Wilson    2019-02-05  172  	return err;
64d6c500a38434 Chris Wilson    2019-02-05  173  }
64d6c500a38434 Chris Wilson    2019-02-05  174  
64d6c500a38434 Chris Wilson    2019-02-05  175  static int live_active_retire(void *arg)
64d6c500a38434 Chris Wilson    2019-02-05  176  {
64d6c500a38434 Chris Wilson    2019-02-05  177  	struct drm_i915_private *i915 = arg;
5361db1a33c7e2 Chris Wilson    2019-06-21  178  	struct live_active *active;
5361db1a33c7e2 Chris Wilson    2019-06-21  179  	int err = 0;
64d6c500a38434 Chris Wilson    2019-02-05  180  
64d6c500a38434 Chris Wilson    2019-02-05  181  	/* Check that we get a callback when requests are indirectly retired */
64d6c500a38434 Chris Wilson    2019-02-05  182  
5361db1a33c7e2 Chris Wilson    2019-06-21  183  	active = __live_active_setup(i915);
b1e3177bd1d8f4 Chris Wilson    2019-10-04  184  	if (IS_ERR(active))
b1e3177bd1d8f4 Chris Wilson    2019-10-04  185  		return PTR_ERR(active);
64d6c500a38434 Chris Wilson    2019-02-05  186  
64d6c500a38434 Chris Wilson    2019-02-05  187  	/* waits for & retires all requests */
7e8057626640cf Chris Wilson    2019-10-04  188  	if (igt_flush_test(i915))
64d6c500a38434 Chris Wilson    2019-02-05  189  		err = -EIO;
64d6c500a38434 Chris Wilson    2019-02-05  190  
274cbf20fd108f Chris Wilson    2019-10-04  191  	if (!READ_ONCE(active->retired)) {
5de34ed13787c4 Chris Wilson    2019-12-10  192  		struct drm_printer p = drm_err_printer(__func__);
5de34ed13787c4 Chris Wilson    2019-12-10  193  
64d6c500a38434 Chris Wilson    2019-02-05  194  		pr_err("i915_active not retired after flushing!\n");
5de34ed13787c4 Chris Wilson    2019-12-10  195  		i915_active_print(&active->base, &p);
5de34ed13787c4 Chris Wilson    2019-12-10  196  
64d6c500a38434 Chris Wilson    2019-02-05  197  		err = -EINVAL;
64d6c500a38434 Chris Wilson    2019-02-05  198  	}
64d6c500a38434 Chris Wilson    2019-02-05  199  
12c255b5dad115 Chris Wilson    2019-06-21  200  	__live_put(active);
5361db1a33c7e2 Chris Wilson    2019-06-21  201  
64d6c500a38434 Chris Wilson    2019-02-05  202  	return err;
64d6c500a38434 Chris Wilson    2019-02-05  203  }
64d6c500a38434 Chris Wilson    2019-02-05  204  
d13a31770077a8 Chris Wilson    2020-02-25  205  static int live_active_barrier(void *arg)
d13a31770077a8 Chris Wilson    2020-02-25  206  {
d13a31770077a8 Chris Wilson    2020-02-25  207  	struct drm_i915_private *i915 = arg;
d13a31770077a8 Chris Wilson    2020-02-25  208  	struct intel_engine_cs *engine;
d13a31770077a8 Chris Wilson    2020-02-25  209  	struct live_active *active;
d13a31770077a8 Chris Wilson    2020-02-25  210  	int err = 0;
d13a31770077a8 Chris Wilson    2020-02-25  211  
d13a31770077a8 Chris Wilson    2020-02-25  212  	/* Check that we get a callback when requests retire upon waiting */
d13a31770077a8 Chris Wilson    2020-02-25  213  
d13a31770077a8 Chris Wilson    2020-02-25  214  	active = __live_alloc(i915);
d13a31770077a8 Chris Wilson    2020-02-25  215  	if (!active)
d13a31770077a8 Chris Wilson    2020-02-25  216  		return -ENOMEM;
d13a31770077a8 Chris Wilson    2020-02-25  217  
d13a31770077a8 Chris Wilson    2020-02-25  218  	err = i915_active_acquire(&active->base);
d13a31770077a8 Chris Wilson    2020-02-25  219  	if (err)
d13a31770077a8 Chris Wilson    2020-02-25  220  		goto out;
d13a31770077a8 Chris Wilson    2020-02-25  221  
d13a31770077a8 Chris Wilson    2020-02-25  222  	for_each_uabi_engine(engine, i915) {
d13a31770077a8 Chris Wilson    2020-02-25  223  		err = i915_active_acquire_preallocate_barrier(&active->base,
d13a31770077a8 Chris Wilson    2020-02-25  224  							      engine);
d13a31770077a8 Chris Wilson    2020-02-25  225  		if (err)
d13a31770077a8 Chris Wilson    2020-02-25  226  			break;
d13a31770077a8 Chris Wilson    2020-02-25  227  
d13a31770077a8 Chris Wilson    2020-02-25  228  		i915_active_acquire_barrier(&active->base);
d13a31770077a8 Chris Wilson    2020-02-25  229  	}
d13a31770077a8 Chris Wilson    2020-02-25  230  
