From: Chris Wilson Date: Thu, 12 Sep 2019 16:08:34 +0000 (+0100) Subject: drm/i915: Don't mix srcu tag and negative error codes X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fda9fa19b09067b6a3ee6ff8d93e977957e0655c;p=linux.git drm/i915: Don't mix srcu tag and negative error codes While srcu may use an integer tag, it does not exclude potential error codes and so may overlap with our own use of -EINTR. Use a separate outparam to store the tag, and report the error code separately. Fixes: 2caffbf11762 ("drm/i915: Revoke mmaps and prevent access to fence registers across reset") Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Ville Syrjälä Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20190912160834.30601-1-chris@chris-wilson.co.uk (cherry picked from commit eebab60f224fcfd560957715d08c31564d8672ed) Signed-off-by: Rodrigo Vivi --- diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c index 261c9bd83f518..1fd2081a905e7 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c @@ -245,11 +245,9 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf) wakeref = intel_runtime_pm_get(rpm); - srcu = intel_gt_reset_trylock(ggtt->vm.gt); - if (srcu < 0) { - ret = srcu; + ret = intel_gt_reset_trylock(ggtt->vm.gt, &srcu); + if (ret) goto err_rpm; - } ret = i915_mutex_lock_interruptible(dev); if (ret) diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c index b9d84d52e9864..eeb3bd0c4d690 100644 --- a/drivers/gpu/drm/i915/gt/intel_reset.c +++ b/drivers/gpu/drm/i915/gt/intel_reset.c @@ -1214,10 +1214,8 @@ out: intel_runtime_pm_put(>->i915->runtime_pm, wakeref); } -int intel_gt_reset_trylock(struct intel_gt *gt) +int intel_gt_reset_trylock(struct intel_gt *gt, int *srcu) { - int srcu; - might_lock(>->reset.backoff_srcu); might_sleep(); @@ -1232,10 +1230,10 @@ int intel_gt_reset_trylock(struct intel_gt *gt) rcu_read_lock(); } - srcu = srcu_read_lock(>->reset.backoff_srcu); + *srcu = srcu_read_lock(>->reset.backoff_srcu); rcu_read_unlock(); - return srcu; + return 0; } void intel_gt_reset_unlock(struct intel_gt *gt, int tag) diff --git a/drivers/gpu/drm/i915/gt/intel_reset.h b/drivers/gpu/drm/i915/gt/intel_reset.h index 37a987b171082..52c00199e0694 100644 --- a/drivers/gpu/drm/i915/gt/intel_reset.h +++ b/drivers/gpu/drm/i915/gt/intel_reset.h @@ -38,7 +38,7 @@ int intel_engine_reset(struct intel_engine_cs *engine, void __i915_request_reset(struct i915_request *rq, bool guilty); -int __must_check intel_gt_reset_trylock(struct intel_gt *gt); +int __must_check intel_gt_reset_trylock(struct intel_gt *gt, int *srcu); void intel_gt_reset_unlock(struct intel_gt *gt, int tag); void intel_gt_set_wedged(struct intel_gt *gt);