[PATCH 4/8] drm/i915: Rename ctx->id to ctx->handle

[oscar.mateo@intel.com]

From: Oscar Mateo <oscar.mateo@intel.com>

This is an Execlists preparatory patch, since they make context ID become an
overloaded term:

- In the software, it was used to distinguish which context userspace was
  trying to use.
- In the BSpec, the term is used to describe the 20-bits long field the
  hardware uses to it to discriminate the contexts that are submitted to
  the ELSP and inform the driver about their current status (via Context
  Switch Interrupts and Context Status Buffers).

Initially, I tried to make the different meanings converge, but it proved
impossible:

- The software ctx->id is per-filp, while the hardware one needs to be
  globally unique.
- Also, we multiplex several backing states objects per intel_context,
  and all of them need unique HW IDs.
- I tried adding a per-filp ID and then composing the HW context ID as:
  ctx->id + file_priv->id + ring->id, but the fact that the hardware only
  uses 20-bits means we have to artificially limit the number of filps or
  contexts the userspace can create.

The ctx->handle bits are done with this Cocci patch (plus manual frobbing
of the struct declaration):

	@@
	struct intel_context c;
	@@
	- (c).id
	+ c.handle

	@@
	struct intel_context *c;
	@@
	- (c)->id
	+ c->handle

Also, while we are at it, s/DEFAULT_CONTEXT_ID/DEFAULT_CONTEXT_HANDLE.

Signed-off-by: Oscar Mateo <oscar.mateo@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c        |  2 +-
 drivers/gpu/drm/i915/i915_drv.h            |  6 +++---
 drivers/gpu/drm/i915/i915_gem_context.c    | 12 ++++++------
 drivers/gpu/drm/i915/i915_gem_execbuffer.c |  2 +-
 drivers/gpu/drm/i915/intel_uncore.c        |  2 +-
 5 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index d4b8391..7484e22 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1867,7 +1867,7 @@ static int per_file_ctx(int id, void *ptr, void *data)
 	if (i915_gem_context_is_default(ctx))
 		seq_puts(m, "  default context:\n");
 	else
-		seq_printf(m, "  context %d:\n", ctx->id);
+		seq_printf(m, "  context %d:\n", ctx->handle);
 	ppgtt->debug_dump(ppgtt, m);
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 122e942..5d2b6ab 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -584,10 +584,10 @@ struct i915_ctx_hang_stats {
 };
 
 /* This must match up with the value previously used for execbuf2.rsvd1. */
-#define DEFAULT_CONTEXT_ID 0
+#define DEFAULT_CONTEXT_HANDLE 0
 struct intel_context {
 	struct kref ref;
-	int id;
+	int handle;
 	bool rcs_is_initialized;
 	uint8_t remap_slice;
 	struct drm_i915_file_private *file_priv;
@@ -2458,7 +2458,7 @@ static inline void i915_gem_context_unreference(struct intel_context *ctx)
 
 static inline bool i915_gem_context_is_default(const struct intel_context *c)
 {
-	return c->id == DEFAULT_CONTEXT_ID;
+	return c->handle == DEFAULT_CONTEXT_HANDLE;
 }
 
 int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index b8b9859..75e903f 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -276,14 +276,14 @@ __create_hw_context(struct drm_device *dev,
 	/* Default context will never have a file_priv */
 	if (file_priv != NULL) {
 		ret = idr_alloc(&file_priv->context_idr, ctx,
-				DEFAULT_CONTEXT_ID, 0, GFP_KERNEL);
+				DEFAULT_CONTEXT_HANDLE, 0, GFP_KERNEL);
 		if (ret < 0)
 			goto err_out;
 	} else
-		ret = DEFAULT_CONTEXT_ID;
+		ret = DEFAULT_CONTEXT_HANDLE;
 
 	ctx->file_priv = file_priv;
-	ctx->id = ret;
+	ctx->handle = ret;
 	/* NB: Mark all slices as needing a remap so that when the context first
 	 * loads it will restore whatever remap state already exists. If there
 	 * is no remap info, it will be a NOP. */
@@ -787,7 +787,7 @@ int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
 
-	args->ctx_id = ctx->id;
+	args->ctx_id = ctx->handle;
 	DRM_DEBUG_DRIVER("HW context %d created\n", args->ctx_id);
 
 	return 0;
@@ -801,7 +801,7 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
 	struct intel_context *ctx;
 	int ret;
 
-	if (args->ctx_id == DEFAULT_CONTEXT_ID)
+	if (args->ctx_id == DEFAULT_CONTEXT_HANDLE)
 		return -ENOENT;
 
 	ret = i915_mutex_lock_interruptible(dev);
@@ -814,7 +814,7 @@ int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
 		return PTR_ERR(ctx);
 	}
 
-	idr_remove(&ctx->file_priv->context_idr, ctx->id);
+	idr_remove(&ctx->file_priv->context_idr, ctx->handle);
 	i915_gem_context_unreference(ctx);
 	mutex_unlock(&dev->struct_mutex);
 
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index d815ef5..c97178e 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -938,7 +938,7 @@ i915_gem_validate_context(struct drm_device *dev, struct drm_file *file,
 	struct intel_context *ctx = NULL;
 	struct i915_ctx_hang_stats *hs;
 
-	if (ring->id != RCS && ctx_id != DEFAULT_CONTEXT_ID)
+	if (ring->id != RCS && ctx_id != DEFAULT_CONTEXT_HANDLE)
 		return ERR_PTR(-EINVAL);
 
 	ctx = i915_gem_context_get(file->driver_priv, ctx_id);
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 29145df..e0f0843 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1010,7 +1010,7 @@ int i915_get_reset_stats_ioctl(struct drm_device *dev,
 	if (args->flags || args->pad)
 		return -EINVAL;
 
-	if (args->ctx_id == DEFAULT_CONTEXT_ID && !capable(CAP_SYS_ADMIN))
+	if (args->ctx_id == DEFAULT_CONTEXT_HANDLE && !capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
-- 
1.9.0