Current devices may contain one or more programmable microcontrollers
that need to have a firmware image (aka "binary blob") loaded from an
external medium and transferred to the device's memory.
This file provides common support functions for doing this; they can
then be used by each uC-specific loader, thus reducing code duplication
and testing effort.
v2:
Local functions should pass dev_priv rather than dev [Chris Wilson]
Various other improvements per Chris Wilson's review comments
v3:
Defeatured version without async prefetch [Daniel Vetter]
Signed-off-by: Dave Gordon <david.s.gordon@xxxxxxxxx>
Signed-off-by: Alex Dai <yu.dai@xxxxxxxxx>
---
drivers/gpu/drm/i915/Makefile | 3 +
drivers/gpu/drm/i915/intel_uc_loader.c | 310 +++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_uc_loader.h | 92 ++++++++++
3 files changed, 405 insertions(+)
create mode 100644 drivers/gpu/drm/i915/intel_uc_loader.c
create mode 100644 drivers/gpu/drm/i915/intel_uc_loader.h
diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index de21965..f1f80fc 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -39,6 +39,9 @@ i915-y += i915_cmd_parser.o \
intel_ringbuffer.o \
intel_uncore.o
+# generic ancilliary microcontroller support
+i915-y += intel_uc_loader.o
+
# autogenerated null render state
i915-y += intel_renderstate_gen6.o \
intel_renderstate_gen7.o \
diff --git a/drivers/gpu/drm/i915/intel_uc_loader.c b/drivers/gpu/drm/i915/intel_uc_loader.c
new file mode 100644
index 0000000..a8fc1dd
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_uc_loader.c
@@ -0,0 +1,310 @@
+/*
+ * Copyright © 2014 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.
+ *
+ * Author:
+ * Dave Gordon <david.s.gordon@xxxxxxxxx>
+ */
+#include <linux/firmware.h>
+#include "i915_drv.h"
+#include "intel_uc_loader.h"
+
+/**
+ * DOC: Common functions for embedded microcontroller (uC) firmware loading
+ *
+ * The functions in this file provide common support code for loading the
+ * firmware that may be required by an embedded microcontroller (uC).
+ *
+ * The function intel_uc_fw_init() should be called first; it requires no
+ * locking, and can be called even before GEM has been initialised. It just
+ * initialises the tracking data and stores its parameters for the subsequent
+ * call to intel_uc_fw_fetch().
+ *
+ * At some convenient point after GEM initialisation, the driver should call
+ * intel_uc_fw_fetch(). The first time, this will use the Linux kernel's
+ * request_firmware() call to open and read the firmware image into memory.
+ * (On subsequent calls, this is skipped, as either the firmware has already
+ * been fetched into memory, or it is already known that no valid firmware
+ * image could be found).
+ *
+ * The callback() function passed to intel_uc_fw_fetch() can further check
+ * the firmware image before it is saved. This function can reject the image
+ * by returning a negative error code (e.g. -ENOEXEC), or accept it. In the
+ * latter case, it can return INTEL_UC_FW_GOOD (which is also the default if
+ * no callback() is supplied), and the common code here will save the whole
+ * of the firmware image in a (pageable, shmfs-backed) GEM object.
+ *
+ * If saving the whole image unmodified is not appropriate (for example, if
+ * only a small part of the image is needed later, or the data needs to be
+ * reorganised before saving), the callback() function can instead make its
+ * own arrangements for saving the required data in a GEM object or otherwise
+ * and then return INTEL_UC_FW_SAVED.
+ *
+ * (If such a callback does stash (some of) the image data in a GEM object,
+ * it can use the uc_fw_obj and uc_fw_size fields; the common framework will
+ * then handle deallocating the object on failure or finalisation. Otherwise
+ * any allocated resources will have to be managed by the uC-specific code).
+ *
+ * After a successful call to intel_uc_fw_fetch(), the uC-specific code can
+ * transfer the data in the GEM object (or its own alternative) to the uC's
+ * memory (in some uC-specific way, not handled here).
+ *
+ * During driver shutdown, or if driver load is aborted, intel_uc_fw_fini()
+ * should be called to release any remaining resources.
