[U-Boot] [PATCH v2 02/13] include: Add generic bitops headers
Jagan Teki
jteki at openedev.com
Sun Oct 25 07:50:07 CET 2015
Hi Febio,
You replaced __always_inline to inline any specific reason? found
__always_inline at some parts of header in code. But my compilation is
not-smooth with this.
On 24 October 2015 at 20:56, Fabio Estevam <festevam at gmail.com> wrote:
> From: Fabio Estevam <fabio.estevam at freescale.com>
>
> Use the generic bitops header files from the kernel.
>
> Imported from kernel 4.2.3.
>
> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> Reviewed-by: Tom Rini <trini at konsulko.com>
> ---
> Changes since v1:
> - None
>
> include/asm-generic/bitops/__ffs.h | 43 ++++++++++++++++++++++++++++++++++++++
> include/asm-generic/bitops/__fls.h | 43 ++++++++++++++++++++++++++++++++++++++
> include/asm-generic/bitops/fls.h | 41 ++++++++++++++++++++++++++++++++++++
> include/asm-generic/bitops/fls64.h | 36 +++++++++++++++++++++++++++++++
> include/linux/bitops.h | 26 +++++++++++++++++++++++
> 5 files changed, 189 insertions(+)
> create mode 100644 include/asm-generic/bitops/__ffs.h
> create mode 100644 include/asm-generic/bitops/__fls.h
> create mode 100644 include/asm-generic/bitops/fls.h
> create mode 100644 include/asm-generic/bitops/fls64.h
>
> diff --git a/include/asm-generic/bitops/__ffs.h b/include/asm-generic/bitops/__ffs.h
> new file mode 100644
> index 0000000..9a3274a
> --- /dev/null
> +++ b/include/asm-generic/bitops/__ffs.h
> @@ -0,0 +1,43 @@
> +#ifndef _ASM_GENERIC_BITOPS___FFS_H_
> +#define _ASM_GENERIC_BITOPS___FFS_H_
> +
> +#include <asm/types.h>
> +
> +/**
> + * __ffs - find first bit in word.
> + * @word: The word to search
> + *
> + * Undefined if no bit exists, so code should check against 0 first.
> + */
> +static inline unsigned long __ffs(unsigned long word)
> +{
> + int num = 0;
> +
> +#if BITS_PER_LONG == 64
> + if ((word & 0xffffffff) == 0) {
> + num += 32;
> + word >>= 32;
> + }
> +#endif
> + if ((word & 0xffff) == 0) {
> + num += 16;
> + word >>= 16;
> + }
> + if ((word & 0xff) == 0) {
> + num += 8;
> + word >>= 8;
> + }
> + if ((word & 0xf) == 0) {
> + num += 4;
> + word >>= 4;
> + }
> + if ((word & 0x3) == 0) {
> + num += 2;
> + word >>= 2;
> + }
> + if ((word & 0x1) == 0)
> + num += 1;
> + return num;
> +}
> +
> +#endif /* _ASM_GENERIC_BITOPS___FFS_H_ */
> diff --git a/include/asm-generic/bitops/__fls.h b/include/asm-generic/bitops/__fls.h
> new file mode 100644
> index 0000000..be24465
> --- /dev/null
> +++ b/include/asm-generic/bitops/__fls.h
> @@ -0,0 +1,43 @@
> +#ifndef _ASM_GENERIC_BITOPS___FLS_H_
> +#define _ASM_GENERIC_BITOPS___FLS_H_
> +
> +#include <asm/types.h>
> +
> +/**
> + * __fls - find last (most-significant) set bit in a long word
> + * @word: the word to search
> + *
> + * Undefined if no set bit exists, so code should check against 0 first.
> + */
> +static inline unsigned long __fls(unsigned long word)
> +{
> + int num = BITS_PER_LONG - 1;
> +
> +#if BITS_PER_LONG == 64
> + if (!(word & (~0ul << 32))) {
> + num -= 32;
> + word <<= 32;
> + }
> +#endif
> + if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
> + num -= 16;
> + word <<= 16;
> + }
> + if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
> + num -= 8;
> + word <<= 8;
> + }
> + if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
> + num -= 4;
> + word <<= 4;
> + }
> + if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
> + num -= 2;
> + word <<= 2;
> + }
> + if (!(word & (~0ul << (BITS_PER_LONG-1))))
> + num -= 1;
> + return num;
> +}
> +
> +#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */
> diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h
> new file mode 100644
> index 0000000..850859b
> --- /dev/null
> +++ b/include/asm-generic/bitops/fls.h
> @@ -0,0 +1,41 @@
> +#ifndef _ASM_GENERIC_BITOPS_FLS_H_
> +#define _ASM_GENERIC_BITOPS_FLS_H_
> +
> +/**
> + * fls - find last (most-significant) bit set
> + * @x: the word to search
> + *
> + * This is defined the same way as ffs.
> + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
> + */
> +
> +static inline int fls(int x)
> +{
> + int r = 32;
> +
> + if (!x)
> + return 0;
> + if (!(x & 0xffff0000u)) {
> + x <<= 16;
> + r -= 16;
> + }
> + if (!(x & 0xff000000u)) {
> + x <<= 8;
> + r -= 8;
> + }
> + if (!(x & 0xf0000000u)) {
> + x <<= 4;
> + r -= 4;
> + }
> + if (!(x & 0xc0000000u)) {
> + x <<= 2;
> + r -= 2;
> + }
> + if (!(x & 0x80000000u)) {
> + x <<= 1;
> + r -= 1;
> + }
> + return r;
> +}
> +
> +#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */
> diff --git a/include/asm-generic/bitops/fls64.h b/include/asm-generic/bitops/fls64.h
> new file mode 100644
> index 0000000..86d403f
> --- /dev/null
> +++ b/include/asm-generic/bitops/fls64.h
> @@ -0,0 +1,36 @@
> +#ifndef _ASM_GENERIC_BITOPS_FLS64_H_
> +#define _ASM_GENERIC_BITOPS_FLS64_H_
> +
> +#include <asm/types.h>
> +
> +/**
> + * fls64 - find last set bit in a 64-bit word
> + * @x: the word to search
> + *
> + * This is defined in a similar way as the libc and compiler builtin
> + * ffsll, but returns the position of the most significant set bit.
> + *
> + * fls64(value) returns 0 if value is 0 or the position of the last
> + * set bit if value is nonzero. The last (most significant) bit is
> + * at position 64.
> + */
> +#if BITS_PER_LONG == 32
> +static inline int fls64(__u64 x)
> +{
> + __u32 h = x >> 32;
> + if (h)
> + return fls(h) + 32;
> + return fls(x);
> +}
> +#elif BITS_PER_LONG == 64
> +static inline int fls64(__u64 x)
> +{
> + if (x == 0)
> + return 0;
> + return __fls(x) + 1;
> +}
> +#else
> +#error BITS_PER_LONG not 32 or 64
> +#endif
> +
> +#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */
> diff --git a/include/linux/bitops.h b/include/linux/bitops.h
> index 7b4011f..57143ac 100644
> --- a/include/linux/bitops.h
> +++ b/include/linux/bitops.h
> @@ -139,6 +139,32 @@ static inline unsigned int generic_hweight8(unsigned int w)
> # define fls generic_fls
> #endif
>
> +static inline unsigned fls_long(unsigned long l)
> +{
> + if (sizeof(l) == 4)
> + return fls(l);
> + return fls64(l);
> +}
> +
> +/**
> + * __ffs64 - find first set bit in a 64 bit word
> + * @word: The 64 bit word
> + *
> + * On 64 bit arches this is a synomyn for __ffs
> + * The result is not defined if no bits are set, so check that @word
> + * is non-zero before calling this.
> + */
> +static inline unsigned long __ffs64(u64 word)
> +{
> +#if BITS_PER_LONG == 32
> + if (((u32)word) == 0UL)
> + return __ffs((u32)(word >> 32)) + 32;
> +#elif BITS_PER_LONG != 64
> +#error BITS_PER_LONG not 32 or 64
> +#endif
> + return __ffs((unsigned long)word);
> +}
> +
> /**
> * __set_bit - Set a bit in memory
> * @nr: the bit to set
> --
> 1.9.1
>
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--
Jagan | openedev.
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