drm/i915/uc: Move uC fw helper code into dedicated files

This is a prerequisite to unblock next steps.

v2: correct include order (Joonas)
v3: use common function prefix (Joonas)
    add kerneldoc (Michal)

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171004153327.32608-5-michal.wajdeczko@intel.com
diff --git a/drivers/gpu/drm/i915/intel_uc_fw.c b/drivers/gpu/drm/i915/intel_uc_fw.c
new file mode 100644
index 0000000..766b1cb
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_uc_fw.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright © 2016-2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/firmware.h>
+
+#include "intel_uc_fw.h"
+#include "i915_drv.h"
+
+/**
+ * intel_uc_fw_fetch - fetch uC firmware
+ *
+ * @dev_priv: device private
+ * @uc_fw: uC firmware
+ *
+ * Fetch uC firmware into GEM obj.
+ */
+void intel_uc_fw_fetch(struct drm_i915_private *dev_priv,
+		       struct intel_uc_fw *uc_fw)
+{
+	struct pci_dev *pdev = dev_priv->drm.pdev;
+	struct drm_i915_gem_object *obj;
+	const struct firmware *fw = NULL;
+	struct uc_css_header *css;
+	size_t size;
+	int err;
+
+	if (!uc_fw->path)
+		return;
+
+	uc_fw->fetch_status = INTEL_UC_FIRMWARE_PENDING;
+
+	DRM_DEBUG_DRIVER("before requesting firmware: uC fw fetch status %s\n",
+			 intel_uc_fw_status_repr(uc_fw->fetch_status));
+
+	err = request_firmware(&fw, uc_fw->path, &pdev->dev);
+	if (err)
+		goto fail;
+	if (!fw)
+		goto fail;
+
+	DRM_DEBUG_DRIVER("fetch uC fw from %s succeeded, fw %p\n",
+			 uc_fw->path, fw);
+
+	/* Check the size of the blob before examining buffer contents */
+	if (fw->size < sizeof(struct uc_css_header)) {
+		DRM_NOTE("Firmware header is missing\n");
+		goto fail;
+	}
+
+	css = (struct uc_css_header *)fw->data;
+
+	/* Firmware bits always start from header */
+	uc_fw->header_offset = 0;
+	uc_fw->header_size = (css->header_size_dw - css->modulus_size_dw -
+			      css->key_size_dw - css->exponent_size_dw) *
+			     sizeof(u32);
+
+	if (uc_fw->header_size != sizeof(struct uc_css_header)) {
+		DRM_NOTE("CSS header definition mismatch\n");
+		goto fail;
+	}
+
+	/* then, uCode */
+	uc_fw->ucode_offset = uc_fw->header_offset + uc_fw->header_size;
+	uc_fw->ucode_size = (css->size_dw - css->header_size_dw) * sizeof(u32);
+
+	/* now RSA */
+	if (css->key_size_dw != UOS_RSA_SCRATCH_MAX_COUNT) {
+		DRM_NOTE("RSA key size is bad\n");
+		goto fail;
+	}
+	uc_fw->rsa_offset = uc_fw->ucode_offset + uc_fw->ucode_size;
+	uc_fw->rsa_size = css->key_size_dw * sizeof(u32);
+
+	/* At least, it should have header, uCode and RSA. Size of all three. */
+	size = uc_fw->header_size + uc_fw->ucode_size + uc_fw->rsa_size;
+	if (fw->size < size) {
+		DRM_NOTE("Missing firmware components\n");
+		goto fail;
+	}
+
+	/*
+	 * The GuC firmware image has the version number embedded at a
+	 * well-known offset within the firmware blob; note that major / minor
+	 * version are TWO bytes each (i.e. u16), although all pointers and
+	 * offsets are defined in terms of bytes (u8).
+	 */
+	switch (uc_fw->type) {
+	case INTEL_UC_FW_TYPE_GUC:
+		/* Header and uCode will be loaded to WOPCM. Size of the two. */
+		size = uc_fw->header_size + uc_fw->ucode_size;
+
+		/* Top 32k of WOPCM is reserved (8K stack + 24k RC6 context). */
+		if (size > intel_guc_wopcm_size(dev_priv)) {
+			DRM_ERROR("Firmware is too large to fit in WOPCM\n");
+			goto fail;
+		}
+		uc_fw->major_ver_found = css->guc.sw_version >> 16;
+		uc_fw->minor_ver_found = css->guc.sw_version & 0xFFFF;
+		break;
+
+	case INTEL_UC_FW_TYPE_HUC:
+		uc_fw->major_ver_found = css->huc.sw_version >> 16;
+		uc_fw->minor_ver_found = css->huc.sw_version & 0xFFFF;
+		break;
+
+	default:
+		DRM_ERROR("Unknown firmware type %d\n", uc_fw->type);
+		err = -ENOEXEC;
+		goto fail;
+	}
+
+	if (uc_fw->major_ver_wanted == 0 && uc_fw->minor_ver_wanted == 0) {
+		DRM_NOTE("Skipping %s firmware version check\n",
+			 intel_uc_fw_type_repr(uc_fw->type));
+	} else if (uc_fw->major_ver_found != uc_fw->major_ver_wanted ||
+		   uc_fw->minor_ver_found < uc_fw->minor_ver_wanted) {
+		DRM_NOTE("%s firmware version %d.%d, required %d.%d\n",
+			 intel_uc_fw_type_repr(uc_fw->type),
+			 uc_fw->major_ver_found, uc_fw->minor_ver_found,
+			 uc_fw->major_ver_wanted, uc_fw->minor_ver_wanted);
+		err = -ENOEXEC;
+		goto fail;
+	}
+
+	DRM_DEBUG_DRIVER("firmware version %d.%d OK (minimum %d.%d)\n",
+			 uc_fw->major_ver_found, uc_fw->minor_ver_found,
+			 uc_fw->major_ver_wanted, uc_fw->minor_ver_wanted);
+
+	obj = i915_gem_object_create_from_data(dev_priv, fw->data, fw->size);
+	if (IS_ERR(obj)) {
+		err = PTR_ERR(obj);
+		goto fail;
+	}
+
+	uc_fw->obj = obj;
+	uc_fw->size = fw->size;
+
+	DRM_DEBUG_DRIVER("uC fw fetch status SUCCESS, obj %p\n",
+			 uc_fw->obj);
+
+	release_firmware(fw);
+	uc_fw->fetch_status = INTEL_UC_FIRMWARE_SUCCESS;
+	return;
+
+fail:
+	DRM_WARN("Failed to fetch valid uC firmware from %s (error %d)\n",
+		 uc_fw->path, err);
+	DRM_DEBUG_DRIVER("uC fw fetch status FAIL; err %d, fw %p, obj %p\n",
+			 err, fw, uc_fw->obj);
+
+	release_firmware(fw);		/* OK even if fw is NULL */
+	uc_fw->fetch_status = INTEL_UC_FIRMWARE_FAIL;
+}
+
+/**
+ * intel_uc_fw_fini - cleanup uC firmware
+ *
+ * @uc_fw: uC firmware
+ *
+ * Cleans up uC firmware by releasing the firmware GEM obj.
+ */
+void intel_uc_fw_fini(struct intel_uc_fw *uc_fw)
+{
+	struct drm_i915_gem_object *obj;
+
+	obj = fetch_and_zero(&uc_fw->obj);
+	if (obj)
+		i915_gem_object_put(obj);
+
+	uc_fw->fetch_status = INTEL_UC_FIRMWARE_NONE;
+}