d13a31770077a8 Chris Wilson    2020-02-25  231  	i915_active_release(&active->base);
d75a92a8146793 Chris Wilson    2020-03-27  232  	if (err)
d75a92a8146793 Chris Wilson    2020-03-27  233  		goto out;
d13a31770077a8 Chris Wilson    2020-02-25  234  
d75a92a8146793 Chris Wilson    2020-03-27  235  	__i915_active_wait(&active->base, TASK_UNINTERRUPTIBLE);
d75a92a8146793 Chris Wilson    2020-03-27  236  	if (!READ_ONCE(active->retired)) {
d13a31770077a8 Chris Wilson    2020-02-25  237  		pr_err("i915_active not retired after flushing barriers!\n");
d13a31770077a8 Chris Wilson    2020-02-25  238  		err = -EINVAL;
d13a31770077a8 Chris Wilson    2020-02-25  239  	}
d13a31770077a8 Chris Wilson    2020-02-25  240  
d13a31770077a8 Chris Wilson    2020-02-25  241  out:
d13a31770077a8 Chris Wilson    2020-02-25  242  	__live_put(active);
d13a31770077a8 Chris Wilson    2020-02-25  243  
d13a31770077a8 Chris Wilson    2020-02-25  244  	if (igt_flush_test(i915))
d13a31770077a8 Chris Wilson    2020-02-25  245  		err = -EIO;
d13a31770077a8 Chris Wilson    2020-02-25  246  
d13a31770077a8 Chris Wilson    2020-02-25  247  	return err;
d13a31770077a8 Chris Wilson    2020-02-25  248  }
d13a31770077a8 Chris Wilson    2020-02-25  249  
64d6c500a38434 Chris Wilson    2019-02-05  250  int i915_active_live_selftests(struct drm_i915_private *i915)
64d6c500a38434 Chris Wilson    2019-02-05  251  {
64d6c500a38434 Chris Wilson    2019-02-05  252  	static const struct i915_subtest tests[] = {
64d6c500a38434 Chris Wilson    2019-02-05  253  		SUBTEST(live_active_wait),
64d6c500a38434 Chris Wilson    2019-02-05  254  		SUBTEST(live_active_retire),
d13a31770077a8 Chris Wilson    2020-02-25  255  		SUBTEST(live_active_barrier),
64d6c500a38434 Chris Wilson    2019-02-05  256  	};
64d6c500a38434 Chris Wilson    2019-02-05  257  
8c2699fad60e3f Andi Shyti      2021-12-14  258  	if (intel_gt_is_wedged(to_gt(i915)))
64d6c500a38434 Chris Wilson    2019-02-05  259  		return 0;
64d6c500a38434 Chris Wilson    2019-02-05  260  
64d6c500a38434 Chris Wilson    2019-02-05  261  	return i915_subtests(tests, i915);
64d6c500a38434 Chris Wilson    2019-02-05  262  }
164a4128869ffc Chris Wilson    2019-10-31  263  
164a4128869ffc Chris Wilson    2019-10-31  264  static struct intel_engine_cs *node_to_barrier(struct active_node *it)
164a4128869ffc Chris Wilson    2019-10-31  265  {
164a4128869ffc Chris Wilson    2019-10-31  266  	struct intel_engine_cs *engine;
164a4128869ffc Chris Wilson    2019-10-31  267  
164a4128869ffc Chris Wilson    2019-10-31  268  	if (!is_barrier(&it->base))
164a4128869ffc Chris Wilson    2019-10-31  269  		return NULL;
164a4128869ffc Chris Wilson    2019-10-31  270  
164a4128869ffc Chris Wilson    2019-10-31  271  	engine = __barrier_to_engine(it);
164a4128869ffc Chris Wilson    2019-10-31  272  	smp_rmb(); /* serialise with add_active_barriers */
164a4128869ffc Chris Wilson    2019-10-31  273  	if (!is_barrier(&it->base))
164a4128869ffc Chris Wilson    2019-10-31  274  		return NULL;
164a4128869ffc Chris Wilson    2019-10-31  275  
164a4128869ffc Chris Wilson    2019-10-31  276  	return engine;
164a4128869ffc Chris Wilson    2019-10-31  277  }
164a4128869ffc Chris Wilson    2019-10-31  278  
164a4128869ffc Chris Wilson    2019-10-31  279  void i915_active_print(struct i915_active *ref, struct drm_printer *m)
164a4128869ffc Chris Wilson    2019-10-31  280  {
2386b492ded48b Chris Wilson    2020-03-19  281  	drm_printf(m, "active %ps:%ps\n", ref->active, ref->retire);
164a4128869ffc Chris Wilson    2019-10-31  282  	drm_printf(m, "\tcount: %d\n", atomic_read(&ref->count));
164a4128869ffc Chris Wilson    2019-10-31  283  	drm_printf(m, "\tpreallocated barriers? %s\n",
01fabda8e3d62e Lucas De Marchi 2022-02-25  284  		   str_yes_no(!llist_empty(&ref->preallocated_barriers)));
164a4128869ffc Chris Wilson    2019-10-31  285  
164a4128869ffc Chris Wilson    2019-10-31  286  	if (i915_active_acquire_if_busy(ref)) {
