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2016-12-16tile: remove #pragma unroll from finv_buffer_remote()Chris Metcalf
This directive was put in the kernel source before the "pragma unroll" support for tilegx gcc was upstreamed. Remove it for now, and we can put it back later if/when the compiler support is upstreamed. This avoids a warning when building the kernel. This routine is not on a hot path in any case, so the extra optimization here was mostly just for its own sake. Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
2016-07-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
Pull tile architecture updates from Chris Metcalf: "A few stray changes" * git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: tile: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO tile: support gcc 7 optimization to use __multi3 tile 32-bit big-endian: fix bugs in syscall argument order tile: allow disabling CONFIG_EARLY_PRINTK
2016-06-24tile: support gcc 7 optimization to use __multi3Chris Metcalf
The tip gcc includes an optimization mode that converts 64-bit divides into 128-bit multiplies using __multi3. Export the symbol so that modules can find it. We just export unconditionally without worrying about the gcc version, since the symbol has been in libgcc forever and the function is less than 300 bytes. Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
2016-06-24locking/atomic, arch/tile: Fix tilepro buildPeter Zijlstra
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 <sudipm.mukherjee@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Chris Metcalf <cmetcalf@mellanox.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Thomas Gleixner <tglx@linutronix.de> 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 <mingo@kernel.org>
2016-06-16locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()Peter Zijlstra
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) <peterz@infradead.org> Acked-by: Chris Metcalf <cmetcalf@mellanox.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14locking/spinlock, arch: Update and fix spin_unlock_wait() implementationsPeter Zijlstra
This patch updates/fixes all spin_unlock_wait() implementations. The update is in semantics; where it previously was only a control dependency, we now upgrade to a full load-acquire to match the store-release from the spin_unlock() we waited on. This ensures that when spin_unlock_wait() returns, we're guaranteed to observe the full critical section we waited on. This fixes a number of spin_unlock_wait() users that (not unreasonably) rely on this. I also fixed a number of ticket lock versions to only wait on the current lock holder, instead of for a full unlock, as this is sufficient. Furthermore; again for ticket locks; I added an smp_rmb() in between the initial ticket load and the spin loop testing the current value because I could not convince myself the address dependency is sufficient, esp. if the loads are of different sizes. I'm more than happy to remove this smp_rmb() again if people are certain the address dependency does indeed work as expected. Note: PPC32 will be fixed independently Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: chris@zankel.net Cc: cmetcalf@mellanox.com Cc: davem@davemloft.net Cc: dhowells@redhat.com Cc: james.hogan@imgtec.com Cc: jejb@parisc-linux.org Cc: linux@armlinux.org.uk Cc: mpe@ellerman.id.au Cc: ralf@linux-mips.org Cc: realmz6@gmail.com Cc: rkuo@codeaurora.org Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: vgupta@synopsys.com Cc: ysato@users.sourceforge.jp Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-27tile: Provide atomic_{or,xor,and}Chris Metcalf
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 <cmetcalf@ezchip.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1436474297-32187-1-git-send-email-cmetcalf@ezchip.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-08modpost: work correctly with tile coldtext sectionsChris Metcalf
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 <cmetcalf@ezchip.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-11tile: improve stack backtraceChris Metcalf
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 <cmetcalf@ezchip.com>
2015-04-30tile: add <asm/word-at-a-time.h> and enable support functionsChris Metcalf
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 <cmetcalf@ezchip.com>
2015-04-28tile: modify arch_spin_unlock_wait() semanticsChris Metcalf
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 <cmetcalf@ezchip.com>
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>
2013-09-03tile: remove support for TILE64Chris Metcalf
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 <cmetcalf@tilera.com>
2013-09-03tile: eliminate no-op "noatomichash" boot argumentChris Metcalf
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-09-03tile: support FRAME_POINTERChris Metcalf
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 <cmetcalf@tilera.com>
2013-08-30tile: fix strncpy_from_user bugChris Metcalf
In strncpy_from_user_asm, when the destination buffer length was the same as the actual string length, we were returning the size of the destination buffer. But since it's a NUL terminated string, we should return the length of the string instead. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-08-30tile: use proper .align directives on __ex_table sectionsChris Metcalf
