[PATCH v6 01/10] drm/print: Fix and add support for NULL as first argument in drm_* macros
Siddh Raman Pant
code at siddh.me
Mon Jan 9 13:00:26 UTC 2023
Comments say macros DRM_DEBUG_* are deprecated in favor of
drm_dbg_*(NULL, ...), but they have broken support for it,
as the macro will result in `(NULL) ? (NULL)->dev : NULL`.
Thus, fix them by separating logic to get dev ptr in a new
function, which will return the dev ptr if arg is not NULL.
Use it in drm_dbg_*, and also in __DRM_DEFINE_DBG_RATELIMITED,
where a similar (but correct) NULL check was in place.
Also, add support for NULL in __drm_printk, so that all the
drm_* macros will hence support NULL as the first argument.
This also means that deprecation comments mentioning pr_()*
can now be changed to the drm equivalents.
There is a need to support device pointers, as in some cases,
we may not have drm_device but just the device ptr, such as
when dealing with struct mipi_dsi_host. Before this change,
passing just mipi_dsi_host would have worked, since due to
preprocessing, the resultant would be "host->dev", but now
due to NULL check that cannot happen.
Signed-off-by: Siddh Raman Pant <code at siddh.me>
---
include/drm/drm_print.h | 114 ++++++++++++++++++++++++++++++----------
1 file changed, 87 insertions(+), 27 deletions(-)
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index a44fb7ef257f..481bf129cc39 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -34,6 +34,7 @@
#include <linux/dynamic_debug.h>
#include <drm/drm.h>
+#include <drm/drm_device.h>
/* Do *not* use outside of drm_print.[ch]! */
extern unsigned long __drm_debug;
@@ -445,15 +446,73 @@ void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
#define DRM_DEV_DEBUG_KMS(dev, fmt, ...) \
drm_dev_dbg(dev, DRM_UT_KMS, fmt, ##__VA_ARGS__)
+/* Helpers for struct drm_device based logging. */
+
+/**
+ * __drm_dev_ptr - Helper function to get drm->dev pointer.
+ * @drm: struct drm_device pointer.
+ *
+ * RETURNS:
+ * The struct device pointer (NULL if @drm is NULL).
+ */
+static inline struct device *__drm_dev_ptr(const struct drm_device *drm)
+{
+ if (drm)
+ return drm->dev;
+
+ return NULL;
+}
+
+/**
+ * __dev_ptr - Helper function to get the same device pointer.
+ * @dev: struct device pointer, or NULL.
+ *
+ * RETURNS:
+ * The struct device pointer (NULL if @dev is NULL).
+ */
+static inline struct device *__dev_ptr(const struct device *dev)
+{
+ return (struct device *)dev;
+}
+
+/**
+ * __get_dev_ptr - Helper to get device pointer given struct drm_device *,
+ * or struct device *, or NULL.
+ *
+ * Primarily for use in drm_*() print macros, since they need to handle NULL
+ * as the first argument passed.
+ *
+ * struct device pointers are supported for edge cases (such as mipi_dsi_host),
+ * the default (and recommended) way is to pass struct drm_device pointer.
+ */
+#define __get_dev_ptr(drm) \
+ _Generic((drm), \
+ struct device * : \
+ __dev_ptr, \
+ const struct device * : \
+ __dev_ptr, \
+ default : \
+ __drm_dev_ptr \
+ )(drm)
+
/*
* struct drm_device based logging
*
* Prefer drm_device based logging over device or prink based logging.
+ *
+ * The below macros support device pointers to cope for edge cases where
+ * we only have device (like in mipi_dsi_host) but not drm_device.
