drm/i915/uc: perma-pin firmwares

Now that each FW has its own reserved area, we can keep them always
pinned and skip the pin/unpin dance on reset. This will make things
easier for the 2-step HuC authentication, which requires the FW to be
pinned in GGTT after the xfer is completed.
Since the vma is now valid for a long time and not just for the quick
pin-load-unpin dance, the name "dummy" is no longer appropriare and has
been replaced with vma_res. All the functions have also been updated to
operate on vma_res for consistency.
Given that we pin the vma behind the allocator's back (which is ok
because we do the pinning in an area that was previously reserved for
thus purpose), we do need to explicitly re-pin on resume because the
automated helper won't cover us.

v2: better comments and commit message, s/dummy/vma_res/

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230531235415.1467475-2-daniele.ceraolospurio@intel.com

1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h
index 6ba00e6b3975..2be9470eb712 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h
@@ -99,13 +99,19 @@ struct intel_uc_fw {
 	struct drm_i915_gem_object *obj;
 
 	/**
-	 * @dummy: A vma used in binding the uc fw to ggtt. We can't define this
-	 * vma on the stack as it can lead to a stack overflow, so we define it
-	 * here. Safe to have 1 copy per uc fw because the binding is single
-	 * threaded as it done during driver load (inherently single threaded)
-	 * or during a GT reset (mutex guarantees single threaded).
+	 * @needs_ggtt_mapping: indicates whether the fw object needs to be
+	 * pinned to ggtt. If true, the fw is pinned at init time and unpinned
+	 * during driver unload.
 	 */
-	struct i915_vma_resource dummy;
+	bool needs_ggtt_mapping;
+
+	/**
+	 * @vma_res: A vma resource used in binding the uc fw to ggtt. The fw is
+	 * pinned in a reserved area of the ggtt (above the maximum address
+	 * usable by GuC); therefore, we can't use the normal vma functions to
+	 * do the pinning and we instead use this resource to do so.
+	 */
+	struct i915_vma_resource vma_res;
 	struct i915_vma *rsa_data;
 
 	u32 rsa_size;
@@ -282,12 +288,14 @@ static inline u32 intel_uc_fw_get_upload_size(struct intel_uc_fw *uc_fw)
 }
 
 void intel_uc_fw_init_early(struct intel_uc_fw *uc_fw,
-			    enum intel_uc_fw_type type);
+			    enum intel_uc_fw_type type,
+			    bool needs_ggtt_mapping);
 int intel_uc_fw_fetch(struct intel_uc_fw *uc_fw);
 void intel_uc_fw_cleanup_fetch(struct intel_uc_fw *uc_fw);
 int intel_uc_fw_upload(struct intel_uc_fw *uc_fw, u32 offset, u32 dma_flags);
 int intel_uc_fw_init(struct intel_uc_fw *uc_fw);
 void intel_uc_fw_fini(struct intel_uc_fw *uc_fw);
+void intel_uc_fw_resume_mapping(struct intel_uc_fw *uc_fw);
 size_t intel_uc_fw_copy_rsa(struct intel_uc_fw *uc_fw, void *dst, u32 max_len);
 int intel_uc_fw_mark_load_failed(struct intel_uc_fw *uc_fw, int err);
 void intel_uc_fw_dump(const struct intel_uc_fw *uc_fw, struct drm_printer *p);