This may fix a reported bug where an R_TILEGX_64 in a module was not pointing to an aligned address. Reported-by: Simon Marchi <simon.marchi@polymtl.ca> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-08-30tile: support ftrace on tilegxTony Lu
This commit adds support for static ftrace, graph function support, and dynamic tracer support. Signed-off-by: Tony Lu <zlu@tilera.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-08-13tile: support CONFIG_PREEMPTChris Metcalf
This change adds support for CONFIG_PREEMPT (full kernel preemption). In addition to the core support, this change includes a number of places where we fix up uses of smp_processor_id() and per-cpu variables. I also eliminate the PAGE_HOME_HERE and PAGE_HOME_UNKNOWN values for page homing, as it turns out they weren't being used. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-08-01tile: optimize strnlen using SIMD instructionsKen Steele
Using strlen as a model, add length checking to create strnlen. Signed-off-by: Ken Steele <ken@tilera.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-08-01tile: optimize and clean up string functionsChris Metcalf
This change cleans up the string code in a number of ways: - For memcpy(), fix bug in prefetch and increase distance to 3 lines; optimize for unaligned data; do all loads before wh64 to make memcpy safe for forward-overlapping calls; etc. Performance is improved. - Use new copy_byte() function on tilegx to spread a single byte value out into a full word using the shufflebytes instruction. - Clean up header include ordering to be more canonical, and remove spurious #undefs of function names. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-07-31tile: convert uses of "inv" to "finv"Chris Metcalf
The "inv" (invalidate) instruction is generally less safe than "finv" (flush and invalidate), as it will drop dirty data from the cache. It turns out we have almost no need for "inv" (other than for the older 32-bit architecture in some limited cases), so convert to "finv" where possible and delete the extra "inv" infrastructure. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-06-15tilepro: work around module link error with gcc 4.7Chris Metcalf
gcc 4.7.x is emitting calls to __ffsdi2 where previously it used to inline the appropriate ctz instructions. While this needs to be fixed in gcc, it's also easy to avoid having it cause build failures when building with those compilers by exporting __ffsdi2 to modules. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Cc: stable@kernel.org
2013-05-09Merge branch 'stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile Pull tile update from Chris Metcalf: "The interesting bug fix is support for the upcoming "4.2" release of the Tilera hypervisor, which by default launches Linux at privilege level 2 instead of 1. The fix lets new and old hypervisors and Linuxes interoperate more smoothly, so I've tagged it for stable@kernel.org so that older Linuxes will be able to boot under the newer hypervisor." * 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: usb: tilegx: fix memleak when create hcd fail arch/tile: remove inline marking of EXPORT_SYMBOL functions rtc: rtc-tile: add missing platform_device_unregister() when module exit tile: support new Tilera hypervisor
2013-05-09arch/tile: remove inline marking of EXPORT_SYMBOL functionsDenis Efremov
EXPORT_SYMBOL and inline directives are contradictory to each other. The patch fixes this inconsistency. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Denis Efremov <yefremov.denis@gmail.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-04-30Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKSStephen Boyd
The help text for this config is duplicated across the x86, parisc, and s390 Kconfig.debug files. Arnd Bergman noted that the help text was slightly misleading and should be fixed to state that enabling this option isn't a problem when using pre 4.4 gcc. To simplify the rewording, consolidate the text into lib/Kconfig.debug and modify it there to be more explicit about when you should say N to this config. Also, make the text a bit more generic by stating that this option enables compile time checks so we can cover architectures which emit warnings vs. ones which emit errors. The details of how an architecture decided to implement the checks isn't as important as the concept of compile time checking of copy_from_user() calls. While we're doing this, remove all the copy_from_user_overflow() code that's duplicated many times and place it into lib/ so that any architecture supporting this option can get the function for free. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Helge Deller <deller@gmx.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-08tile: export a handful of symbols appropriatelyChris Metcalf
This was shown up by running with "allmodconfig". I used EXPORT_SYMBOL() to match existing conventions in files that were already exporting symbols, or that were exported that way by other architectures, and otherwise EXPORT_SYMBOL_GPL(). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-07-11arch/tile: break out the "csum a long" function to <asm/checksum.h>Chris Metcalf
This makes it available to the tilegx network driver. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-05-25arch/tile: Allow tilegx to build with either 16K or 64K page sizeChris Metcalf
