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2015-09-21xtensa: fix kernel register spillingMax Filippov
commit 77d6273e79e3a86552fcf10cdd31a69b46ed2ce6 upstream. call12 can't be safely used as the first call in the inline function, because the compiler does not extend the stack frame of the bounding function accordingly, which may result in corruption of local variables. If a call needs to be done, do call8 first followed by call12. For pure assembly code in _switch_to increase stack frame size of the bounding function. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21xtensa: fix threadptr reload on return to userspaceMax Filippov
commit 4229fb12a03e5da5882b420b0aa4a02e77447b86 upstream. Userspace return code may skip restoring THREADPTR register if there are no registers that need to be zeroed. This leads to spurious failures in libc NPTL tests. Always restore THREADPTR on return to userspace. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05xtensa: fix a6 and a7 handling in fast_syscall_xtensaMax Filippov
commit d1b6ba82a50cecf94be540a3a153aa89d97511a0 upstream. Remove restoring a6 on some return paths and instead modify and restore it in a single place, using symbolic name. Correctly restore a7 from PT_AREG7 in case of illegal a6 value. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05xtensa: fix TLBTEMP_BASE_2 region handling in fast_second_level_missMax Filippov
commit 7128039fe2dd3d59da9e4ffa036f3aaa3ba87b9f upstream. Current definition of TLBTEMP_BASE_2 is always 32K above the TLBTEMP_BASE_1, whereas fast_second_level_miss handler for the TLBTEMP region analyzes virtual address bit (PAGE_SHIFT + DCACHE_ALIAS_ORDER) to determine TLBTEMP region where the fault happened. The size of the TLBTEMP region is also checked incorrectly: not 64K, but twice data cache way size (whicht may as well be less than the instruction cache way size). Fix TLBTEMP_BASE_2 to be TLBTEMP_BASE_1 + data cache way size. Provide TLBTEMP_SIZE that is a greater of doubled data cache way size or the instruction cache way size, and use it to determine if the second level TLB miss occured in the TLBTEMP region. Practical occurence of page faults in the TLBTEMP area is extremely rare, this code can be tested by deletion of all w[di]tlb instructions in the tlbtemp_mapping region. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-05xtensa: fix access to THREAD_RA/THREAD_SP/THREAD_DSMax Filippov
commit 52247123749cc3cbc30168b33ad8c69515c96d23 upstream. With SMP and a lot of debug options enabled task_struct::thread gets out of reach of s32i/l32i instructions with base pointing at task_struct, breaking build with the following messages: arch/xtensa/kernel/entry.S: Assembler messages: arch/xtensa/kernel/entry.S:1002: Error: operand 3 of 'l32i.n' has invalid value '1048' arch/xtensa/kernel/entry.S:1831: Error: operand 3 of 's32i.n' has invalid value '1040' arch/xtensa/kernel/entry.S:1832: Error: operand 3 of 's32i.n' has invalid value '1044' Change base to point to task_struct::thread in such cases. Don't use a10 in _switch_to to save/restore prev pointer as a2 is not clobbered. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-06xtensa: introduce spill_registers_kernel macroMax Filippov
commit e2fd1374c705abe4661df3fb6fadb3879c7c1846 upstream. Most in-kernel users want registers spilled on the kernel stack and don't require PS.EXCM to be set. That means that they don't need fixup routine and could reuse regular window overflow mechanism for that, which makes spill routine very simple. Suggested-by: Chris Zankel <chris@zankel.net> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-09xtensa: disable IRQs while IRQ handler is runningMax Filippov
IRQ handlers are expected to run with IRQs disabled. See e.g. http://lwn.net/Articles/380931/ for a longer story. This was overlooked in the commit 2d1c645 xtensa: dispatch medium-priority interrupts Revert to old behavior and simplify interrupt entry and exit code. Interrupt handler still honours IRQ priority. do_notify_resume/schedule must be called with interrupts enabled, enable interrupts if we return from user exception. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2013-05-09xtensa: add irq flags trace supportMax Filippov
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2013-02-23xtensa: add support for TLSChris Zankel
The Xtensa architecture provides a global register called THREADPTR for the purpose of Thread Local Storage (TLS) support. This allows us to use a fairly simple implementation, keeping the thread pointer in the regset and simply saving and restoring it upon entering/exiting the from user space. Signed-off-by: Chris Zankel <chris@zankel.net>
