[Intel-gfx] [PATCH 8/8] drm/print: introduce new struct drm_device based logging macros

[Jani Nikula]

Add new struct drm_device based logging macros modeled after the core
kernel device based logging macros. These would be preferred over the
drm printk and struct device based macros in drm code, where possible.

We have existing drm specific struct device based logging functions, but
they are too verbose to use for two main reasons:

 * The names are unnecessarily long, for example DRM_DEV_DEBUG_KMS().

 * The use of struct device over struct drm_device is too generic for
   most users, leading to an extra dereference.

For example:

	DRM_DEV_DEBUG_KMS(drm->dev, "Hello, world\n");

vs.

	drm_dbg_kms(drm, "Hello, world\n");

It's a matter of taste, but the SHOUTING UPPERCASE has been argued to be
less readable than lowercase.

Some names are changed from old DRM names to be based on the core kernel
logging functions. For example, NOTE -> notice, ERROR -> err, DEBUG ->
dbg.

Due to the conflation of DRM_DEBUG and DRM_DEBUG_DRIVER macro use
(DRM_DEBUG is used widely in drivers though it's supposed to be a core
debugging category), they are named as drm_dbg_core and drm_dbg,
respectively.

The drm_err and _once/_ratelimited variants no longer include the
function name in order to be able to use the core device based logging
macros. Arguably this is not a significant change; error messages should
not be so common to be only distinguishable by the function name.

Ratelimited debug logging macros are to be added later.

Cc: Sam Ravnborg <sam at ravnborg.org>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>

---

With something like this, I think i915 could start migrating to
drm_device based logging. I have a hard time convincing myself or anyone
about migrating to the DRM_DEV_* variants.
---
 include/drm/drm_print.h | 65 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 085a9685270c..e4040dea0d8c 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -322,6 +322,8 @@ static inline bool drm_debug_enabled(enum drm_debug_category category)
 
 /*
  * struct device based logging
+ *
+ * Prefer drm_device based logging over device or prink based logging.
  */
 
 __printf(3, 4)
@@ -417,8 +419,71 @@ void drm_dev_dbg(const struct device *dev, enum drm_debug_category category,
 	_DRM_DEV_DEFINE_DEBUG_RATELIMITED(dev, DRM_UT_PRIME,		\
 					  fmt, ##__VA_ARGS__)
 
+/*
+ * struct drm_device based logging
+ *
+ * Prefer drm_device based logging over device or prink based logging.
+ */
+
+/* Helper for struct drm_device based logging. */
+#define __drm_printk(drm, level, type, fmt, ...)			\
+	dev_##level##type(drm->dev, "[drm] " fmt, ##__VA_ARGS__)
+
+
+#define drm_info(drm, fmt, ...)					\
+	__drm_printk(drm, info,, fmt, ##__VA_ARGS__)
+
+#define drm_notice(drm, fmt, ...)				\
+	__drm_printk(drm, notice,, fmt, ##__VA_ARGS__)
+
+#define drm_warn(drm, fmt, ...)					\
+	__drm_printk(drm, warn,, fmt, ##__VA_ARGS__)
+
+#define drm_err(drm, fmt, ...)					\
+	__drm_printk(drm, err,, "*ERROR* " fmt, ##__VA_ARGS__)
+
+
+#define drm_info_once(drm, fmt, ...)				\
+	__drm_printk(drm, info, _once, fmt, ##__VA_ARGS__)
+
+#define drm_notice_once(drm, fmt, ...)				\
+	__drm_printk(drm, notice, _once, fmt, ##__VA_ARGS__)
+
+#define drm_warn_once(drm, fmt, ...)				\
+	__drm_printk(drm, warn, _once, fmt, ##__VA_ARGS__)
+
+#define drm_err_once(drm, fmt, ...)				\
+	__drm_printk(drm, err, _once, "*ERROR* " fmt, ##__VA_ARGS__)
+
+
+#define drm_err_ratelimited(drm, fmt, ...)				\
+	__drm_printk(drm, err, _ratelimited, "*ERROR* " fmt, ##__VA_ARGS__)
+
+
+#define drm_dbg_core(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_CORE, fmt, ##__VA_ARGS__)
+#define drm_dbg(drm, fmt, ...)						\
+	drm_dev_dbg(drm->dev, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
+#define drm_dbg_kms(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_KMS, fmt, ##__VA_ARGS__)
+#define drm_dbg_prime(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_PRIME, fmt, ##__VA_ARGS__)
+#define drm_dbg_atomic(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_ATOMIC, fmt, ##__VA_ARGS__)
+#define drm_dbg_vbl(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_VBL, fmt, ##__VA_ARGS__)
+#define drm_dbg_state(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_STATE, fmt, ##__VA_ARGS__)
+#define drm_dbg_lease(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_LEASE, fmt, ##__VA_ARGS__)
+#define drm_dbg_dp(drm, fmt, ...)					\
+	drm_dev_dbg(drm->dev, DRM_UT_DP, fmt, ##__VA_ARGS__)
+
+
 /*
  * printk based logging
+ *
+ * Prefer drm_device based logging over device or prink based logging.
  */
 
 __printf(2, 3)
-- 
2.20.1