drm/i915/gt: Make deferred context allocation explicit

Refactor the backends to handle the deferred context allocation in a
consistent manner, and allow calling it as an explicit first step in
pinning a context for the first time. This should make it easier for
backends to keep track of partially constructed contexts from
initialisation.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809182518.20486-2-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index c8777e222b12d2b172588193a273f83b66917fde..41d38e661de740e174baac7c5ee09155bb7a376b 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -53,6 +53,14 @@ int __intel_context_do_pin(struct intel_context *ce)
        if (likely(!atomic_read(&ce->pin_count))) {
                intel_wakeref_t wakeref;
 
+               if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
+                       err = ce->ops->alloc(ce);
+                       if (unlikely(err))
+                               goto err;
+
+                       __set_bit(CONTEXT_ALLOC_BIT, &ce->flags);
+               }
+
                err = 0;
                with_intel_runtime_pm(&ce->engine->i915->runtime_pm, wakeref)
                        err = ce->ops->pin(ce);

diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 68a7e979b1a950c4ef6b1c3936aec2651e5b44a6..cff6238c213aba83d6b0617ab86250a14ad0a48f 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -23,6 +23,8 @@ struct intel_context;
 struct intel_ring;
 
 struct intel_context_ops {
+       int (*alloc)(struct intel_context *ce);
+
        int (*pin)(struct intel_context *ce);
        void (*unpin)(struct intel_context *ce);
 
@@ -52,6 +54,9 @@ struct intel_context {
        struct i915_vma *state;
        struct intel_ring *ring;
 
+       unsigned long flags;
+#define CONTEXT_ALLOC_BIT 0
+
        u32 *lrc_reg_state;
        u64 lrc_desc;
 

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 14c5bfbe0a74e6b525c3daa687b565eac4b13bb6..a986ea87fbd9230a6079c8befeb75932ab01964b 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -219,8 +219,9 @@ static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine)
        return container_of(engine, struct virtual_engine, base);
 }
 
-static int execlists_context_deferred_alloc(struct intel_context *ce,
-                                           struct intel_engine_cs *engine);
+static int __execlists_context_alloc(struct intel_context *ce,
+                                    struct intel_engine_cs *engine);
+
 static void execlists_init_reg_state(u32 *reg_state,
                                     struct intel_context *ce,
                                     struct intel_engine_cs *engine,
@@ -1614,9 +1615,6 @@ __execlists_context_pin(struct intel_context *ce,
        void *vaddr;
        int ret;
 
-       ret = execlists_context_deferred_alloc(ce, engine);
-       if (ret)
-               goto err;
        GEM_BUG_ON(!ce->state);
 
        ret = intel_context_active_acquire(ce);
@@ -1655,6 +1653,11 @@ static int execlists_context_pin(struct intel_context *ce)
        return __execlists_context_pin(ce, ce->engine);
 }
 
+static int execlists_context_alloc(struct intel_context *ce)
+{
+       return __execlists_context_alloc(ce, ce->engine);
+}
+
 static void execlists_context_reset(struct intel_context *ce)
 {
        /*
@@ -1678,6 +1681,8 @@ static void execlists_context_reset(struct intel_context *ce)
 }
 
 static const struct intel_context_ops execlists_context_ops = {
+       .alloc = execlists_context_alloc,
+
        .pin = execlists_context_pin,
        .unpin = execlists_context_unpin,
 
@@ -3075,8 +3080,8 @@ get_timeline(struct i915_gem_context *ctx, struct intel_gt *gt)
                return intel_timeline_create(gt, NULL);
 }
 
-static int execlists_context_deferred_alloc(struct intel_context *ce,
-                                           struct intel_engine_cs *engine)
+static int __execlists_context_alloc(struct intel_context *ce,
+                                    struct intel_engine_cs *engine)
 {
        struct drm_i915_gem_object *ctx_obj;
        struct i915_vma *vma;
@@ -3085,9 +3090,7 @@ static int execlists_context_deferred_alloc(struct intel_context *ce,
        struct intel_timeline *timeline;
        int ret;
 
-       if (ce->state)
-               return 0;
-
+       GEM_BUG_ON(ce->state);
        context_size = round_up(engine->context_size, I915_GTT_PAGE_SIZE);
 
        /*
@@ -3533,6 +3536,12 @@ intel_execlists_create_virtual(struct i915_gem_context *ctx,
 
        ve->base.flags |= I915_ENGINE_IS_VIRTUAL;
 
+       err = __execlists_context_alloc(&ve->context, siblings[0]);
+       if (err)
+               goto err_put;
+
+       __set_bit(CONTEXT_ALLOC_BIT, &ve->context.flags);
+
        return &ve->context;
 
 err_put:

diff --git a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
index 78b4235f9c0ffaa1c1cd364f0498f750abedc890..6a28920334574eb8de5f0eaeb04139754715561f 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
@@ -1480,16 +1480,16 @@ err_obj:
        return ERR_PTR(err);
 }
 
-static int ring_context_pin(struct intel_context *ce)
+static int ring_context_alloc(struct intel_context *ce)
 {
        struct intel_engine_cs *engine = ce->engine;
-       int err;
 
        /* One ringbuffer to rule them all */
        GEM_BUG_ON(!engine->buffer);
        ce->ring = engine->buffer;
 
-       if (!ce->state && engine->context_size) {
+       GEM_BUG_ON(ce->state);
+       if (engine->context_size) {
                struct i915_vma *vma;
 
                vma = alloc_context_vma(engine);
@@ -1499,6 +1499,13 @@ static int ring_context_pin(struct intel_context *ce)
                ce->state = vma;
        }
 
+       return 0;
+}
+
+static int ring_context_pin(struct intel_context *ce)
+{
+       int err;
+
        err = intel_context_active_acquire(ce);
        if (err)
                return err;
@@ -1520,6 +1527,8 @@ static void ring_context_reset(struct intel_context *ce)
 }
 
 static const struct intel_context_ops ring_context_ops = {
+       .alloc = ring_context_alloc,
+
        .pin = ring_context_pin,
        .unpin = ring_context_unpin,
 

diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c
index dd02e59b192fb5e3c04659c794e64d814e55f3e5..848a83a38b0884de2ce8e3c0bb7bde487e63a050 100644 (file)
--- a/drivers/gpu/drm/i915/gt/mock_engine.c
+++ b/drivers/gpu/drm/i915/gt/mock_engine.c
@@ -147,16 +147,19 @@ static void mock_context_destroy(struct kref *ref)
        intel_context_free(ce);
 }
 
+static int mock_context_alloc(struct intel_context *ce)
+{
+       ce->ring = mock_ring(ce->engine);
+       if (!ce->ring)
+               return -ENOMEM;
+
+       return 0;
+}
+
 static int mock_context_pin(struct intel_context *ce)
 {
        int ret;
 
-       if (!ce->ring) {
-               ce->ring = mock_ring(ce->engine);
-               if (!ce->ring)
-                       return -ENOMEM;
-       }
-
        ret = intel_context_active_acquire(ce);
        if (ret)
                return ret;
@@ -166,6 +169,8 @@ static int mock_context_pin(struct intel_context *ce)
 }
 
 static const struct intel_context_ops mock_context_ops = {
+       .alloc = mock_context_alloc,
+
        .pin = mock_context_pin,
        .unpin = mock_context_unpin,