2013-02-23xtensa: add support for oprofiledann
Support call graph profiling. Keep upper two bits of PC unchanged through backtrace rather than take them from sp (a1). The stack pointer is usually in the same GB (same upper 2 bits) as PC, but technically doesn't always have to be (and might not in the future, when taking full advantage of MMU v3). Signed-off-by: Dan Nicolaescu <dann@xtensa-linux.org> Signed-off-by: Pete Delaney <piet@tensilica.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2013-02-23xtensa: dispatch medium-priority interruptsMarc Gauthier
Add support for dispatching medium-priority interrupts, that is, interrupts of priority levels 2 to EXCM_LEVEL. IRQ handling may be preempted by higher priority IRQ. Signed-off-by: Marc Gauthier <marc@tensilica.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2012-12-18xtensa: clean up files to make them code-style compliantChris Zankel
Remove heading and trailing spaces, trim trailing lines, and wrap lines that are longer than 80 characters. Signed-off-by: Chris Zankel <chris@zankel.net>
2012-12-18xtensa: save and restore scompare1 SR on kernel entryMax Filippov
Although scompare1 may be saved/restored by xchal_ncp_{load,store} macros, explicit save/restore of registers manipulated by the kernel itself is considered more correct. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2012-12-18xtensa: provide proper assembler function boundaries with ENDPROC()Chris Zankel
Use ENDPROC() to mark the end of assembler functions. Signed-off-by: Chris Zankel <chris@zankel.net>
2012-10-25xtensa: switch to generic kernel_execve()Max Filippov
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2012-10-25xtensa: switch to generic kernel_thread()Max Filippov
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2012-10-19xtensa: minor compiler warning fixChris Zankel
Fix two compiler warnings complaining about truncating a value on a 64-bit host, and about declaring an unused variable that is only used for a specific configuration. Signed-off-by: Chris Zankel <chris@zankel.net>
2012-10-15xtensa: reorganize SR referencingMax Filippov
- reference SRs by names where possible, not by numbers; - get rid of __stringify around SR names where possible; - remove unneeded SR names from asm/regs.h; - add SREG_ prefix to remaining SR names; Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2012-05-21xtensa: add handling of TIF_NOTIFY_RESUMEAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-21xtensa: switch to generic rt_sigsuspend(2)Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2010-05-02xtensa: Shuffle include statements to fix linker scriptChris Zankel
The linker script was including assembly macros from the coprocessor header file that is not otherwise used by the script. Signed-off-by: Chris Zankel <chris@zankel.net>
2010-02-09tree-wide: Assorted spelling fixesDaniel Mack
In particular, several occurances of funny versions of 'success', 'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address', 'beginning', 'desirable', 'separate' and 'necessary' are fixed. Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Joe Perches <joe@perches.com> Cc: Junio C Hamano <gitster@pobox.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-04-02xtensa: nommu supportJohannes Weiner
Add support for !CONFIG_MMU setups. Signed-off-by: Johannes Weiner <jw@emlix.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2008-11-06xtensa: move headers files to arch/xtensa/includeChris Zankel
Move all header files for xtensa to arch/xtensa/include and platform and variant header files to the appropriate arch/xtensa/platforms/ and arch/xtensa/variants/ directories. Moving the files gets also rid of all uses of symlinks in the Makefile. This has been completed already for the majority of the architectures and xtensa is one out of six missing. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Chris Zankel <chris@zankel.net>
2008-02-13[XTENSA] Fix register corruption for certain processor configurationsChris Zankel
For processor configurations that have optional registers (compiler-used but non-coprocessor), user space registers might get corrupted when there are only 4 registers in the current window-frame, ie. register a4 belongs to the oldest frame in the register file. Signed-off-by: Chris Zankel <chris@zankel.net>
2008-02-13[XTENSA] Add support for configurable registers and coprocessorsChris Zankel