This change introduces new flags for the hv_install_context() API that passes a page table pointer to the hypervisor. Clients can explicitly request 4K, 16K, or 64K small pages when they install a new context. In practice, the page size is fixed at kernel compile time and the same size is always requested every time a new page table is installed. The <hv/hypervisor.h> header changes so that it provides more abstract macros for managing "page" things like PFNs and page tables. For example there is now a HV_DEFAULT_PAGE_SIZE_SMALL instead of the old HV_PAGE_SIZE_SMALL. The various PFN routines have been eliminated and only PA- or PTFN-based ones remain (since PTFNs are always expressed in fixed 2KB "page" size). The page-table management macros are renamed with a leading underscore and take page-size arguments with the presumption that clients will use those macros in some single place to provide the "real" macros they will use themselves. I happened to notice the old hv_set_caching() API was totally broken (it assumed 4KB pages) so I changed it so it would nominally work correctly with other page sizes. Tag modules with the page size so you can't load a module built with a conflicting page size. (And add a test for SMP while we're at it.) Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-05-25arch/tile: optimize get_user/put_user and friendsChris Metcalf
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 <cmetcalf@tilera.com>
2012-05-25arch/tile: support building big-endian kernelChris Metcalf
The toolchain supports big-endian mode now, so add support for building the kernel to run big-endian as well. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-04-02arch/tile: fix finv_buffer_remote() for tilegxChris Metcalf
There were some correctness issues with this code that are now fixed with this change. The change is likely less performant than it could be, but it should no longer be vulnerable to any races with memory operations on the memory network while invalidating a range of memory. This code is run infrequently so performance isn't critical, but correctness definitely is. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-04-02arch/tile: fix pointer cast in cacheflush.cChris Metcalf
Pragmatically it couldn't be wrong to cast pointers to long to compare them (since all kernel addresses are in the top half of VA space), but it's more correct to cast to unsigned long. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-04-02arch/tile: fix bug in delay_backoff()Chris Metcalf
We were carefully computing a value to use for the number of loops to spin for, and then ignoring it. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-04-02arch/tile: make sure to build memcpy_user_64 without frame pointerChris Metcalf
Add a comment explaining why this is important, and add a CFLAGS_REMOVE clause to the Makefile to make sure it happens. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2012-03-12arch/tile: misplaced parens near likelyroel
Parentheses were missing. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-12-03arch/tile: add a few #includes and an EXPORT to catch up with kernel changes.Chris Metcalf
The empty_zero_page[] export is required for ZERO_PAGE() module references. The #includes are due to changes in implicit inclusion, and should of course have been in the sources from the beginning. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-11-03arch/tile: avoid exporting a symbol no longer used by gccChris Metcalf
An earlier Tilera compiler generated calls to an "__ll_mul" function for long long multiplication. Our libgcc supported that as an alias for the normal __muldi3 routine, so we made it available to kernel modules as well. However, for a while now the compiler has internally been generating only the standard __muldi3 symbol, and the version we are giving back to the community does not have the __ll_mul alias, so we are removing it from the kernel too. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-10-13tile: revert change from <asm/atomic.h> to <linux/atomic.h> in asm filesChris Metcalf
The 32-bit TILEPro support uses some #defines in <asm/atomic_32.h> for atomic support routines in assembly. To make this more explicit, I've turned those includes into includes of <asm/atomic_32.h>, which should hopefully make it clear that they shouldn't be bombed into <linux/atomic.h> in any cleanups. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
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>
2011-05-12arch/tile: finish enabling support for TILE-Gx 64-bit chipChris Metcalf
This support was partially present in the existing code (look for "__tilegx__" ifdefs) but with this change you can build a working kernel using the TILE-Gx toolchain and ARCH=tilegx. Most of these files are new, generally adding a foo_64.c file where previously there was just a foo_32.c file. The ARCH=tilegx directive redirects to arch/tile, not arch/tilegx, using the existing SRCARCH mechanism in the top-level Makefile. Changes to existing files: - <asm/bitops.h> and <asm/bitops_32.h> changed to factor the include of <asm-generic/bitops/non-atomic.h> in the common header. - <asm/compat.h> and arch/tile/kernel/compat.c changed to remove the "const" markers I had put on compat_sys_execve() when trying to match some recent similar changes to the non-compat execve. It turns out the compat version wasn't "upgraded" to use const. - <asm/opcode-tile_64.h> and <asm/opcode_constants_64.h> were previously included accidentally, with the 32-bit contents. Now they have the proper 64-bit contents. Finally, I had to hack the existing hacky drivers/input/input-compat.h to add yet another "#ifdef" for INPUT_COMPAT_TEST (same as x86_64). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [drivers/input]
