For CONFIG_DRM_USE_DYNAMIC_DEBUG=y, wrap __drm_dbg() & __drm_dev_dbg()
in one of dyndbg's Factory macros: _dynamic_func_call_no_desc().
Next, those functions are adapted to accept a descriptor arg, and we
drop the _no_desc suffix, then the (~4000) drm.debug callsites will be
controllable by their class-names:
#> echo class DRM_UT_ATOMIC +p > /proc/dynamic_debug/control
CONFIG_DRM_USE_DYNAMIC_DEBUG=y/n is configurable because of the .data
footprint cost of per-callsite control; 56 bytes/site * ~2k for i915,
~4k callsites for amdgpu. This is large enough that a kernel builder
might not want it.
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
drivers/gpu/drm/Kconfig | 12 ++++++++++++
drivers/gpu/drm/Makefile | 2 ++
drivers/gpu/drm/drm_print.c | 2 +-
include/drm/drm_print.h | 12 ++++++++++++
4 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index f1422bee3dcc..5ab31753c25d 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -63,6 +63,18 @@ config DRM_DEBUG_MM
If in doubt, say "N".
+config DRM_USE_DYNAMIC_DEBUG
+ bool "use dynamic debug to implement drm.debug"
+ default y
+ depends on DRM
+ depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
+ depends on JUMP_LABEL
+ help
+ Use dynamic-debug to avoid drm_debug_enabled() runtime overheads.
+ Due to callsite counts in DRM drivers (~4k in amdgpu) and 56
+ bytes per callsite, the .data costs can be substantial, and
+ are therefore configurable.
+
config DRM_DEBUG_SELFTEST
tristate "kselftests for DRM"
depends on DRM
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index c2ef5f9fce54..e93b7902994a 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -3,6 +3,8 @@
# Makefile for the drm device driver. This driver provides support for the
# Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
+CFLAGS-$(CONFIG_DRM_USE_DYNAMIC_DEBUG) += -DDYNAMIC_DEBUG_MODULE
+
drm-y := drm_aperture.o drm_auth.o drm_cache.o \
drm_file.o drm_gem.o drm_ioctl.o \
drm_drv.o \
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index e77b49c7725b..5192533794a2 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -53,7 +53,7 @@ MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug cat
"\t\tBit 7 (0x80) will enable LEASE messages (leasing code)\n"
"\t\tBit 8 (0x100) will enable DP messages (displayport code)");
-#if !defined(CONFIG_DYNAMIC_DEBUG_CORE)
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
module_param_named(debug, __drm_debug, ulong, 0600);
#else
static struct ddebug_classes_bitmap_param drm_debug_bitmap = {
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 383feb0d34fe..5c39bacac2b3 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -388,8 +388,14 @@ void __drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
} \
})
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
#define drm_dev_dbg(dev, cat, fmt, ...) \
__drm_dev_dbg(dev, cat, fmt, ##__VA_ARGS__)
+#else
+#define drm_dev_dbg(dev, cat, fmt, ...) \
+ _dynamic_func_call_no_desc(fmt, __drm_dev_dbg, \
+ dev, cat, fmt, ##__VA_ARGS__)
+#endif
/**
* DRM_DEV_DEBUG() - Debug output for generic drm code
@@ -496,7 +502,13 @@ void ___drm_dbg(enum drm_debug_category category, const char *format, ...);
__printf(1, 2)
void __drm_err(const char *format, ...);
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
#define __drm_dbg(fmt, ...) ___drm_dbg(fmt, ##__VA_ARGS__)
+#else
+#define __drm_dbg(cat, fmt, ...) \
+ _dynamic_func_call_no_desc(fmt, ___drm_dbg, \
+ cat, fmt, ##__VA_ARGS__)
+#endif
/* Macros to make printk easier */
--
2.35.3