164a4128869ffc Chris Wilson    2019-10-31  287  		struct active_node *it, *n;
164a4128869ffc Chris Wilson    2019-10-31  288  
164a4128869ffc Chris Wilson    2019-10-31  289  		rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
164a4128869ffc Chris Wilson    2019-10-31  290  			struct intel_engine_cs *engine;
164a4128869ffc Chris Wilson    2019-10-31  291  
164a4128869ffc Chris Wilson    2019-10-31  292  			engine = node_to_barrier(it);
164a4128869ffc Chris Wilson    2019-10-31  293  			if (engine) {
164a4128869ffc Chris Wilson    2019-10-31  294  				drm_printf(m, "\tbarrier: %s\n", engine->name);
164a4128869ffc Chris Wilson    2019-10-31  295  				continue;
164a4128869ffc Chris Wilson    2019-10-31  296  			}
164a4128869ffc Chris Wilson    2019-10-31  297  
164a4128869ffc Chris Wilson    2019-10-31  298  			if (i915_active_fence_isset(&it->base)) {
164a4128869ffc Chris Wilson    2019-10-31  299  				drm_printf(m,
164a4128869ffc Chris Wilson    2019-10-31  300  					   "\ttimeline: %llx\n", it->timeline);
164a4128869ffc Chris Wilson    2019-10-31  301  				continue;
164a4128869ffc Chris Wilson    2019-10-31  302  			}
164a4128869ffc Chris Wilson    2019-10-31  303  		}
164a4128869ffc Chris Wilson    2019-10-31  304  
164a4128869ffc Chris Wilson    2019-10-31  305  		i915_active_release(ref);
164a4128869ffc Chris Wilson    2019-10-31  306  	}
164a4128869ffc Chris Wilson    2019-10-31  307  }
38813767c7c5d9 Chris Wilson    2019-11-01  308  
38813767c7c5d9 Chris Wilson    2019-11-01  309  static void spin_unlock_wait(spinlock_t *lock)
38813767c7c5d9 Chris Wilson    2019-11-01  310  {
38813767c7c5d9 Chris Wilson    2019-11-01  311  	spin_lock_irq(lock);
38813767c7c5d9 Chris Wilson    2019-11-01  312  	spin_unlock_irq(lock);
38813767c7c5d9 Chris Wilson    2019-11-01  313  }
38813767c7c5d9 Chris Wilson    2019-11-01  314  
e3e7aeec3281af Chris Wilson    2020-03-06  315  static void active_flush(struct i915_active *ref,
e3e7aeec3281af Chris Wilson    2020-03-06  316  			 struct i915_active_fence *active)
e3e7aeec3281af Chris Wilson    2020-03-06  317  {
e3e7aeec3281af Chris Wilson    2020-03-06  318  	struct dma_fence *fence;
e3e7aeec3281af Chris Wilson    2020-03-06  319  
e3e7aeec3281af Chris Wilson    2020-03-06  320  	fence = xchg(__active_fence_slot(active), NULL);
e3e7aeec3281af Chris Wilson    2020-03-06  321  	if (!fence)
e3e7aeec3281af Chris Wilson    2020-03-06  322  		return;
e3e7aeec3281af Chris Wilson    2020-03-06  323  
e3e7aeec3281af Chris Wilson    2020-03-06  324  	spin_lock_irq(fence->lock);
e3e7aeec3281af Chris Wilson    2020-03-06  325  	__list_del_entry(&active->cb.node);
e3e7aeec3281af Chris Wilson    2020-03-06  326  	spin_unlock_irq(fence->lock); /* serialise with fence->cb_list */
e3e7aeec3281af Chris Wilson    2020-03-06 @327  	atomic_dec(&ref->count);
e3e7aeec3281af Chris Wilson    2020-03-06  328  
e3e7aeec3281af Chris Wilson    2020-03-06  329  	GEM_BUG_ON(!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags));
e3e7aeec3281af Chris Wilson    2020-03-06  330  }
e3e7aeec3281af Chris Wilson    2020-03-06  331
kernel test robot Dec. 25, 2022, 3:43 a.m. UTC | #2 
Hi Deepak,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on drm-intel/for-linux-next-fixes linus/master v6.1 next-20221220]
[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/Deepak-R-Varma/drm-i915-convert-i915_active-count-from-atomic_t-to-refcount_t/20221225-055105
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
patch link:    https://lore.kernel.org/r/Y6d0EDmyqJILVoRw%40qemulion
patch subject: [PATCH] drm/i915: convert i915_active.count from atomic_t to refcount_t
config: x86_64-randconfig-c002
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/04a191f9a3d0f02bbd37735a47401bc92d685234
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Deepak-R-Varma/drm-i915-convert-i915_active-count-from-atomic_t-to-refcount_t/20221225-055105
        git checkout 04a191f9a3d0f02bbd37735a47401bc92d685234
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/i915/

