drm/imagination: Add firmware trace to debugfs

Firmware trace is exposed at /sys/debug/dri/<dev_nr>/pvr_fw/trace_0.
Trace is enabled via the group mask at
/sys/debug/dri/<dev_nr>/pvr_params/fw_trace_mask.

Changes since v8:
- Corrected license identifiers

Changes since v3:
- Use drm_dev_{enter,exit}

Co-developed-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Link: https://lore.kernel.org/r/009cf9fee347fa96c8a665dc368fc54a5ffceff0.1700668843.git.donald.robson@imgtec.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

1 files changed, 72 insertions, 0 deletions

diff --git a/drivers/gpu/drm/imagination/pvr_params.h b/drivers/gpu/drm/imagination/pvr_params.h
new file mode 100644
index 000000000000..5807915b456b
--- /dev/null
+++ b/drivers/gpu/drm/imagination/pvr_params.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
+/* Copyright (c) 2023 Imagination Technologies Ltd. */
+
+#ifndef PVR_PARAMS_H
+#define PVR_PARAMS_H
+
+#include "pvr_rogue_fwif.h"
+
+#include <linux/cache.h>
+#include <linux/compiler_attributes.h>
+
+/*
+ * This is the definitive list of types allowed in the definition of
+ * %PVR_DEVICE_PARAMS.
+ */
+#define PVR_PARAM_TYPE_X32_C u32
+
+/*
+ * This macro defines all device-specific parameters; that is parameters which
+ * are set independently per device.
+ *
+ * The X-macro accepts the following arguments. Arguments marked with [debugfs]
+ * are ignored when debugfs is disabled; values used for these arguments may
+ * safely be gated behind CONFIG_DEBUG_FS.
+ *
+ * @type_: The definitive list of allowed values is PVR_PARAM_TYPE_*_C.
+ * @name_: Name of the parameter. This is used both as the field name in C and
+ *         stringified as the parameter name.
+ * @value_: Initial/default value.
+ * @desc_: String literal used as help text to describe the usage of this
+ *         parameter.
+ * @mode_: [debugfs] One of {RO,RW}. The access mode of the debugfs entry for
+ *         this parameter.
+ * @update_: [debugfs] When debugfs support is enabled, parameters may be
+ *           updated at runtime. When this happens, this function will be
+ *           called to allow changes to propagate. The signature of this
+ *           function is:
+ *
+ *              void (*)(struct pvr_device *pvr_dev, T old_val, T new_val)
+ *
+ *           Where T is the C type associated with @type_.
+ *
+ *           If @mode_ does not allow write access, this function will never be
+ *           called. In this case, or if no update callback is required, you
+ *           should specify NULL for this argument.
+ */
+#define PVR_DEVICE_PARAMS                                                    \
+	X(X32, fw_trace_mask, ROGUE_FWIF_LOG_TYPE_NONE,                      \
+	  "Enable FW trace for the specified groups. Specifying 0 disables " \
+	  "all FW tracing.",                                                 \
+	  RW, pvr_fw_trace_mask_update)
+
+struct pvr_device_params {
+#define X(type_, name_, value_, desc_, ...) \
+	PVR_PARAM_TYPE_##type_##_C name_;
+	PVR_DEVICE_PARAMS
+#undef X
+};
+
+int pvr_device_params_init(struct pvr_device_params *params);
+
+#if defined(CONFIG_DEBUG_FS)
+/* Forward declaration from "pvr_device.h". */
+struct pvr_device;
+
+/* Forward declaration from <linux/dcache.h>. */
+struct dentry;
+
+void pvr_params_debugfs_init(struct pvr_device *pvr_dev, struct dentry *dir);
+#endif /* defined(CONFIG_DEBUG_FS) */
+
+#endif /* PVR_PARAMS_H */