+ */
+
+/* User-friendly representation of an enum */
+const char *intel_uc_fw_status_repr(enum intel_uc_fw_status status)
+{
+ switch (status) {
+ case INTEL_UC_FIRMWARE_FAIL:
+ return "FAIL";
+ case INTEL_UC_FIRMWARE_NONE:
+ return "NONE";
+ case INTEL_UC_FIRMWARE_PENDING:
+ return "PENDING";
+ case INTEL_UC_FIRMWARE_SUCCESS:
+ return "SUCCESS";
+ default:
+ return "UNKNOWN!";
+ }
+};
+
+/*
+ * Called once per uC, late in driver initialisation, after GEM is set up.
+ * First, we fetch the firmware image using request_firmware(), then allow
+ * the optional callback() function to check it. If it's good, and callback()
+ * doesn't say it's already saved the image, we will save it here by copying
+ * the whole thing into a (pageable, shmfs-backed) GEM object,
+ */
+static void
+uc_fw_fetch(struct intel_uc_fw *uc_fw,
+ int callback(struct intel_uc_fw *))
+{
+ struct drm_device *dev = uc_fw->uc_dev;
+ struct drm_i915_gem_object *obj;
+ const struct firmware *fw;
+ int cb_status = INTEL_UC_FW_GOOD;
+
+ DRM_DEBUG_DRIVER("before waiting: %s fw fetch status %s, fw %p\n",
+ uc_fw->uc_name,
+ intel_uc_fw_status_repr(uc_fw->uc_fw_fetch_status),
+ uc_fw->uc_fw_blob);
+
+ WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+ WARN_ON(uc_fw->uc_fw_fetch_status != INTEL_UC_FIRMWARE_PENDING);
+
+ if (request_firmware(&fw, uc_fw->uc_fw_path, &dev->pdev->dev))
+ goto fail;
+ if (!fw)
+ goto fail;
+
+ DRM_DEBUG_DRIVER("fetch %s fw from %s succeeded, fw %p\n",
+ uc_fw->uc_name, uc_fw->uc_fw_path, fw);
+ uc_fw->uc_fw_blob = fw;
+
+ /* Callback to the optional uC-specific function, if supplied */
+ if (callback)
+ cb_status = callback(uc_fw);
+ if (cb_status < 0)
+ goto fail;
+ switch (cb_status) {
+ default:
+ WARN(1, "Invalid status %d from fw checking callback %pf\n",
+ cb_status, callback);
+ goto fail;
+
+ case INTEL_UC_FW_SAVED:
+ // Good, already saved, nothing to do
+ break;
+
+ case INTEL_UC_FW_GOOD:
+ // Good, save in GEM object
+ obj = i915_gem_object_create_from_data(dev, fw->data, fw->size);
+ if (!obj)
+ goto fail;
+
+ uc_fw->uc_fw_obj = obj;
+ uc_fw->uc_fw_size = fw->size;
+ }
+
+ DRM_DEBUG_DRIVER("%s fw fetch status SUCCESS, cb %d, obj %p\n",
+ uc_fw->uc_name, cb_status, uc_fw->uc_fw_obj);
+
+ release_firmware(fw);
+ uc_fw->uc_fw_blob = NULL;
+ uc_fw->uc_fw_fetch_status = INTEL_UC_FIRMWARE_SUCCESS;
+ return;
+
+fail:
+ DRM_DEBUG_DRIVER("%s fw fetch status FAIL; fw %p, obj %p\n",
+ uc_fw->uc_name, fw, uc_fw->uc_fw_obj);
+ DRM_ERROR("Failed to fetch %s firmware from %s\n",
+ uc_fw->uc_name, uc_fw->uc_fw_path);
+
+ obj = uc_fw->uc_fw_obj;
+ if (obj)
+ drm_gem_object_unreference(&obj->base);
+ uc_fw->uc_fw_obj = NULL;
+
+ release_firmware(fw); /* OK even if fw is NULL */
+ uc_fw->uc_fw_blob = NULL;
+ uc_fw->uc_fw_fetch_status = INTEL_UC_FIRMWARE_FAIL;
+}