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 >>):

   drivers/gpu/drm/i915/i915_active.c: In function 'debug_active_activate':
>> drivers/gpu/drm/i915/i915_active.c:95:26: error: passing argument 1 of 'atomic_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
      95 |         if (!atomic_read(&ref->count)) /* before the first inc */
         |                          ^~~~~~~~~~~
         |                          |
         |                          refcount_t * {aka struct refcount_struct *}
   In file included from include/linux/atomic.h:82,
                    from include/linux/jump_label.h:254,
                    from include/linux/static_key.h:1,
                    from arch/x86/include/asm/nospec-branch.h:6,
                    from arch/x86/include/asm/paravirt_types.h:40,
                    from arch/x86/include/asm/ptrace.h:97,
                    from arch/x86/include/asm/math_emu.h:5,
                    from arch/x86/include/asm/processor.h:13,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:60,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:56,
                    from include/linux/debugobjects.h:6,
                    from drivers/gpu/drm/i915/i915_active.c:7:
   include/linux/atomic/atomic-instrumented.h:25:29: note: expected 'const atomic_t *' but argument is of type 'refcount_t *' {aka 'struct refcount_struct *'}
      25 | atomic_read(const atomic_t *v)
         |             ~~~~~~~~~~~~~~~~^
   drivers/gpu/drm/i915/i915_active.c: In function 'debug_active_deactivate':
   drivers/gpu/drm/i915/i915_active.c:102:26: error: passing argument 1 of 'atomic_read' from incompatible pointer type [-Werror=incompatible-pointer-types]
     102 |         if (!atomic_read(&ref->count)) /* after the last dec */
         |                          ^~~~~~~~~~~
         |                          |
         |                          refcount_t * {aka struct refcount_struct *}
   In file included from include/linux/atomic.h:82,
                    from include/linux/jump_label.h:254,
                    from include/linux/static_key.h:1,
                    from arch/x86/include/asm/nospec-branch.h:6,
                    from arch/x86/include/asm/paravirt_types.h:40,
                    from arch/x86/include/asm/ptrace.h:97,
                    from arch/x86/include/asm/math_emu.h:5,
                    from arch/x86/include/asm/processor.h:13,
                    from arch/x86/include/asm/cpufeature.h:5,
                    from arch/x86/include/asm/thread_info.h:53,
                    from include/linux/thread_info.h:60,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:56,
                    from include/linux/debugobjects.h:6,
                    from drivers/gpu/drm/i915/i915_active.c:7:
   include/linux/atomic/atomic-instrumented.h:25:29: note: expected 'const atomic_t *' but argument is of type 'refcount_t *' {aka 'struct refcount_struct *'}
      25 | atomic_read(const atomic_t *v)
         |             ~~~~~~~~~~~~~~~~^
   cc1: all warnings being treated as errors


