[Intel-gfx] [PATCH v3 2/3] drm/i915: abolish separate per-ring default_context pointers
Nick Hoath
nicholas.hoath at intel.com
Mon Jan 18 08:16:39 PST 2016
On 07/01/2016 10:20, Dave Gordon wrote:
> Now that we've eliminated a lot of uses of ring->default_context,
> we can eliminate the pointer itself.
>
> All the engines share the same default intel_context, so we can just
> keep a single reference to it in the dev_priv structure rather than one
> in each of the engine[] elements. This make refcounting more sensible
> too, as we now have a refcount of one for the one pointer, rather than
> a refcount of one but multiple pointers.
>
> From an idea by Chris Wilson.
>
> Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
Reviewed-by: Nick Hoath <nicholas.hoath at intel.com>
> ---
> drivers/gpu/drm/i915/i915_debugfs.c | 4 ++--
> drivers/gpu/drm/i915/i915_drv.h | 2 ++
> drivers/gpu/drm/i915/i915_gem.c | 6 +++---
> drivers/gpu/drm/i915/i915_gem_context.c | 22 ++++++++--------------
> drivers/gpu/drm/i915/i915_gpu_error.c | 2 +-
> drivers/gpu/drm/i915/i915_guc_submission.c | 6 +++---
> drivers/gpu/drm/i915/intel_lrc.c | 24 +++++++++++++-----------
> drivers/gpu/drm/i915/intel_ringbuffer.h | 1 -
> 8 files changed, 32 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 0fc38bb..2613708 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -1943,7 +1943,7 @@ static int i915_context_status(struct seq_file *m, void *unused)
> seq_puts(m, "HW context ");
> describe_ctx(m, ctx);
> for_each_ring(ring, dev_priv, i) {
> - if (ring->default_context == ctx)
> + if (dev_priv->kernel_context == ctx)
> seq_printf(m, "(default context %s) ",
> ring->name);
> }
> @@ -2039,7 +2039,7 @@ static int i915_dump_lrc(struct seq_file *m, void *unused)
>
> list_for_each_entry(ctx, &dev_priv->context_list, link) {
> for_each_ring(ring, dev_priv, i) {
> - if (ring->default_context != ctx)
> + if (dev_priv->kernel_context != ctx)
> i915_dump_lrc_obj(m, ring,
> ctx->engine[i].state);
> }
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index c2b000a..aef86a8 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1940,6 +1940,8 @@ struct drm_i915_private {
> void (*stop_ring)(struct intel_engine_cs *ring);
> } gt;
>
> + struct intel_context *kernel_context;
> +
> bool edp_low_vswing;
>
> /* perform PHY state sanity checks? */
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index c908ed1..8f101121 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2678,7 +2678,7 @@ void i915_gem_request_free(struct kref *req_ref)
>
> if (ctx) {
> if (i915.enable_execlists) {
> - if (ctx != req->ring->default_context)
> + if (ctx != req->i915->kernel_context)
> intel_lr_context_unpin(req);
> }
>
> @@ -2774,7 +2774,7 @@ i915_gem_request_alloc(struct intel_engine_cs *engine,
> int err;
>
> if (ctx == NULL)
> - ctx = engine->default_context;
> + ctx = to_i915(engine->dev)->kernel_context;
> err = __i915_gem_request_alloc(engine, ctx, &req);
> return err ? ERR_PTR(err) : req;
> }
> @@ -4862,7 +4862,7 @@ i915_gem_init_hw(struct drm_device *dev)
> */
> init_unused_rings(dev);
>
> - BUG_ON(!dev_priv->ring[RCS].default_context);
> + BUG_ON(!dev_priv->kernel_context);
>
> ret = i915_ppgtt_init_hw(dev);
> if (ret) {
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index 900ffd0..e1d767e 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -354,11 +354,10 @@ int i915_gem_context_init(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct intel_context *ctx;
> - int i;
