[RESEND PATCH v2 3/9] asm-generic: Move some macros from linux/bitops.h to a new bits.h file
From: Will Deacon <hidden>
Date: 2018-07-09 11:32:30
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lkml
Hi Andrew, On Fri, Jul 06, 2018 at 05:30:49PM -0700, Andrew Morton wrote:
On Tue, 19 Jun 2018 13:53:08 +0100 Will Deacon [off-list ref] wrote:quoted
In preparation for implementing the asm-generic atomic bitops in terms of atomic_long_*, we need to prevent asm/atomic.h implementations from pulling in linux/bitops.h. A common reason for this include is for the BITS_PER_BYTE definition, so move this and some other BIT() and masking macros into a new header file, linux/bits.h--- a/include/linux/bitops.h +++ b/include/linux/bitops.h@@ -2,29 +2,9 @@ #ifndef _LINUX_BITOPS_H #define _LINUX_BITOPS_H #include <asm/types.h> +#include <linux/bits.h> -#ifdef __KERNEL__ -#define BIT(nr) (1UL << (nr)) -#define BIT_ULL(nr) (1ULL << (nr)) -#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) -#define BIT_WORD(nr) ((nr) / BITS_PER_LONG) -#define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG)) -#define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG) -#define BITS_PER_BYTE 8 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) -#endifWhy does it leave BITS_TO_LONGS() in place? That becomes unfortunate with Chris's patch, so I'm moving BITS_TO_LONGS() into bits.h.
The reason I avoided that was because it would pull in the dreaded kernel.h for DIV_ROUND_UP, and then we're back to circular include hell :( Will
quoted hunk ↗ jump to hunk
From: Chris Wilson <redacted> Subject: include/linux/bitops.h: introduce BITS_PER_TYPE net_dim.h has a rather useful extension to BITS_PER_BYTE to compute the number of bits in a type (BITS_PER_BYTE * sizeof(T)), so promote the macro to bitops.h, alongside BITS_PER_BYTE, for wider usage. Link: http://lkml.kernel.org/r/20180706094458.14116-1-chris at chris-wilson.co.uk Signed-off-by: Chris Wilson <redacted> Reviewed-by: Jani Nikula <redacted> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andy Gospodarek <redacted> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <redacted> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- include/linux/bitops.h | 3 ++- include/linux/net_dim.h | 1 - 2 files changed, 2 insertions(+), 2 deletions(-) diff -puN include/linux/bitops.h~bitops-introduce-bits_per_type include/linux/bitops.h--- a/include/linux/bitops.h~bitops-introduce-bits_per_type +++ a/include/linux/bitops.h@@ -11,7 +11,8 @@ #define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG)) #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG) #define BITS_PER_BYTE 8 -#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) +#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) +#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_TYPE(long)) #endif /*diff -puN include/linux/net_dim.h~bitops-introduce-bits_per_type include/linux/net_dim.h--- a/include/linux/net_dim.h~bitops-introduce-bits_per_type +++ a/include/linux/net_dim.h@@ -363,7 +363,6 @@ static inline void net_dim_sample(u16 ev } #define NET_DIM_NEVENTS 64 -#define BITS_PER_TYPE(type) (sizeof(type) * BITS_PER_BYTE) #define BIT_GAP(bits, end, start) ((((end) - (start)) + BIT_ULL(bits)) & (BIT_ULL(bits) - 1)) static inline void net_dim_calc_stats(struct net_dim_sample *start,_