[RFC PATCH 029/162] drm/i915: Handle ww locking in init_status_page

[Matthew Auld]

From: Maarten Lankhorst <maarten.lankho...@linux.intel.com>

Try to pin to ggtt first, and use a full ww loop to handle
eviction correctly.

Signed-off-by: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
Cc: Thomas Hellström <thomas.hellst...@linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_engine_cs.c | 37 +++++++++++++++--------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c 
b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 97ceaf7116e8..420c6a35f3ed 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -618,6 +618,7 @@ static void cleanup_status_page(struct intel_engine_cs 
*engine)
 }
 
 static int pin_ggtt_status_page(struct intel_engine_cs *engine,
+                               struct i915_gem_ww_ctx *ww,
                                struct i915_vma *vma)
 {
        unsigned int flags;
@@ -638,12 +639,13 @@ static int pin_ggtt_status_page(struct intel_engine_cs 
*engine,
        else
                flags = PIN_HIGH;
 
-       return i915_ggtt_pin(vma, NULL, 0, flags);
+       return i915_ggtt_pin(vma, ww, 0, flags);
 }
 
 static int init_status_page(struct intel_engine_cs *engine)
 {
        struct drm_i915_gem_object *obj;
+       struct i915_gem_ww_ctx ww;
        struct i915_vma *vma;
        void *vaddr;
        int ret;
@@ -667,30 +669,39 @@ static int init_status_page(struct intel_engine_cs 
*engine)
        vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL);
        if (IS_ERR(vma)) {
                ret = PTR_ERR(vma);
-               goto err;
+               goto err_put;
        }
 
+       i915_gem_ww_ctx_init(&ww, true);
+retry:
+       ret = i915_gem_object_lock(obj, &ww);
+       if (!ret && !HWS_NEEDS_PHYSICAL(engine->i915))
+               ret = pin_ggtt_status_page(engine, &ww, vma);
+       if (ret)
+               goto err;
+
        vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
        if (IS_ERR(vaddr)) {
                ret = PTR_ERR(vaddr);
-               goto err;
+               goto err_unpin;
        }
 
        engine->status_page.addr = memset(vaddr, 0, PAGE_SIZE);
        engine->status_page.vma = vma;
 
-       if (!HWS_NEEDS_PHYSICAL(engine->i915)) {
-               ret = pin_ggtt_status_page(engine, vma);
-               if (ret)
-                       goto err_unpin;
-       }
-
-       return 0;
-
 err_unpin:
-       i915_gem_object_unpin_map(obj);
+       if (ret)
+               i915_vma_unpin(vma);
 err:
-       i915_gem_object_put(obj);
+       if (ret == -EDEADLK) {
+               ret = i915_gem_ww_ctx_backoff(&ww);
+               if (!ret)
+                       goto retry;
+       }
+       i915_gem_ww_ctx_fini(&ww);
+err_put:
+       if (ret)
+               i915_gem_object_put(obj);
        return ret;
 }
 
-- 
2.26.2

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