user/sven/linux.git/arch/tile/lib, branch v4.4.118

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

modpost: work correctly with tile coldtext sections

2015-07-08T22:53:49Z

The tilegx and tilepro compilers use .coldtext for their unlikely executed text section name, so an __attribute__((cold)) function will (when compiled with higher optimization levels) land in the .coldtext section. Modify modpost to add .coldtext to the set of OTHER_TEXT_SECTIONS so we don't get warnings about referencing such a section in an __ex_table block, and then also modify arch/tile/lib/memcpy_user_64.c so that it uses plain ".coldtext" instead of ".coldtext.memcpy". The latter naming is a relic of an earlier use of -ffunction-sections, which we no longer use by default. Signed-off-by: Chris Metcalf Acked-by: Rusty Russell

tile: improve stack backtrace

2015-05-11T15:22:40Z

This commit fixes a number of issues with the tile backtrace code. - Don't try to identify userspace shared object or executable paths if we are doing a backtrace from an interrupt; it's not legal, and also unlikely to be interesting. Likewise, don't try to do it for other address spaces, since d_path() assumes it is being called in "current" context. - Move "in_backtrace" from thread_struct to thread_info. This way we can access it even if our stack thread_info has been clobbered, which makes backtracing more robust. - Avoid using "current" directly when testing for is_sigreturn(). Since "current" may be corrupt, we're better off using kbt->task explicitly to look up the vdso_base for the current task. Conveniently, this simplifies the internal APIs (we only need one is_sigreturn() function now). - Avoid bogus "Odd fault" warning when pc/sp/ex1 are all zero, as is true for kernel threads above the last frame. - Hook into Tejun Heo's dump_stack() framework in lib/dump_stack.c. - Write last entry in save_stack_trace() as ULONG_MAX, not zero, since ftrace (at least) relies on finding that marker. - Implement save_stack_trace_regs() and save_strack_trace_user(), and set CONFIG_USER_STACKTRACE_SUPPORT. Signed-off-by: Chris Metcalf

tile: add and enable support functions

2015-04-30T19:23:37Z

This change enables the generic strncpy_from_user() and strnlen_user() using word-at-a-time.h. The tile implementation is trivial since both tilepro and tilegx have SIMD operations that do byte-wise comparisons against immediate zero for each byte, and return an 0x01 byte in each position where there is a 0x00 byte. Signed-off-by: Chris Metcalf

tile: modify arch_spin_unlock_wait() semantics

2015-04-29T02:43:13Z

Rather than trying to wait until all possible lockers have unlocked the lock, we now only wait until the current locker (if any) has released the lock. The old code was correct, but the new code works more like the x86 code and thus hopefully is more appropriate under contention. See commit 78bff1c8684f ("x86/ticketlock: Fix spin_unlock_wait() livelock") for x86. Signed-off-by: Chris Metcalf

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

tile: support FRAME_POINTER

2013-09-03T18:52:09Z

Allow enabling frame pointer support; this makes it easier to hook into the various kernel features that claim they require it without having to add Kconfig conditionals everywhere (a la mips, ppc, s390, and microblaze). When enabled, it basically eliminates leaf functions as such, and stops optimizing tail and sibling calls. It adds around 3% to the size of the kernel when enabled. Signed-off-by: Chris Metcalf