*/
/* Helper for struct drm_device based logging. */
#define __drm_printk(drm, level, type, fmt, ...) \
- dev_##level##type((drm)->dev, "[drm] " fmt, ##__VA_ARGS__)
+({ \
+ struct device *__dev_ = __get_dev_ptr(drm); \
+ if (__dev_) \
+ dev_##level##type(__dev_, "[drm] " fmt, ##__VA_ARGS__); \
+ else \
+ pr_##level##type("[drm] " fmt, ##__VA_ARGS__); \
+})
#define drm_info(drm, fmt, ...) \
@@ -487,25 +546,25 @@ void __drm_dev_dbg(struct _ddebug *desc, const struct device *dev,
#define drm_dbg_core(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_CORE, fmt, ##__VA_ARGS__)
-#define drm_dbg_driver(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_CORE, fmt, ##__VA_ARGS__)
+#define drm_dbg_driver(drm, fmt, ...) \
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
#define drm_dbg_kms(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_KMS, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_KMS, fmt, ##__VA_ARGS__)
#define drm_dbg_prime(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_PRIME, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_PRIME, fmt, ##__VA_ARGS__)
#define drm_dbg_atomic(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_ATOMIC, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_ATOMIC, fmt, ##__VA_ARGS__)
#define drm_dbg_vbl(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_VBL, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_VBL, fmt, ##__VA_ARGS__)
#define drm_dbg_state(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_STATE, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_STATE, fmt, ##__VA_ARGS__)
#define drm_dbg_lease(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_LEASE, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_LEASE, fmt, ##__VA_ARGS__)
#define drm_dbg_dp(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DP, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_DP, fmt, ##__VA_ARGS__)
#define drm_dbg_drmres(drm, fmt, ...) \
- drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRMRES, fmt, ##__VA_ARGS__)
+ drm_dev_dbg(__get_dev_ptr(drm), DRM_UT_DRMRES, fmt, ##__VA_ARGS__)
#define drm_dbg(drm, fmt, ...) drm_dbg_driver(drm, fmt, ##__VA_ARGS__)
@@ -533,31 +592,31 @@ void __drm_err(const char *format, ...);
#define _DRM_PRINTK(once, level, fmt, ...) \
printk##once(KERN_##level "[" DRM_NAME "] " fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_info(). */
+/* NOTE: this is deprecated in favor of drm_info(NULL, ...). */
#define DRM_INFO(fmt, ...) \
_DRM_PRINTK(, INFO, fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_notice(). */
+/* NOTE: this is deprecated in favor of drm_notice(NULL, ...). */
#define DRM_NOTE(fmt, ...) \
_DRM_PRINTK(, NOTICE, fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_warn(). */
+/* NOTE: this is deprecated in favor of drm_warn(NULL, ...). */
#define DRM_WARN(fmt, ...) \
_DRM_PRINTK(, WARNING, fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_info_once(). */
+/* NOTE: this is deprecated in favor of drm_info_once(NULL, ...). */
#define DRM_INFO_ONCE(fmt, ...) \
_DRM_PRINTK(_once, INFO, fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_notice_once(). */
+/* NOTE: this is deprecated in favor of drm_notice_once(NULL, ...). */
#define DRM_NOTE_ONCE(fmt, ...) \
_DRM_PRINTK(_once, NOTICE, fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_warn_once(). */
+/* NOTE: this is deprecated in favor of drm_warn_once(NULL, ...). */
#define DRM_WARN_ONCE(fmt, ...) \
_DRM_PRINTK(_once, WARNING, fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_err(). */
+/* NOTE: this is deprecated in favor of drm_err(NULL, ...). */
#define DRM_ERROR(fmt, ...) \
__drm_err(fmt, ##__VA_ARGS__)
-/* NOTE: this is deprecated in favor of pr_err_ratelimited(). */
+/* NOTE: this is deprecated in favor of drm_err_ratelimited(NULL, ...). */
#define DRM_ERROR_RATELIMITED(fmt, ...) \
DRM_DEV_ERROR_RATELIMITED(NULL, fmt, ##__VA_ARGS__)
@@ -593,13 +652,14 @@ void __drm_err(const char *format, ...);
#define DRM_DEBUG_DP(fmt, ...) \
__drm_dbg(DRM_UT_DP, fmt, ## __VA_ARGS__)
-#define __DRM_DEFINE_DBG_RATELIMITED(category, drm, fmt, ...) \
-({ \
- static DEFINE_RATELIMIT_STATE(rs_, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST);\
- 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__); \
+#define __DRM_DEFINE_DBG_RATELIMITED(category, drm, fmt, ...) \
+({ \
+ static DEFINE_RATELIMIT_STATE(rs_, DEFAULT_RATELIMIT_INTERVAL, \
+ DEFAULT_RATELIMIT_BURST); \
+ \
+ if (drm_debug_enabled(DRM_UT_ ## category) && __ratelimit(&rs_))\
+ drm_dev_printk(__get_dev_ptr(drm), KERN_DEBUG, \
+ fmt, ## __VA_ARGS__); \
})
#define drm_dbg_kms_ratelimited(drm, fmt, ...) \
--
2.39.0
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