Commit 2c533cf4 authored by Lorenzo Stoakes's avatar Lorenzo Stoakes Committed by Wen Zhiwei
Browse files

minmax: reduce min/max macro expansion in atomisp driver 

stable inclusion
from stable-v6.6.52
commit 1705209b3e2a3d8c5a6296061cd6333140467147
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAYXOD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1705209b3e2a3d8c5a6296061cd6333140467147



--------------------------------

commit 7c6a3a65ace70f12b27b1a27c9a69cb791dc6e91 upstream.

Avoid unnecessary nested min()/max() which results in egregious macro
expansion.

Use clamp_t() as this introduces the least possible expansion, and turn
the {s,u}DIGIT_FITTING() macros into inline functions to avoid the
nested expansion.

This resolves an issue with slackware 15.0 32-bit compilation as
reported by Richard Narron.

Presumably the min/max fixups would be difficult to backport, this patch
should be easier and fix's Richard's problem in 5.15.

Reported-by: default avatarRichard Narron <richard@aaazen.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Closes: https://lore.kernel.org/all/4a5321bd-b1f-1832-f0c-cea8694dc5aa@aaazen.com/


Fixes: 867046cc7027 ("minmax: relax check to allow comparison between unsigned arguments and signed constants")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarLorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent c2b717b1

drivers/staging/media/atomisp/pci/sh_css_frac.h

+19 −7
Original line number Diff line number Diff line
@@ -30,12 +30,24 @@ 
#define uISP_VAL_MAX		      ((unsigned int)((1 << uISP_REG_BIT) - 1))



/* a:fraction bits for 16bit precision, b:fraction bits for ISP precision */

#define sDIGIT_FITTING(v, a, b) \

	min_t(int, max_t(int, (((v) >> sSHIFT) >> max(sFRACTION_BITS_FITTING(a) - (b), 0)), \

	  sISP_VAL_MIN), sISP_VAL_MAX)

#define uDIGIT_FITTING(v, a, b) \

	min((unsigned int)max((unsigned)(((v) >> uSHIFT) \

	>> max((int)(uFRACTION_BITS_FITTING(a) - (b)), 0)), \

	  uISP_VAL_MIN), uISP_VAL_MAX)

static inline int sDIGIT_FITTING(int v, int a, int b)

{

	int fit_shift = sFRACTION_BITS_FITTING(a) - b;



	v >>= sSHIFT;

	v >>= fit_shift > 0 ? fit_shift : 0;



	return clamp_t(int, v, sISP_VAL_MIN, sISP_VAL_MAX);

}



static inline unsigned int uDIGIT_FITTING(unsigned int v, int a, int b)

{

	int fit_shift = uFRACTION_BITS_FITTING(a) - b;



	v >>= uSHIFT;

	v >>= fit_shift > 0 ? fit_shift : 0;



	return clamp_t(unsigned int, v, uISP_VAL_MIN, uISP_VAL_MAX);

}



#endif /* __SH_CSS_FRAC_H */