vim +/atomic_read +95 drivers/gpu/drm/i915/i915_active.c

5361db1a33c7e2 Chris Wilson 2019-06-21  91  
5361db1a33c7e2 Chris Wilson 2019-06-21  92  static void debug_active_activate(struct i915_active *ref)
5361db1a33c7e2 Chris Wilson 2019-06-21  93  {
bbca083de291a0 Chris Wilson 2019-12-05  94  	lockdep_assert_held(&ref->tree_lock);
f52c6d0df6909a Chris Wilson 2019-08-27 @95  	if (!atomic_read(&ref->count)) /* before the first inc */
5361db1a33c7e2 Chris Wilson 2019-06-21  96  		debug_object_activate(ref, &active_debug_desc);
5361db1a33c7e2 Chris Wilson 2019-06-21  97  }
5361db1a33c7e2 Chris Wilson 2019-06-21  98
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index 7412abf166a8..4a8d873b4347 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -133,7 +133,7 @@  __active_retire(struct i915_active *ref)
 	GEM_BUG_ON(i915_active_is_idle(ref));

 	/* return the unused nodes to our slabcache -- flushing the allocator */
-	if (!atomic_dec_and_lock_irqsave(&ref->count, &ref->tree_lock, flags))
+	if (!refcount_dec_and_lock_irqsave(&ref->count, &ref->tree_lock, &flags))
 		return;

 	GEM_BUG_ON(rcu_access_pointer(ref->excl.fence));
@@ -179,8 +179,8 @@  active_work(struct work_struct *wrk)
 {
 	struct i915_active *ref = container_of(wrk, typeof(*ref), work);

-	GEM_BUG_ON(!atomic_read(&ref->count));
-	if (atomic_add_unless(&ref->count, -1, 1))
+	GEM_BUG_ON(!refcount_read(&ref->count));
+	if (refcount_dec_not_one(&ref->count))
 		return;

