| Message ID | 20201209155452.28376-3-olaf@aepfle.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v1,1/3] tools: allocate bitmaps in units of unsigned long | expand |
On Wed, Dec 09, 2020 at 04:54:51PM +0100, Olaf Hering wrote: > Introduce new API to test if a fixed number of bits is clear or set, > and clear or set them all at once. > > The caller has to make sure the input bitnumber is a multiply of BITS_PER_LONG. > > This API avoids the loop over each bit in a known range just to see > if all of them are either clear or set. > > Signed-off-by: Olaf Hering <olaf@aepfle.de> I would rather these be introduced along side their callers. > --- > tools/libs/ctrl/xc_bitops.h | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/tools/libs/ctrl/xc_bitops.h b/tools/libs/ctrl/xc_bitops.h > index f0bac4a071..92f38872fb 100644 > --- a/tools/libs/ctrl/xc_bitops.h > +++ b/tools/libs/ctrl/xc_bitops.h > @@ -77,4 +77,29 @@ static inline void bitmap_or(void *_dst, const void *_other, > dst[i] |= other[i]; > } > > +static inline int test_bit_long_set(unsigned long nr_base, const void *_addr) What's wrong with requiring the input addr be const unsigned long *?
Am Tue, 15 Dec 2020 16:22:44 +0000
schrieb Wei Liu <wl@xen.org>:
> What's wrong with requiring the input addr be const unsigned long *?
Probably nothing. In the end I just borrowed the prototypes from the other functions in this file.
I will resend with this change once I have the consumers ready.
Olaf
On Tue, Dec 15, 2020 at 05:29:17PM +0100, Olaf Hering wrote: > Am Tue, 15 Dec 2020 16:22:44 +0000 > schrieb Wei Liu <wl@xen.org>: > > > What's wrong with requiring the input addr be const unsigned long *? > > Probably nothing. In the end I just borrowed the prototypes from the other functions in this file. > > I will resend with this change once I have the consumers ready. Okay. I will push the first two shortly. Wei. > > Olaf
diff --git a/tools/libs/ctrl/xc_bitops.h b/tools/libs/ctrl/xc_bitops.h index f0bac4a071..92f38872fb 100644 --- a/tools/libs/ctrl/xc_bitops.h +++ b/tools/libs/ctrl/xc_bitops.h @@ -77,4 +77,29 @@ static inline void bitmap_or(void *_dst, const void *_other, dst[i] |= other[i]; } +static inline int test_bit_long_set(unsigned long nr_base, const void *_addr) +{ + const unsigned long *addr = _addr; + unsigned long val = addr[nr_base / BITS_PER_LONG]; + return val == ~0; +} + +static inline int test_bit_long_clear(unsigned long nr_base, const void *_addr) +{ + const unsigned long *addr = _addr; + unsigned long val = addr[nr_base / BITS_PER_LONG]; + return val == 0; +} + +static inline void clear_bit_long(unsigned long nr_base, void *_addr) +{ + unsigned long *addr = _addr; + addr[nr_base / BITS_PER_LONG] = 0; +} + +static inline void set_bit_long(unsigned long nr_base, void *_addr) +{ + unsigned long *addr = _addr; + addr[nr_base / BITS_PER_LONG] = ~0; +} #endif /* XC_BITOPS_H */
Introduce new API to test if a fixed number of bits is clear or set, and clear or set them all at once. The caller has to make sure the input bitnumber is a multiply of BITS_PER_LONG. This API avoids the loop over each bit in a known range just to see if all of them are either clear or set. Signed-off-by: Olaf Hering <olaf@aepfle.de> --- tools/libs/ctrl/xc_bitops.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)