summaryrefslogtreecommitdiffstats
path: root/arch/tile/include/asm/atomic.h
AgeCommit message (Collapse)Author
2013-09-27tile: include: asm: use 'long long' instead of 'u64' for atomic64_t and its ↵Chen Gang
related functions atomic* value is signed value, and atomic* functions need also process signed value (parameter value, and return value), so use 'long long' instead of 'u64'. After replacement, it will also fix a bug for atomic64_add_negative(): "u64 is never less than 0". The modifications are: in vim, use "1,% s/\<u64\>/long long/g" command. remove redundant '__aligned(8)'. be sure of 80 (and macro '\') columns limitation after replacement. Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [re-instated const cast]
2013-09-06tile: rework <asm/cmpxchg.h>Chris Metcalf
The macrology in cmpxchg.h was designed to allow arbitrary pointer and integer values to be passed through the routines. To support cmpxchg() on 64-bit values on the 32-bit tilepro architecture, we used the idiom "(typeof(val))(typeof(val-val))". This way, in the "size 8" branch of the switch, when the underlying cmpxchg routine returns a 64-bit quantity, we cast it first to a typeof(val-val) quantity (i.e. size_t if "val" is a pointer) with no warnings about casting between pointers and integers of different sizes, then cast onwards to typeof(val), again with no warnings. If val is not a pointer type, the additional cast is a no-op. We can't replace the typeof(val-val) cast with (for example) unsigned long, since then if "val" is really a 64-bit type, we cast away the high bits. HOWEVER, this fails with current gcc (through 4.7 at least) if "val" is a pointer to an incomplete type. Unfortunately gcc isn't smart enough to realize that "val - val" will always be a size_t type even if it's an incomplete type pointer. Accordingly, I've reworked the way we handle the casting. We have given up the ability to use cmpxchg() on 64-bit values on tilepro, which is OK in the kernel since we should use cmpxchg64() explicitly on such values anyway. As a result, I can just use simple "unsigned long" casts internally. As I reworked it, I realized it would be cleaner to move the architecture-specific conditionals for cmpxchg and xchg out of the atomic.h headers and into cmpxchg, and then use the cmpxchg() and xchg() primitives directly in atomic.h and elsewhere. This allowed the cmpxchg.h header to stand on its own without relying on the implicit include of it that is performed by <asm/atomic.h>. It also allowed collapsing the atomic_xchg/atomic_cmpxchg routines from atomic_{32,64}.h into atomic.h. I improved the tests that guard the allowed size of the arguments to the routines to use a __compiletime_error() test. (By avoiding the use of BUILD_BUG, I could include cmpxchg.h into bitops.h as well and use the macros there, which is otherwise impossible due to include order dependency issues.) The tilepro _atomic_xxx internal methods were previously set up to take atomic_t and atomic64_t arguments, which isn't as convenient with the new model, so I modified them to take int or u64 arguments, which is consistent with how they used the arguments internally anyway, so provided some nice simplification there too. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-03-22tile: support atomic64_dec_if_positive()Chris Metcalf
Use the normal cmpxchg() idiom to implement this functionality. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-04-02tile: fix multiple build failures from system.h dismantlePaul Gortmaker
Commit bd119c69239322caafdb64517a806037d0d0c70a "Disintegrate asm/system.h for Tile" created the asm/switch_to.h file, but did not add an include of it to all its users. Also, commit b4816afa3986704d1404fc48e931da5135820472 "Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h" introduced the concept of asm/cmpxchg.h but the tile arch never got one. Fork the cmpxchg content out of the asm/atomic.h file to create one. Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-03-28Disintegrate asm/system.h for TileDavid Howells
Disintegrate asm/system.h for Tile. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com>
2011-07-26atomic: cleanup asm-generic atomic*.h inclusionArun Sharma
After changing all consumers of atomics to include <linux/atomic.h>, we ran into some compile time errors due to this dependency chain: linux/atomic.h -> asm/atomic.h -> asm-generic/atomic-long.h where atomic-long.h could use funcs defined later in linux/atomic.h without a prototype. This patches moves the code that includes asm-generic/atomic*.h to linux/atomic.h. Archs that need <asm-generic/atomic64.h> need to select CONFIG_GENERIC_ATOMIC64 from now on (some of them used to include it unconditionally). Compile tested on i386 and x86_64 with allnoconfig. Signed-off-by: Arun Sharma <asharma@fb.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-19arch/tile: use better definitions of xchg() and cmpxchg()Chris Metcalf
These definitions use a ({}) construct to avoid some cases where we were getting warnings about unused return values. We also promote the definition to the common <asm/atomic.h>, since it applies to both the 32- and 64-bit atomics. In addition, define __HAVE_ARCH_CMPXCHG for TILE-Gx since it has efficient direct atomic instructions. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-02-25arch/tile: Fix atomic_read() definition to use ACCESS_ONCEChris Metcalf
This adds the volatile cast which forces the compiler to emit the load. Suggested by Peter Zijlstra <peterz@infradead.org>. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-06-04arch/tile: core support for Tilera 32-bit chips.Chris Metcalf
This change is the core kernel support for TILEPro and TILE64 chips. No driver support (except the console driver) is included yet. This includes the relevant Linux headers in asm/; the low-level low-level "Tile architecture" headers in arch/, which are shared with the hypervisor, etc., and are build-system agnostic; and the relevant hypervisor headers in hv/. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Reviewed-by: Paul Mundt <lethal@linux-sh.org>