drm/i915: Add i915_gem_context_is_full_ppgtt

And use it anywhere we have open-coded checks for ctx->vm that really
only check for full ppgtt.

Plus for paranoia add a GEM_BUG_ON that checks it's really only set
when we have full ppgtt, just in case. gem_context->vm is different
since it's NULL in ggtt mode, unlike intel_context->vm or gt->vm,
which is always set.

v2: 0day found a testcase that I missed.

v3: Repaint shed (Jon, Tvrtko)

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jason Ekstrand <jason@jlekstrand.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20210902142057.929669-7-daniel.vetter@ffwll.ch

4 files changed, 12 insertions, 5 deletions

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 7a566fb7cca4..b8067b35d2d6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -1566,7 +1566,7 @@ static int get_ppgtt(struct drm_i915_file_private *file_priv,
 	int err;
 	u32 id;
 
-	if (!rcu_access_pointer(ctx->vm))
+	if (!i915_gem_context_has_full_ppgtt(ctx))
 		return -ENODEV;
 
 	rcu_read_lock();
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.h b/drivers/gpu/drm/i915/gem/i915_gem_context.h
index da6e8b506d96..c50ded3d1cd3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.h
@@ -154,6 +154,13 @@ i915_gem_context_vm(struct i915_gem_context *ctx)
 	return rcu_dereference_protected(ctx->vm, lockdep_is_held(&ctx->mutex));
 }
 
+static inline bool i915_gem_context_has_full_ppgtt(struct i915_gem_context *ctx)
+{
+	GEM_BUG_ON(!!rcu_access_pointer(ctx->vm) != HAS_FULL_PPGTT(ctx->i915));
+
+	return !!rcu_access_pointer(ctx->vm);
+}
+
 static inline struct i915_address_space *
 i915_gem_context_get_eb_vm(struct i915_gem_context *ctx)
 {
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 4816359c4c21..d2308145b4f1 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -733,7 +733,7 @@ static int eb_select_context(struct i915_execbuffer *eb)
 		return PTR_ERR(ctx);
 
 	eb->gem_context = ctx;
-	if (rcu_access_pointer(ctx->vm))
+	if (i915_gem_context_has_full_ppgtt(ctx))
 		eb->invalid_flags |= EXEC_OBJECT_NEEDS_GTT;
 
 	return 0;
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
index fc7fb33a3a52..1536c50144f8 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c
@@ -704,7 +704,7 @@ static int igt_ctx_exec(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       engine->name,
-				       yesno(!!rcu_access_pointer(ctx->vm)),
+				       yesno(i915_gem_context_has_full_ppgtt(ctx)),
 				       err);
 				intel_context_put(ce);
 				kernel_context_close(ctx);
@@ -838,7 +838,7 @@ static int igt_shared_ctx_exec(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       engine->name,
-				       yesno(!!rcu_access_pointer(ctx->vm)),
+				       yesno(i915_gem_context_has_full_ppgtt(ctx)),
 				       err);
 				intel_context_put(ce);
 				kernel_context_close(ctx);
@@ -1417,7 +1417,7 @@ static int igt_ctx_readonly(void *arg)
 				pr_err("Failed to fill dword %lu [%lu/%lu] with gpu (%s) [full-ppgtt? %s], err=%d\n",
 				       ndwords, dw, max_dwords(obj),
 				       ce->engine->name,
-				       yesno(!!ctx_vm(ctx)),
+				       yesno(i915_gem_context_has_full_ppgtt(ctx)),
 				       err);
 				i915_gem_context_unlock_engines(ctx);
 				goto out_file;