>
> /* Init should only be called once per module load. Eventually the
> * restriction on the context_disabled check can be loosened. */
> - if (WARN_ON(dev_priv->ring[RCS].default_context))
> + if (WARN_ON(dev_priv->kernel_context))
> return 0;
>
> if (intel_vgpu_active(dev) && HAS_LOGICAL_RING_CONTEXTS(dev)) {
> @@ -388,12 +387,7 @@ int i915_gem_context_init(struct drm_device *dev)
> return PTR_ERR(ctx);
> }
>
> - for (i = 0; i < I915_NUM_RINGS; i++) {
> - struct intel_engine_cs *ring = &dev_priv->ring[i];
> -
> - /* NB: RCS will hold a ref for all rings */
> - ring->default_context = ctx;
> - }
> + dev_priv->kernel_context = ctx;
>
> DRM_DEBUG_DRIVER("%s context support initialized\n",
> i915.enable_execlists ? "LR" :
> @@ -404,7 +398,7 @@ int i915_gem_context_init(struct drm_device *dev)
> void i915_gem_context_fini(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> - struct intel_context *dctx = dev_priv->ring[RCS].default_context;
> + struct intel_context *dctx = dev_priv->kernel_context;
> int i;
>
> if (dctx->legacy_hw_ctx.rcs_state) {
> @@ -431,17 +425,17 @@ void i915_gem_context_fini(struct drm_device *dev)
> i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
> }
>
> - for (i = 0; i < I915_NUM_RINGS; i++) {
> + for (i = I915_NUM_RINGS; --i >= 0;) {
> struct intel_engine_cs *ring = &dev_priv->ring[i];
>
> - if (ring->last_context)
> + if (ring->last_context) {
> i915_gem_context_unreference(ring->last_context);
> -
> - ring->default_context = NULL;
> - ring->last_context = NULL;
> + ring->last_context = NULL;
> + }
> }
>
> i915_gem_context_unreference(dctx);
> + dev_priv->kernel_context = NULL;
> }
>
> int i915_gem_context_enable(struct drm_i915_gem_request *req)
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 06ca408..7eeb244 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -1050,7 +1050,7 @@ static void i915_gem_record_rings(struct drm_device *dev,
> if (request)
> rbuf = request->ctx->engine[ring->id].ringbuf;
> else
> - rbuf = ring->default_context->engine[ring->id].ringbuf;
> + rbuf = dev_priv->kernel_context->engine[ring->id].ringbuf;
> } else
> rbuf = ring->buffer;
>
> diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
> index 9c24424..51ae5c1 100644
> --- a/drivers/gpu/drm/i915/i915_guc_submission.c
> +++ b/drivers/gpu/drm/i915/i915_guc_submission.c
> @@ -964,7 +964,7 @@ int i915_guc_submission_enable(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct intel_guc *guc = &dev_priv->guc;
> - struct intel_context *ctx = dev_priv->ring[RCS].default_context;
> + struct intel_context *ctx = dev_priv->kernel_context;
> struct i915_guc_client *client;
>
> /* client for execbuf submission */
> @@ -1021,7 +1021,7 @@ int intel_guc_suspend(struct drm_device *dev)
> if (!i915.enable_guc_submission)
> return 0;
>
> - ctx = dev_priv->ring[RCS].default_context;
> + ctx = dev_priv->kernel_context;
>
> data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
> /* any value greater than GUC_POWER_D0 */
> @@ -1047,7 +1047,7 @@ int intel_guc_resume(struct drm_device *dev)
> if (!i915.enable_guc_submission)
> return 0;
>
> - ctx = dev_priv->ring[RCS].default_context;
> + ctx = dev_priv->kernel_context;
>
> data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
> data[1] = GUC_POWER_D0;
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 8b6542d..aaaa5a3 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -571,7 +571,7 @@ static int execlists_context_queue(struct drm_i915_gem_request *request)
