Commit Graph

12 Commits

Author SHA1 Message Date
Stefan Hajnoczi 9f02cfc84b bitmap: add atomic set functions
Use atomic_or() for atomic bitmaps where several threads may set bits at
the same time.  This avoids the race condition between threads loading
an element, bitwise ORing, and then storing the element.

When setting all bits in a word we can avoid atomic ops and instead just
use an smp_mb() at the end.

Most bitmap users don't need atomicity so introduce new functions.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1417519399-3166-2-git-send-email-stefanha@redhat.com>
[Avoid barrier in the single word case, use full barrier instead of write.
 - Paolo]
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-06-05 17:10:00 +02:00
Chih-Min Chao 4188e39055 bitops : fix coding style
don't mix tab and space. The rule is 4 spaces

Signed-off-by: Chih-Min Chao <cmchao@gmail.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-04-30 16:05:48 +03:00
Peter Maydell 4f9950520a bitops.h: sextract64() return type should be int64_t, not uint64_t
The documentation for sextract64() claims that the return type is
an int64_t, but the code itself disagrees. Fix the return type to
conform to the documentation and to bring it into line with
sextract32(), which returns int32_t.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1423231328-15662-1-git-send-email-peter.maydell@linaro.org
2015-03-11 13:21:06 +00:00
Eduardo Habkost afeeead1bc bitops.h: Don't include qemu-common.h
This removes the following circular dependency:

bitops.h -> qemu-common.h -> target-i386/cpu.h -> target-i386/cpu-qom.h ->
qom/cpu.h -> qdev-core.h -> bitmap.h -> bitops.h.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-11-02 10:04:34 +03:00
Aurelien Jarno 739b7a9075 bitops: provide an inline implementation of find_first_bit
find_first_bit has started to be used heavily in TCG code. The current
implementation based on find_next_bit is not optimal and can't be
optimized be the compiler if the bit array has a fixed size, which is
the case most of the time.

This new implementation does not use find_next_bit and is yet small
enough to be inlined.

Cc: Corentin Chary <corentin.chary@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2014-06-18 18:10:47 +02:00
Juan Quintela 9c22687ea8 bitmap: use long as index
Move index and size fields from int to long.  We need that for
migration.  long is 64 bits on sane architectures, and 32bits should
be enough on all the 32bits architectures.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
2014-01-13 14:04:53 +01:00
Stefan Weil 6aa25b4a7b bitops: Add rotate functions (rol8, ror8, ...)
These functions were copies from include/linux/bitopts.h.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
2013-09-25 21:22:33 +02:00
Peter Maydell 2dc6bebde9 bitops: Provide sextract32() and sextract64()
A common operation in instruction decoding is to take a field
from an instruction that represents a signed integer in some
arbitrary number of bits, and sign extend it into a C signed
integer type for manipulation. Provide new functions sextract32()
and sextract64() which perform this operation; they are like
the existing extract32() and extract64() except that the field
is sign-extended into the returned result.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-id: 1372419632-5521-2-git-send-email-peter.maydell@linaro.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-22 15:41:11 -05:00
Richard Henderson 453776e574 bitops: Remove routines redundant with host-utils
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2013-02-16 11:12:52 +00:00
Richard Henderson 0cfa6adc7f bitops: Write bitops_flsl in terms of clzl
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2013-02-16 11:12:21 +00:00
Paolo Bonzini fbeadf50f2 bitops: unify bitops_ffsl with the one in host-utils.h, call it bitops_ctzl
We had two copies of a ffs function for longs with subtly different
semantics and, for the one in bitops.h, a confusing name: the result
was off-by-one compared to the library function ffsl.

Unify the functions into one, and solve the name problem by calling
the 0-based functions "bitops_ctzl" and "bitops_ctol" respectively.

This also fixes the build on platforms with ffsl, including Mac OS X
and Windows.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Tested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2013-02-02 20:16:00 +00:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00