kernel/arch/tile/lib/atomic_32.c, branch linux-rolling-stable

arch: remove tile port

2018-03-16T09:56:03Z

The Tile architecture port was added by Chris Metcalf in 2010, and maintained until early 2018 when he orphaned it due to his departure from Mellanox, and nobody else stepped up to maintain it. The product line is still around in the form of the BlueField SoC, but no longer uses the Tile architecture. There are also still products for sale with Tile-GX SoCs, notably the Mikrotik CCR router family. The products all use old (linux-3.3) kernels with lots of patches and won't be upgraded by their manufacturers. There have been efforts to port both OpenWRT and Debian to these, but both projects have stalled and are very unlikely to be continued in the future. Given that we are reasonably sure that nobody is still using the port with an upstream kernel any more, it seems better to remove it now while the port is in a good shape than to let it bitrot for a few years first. Cc: Chris Metcalf Cc: John Paul Adrian Glaubitz Link: http://www.mellanox.com/page/npu_multicore_overview Link: https://jenkins.debian.net/view/rebootstrap/job/rebootstrap_tilegx_gcc7/ Signed-off-by: Arnd Bergmann

locking/atomic, arch/tile: Fix tilepro build

2016-06-24T06:17:04Z

The tilepro change wasn't ever compiled it seems (the 0day built bot also doesn't have a toolchain for it). Make it work. The thing that makes the patch bigger than desired is namespace collision with the C11 __atomic builtin functions. So rename the tilepro functions to __atomic32. Reported-by: Sudip Mukherjee Signed-off-by: Peter Zijlstra (Intel) Acked-by: Chris Metcalf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephen Rothwell Cc: Thomas Gleixner Fixes: 1af5de9af138 ("locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()") Link: http://lkml.kernel.org/r/20160622091649.GB30154@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar

locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()

2016-06-16T08:48:30Z

Implement FETCH-OP atomic primitives, these are very similar to the existing OP-RETURN primitives we already have, except they return the value of the atomic variable _before_ modification. This is especially useful for irreversible operations -- such as bitops (because it becomes impossible to reconstruct the state prior to modification). Signed-off-by: Peter Zijlstra (Intel) Acked-by: Chris Metcalf Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

tile: Provide atomic_{or,xor,and}

2015-07-27T12:06:24Z

Implement atomic logic ops -- atomic_{or,xor,and}. For tilegx, these are relatively straightforward; the architecture provides atomic "or" and "and", both 32-bit and 64-bit. To support xor we provide a loop using "cmpexch". For the older 32-bit tilepro architecture, we have to extend the set of low-level assembly routines to include 32-bit "and", as well as all three 64-bit routines. Somewhat confusingly, some 32-bit versions are already used by the bitops inlines, with parameter types appropriate for bitops, so we have to do a bit of casting to match "int" to "unsigned long". Signed-off-by: Chris Metcalf Signed-off-by: Peter Zijlstra (Intel) Link: http://lkml.kernel.org/r/1436474297-32187-1-git-send-email-cmetcalf@ezchip.com Signed-off-by: Thomas Gleixner

tile: include: asm: use 'long long' instead of 'u64' for atomic64_t and its related functions

2013-09-27T20:08:56Z

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/\/long long/g" command. remove redundant '__aligned(8)'. be sure of 80 (and macro '\') columns limitation after replacement. Signed-off-by: Chen Gang Signed-off-by: Chris Metcalf [re-instated const cast]

tile: rework

2013-09-06T17:06:25Z

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 . 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

tile: remove support for TILE64

2013-09-03T18:53:29Z

This chip is no longer being actively developed for (it was superceded by the TILEPro64 in 2008), and in any case the existing compiler and toolchain in the community do not support it. It's unlikely that the kernel works with TILE64 at this point as the configuration has not been tested in years. The support is also awkward as it requires maintaining a significant number of ifdefs. So, just remove it altogether. Signed-off-by: Chris Metcalf

tile: eliminate no-op "noatomichash" boot argument

2013-09-03T18:53:24Z

Signed-off-by: Chris Metcalf

arch/tile: optimize get_user/put_user and friends

2012-05-25T16:48:23Z

Use direct load/store for the get_user/put_user. Previously, we would call out to a helper routine that would do the appropriate thing and then return, handling the possible exception internally. Now we inline the load or store, along with a "we succeeded" indication in a register; if the load or store faults, we write a "we failed" indication into the same register and then return to the following instruction. This is more efficient and gives us more compact code, as well as being more in line with what other architectures do. The special futex assembly source file for TILE-Gx also disappears in this change; we just use the same inlining idiom there as well, putting the appropriate atomic operations directly into futex_atomic_op_inuser() (and thus into the FUTEX_WAIT function). The underlying atomic copy_from_user, copy_to_user functions were renamed using the (cryptic) x86 convention as copy_from_user_ll and copy_to_user_ll. Signed-off-by: Chris Metcalf

atomic: use

2011-07-26T23:49:47Z

This allows us to move duplicated code in (atomic_inc_not_zero() for now) to Signed-off-by: Arun Sharma Reviewed-by: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Cc: Eric Dumazet Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds