drm/i915: Reserve some priority bits for internal use

In the next few patches, we will want to give a small priority boost to
some requests/queues but not so much that we perturb the user controlled
order. As such we will shift the user priority bits higher leaving
ourselves a few low priority bits for our internal bumping.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181001123204.23982-3-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3019152..b672ed0 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3236,7 +3236,7 @@ int i915_gem_object_wait(struct drm_i915_gem_object *obj,
 int i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
                                  unsigned int flags,
                                  const struct i915_sched_attr *attr);
-#define I915_PRIORITY_DISPLAY I915_PRIORITY_MAX
+#define I915_PRIORITY_DISPLAY I915_USER_PRIORITY(I915_PRIORITY_MAX)
 
 int __must_check
 i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write);

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 15c92f7..8cbe580 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -337,7 +337,7 @@ __create_hw_context(struct drm_i915_private *dev_priv,
        kref_init(&ctx->ref);
        list_add_tail(&ctx->link, &dev_priv->contexts.list);
        ctx->i915 = dev_priv;
-       ctx->sched.priority = I915_PRIORITY_NORMAL;
+       ctx->sched.priority = I915_USER_PRIORITY(I915_PRIORITY_NORMAL);
 
        for (n = 0; n < ARRAY_SIZE(ctx->__engine); n++) {
                struct intel_context *ce = &ctx->__engine[n];
@@ -504,7 +504,7 @@ i915_gem_context_create_kernel(struct drm_i915_private *i915, int prio)
        }
 
        i915_gem_context_clear_bannable(ctx);
-       ctx->sched.priority = prio;
+       ctx->sched.priority = I915_USER_PRIORITY(prio);
        ctx->ring_size = PAGE_SIZE;
 
        GEM_BUG_ON(!i915_gem_context_is_kernel(ctx));
@@ -879,7 +879,7 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
                args->value = i915_gem_context_is_bannable(ctx);
                break;
        case I915_CONTEXT_PARAM_PRIORITY:
-               args->value = ctx->sched.priority;
+               args->value = ctx->sched.priority >> I915_USER_PRIORITY_SHIFT;
                break;
        default:
                ret = -EINVAL;
@@ -948,7 +948,8 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
                                 !capable(CAP_SYS_NICE))
                                ret = -EPERM;
                        else
-                               ctx->sched.priority = priority;
+                               ctx->sched.priority =
+                                       I915_USER_PRIORITY(priority);
                }
                break;
 

diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 70a4222..89d4563 100644 (file)
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -19,6 +19,12 @@ enum {
        I915_PRIORITY_INVALID = INT_MIN
 };
 
+#define I915_USER_PRIORITY_SHIFT 0
+#define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT)
+
+#define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT)
+#define I915_PRIORITY_MASK (I915_PRIORITY_COUNT - 1)
+
 struct i915_sched_attr {
        /**
         * @priority: execution and service priority

diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c
index d67fe83..c8b7f03 100644 (file)
--- a/drivers/gpu/drm/i915/selftests/intel_lrc.c
+++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c
@@ -292,12 +292,14 @@ static int live_preempt(void *arg)
        ctx_hi = kernel_context(i915);
        if (!ctx_hi)
                goto err_spin_lo;
-       ctx_hi->sched.priority = I915_CONTEXT_MAX_USER_PRIORITY;
+       ctx_hi->sched.priority =
+               I915_USER_PRIORITY(I915_CONTEXT_MAX_USER_PRIORITY);
 
        ctx_lo = kernel_context(i915);
        if (!ctx_lo)
                goto err_ctx_hi;
-       ctx_lo->sched.priority = I915_CONTEXT_MIN_USER_PRIORITY;
+       ctx_lo->sched.priority =
+               I915_USER_PRIORITY(I915_CONTEXT_MIN_USER_PRIORITY);
 
        for_each_engine(engine, i915, id) {
                struct i915_request *rq;
@@ -418,7 +420,7 @@ static int live_late_preempt(void *arg)
                        goto err_wedged;
                }
 
-               attr.priority = I915_PRIORITY_MAX;
+               attr.priority = I915_USER_PRIORITY(I915_PRIORITY_MAX);
                engine->schedule(rq, &attr);
 
                if (!wait_for_spinner(&spin_hi, rq)) {