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* arch/tile: move user_exit() to early kernel entry sequenceChris Metcalf2016-01-181-9/+4
| | | | | | | | | | | | This ensures that we always notify context tracking that we have exited from user space no matter how we enter the kernel. It is similar to how arm64 handles context tracking, for example. This allows the removal of all the exception_enter() calls that were added in commit 49e4e15619cd ("tile: support CONTEXT_TRACKING and thus NOHZ_FULL"). Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
* tile: support CONTEXT_TRACKING and thus NOHZ_FULLChris Metcalf2015-04-171-9/+13
| | | | | | | | | | | | | | | | Add the TIF_NOHZ flag appropriately. Add call to user_exit() on entry to do_work_pending() and on entry to syscalls via do_syscall_trace_enter(), and also the top of do_syscall_trace_exit() just because it's done in x86. Add call to user_enter() at the bottom of do_work_pending() once we have no more work to do before returning to userspace. Wrap all the trap code in exception_enter() / exception_exit(). Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
* tile: Use the more common pr_warn instead of pr_warningJoe Perches2014-11-111-12/+10
| | | | | | | | | | | | | | And other message logging neatening. Other miscellanea: o coalesce formats o realign arguments o standardize a couple of macros o use __func__ instead of embedding the function name Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* arch: tile: kernel: unaligned.c: Cleaning up uninitialized variablesRickard Strandqvist2014-06-071-13/+2
| | | | | | | | | There is a risk that the variable will be used without being initialized. This was largely found by using a static code analysis program called cppcheck. Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [minor cleanups]
* tile: fix typos in comment in arch/tile/kernel/unaligned.cChris Metcalf2013-09-131-2/+2
| | | | Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
* tile: fast-path unaligned memory access for tilegxChris Metcalf2013-08-131-0/+1609
This change enables unaligned userspace memory access via a kernel fast path on tilegx. The kernel tracks user PC/instruction pairs per-thread using a direct-mapped cache in userspace. The cache maps those PC/instruction pairs to JIT'ed instruction sequences that load or store using byte-wide load store intructions and then synthesize 2-, 4- or 8-byte load or store results. Once an instruction has been seen to generate an unaligned access once, subsequent hits on that instruction typically require overhead of only around 50 cycles if cache and TLB is hot. We support the prctl() PR_GET_UNALIGN / PR_SET_UNALIGN sys call to enable or disable unaligned fixups on a per-process basis. To do this we pull some of the tilepro unaligned support out of the single_step.c file; tilepro uses instruction disassembly for both single-step and unaligned access support. Since tilegx actually has hardware singlestep support, though, it's cleaner to keep the tilegx unaligned access code in a separate file. While we're at it, properly rename the tilepro-specific types, etc., to have tilepro suffixes instead of generic tile suffixes. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
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