 	__active_retire(ref);
@@ -189,8 +189,8 @@  active_work(struct work_struct *wrk)
 static void
 active_retire(struct i915_active *ref)
 {
-	GEM_BUG_ON(!atomic_read(&ref->count));
-	if (atomic_add_unless(&ref->count, -1, 1))
+	GEM_BUG_ON(!refcount_read(&ref->count));
+	if (refcount_dec_not_one(&ref->count))
 		return;

 	if (ref->flags & I915_ACTIVE_RETIRE_SLEEPS) {
@@ -354,7 +354,7 @@  void __i915_active_init(struct i915_active *ref,
 	ref->cache = NULL;

 	init_llist_head(&ref->preallocated_barriers);
-	atomic_set(&ref->count, 0);
+	refcount_set(&ref->count, 0);
 	__mutex_init(&ref->mutex, "i915_active", mkey);
 	__i915_active_fence_init(&ref->excl, NULL, excl_retire);
 	INIT_WORK(&ref->work, active_work);
@@ -445,7 +445,7 @@  int i915_active_add_request(struct i915_active *ref, struct i915_request *rq)

 	if (replace_barrier(ref, active)) {
 		RCU_INIT_POINTER(active->fence, NULL);
-		atomic_dec(&ref->count);
+		refcount_dec(&ref->count);
 	}
 	if (!__i915_active_fence_set(active, fence))
 		__i915_active_acquire(ref);
@@ -488,14 +488,16 @@  i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f)
 bool i915_active_acquire_if_busy(struct i915_active *ref)
 {
 	debug_active_assert(ref);
-	return atomic_add_unless(&ref->count, 1, 0);
+	return refcount_add_not_zero(1, &ref->count);
 }

 static void __i915_active_activate(struct i915_active *ref)
 {
 	spin_lock_irq(&ref->tree_lock); /* __active_retire() */
-	if (!atomic_fetch_inc(&ref->count))
+	if (!refcount_inc_not_zero(&ref->count)) {
+		refcount_inc(&ref->count);
 		debug_active_activate(ref);
+	}
 	spin_unlock_irq(&ref->tree_lock);
 }

@@ -757,7 +759,7 @@  int i915_sw_fence_await_active(struct i915_sw_fence *fence,
 void i915_active_fini(struct i915_active *ref)
 {
 	debug_active_fini(ref);
-	GEM_BUG_ON(atomic_read(&ref->count));
+	GEM_BUG_ON(refcount_read(&ref->count));
 	GEM_BUG_ON(work_pending(&ref->work));
 	mutex_destroy(&ref->mutex);

@@ -927,7 +929,7 @@  int i915_active_acquire_preallocate_barrier(struct i915_active *ref,

 		first = first->next;

-		atomic_dec(&ref->count);
+		refcount_dec(&ref->count);
 		intel_engine_pm_put(barrier_to_engine(node));

 		kmem_cache_free(slab_cache, node);
diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h
index 7eb44132183a..116c7c28466a 100644
--- a/drivers/gpu/drm/i915/i915_active.h
+++ b/drivers/gpu/drm/i915/i915_active.h
@@ -193,14 +193,14 @@  void i915_active_release(struct i915_active *ref);

 static inline void __i915_active_acquire(struct i915_active *ref)
 {
-	GEM_BUG_ON(!atomic_read(&ref->count));
-	atomic_inc(&ref->count);
+	GEM_BUG_ON(!refcount_read(&ref->count));
+	refcount_inc(&ref->count);
 }

 static inline bool
 i915_active_is_idle(const struct i915_active *ref)
 {
-	return !atomic_read(&ref->count);
+	return !refcount_read(&ref->count);
 }

 void i915_active_fini(struct i915_active *ref);
diff --git a/drivers/gpu/drm/i915/i915_active_types.h b/drivers/gpu/drm/i915/i915_active_types.h
index b02a78ac87db..152a3a25d9f7 100644
--- a/drivers/gpu/drm/i915/i915_active_types.h
+++ b/drivers/gpu/drm/i915/i915_active_types.h
@@ -7,7 +7,7 @@ 
 #ifndef _I915_ACTIVE_TYPES_H_
 #define _I915_ACTIVE_TYPES_H_

-#include <linux/atomic.h>
+#include <linux/refcount.h>
 #include <linux/dma-fence.h>
 #include <linux/llist.h>
 #include <linux/mutex.h>
@@ -23,7 +23,7 @@  struct i915_active_fence {
 struct active_node;

 struct i915_active {
-	atomic_t count;
+	refcount_t count;
 	struct mutex mutex;

 	spinlock_t tree_lock;