2011-05-04arch/tile: disable GX prefetcher during cache flushChris Metcalf
Otherwise, it's possible to end up with the prefetcher pulling data into cache that the code believes has been flushed. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04arch/tile: allow nonatomic stores to interoperate with fast atomic syscallsChris Metcalf
This semantic was already true for atomic operations within the kernel, and this change makes it true for the fast atomic syscalls (__NR_cmpxchg and __NR_atomic_update) as well. Previously, user-space had to use the fast atomic syscalls exclusively to update memory, since raw stores could lose a race with the atomic update code even when the atomic update hadn't actually modified the value. With this change, we no longer write back the value to memory if it hasn't changed. This allows certain types of idioms in user space to work as expected, e.g. "atomic exchange" to acquire a spinlock, followed by a raw store of zero to release the lock. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-20arch/tile: fix futex sanitization definition/prototype mismatchChris Metcalf
Commit 8d7718aa082aaf30a0b4989e1f04858952f941bc changed "int" to "u32" in the prototypes but not the definition. I missed this when I saw the patch go by on LKML. We cast "u32 *" to "int *" since we are tying into the underlying atomics framework, and atomic_t uses int as its value type. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Reviewed-by: Michel Lespinasse <walken@google.com>
2011-03-10arch/tile: fix deadlock bugs in rwlock implementationChris Metcalf
The first issue fixed in this patch is that pending rwlock write locks could lock out new readers; this could cause a deadlock if a read lock was held on cpu 1, a write lock was then attempted on cpu 2 and was pending, and cpu 1 was interrupted and attempted to re-acquire a read lock. The write lock code was modified to not lock out new readers. The second issue fixed is that there was a narrow race window where a tns instruction had been issued (setting the lock value to "1") and the store instruction to reset the lock value correctly had not yet been issued. In this case, if an interrupt occurred and the same cpu then tried to manipulate the lock, it would find the lock value set to "1" and spin forever, assuming some other cpu was partway through updating it. The fix is to enforce an interrupt critical section around the tns/store pair. In addition, this change now arranges to always validate that after a readlock we have not wrapped around the count of readers, which is only eight bits. Since these changes make the rwlock "fast path" code heavier weight, I decided to move all the rwlock code all out of line, leaving only the conventional spinlock code with fastpath inlines. Since the read_lock and read_trylock implementations ended up very similar, I just expressed read_lock in terms of read_trylock. As part of this change I also eliminate support for the now-obsolete tns_atomic mode. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-10arch/tile: support 4KB page size as well as 64KBChris Metcalf
The Tilera architecture traditionally supports 64KB page sizes to improve TLB utilization and improve performance when the hardware is being used primarily to run a single application. For more generic server scenarios, it can be beneficial to run with 4KB page sizes, so this commit allows that to be specified (by modifying the arch/tile/include/hv/pagesize.h header). As part of this change, we also re-worked the PTE management slightly so that PTE writes all go through a __set_pte() function where we can do some additional validation. The set_pte_order() function was eliminated since the "order" argument wasn't being used. One bug uncovered was in the PCI DMA code, which wasn't properly flushing the specified range. This was benign with 64KB pages, but with 4KB pages we were getting some larger flushes wrong. The per-cpu memory reservation code also needed updating to conform with the newer percpu stuff; before it always chose 64KB, and that was always correct, but with 4KB granularity we now have to pay closer attention and reserve the amount of memory that will be requested when the percpu code starts allocating. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-10arch/tile: fix some comments and whitespaceChris Metcalf
This is a grab bag of changes with no actual change to generated code. This includes whitespace and comment typos, plus a couple of stale comments being removed. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: export some additional module symbolsChris Metcalf
This adds a grab bag of symbols that have been missing for various modules. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: enhance existing finv_buffer_remote() routineChris Metcalf
It now takes an additional argument so it can be used to flush-and-invalidate pages that are cached using hash-for-home as well those that are cached with coherence point on a single cpu. This allows it to be used more widely for changing the coherence point of arbitrary pages when necessary. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>