linux-kernel - [PATCH 13/13] drm_print: use DEFINE_DYNAMIC_DEBUG

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Message-Id: <20220301164629.3814634-14-jim.cromie@gmail.com>
Date:   Tue,  1 Mar 2022 09:46:29 -0700
From:   Jim Cromie <jim.cromie@...il.com>
To:     jbaron@...mai.com, gregkh@...uxfoundation.org,
        daniel.vetter@...ll.ch, seanpaul@...omium.org, robdclark@...il.com,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        amd-gfx@...ts.freedesktop.org, intel-gvt-dev@...ts.freedesktop.org,
        intel-gfx@...ts.freedesktop.org
Cc:     Jim Cromie <jim.cromie@...il.com>
Subject: [PATCH 13/13] drm_print: use DEFINE_DYNAMIC_DEBUG_CLASSBITS for drm.debug

if CONFIG_DRM_USE_DYNAMIC_DEBUG=y, use new macro to create the sysfs
bitmap to control drm.debug callsites.

DEFINE_DYNAMIC_DEBUG_CLASSBITS( debug, __drm_debug, "p",
	"drm.debug - control summary",
	/* inline vector of _ddebug.class_id's to be controlled, max 14 vals */
	DRM_UT_CORE,
	DRM_UT_DRIVER,
	DRM_UT_KMS,
	DRM_UT_PRIME,
	DRM_UT_ATOMIC,
	DRM_UT_VBL,
	DRM_UT_STATE,
	DRM_UT_LEASE,
	DRM_UT_DP,
	DRM_UT_DRMRES );

NOTES:

The @_flgs used here is "p", so this bitmap enables input to syslog
only, matching legacy behavior.

Also, no "fmlt" decorator flags are used here; that is discouraged, as
it then toggles those flags along with the "p".  This would overwrite
any customizations a user added since the sysfs-knob was last used.
Still, there may be cases/reasons.

_ddebug.class_id is uint:4, values 0-14 are valid. 15 is reserved for
non-classified callsites (regular pr_debugs).  Using it terminates the
scan, don't use it halfway through your list.

Signed-off-by: Jim Cromie <jim.cromie@...il.com>
---
 drivers/gpu/drm/drm_print.c | 20 ++++++++++++++++++--
 include/drm/drm_print.h     |  4 ++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index c9b2a2ab0d3d..d916daa384e5 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -38,7 +38,7 @@
  * __drm_debug: Enable debug output.
  * Bitmask of DRM_UT_x. See include/drm/drm_print.h for details.
  */
-unsigned int __drm_debug;
+unsigned long __drm_debug;
 EXPORT_SYMBOL(__drm_debug);
 
 MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
@@ -50,7 +50,23 @@ MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug cat
 "\t\tBit 5 (0x20)  will enable VBL messages (vblank code)\n"
 "\t\tBit 7 (0x80)  will enable LEASE messages (leasing code)\n"
 "\t\tBit 8 (0x100) will enable DP messages (displayport code)");
-module_param_named(debug, __drm_debug, int, 0600);
+
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
+module_param_named(debug, __drm_debug, ulong, 0600);
+#else
+DEFINE_DYNAMIC_DEBUG_CLASSBITS(debug, __drm_debug, "p",
+	"enable drm.debug categories - 1 bit per category",
+	DRM_UT_CORE,
+	DRM_UT_DRIVER,
+	DRM_UT_KMS,
+	DRM_UT_PRIME,
+	DRM_UT_ATOMIC,
+	DRM_UT_VBL,
+	DRM_UT_STATE,
+	DRM_UT_LEASE,
+	DRM_UT_DP,
+	DRM_UT_DRMRES);
+#endif
 
 void __drm_puts_coredump(struct drm_printer *p, const char *str)
 {
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 13d52b60f388..419140bf992d 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -36,7 +36,7 @@
 #include <drm/drm.h>
 
 /* Do *not* use outside of drm_print.[ch]! */
-extern unsigned int __drm_debug;
+extern unsigned long __drm_debug;
 
 /**
  * DOC: print
@@ -527,7 +527,7 @@ __printf(1, 2)
 void __drm_err(const char *format, ...);
 
 #if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
-#define __drm_dbg(fmt, ...)		___drm_dbg(NULL, fmt, ##__VA_ARGS__)
+#define __drm_dbg(cat, fmt, ...)	___drm_dbg(NULL, cat, fmt, ##__VA_ARGS__)
 #else
 #define __drm_dbg(cat, fmt, ...)					\
 	_dynamic_func_call_cls(cat, fmt, ___drm_dbg,			\
-- 
2.35.1