The Xtensa architecture allows to define custom instructions and registers. Registers that are bound to a coprocessor are only accessible if the corresponding enable bit is set, which allows to implement a 'lazy' context switch mechanism. Other registers needs to be saved and restore at the time of the context switch or during interrupt handling. This patch adds support for these additional states: - save and restore registers that are used by the compiler upon interrupt entry and exit. - context switch additional registers unbound to any coprocessor - 'lazy' context switch of registers bound to a coprocessor - ptrace interface to provide access to additional registers - update configuration files in include/asm-xtensa/variant-fsf Signed-off-by: Chris Zankel <chris@zankel.net>
2008-02-13[XTENSA] Remove unused codeChris Zankel
We will never (need to) support signal handling coming from a double exception. There are too many things that could go wrong and delivering signals is not the fastest method for IPC, anyway. Signed-off-by: Chris Zankel <chris@zankel.net>
2008-02-13[XTENSA] Fix comments regarding the number of frames to saveChris Zankel
Signed-off-by: Marc Gauthier <marc@tensilica.com> Signed-off-by: Chris Zankel <chris@zankel.net>
2008-02-13[XTENSA] Add missing a2 register restore in register spill routineChris Zankel
Register a2 is saved in depc but wasn't getting restored before returning from _spill_registers when there weren't any registers to spill. The mask to cut the top bit from the rotated WINDOWMASK register was also one bit short. Signed-off-by: CHris Zankel <chris@zankel.net>
2007-08-27[XTENSA] Add support for cache-aliasingChris Zankel
Add support for processors that have cache-aliasing issues, such as the Stretch S5000 processor. Cache-aliasing means that the size of the cache (for one way) is larger than the page size, thus, a page can end up in several places in cache depending on the virtual to physical translation. The method used here is to map a user page temporarily through the auto-refill way 0 and of of the DTLB. We probably will want to revisit this issue and use a better approach with kmap/kunmap. Signed-off-by: Chris Zankel <chris@zankel.net>
2007-08-27[XTENSA] Add support for executable/non-executable feature in the mmuChris Zankel
Newer processor versions starting with Xtensa6/LX2 support an 'executable' bit for memory pages. This bit replaces the 'valid' bit, so it must be always set to one for older processor versions. To mark a page invalid, we now set the cache-attributes to b11, which is backward compatible. Signed-off-by: Chris Zankel <chris@zankel.net>
2007-05-31[XTENSA] Remove non-rt signal handlingChris Zankel
The non-rt signal handling was never really used, so we don't break anything. This patch also cleans up the signal stack-frame to make it independent from the processor configuration. It also improves the method used for controlling single-stepping. We now save and restore the 'icountlevel' register that controls single stepping and set or clear the saved state to enable or disable it. Signed-off-by: Chris Zankel <chris@zankel.net>
2006-12-10[PATCH] xtensa: fix system call interfaceChris Zankel
This is a long outstanding patch to finally fix the syscall interface. The constants used for the system calls are those we have provided in our libc patches. This patch also fixes the shmbuf and stat structure, and fcntl definitions. Signed-off-by: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10[PATCH] xtensa: remove extra header filesChris Zankel
The Xtensa port contained many header files that were never needed. This rather lengthy patch removes all those files. Unfortunately, there were many dependencies that needed to be updated, so this patch touches quite a few source files. Signed-off-by: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] xtensa: remove verify_area macrosJesper Juhl
verify_area() is still alive on xtensa in 2.6.17-rc3-git13 It would be nice to finally be rid of that function across the board. Signed-off-by: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09kbuild: m68k,parisc,ppc,ppc64,s390,xtensa use generic asm-offsets.h supportSam Ravnborg
Delete obsoleted parts form arch makefiles and rename to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-06-24[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 3Chris Zankel
The attached patches provides part 3 of an architecture implementation for the Tensilica Xtensa CPU series. Signed-off-by: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>