linux-kernel - [PATCH v7 1/9] drm_print: condense enum drm_debug

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Message-Id: <20220912052852.1123868-2-jim.cromie@gmail.com>
Date:   Sun, 11 Sep 2022 23:28:44 -0600
From:   Jim Cromie <jim.cromie@...il.com>
To:     jbaron@...mai.com, gregkh@...uxfoundation.org,
        dri-devel@...ts.freedesktop.org, amd-gfx@...ts.freedesktop.org,
        intel-gvt-dev@...ts.freedesktop.org,
        intel-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Cc:     daniel.vetter@...ll.ch, seanpaul@...omium.org, robdclark@...il.com,
        linux@...musvillemoes.dk, joe@...ches.com,
        Jim Cromie <jim.cromie@...il.com>
Subject: [PATCH v7 1/9] drm_print: condense enum drm_debug_category

enum drm_debug_category has 10 categories, but is initialized with
bitmasks which require 10 bits of underlying storage.  By using
natural enumeration, and moving the BIT(cat) into drm_debug_enabled(),
the enum fits in 4 bits, allowing the category to be represented
directly in pr_debug callsites, via the ddebug.class_id field.

While this slightly pessimizes the bit-test in drm_debug_enabled(),
using dyndbg with JUMP_LABEL will avoid the function entirely.

NOTE: this change forecloses the possibility of doing:

  drm_dbg(DRM_UT_CORE|DRM_UT_KMS, "weird 2-cat experiment")

but thats already strongly implied by the use of the enum itself; its
not a normal enum if it can be 2 values simultaneously.

Signed-off-by: Jim Cromie <jim.cromie@...il.com>
---
 include/drm/drm_print.h | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 22fabdeed297..b3b470440e46 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -279,49 +279,49 @@ enum drm_debug_category {
 	 * @DRM_UT_CORE: Used in the generic drm code: drm_ioctl.c, drm_mm.c,
 	 * drm_memory.c, ...
 	 */
-	DRM_UT_CORE		= 0x01,
+	DRM_UT_CORE,
 	/**
 	 * @DRM_UT_DRIVER: Used in the vendor specific part of the driver: i915,
 	 * radeon, ... macro.
 	 */
-	DRM_UT_DRIVER		= 0x02,
+	DRM_UT_DRIVER,
 	/**
 	 * @DRM_UT_KMS: Used in the modesetting code.
 	 */
-	DRM_UT_KMS		= 0x04,
+	DRM_UT_KMS,
 	/**
 	 * @DRM_UT_PRIME: Used in the prime code.
 	 */
-	DRM_UT_PRIME		= 0x08,
+	DRM_UT_PRIME,
 	/**
 	 * @DRM_UT_ATOMIC: Used in the atomic code.
 	 */
-	DRM_UT_ATOMIC		= 0x10,
+	DRM_UT_ATOMIC,
 	/**
 	 * @DRM_UT_VBL: Used for verbose debug message in the vblank code.
 	 */
-	DRM_UT_VBL		= 0x20,
+	DRM_UT_VBL,
 	/**
 	 * @DRM_UT_STATE: Used for verbose atomic state debugging.
 	 */
-	DRM_UT_STATE		= 0x40,
+	DRM_UT_STATE,
 	/**
 	 * @DRM_UT_LEASE: Used in the lease code.
 	 */
-	DRM_UT_LEASE		= 0x80,
+	DRM_UT_LEASE,
 	/**
 	 * @DRM_UT_DP: Used in the DP code.
 	 */
-	DRM_UT_DP		= 0x100,
+	DRM_UT_DP,
 	/**
 	 * @DRM_UT_DRMRES: Used in the drm managed resources code.
 	 */
-	DRM_UT_DRMRES		= 0x200,
+	DRM_UT_DRMRES
 };
 
 static inline bool drm_debug_enabled(enum drm_debug_category category)
 {
-	return unlikely(__drm_debug & category);
+	return unlikely(__drm_debug & BIT(category));
 }
 
 /*
-- 
2.37.3