Re: [PATCH 18/98] include/uapi/sound/emu10k1.h: added EMU10K1 version of DECLARE_BITMAP etc macros

At Sun, 31 May 2015 09:18:57 +0200,
Takashi Iwai wrote:

At Sat, 30 May 2015 17:38:10 +0200,
Mikko Rapeli wrote:

quoted

Fixes userspace compilation error:

error: expected specifier-qualifier-list before ‘DECLARE_BITMAP’
  DECLARE_BITMAP(gpr_valid, 0x200); /* bitmask of valid initializers */

DECLARE_BITMAP etc macros are not meant for userspace headers and thus
added here as private copies for emu10k.h.

Fix was suggested by Arnd Bergmann [off-list ref] in message
<2168807.4Yxh5gl11Q@wuerfel> on lkml.

Signed-off-by: Mikko Rapeli <redacted>
---
 include/uapi/sound/emu10k1.h | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/include/uapi/sound/emu10k1.h b/include/uapi/sound/emu10k1.h
index ec1535b..7575f0f 100644
--- a/include/uapi/sound/emu10k1.h
+++ b/include/uapi/sound/emu10k1.h

@@ -34,6 +34,23 @@
 
 #define EMU10K1_FX8010_PCM_COUNT		8
 
+/*
+ * Following definitions are copies from kernel headers to support compiling
+ * this header file in userspace. The definitions are not generally available
+ * in uapi headers so the needed things are copied here wtih __EMU10k1 prefix.
+ */
+
+/* From include/linux/bitops.h */
+#define __EMU10K1_BITS_PER_BYTE           8
+/* From include/linux/kernel.h */
+#define __EMU10K1_DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
+/* From include/linux/bitops.h */
+#define __EMU10K1_BITS_TO_LONGS(nr) \
+        __EMU10K1_DIV_ROUND_UP(nr, __EMU10K1_BITS_PER_BYTE * sizeof(long))
+/* From include/linux/types.h */
+#define __EMU10K1_DECLARE_BITMAP(name,bits) \
+        unsigned long name[__EMU10K1_BITS_TO_LONGS(bits)]

This is way too complicated just for a few expansion of the aligned
size arrays, IMO.  Rather simplify it like below with a comment:

/* the array must be aligned to unsigned long (i.e. 4 or 8 bytes) */
#define __EMU10K1_DECLARE_BITMAP(name) \
	unsigned long name[(bits) / sizeof(unsigned long)]

Crap, of course, it must be multiplied with 8.

/* the array must be aligned to unsigned long (i.e. 32 or 64) */
#define __EMU10K1_DECLARE_BITMAP(name) \
	unsigned long name[(bits) / (sizeof(unsigned long) * 8)]


Takashi