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authorGerd Hoffmann <kraxel@redhat.com>2019-09-04 08:47:34 +0300
committerGerd Hoffmann <kraxel@redhat.com>2019-09-10 09:53:08 +0300
commit2dc5d44ccc5e7f032dbea2735b243f7f50ff863e (patch)
treed7ae7f83367e4f21dc3ca880ed95223a2e7c0239
parent2236439bc6679caa905d65def47dacd12466c2e9 (diff)
downloadlinux-2dc5d44ccc5e7f032dbea2735b243f7f50ff863e.tar.xz
drm: add drm_print_bits
New helper to print named bits of some value (think flags fields). Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Link: http://patchwork.freedesktop.org/patch/msgid/20190904054740.20817-2-kraxel@redhat.com
-rw-r--r--drivers/gpu/drm/drm_print.c33
-rw-r--r--include/drm/drm_print.h3
2 files changed, 36 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index ad302d71eeee..dfa27367ebb8 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -185,6 +185,39 @@ void drm_printf(struct drm_printer *p, const char *f, ...)
}
EXPORT_SYMBOL(drm_printf);
+/**
+ * drm_print_bits - print bits to a &drm_printer stream
+ *
+ * Print bits (in flag fields for example) in human readable form.
+ * The first name in the @bits array is for the bit indexed by @from.
+ *
+ * @p: the &drm_printer
+ * @value: field value.
+ * @bits: Array with bit names.
+ * @from: start of bit range to print (inclusive).
+ * @to: end of bit range to print (exclusive).
+ */
+void drm_print_bits(struct drm_printer *p,
+ unsigned long value, const char *bits[],
+ unsigned int from, unsigned int to)
+{
+ bool first = true;
+ unsigned int i;
+
+ for (i = from; i < to; i++) {
+ if (!(value & (1 << i)))
+ continue;
+ if (WARN_ON_ONCE(!bits[i-from]))
+ continue;
+ drm_printf(p, "%s%s", first ? "" : ",",
+ bits[i-from]);
+ first = false;
+ }
+ if (first)
+ drm_printf(p, "(none)");
+}
+EXPORT_SYMBOL(drm_print_bits);
+
void drm_dev_printk(const struct device *dev, const char *level,
const char *format, ...)
{
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 112165d3195d..12d4916254b4 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -89,6 +89,9 @@ __printf(2, 3)
void drm_printf(struct drm_printer *p, const char *f, ...);
void drm_puts(struct drm_printer *p, const char *str);
void drm_print_regset32(struct drm_printer *p, struct debugfs_regset32 *regset);
+void drm_print_bits(struct drm_printer *p,
+ unsigned long value, const char *bits[],
+ unsigned int from, unsigned int to);
__printf(2, 0)
/**