drm/i915/uc: Place uC firmware in upper range of GGTT

Currently we pin the GuC or HuC firmware image just before uploading.
Perma-pin during uC initialization instead and use the range reserved at
the top of the address space.

Moving the firmware resulted in needing to:
- use an additional pinning for the rsa signature which will be used
  during HuC auth as addresses above GUC_GGTT_TOP do not map through GTT.

v2: Remove call to set to gtt domain
    Do not restore fw gtt mapping unconditionally
    Separate out pin/unpin functions and drop usage of pin/unpin
    Use uc_fw init/fini functions to bind/unbind fw object

v3: Bind is only needed during xfer (Chris)
    Remove attempts to bind outside of xfer (Chris)
    Mark fw bind/unbind static

Signed-off-by: Fernando Pacheco <fernando.pacheco@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190419230015.18121-4-fernando.pacheco@intel.com

1 files changed, 58 insertions, 16 deletions

diff --git a/drivers/gpu/drm/i915/intel_huc.c b/drivers/gpu/drm/i915/intel_huc.c
index 94c04f16a2ad..1ff1fb015e58 100644
--- a/drivers/gpu/drm/i915/intel_huc.c
+++ b/drivers/gpu/drm/i915/intel_huc.c
@@ -40,6 +40,61 @@ int intel_huc_init_misc(struct intel_huc *huc)
 	return 0;
 }
 
+static int intel_huc_rsa_data_create(struct intel_huc *huc)
+{
+	struct drm_i915_private *i915 = huc_to_i915(huc);
+	struct intel_guc *guc = &i915->guc;
+	struct i915_vma *vma;
+	void *vaddr;
+
+	/*
+	 * HuC firmware will sit above GUC_GGTT_TOP and will not map
+	 * through GTT. Unfortunately, this means GuC cannot perform
+	 * the HuC auth. as the rsa offset now falls within the GuC
+	 * inaccessible range. We resort to perma-pinning an additional
+	 * vma within the accessible range that only contains the rsa
+	 * signature. The GuC can use this extra pinning to perform
+	 * the authentication since its GGTT offset will be GuC
+	 * accessible.
+	 */
+	vma = intel_guc_allocate_vma(guc, PAGE_SIZE);
+	if (IS_ERR(vma))
+		return PTR_ERR(vma);
+
+	vaddr = i915_gem_object_pin_map(vma->obj, I915_MAP_WB);
+	if (IS_ERR(vaddr)) {
+		i915_vma_unpin_and_release(&vma, 0);
+		return PTR_ERR(vaddr);
+	}
+
+	huc->rsa_data = vma;
+	huc->rsa_data_vaddr = vaddr;
+
+	return 0;
+}
+
+static void intel_huc_rsa_data_destroy(struct intel_huc *huc)
+{
+	i915_vma_unpin_and_release(&huc->rsa_data, I915_VMA_RELEASE_MAP);
+}
+
+int intel_huc_init(struct intel_huc *huc)
+{
+	int err;
+
+	err = intel_huc_rsa_data_create(huc);
+	if (err)
+		return err;
+
+	return intel_uc_fw_init(&huc->fw);
+}
+
+void intel_huc_fini(struct intel_huc *huc)
+{
+	intel_uc_fw_fini(&huc->fw);
+	intel_huc_rsa_data_destroy(huc);
+}
+
 /**
  * intel_huc_auth() - Authenticate HuC uCode
  * @huc: intel_huc structure
@@ -55,27 +110,17 @@ int intel_huc_auth(struct intel_huc *huc)
 {
 	struct drm_i915_private *i915 = huc_to_i915(huc);
 	struct intel_guc *guc = &i915->guc;
-	struct i915_vma *vma;
 	u32 status;
 	int ret;
 
 	if (huc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
 		return -ENOEXEC;
 
-	vma = i915_gem_object_ggtt_pin(huc->fw.obj, NULL, 0, 0,
-				       PIN_OFFSET_BIAS | i915->ggtt.pin_bias);
-	if (IS_ERR(vma)) {
-		ret = PTR_ERR(vma);
-		DRM_ERROR("HuC: Failed to pin huc fw object %d\n", ret);
-		goto fail;
-	}
-
 	ret = intel_guc_auth_huc(guc,
-				 intel_guc_ggtt_offset(guc, vma) +
-				 huc->fw.rsa_offset);
+				 intel_guc_ggtt_offset(guc, huc->rsa_data));
 	if (ret) {
 		DRM_ERROR("HuC: GuC did not ack Auth request %d\n", ret);
-		goto fail_unpin;
+		goto fail;
 	}
 
 	/* Check authentication status, it should be done by now */
@@ -86,14 +131,11 @@ int intel_huc_auth(struct intel_huc *huc)
 					2, 50, &status);
 	if (ret) {
 		DRM_ERROR("HuC: Firmware not verified %#x\n", status);
-		goto fail_unpin;
+		goto fail;
 	}
 
-	i915_vma_unpin(vma);
 	return 0;
 
-fail_unpin:
-	i915_vma_unpin(vma);
 fail:
 	huc->fw.load_status = INTEL_UC_FIRMWARE_FAIL;