[PATCH v4 5/7] i915/gvt: control pr_debug("gvt:")s with bits in parameters/debug_gvt

[Jim Cromie]

The gvt component of this driver has ~120 pr_debugs, in 9 "classes".
Following the interface model of drm.debug, add a parameter to map
bits to these classes.

If CONFIG_DRM_USE_DYNAMIC_DEBUG=y (and CONFIG_DYNAMIC_DEBUG_CORE), add
-DDYNAMIC_DEBUG_MODULE into Makefile.  TBD: maybe add a separate
CONFIG_I915_USE_DYNAMIC_DEBUG to more fully optionalize this.

this is close to our target:

DYNDBG_BITMAP_DESC(__gvt_debug, "dyndbg bitmap desc",
	{ "gvt: cmd: ",  "command processing" },
	{ "gvt: core: ", "core help" },
	{ "gvt: dpy: ",  "display help" },
	{ "gvt: el: ",   "help" },
	{ "gvt: irq: ",  "help" },
	{ "gvt: mm: ",   "help" },
	{ "gvt: mmio: ", "help" },
	{ "gvt: render: ", "help" },
	{ "gvt: sched: " "help" });

actual patch has a few details different, helper macros mainly.

Signed-off-by: Jim Cromie <jim.cromie at gmail.com>
---
 drivers/gpu/drm/i915/gvt/Makefile  |  4 ++++
 drivers/gpu/drm/i915/i915_params.c | 34 ++++++++++++++++++++++++++++++
 include/drm/drm_print.h            |  3 ++-
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/Makefile b/drivers/gpu/drm/i915/gvt/Makefile
index ea8324abc784..846ba73b8de6 100644
--- a/drivers/gpu/drm/i915/gvt/Makefile
+++ b/drivers/gpu/drm/i915/gvt/Makefile
@@ -7,3 +7,7 @@ GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \
 
 ccflags-y				+= -I $(srctree)/$(src) -I $(srctree)/$(src)/$(GVT_DIR)/
 i915-y					+= $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))
+
+#ifdef CONFIG_DRM_USE_DYNAMIC_DEBUG
+ccflags-y	+= -DDYNAMIC_DEBUG_MODULE
+#endif
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index e07f4cfea63a..c951ef76454f 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -265,3 +265,37 @@ void i915_params_free(struct i915_params *params)
 	I915_PARAMS_FOR_EACH(FREE);
 #undef FREE
 }
+
+/* POC for callback -> dynamic_debug_exec_queries */
+unsigned long __gvt_debug;
+EXPORT_SYMBOL(__gvt_debug);
+
+#define _help(key)	"\t\"" key "\"\t: help for " key "\n"
+#define cmd_help(key)	{ .prefix = key, .help = key ": help for " key }
+
+#define I915_DYNDBG_PARM_DESC(name) \
+	"Enable debug output via /sys/module/i915/parameters/" #name	\
+	", where each bit enables a debug category.\n"			\
+	_help("gvt:cmd:")						\
+	_help("gvt:core:")						\
+	_help("gvt:dpy:")						\
+	_help("gvt:el:")						\
+	_help("gvt:irq:")						\
+	_help("gvt:mm:")						\
+	_help("gvt:mmio:")						\
+	_help("gvt:render:")						\
+	_help("gvt:sched:")
+
+MODULE_PARM_DESC(debug_gvt, I915_DYNDBG_PARM_DESC(debug_gvt));
+
+DEFINE_DYNDBG_BITMAP(debug_gvt, &__gvt_debug,
+		   I915_DYNDBG_PARM_DESC(debug_gvt),
+		   cmd_help("gvt:cmd:"),
+		   cmd_help("gvt:core:"),
+		   cmd_help("gvt:dpy:"),
+		   cmd_help("gvt:el:"),
+		   cmd_help("gvt:irq:"),
+		   cmd_help("gvt:mm:"),
+		   cmd_help("gvt:mmio:"),
+		   cmd_help("gvt:render:"),
+		   cmd_help("gvt:sched:"));
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 15a089a87c22..47803c64b144 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -530,7 +530,8 @@ void __drm_err(const char *format, ...);
 	const struct drm_device *drm_ = (drm);							\
 												\
 	if (drm_debug_enabled(DRM_UT_ ## category) && __ratelimit(&rs_))			\
-		drm_dev_printk(drm_ ? drm_->dev : NULL, KERN_DEBUG, fmt, ## __VA_ARGS__);	\
+		drm_dev_dbg((drm_) ? (drm_)->dev : NULL,					\
+			    DRM_DBG_CLASS_ ## category, fmt, ##__VA_ARGS__);			\
 })
 
 #define drm_dbg_kms_ratelimited(drm, fmt, ...) \
-- 
2.31.1