drm/i915: Convert i915_perf to ww locking as well

We have the ordering of timeline->mutex vs resv_lock wrong,
convert the i915_pin_vma and intel_context_pin as well to
future-proof this.

We may need to do future changes to do this more transaction-like,
and only get down to a single i915_gem_ww_ctx, but for now this
should work.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-18-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index c6f6370283cf44bf6f82dcc57bf1d2ae34bc4029..e94976976571fe61181dd87f24cb3227eb7a544a 100644 (file)
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1195,24 +1195,39 @@ static struct intel_context *oa_pin_context(struct i915_perf_stream *stream)
        struct i915_gem_engines_iter it;
        struct i915_gem_context *ctx = stream->ctx;
        struct intel_context *ce;
-       int err;
+       struct i915_gem_ww_ctx ww;
+       int err = -ENODEV;
 
        for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
                if (ce->engine != stream->engine) /* first match! */
                        continue;
 
-               /*
-                * As the ID is the gtt offset of the context's vma we
-                * pin the vma to ensure the ID remains fixed.
-                */
-               err = intel_context_pin(ce);
-               if (err == 0) {
-                       stream->pinned_ctx = ce;
-                       break;
-               }
+               err = 0;
+               break;
        }
        i915_gem_context_unlock_engines(ctx);
 
+       if (err)
+               return ERR_PTR(err);
+
+       i915_gem_ww_ctx_init(&ww, true);
+retry:
+       /*
+        * As the ID is the gtt offset of the context's vma we
+        * pin the vma to ensure the ID remains fixed.
+        */
+       err = intel_context_pin_ww(ce, &ww);
+       if (err == -EDEADLK) {
+               err = i915_gem_ww_ctx_backoff(&ww);
+               if (!err)
+                       goto retry;
+       }
+       i915_gem_ww_ctx_fini(&ww);
+
+       if (err)
+               return ERR_PTR(err);
+
+       stream->pinned_ctx = ce;
        return stream->pinned_ctx;
 }
 
@@ -1923,15 +1938,22 @@ emit_oa_config(struct i915_perf_stream *stream,
 {
        struct i915_request *rq;
        struct i915_vma *vma;
+       struct i915_gem_ww_ctx ww;
        int err;
 
        vma = get_oa_vma(stream, oa_config);
        if (IS_ERR(vma))
                return PTR_ERR(vma);
 
-       err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
+       i915_gem_ww_ctx_init(&ww, true);
+retry:
+       err = i915_gem_object_lock(vma->obj, &ww);
+       if (err)
+               goto err;
+
+       err = i915_vma_pin_ww(vma, &ww, 0, 0, PIN_GLOBAL | PIN_HIGH);
        if (err)
-               goto err_vma_put;
+               goto err;
 
        intel_engine_pm_get(ce->engine);
        rq = i915_request_create(ce);
@@ -1953,11 +1975,9 @@ emit_oa_config(struct i915_perf_stream *stream,
                        goto err_add_request;
        }
 
-       i915_vma_lock(vma);
        err = i915_request_await_object(rq, vma->obj, 0);
        if (!err)
                err = i915_vma_move_to_active(vma, rq, 0);
-       i915_vma_unlock(vma);
        if (err)
                goto err_add_request;
 
@@ -1971,7 +1991,14 @@ err_add_request:
        i915_request_add(rq);
 err_vma_unpin:
        i915_vma_unpin(vma);
-err_vma_put:
+err:
+       if (err == -EDEADLK) {
+               err = i915_gem_ww_ctx_backoff(&ww);
+               if (!err)
+                       goto retry;
+       }
+
+       i915_gem_ww_ctx_fini(&ww);
        i915_vma_put(vma);
        return err;
 }