drm/i915/gvt: Introduce per object locking in GVT scheduler.

To support ww locking and per-object implemented in i915, GVT scheduler needs
to be refined. Most of the changes are located in shadow batch buffer, shadow
wa context in GVT-g, where use quite a lot of i915 gem object APIs.

v2:

- Adjust the usage of ww lock on context pin/unpin. (maarten)
- Rebase the patch on the newest staging branch.

Fixes: 6b05030496f7 ("drm/i915: Convert i915_gem_object/client_blt.c to use ww locking as well, v2.")
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1610314985-26065-1-git-send-email-zhi.wang.linux@gmail.com
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index a55ae50..fc73569 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -412,7 +412,9 @@ static void release_shadow_wa_ctx(struct intel_shadow_wa_ctx *wa_ctx)
        if (!wa_ctx->indirect_ctx.obj)
                return;
 
+       i915_gem_object_lock(wa_ctx->indirect_ctx.obj, NULL);
        i915_gem_object_unpin_map(wa_ctx->indirect_ctx.obj);
+       i915_gem_object_unlock(wa_ctx->indirect_ctx.obj);
        i915_gem_object_put(wa_ctx->indirect_ctx.obj);
 
        wa_ctx->indirect_ctx.obj = NULL;
@@ -520,6 +522,7 @@ static int prepare_shadow_batch_buffer(struct intel_vgpu_workload *workload)
        struct intel_gvt *gvt = workload->vgpu->gvt;
        const int gmadr_bytes = gvt->device_info.gmadr_bytes_in_cmd;
        struct intel_vgpu_shadow_bb *bb;
+       struct i915_gem_ww_ctx ww;
        int ret;
 
        list_for_each_entry(bb, &workload->shadow_bb, list) {
@@ -544,10 +547,19 @@ static int prepare_shadow_batch_buffer(struct intel_vgpu_workload *workload)
                 * directly
                 */
                if (!bb->ppgtt) {
-                       bb->vma = i915_gem_object_ggtt_pin(bb->obj,
-                                                          NULL, 0, 0, 0);
+                       i915_gem_ww_ctx_init(&ww, false);
+retry:
+                       i915_gem_object_lock(bb->obj, &ww);
+
+                       bb->vma = i915_gem_object_ggtt_pin_ww(bb->obj, &ww,
+                                                             NULL, 0, 0, 0);
                        if (IS_ERR(bb->vma)) {
                                ret = PTR_ERR(bb->vma);
+                               if (ret == -EDEADLK) {
+                                       ret = i915_gem_ww_ctx_backoff(&ww);
+                                       if (!ret)
+                                               goto retry;
+                               }
                                goto err;
                        }
 
@@ -561,13 +573,15 @@ static int prepare_shadow_batch_buffer(struct intel_vgpu_workload *workload)
                                                      0);
                        if (ret)
                                goto err;
-               }
 
-               /* No one is going to touch shadow bb from now on. */
-               i915_gem_object_flush_map(bb->obj);
+                       /* No one is going to touch shadow bb from now on. */
+                       i915_gem_object_flush_map(bb->obj);
+                       i915_gem_object_unlock(bb->obj);
+               }
        }
        return 0;
 err:
+       i915_gem_ww_ctx_fini(&ww);
        release_shadow_batch_buffer(workload);
        return ret;
 }
@@ -594,14 +608,29 @@ static int prepare_shadow_wa_ctx(struct intel_shadow_wa_ctx *wa_ctx)
        unsigned char *per_ctx_va =
                (unsigned char *)wa_ctx->indirect_ctx.shadow_va +
                wa_ctx->indirect_ctx.size;
+       struct i915_gem_ww_ctx ww;
+       int ret;
 
        if (wa_ctx->indirect_ctx.size == 0)
                return 0;
 
-       vma = i915_gem_object_ggtt_pin(wa_ctx->indirect_ctx.obj, NULL,
-                                      0, CACHELINE_BYTES, 0);
-       if (IS_ERR(vma))
-               return PTR_ERR(vma);
+       i915_gem_ww_ctx_init(&ww, false);
+retry:
+       i915_gem_object_lock(wa_ctx->indirect_ctx.obj, &ww);
+
+       vma = i915_gem_object_ggtt_pin_ww(wa_ctx->indirect_ctx.obj, &ww, NULL,
+                                         0, CACHELINE_BYTES, 0);
+       if (IS_ERR(vma)) {
+               ret = PTR_ERR(vma);
+               if (ret == -EDEADLK) {
+                       ret = i915_gem_ww_ctx_backoff(&ww);
+                       if (!ret)
+                               goto retry;
+               }
+               return ret;
+       }
+
+       i915_gem_object_unlock(wa_ctx->indirect_ctx.obj);
 
        /* FIXME: we are not tracking our pinned VMA leaving it
         * up to the core to fix up the stray pin_count upon
@@ -635,12 +664,14 @@ static void release_shadow_batch_buffer(struct intel_vgpu_workload *workload)
 
        list_for_each_entry_safe(bb, pos, &workload->shadow_bb, list) {
                if (bb->obj) {
+                       i915_gem_object_lock(bb->obj, NULL);
                        if (bb->va && !IS_ERR(bb->va))
                                i915_gem_object_unpin_map(bb->obj);
 
                        if (bb->vma && !IS_ERR(bb->vma))
                                i915_vma_unpin(bb->vma);
 
+                       i915_gem_object_unlock(bb->obj);
                        i915_gem_object_put(bb->obj);
                }
                list_del(&bb->list);