> struct drm_i915_gem_request *cursor;
> int num_elements = 0;
>
> - if (request->ctx != ring->default_context)
> + if (request->ctx != request->i915->kernel_context)
> intel_lr_context_pin(request);
>
> i915_gem_request_reference(request);
> @@ -664,7 +664,7 @@ int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request
>
> request->ringbuf = request->ctx->engine[request->ring->id].ringbuf;
>
> - if (request->ctx != request->ring->default_context) {
> + if (request->ctx != request->i915->kernel_context) {
> ret = intel_lr_context_pin(request);
> if (ret)
> return ret;
> @@ -980,7 +980,7 @@ void intel_execlists_retire_requests(struct intel_engine_cs *ring)
> struct drm_i915_gem_object *ctx_obj =
> ctx->engine[ring->id].state;
>
> - if (ctx_obj && (ctx != ring->default_context))
> + if (ctx_obj && (ctx != req->i915->kernel_context))
> intel_lr_context_unpin(req);
> list_del(&req->execlist_link);
> i915_gem_request_unreference(req);
> @@ -1487,7 +1487,7 @@ static int gen8_init_common_ring(struct intel_engine_cs *ring)
> u8 next_context_status_buffer_hw;
>
> lrc_setup_hardware_status_page(ring,
> - ring->default_context->engine[ring->id].state);
> + dev_priv->kernel_context->engine[ring->id].state);
>
> I915_WRITE_IMR(ring, ~(ring->irq_enable_mask | ring->irq_keep_mask));
> I915_WRITE(RING_HWSTAM(ring->mmio_base), 0xffffffff);
> @@ -1929,6 +1929,9 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *ring)
>
> static int logical_ring_init(struct drm_device *dev, struct intel_engine_cs *ring)
> {
> + struct drm_i915_private *dev_priv = to_i915(dev);
> + struct intel_context *dctx = dev_priv->kernel_context;
> + int ring_id = ring->id;
> int ret;
>
> /* Intentionally left blank. */
> @@ -1949,15 +1952,14 @@ static int logical_ring_init(struct drm_device *dev, struct intel_engine_cs *rin
> if (ret)
> goto error;
>
> - ret = intel_lr_context_deferred_alloc(ring->default_context, ring);
> + ret = intel_lr_context_deferred_alloc(dctx, ring);
> if (ret)
> goto error;
>
> /* As this is the default context, always pin it */
> - ret = intel_lr_context_do_pin(
> - ring,
> - ring->default_context->engine[ring->id].state,
> - ring->default_context->engine[ring->id].ringbuf);
> + ret = intel_lr_context_do_pin(ring,
> + dctx->engine[ring_id].state,
> + dctx->engine[ring_id].ringbuf);
> if (ret) {
> DRM_ERROR(
> "Failed to pin and map ringbuffer %s: %d\n",
> @@ -2388,7 +2390,7 @@ void intel_lr_context_free(struct intel_context *ctx)
> ctx->engine[i].ringbuf;
> struct intel_engine_cs *ring = ringbuf->ring;
>
> - if (ctx == ring->default_context) {
> + if (ctx == ctx->i915->kernel_context) {
> intel_unpin_ringbuffer_obj(ringbuf);
> i915_gem_object_ggtt_unpin(ctx_obj);
> }
> @@ -2507,7 +2509,7 @@ int intel_lr_context_deferred_alloc(struct intel_context *ctx,
> ctx->engine[ring->id].ringbuf = ringbuf;
> ctx->engine[ring->id].state = ctx_obj;
>
> - if (ctx != ring->default_context && ring->init_context) {
> + if (ctx != ctx->i915->kernel_context && ring->init_context) {
> struct drm_i915_gem_request *req;
>
> req = i915_gem_request_alloc(ring, ctx);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 49574ff..e950f6c 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -305,7 +305,6 @@ struct intel_engine_cs {
>
> wait_queue_head_t irq_queue;
>
> - struct intel_context *default_context;
> struct intel_context *last_context;
>
> struct intel_ring_hangcheck hangcheck;
>
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