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* xtensa: don't allow overflow/underflow on unaligned stackMax Filippov2014-08-14
| | | | | | | | | | | | | | | | Double exceptions that happen during register window overflow/underflow are handled in the topmost stack frame, as if it was the only exception that occured. However unaligned access exception handler is special because it needs to analyze instruction that caused the exception, but the userspace instruction that triggered window exception is completely irrelevant. Unaligned data access is rather normal in the generic userspace code, but stack pointer manipulation must always be done by architecture-aware code and thus unaligned stack means a serious problem anyway. Use the default unaligned access handler that raises SIGBUS in case of unaligned access in window overflow/underflow handler. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: add fixup for double exception raised in window overflowMax Filippov2014-06-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two FIXMEs in the double exception handler 'for the extremely unlikely case'. This case gets hit by gcc during kernel build once in a few hours, resulting in an unrecoverable exception condition. Provide missing fixup routine to handle this case. Double exception literals now need 8 more bytes, add them to the linker script. Also replace bbsi instructions with bbsi.l as we're branching depending on 8th and 7th LSB-based bits of exception address. This may be tested by adding the explicit DTLB invalidation to window overflow handlers, like the following: --- a/arch/xtensa/kernel/vectors.S +++ b/arch/xtensa/kernel/vectors.S @@ -592,6 +592,14 @@ ENDPROC(_WindowUnderflow4) ENTRY_ALIGN64(_WindowOverflow8) s32e a0, a9, -16 + bbsi.l a9, 31, 1f + rsr a0, ccount + bbsi.l a0, 4, 1f + pdtlb a0, a9 + idtlb a0 + movi a0, 9 + idtlb a0 +1: l32e a0, a1, -12 s32e a2, a9, -8 s32e a1, a9, -12 Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
* xtensa: fix fast_syscall_spill_registersChris Zankel2014-01-29
| | | | | | | | | | | | | | | The original implementation could clobber registers under certain conditions. The Xtensa processor architecture uses windowed registers and the original implementation was using a4 as a temporary register, which under certain conditions could be register a0 of the oldest window frame, and didn't always restore the content correctly. By moving the _spill_registers routine inside the fast system call, it frees up one more register (the return address is not required anymore) for the spill routine. Signed-off-by: Chris Zankel <chris@zankel.net>
* xtensa: keep a3 and excsave1 on entry to exception handlersMax Filippov2013-09-06
| | | | | | | | | Based on the SMP patch by Joe Taylor and subsequent fixes. Preserve exception table pointer (normally stored in excsave1 SR) as it cannot be easily restored in SMP environment. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
* xtensa: disable IRQs while IRQ handler is runningMax Filippov2013-05-09
| | | | | | | | | | | | | | | | 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>
* xtensa: add MMU v3 supportMax Filippov2013-05-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MMUv3 comes out of reset with identity vaddr -> paddr mapping in the TLB way 6: Way 6 (512 MB) Vaddr Paddr ASID Attr RWX Cache ---------- ---------- ---- ---- --- ------- 0x00000000 0x00000000 0x01 0x03 RWX Bypass 0x20000000 0x20000000 0x01 0x03 RWX Bypass 0x40000000 0x40000000 0x01 0x03 RWX Bypass 0x60000000 0x60000000 0x01 0x03 RWX Bypass 0x80000000 0x80000000 0x01 0x03 RWX Bypass 0xa0000000 0xa0000000 0x01 0x03 RWX Bypass 0xc0000000 0xc0000000 0x01 0x03 RWX Bypass 0xe0000000 0xe0000000 0x01 0x03 RWX Bypass This patch adds remapping code at the reset vector or at the kernel _start (depending on CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX) that reconfigures MMUv3 as MMUv2: Way 5 (128 MB) Vaddr Paddr ASID Attr RWX Cache ---------- ---------- ---- ---- --- ------- 0xd0000000 0x00000000 0x01 0x07 RWX WB 0xd8000000 0x00000000 0x01 0x03 RWX Bypass Way 6 (256 MB) Vaddr Paddr ASID Attr RWX Cache ---------- ---------- ---- ---- --- ------- 0xe0000000 0xf0000000 0x01 0x07 RWX WB 0xf0000000 0xf0000000 0x01 0x03 RWX Bypass Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
* xtensa: dispatch medium-priority interruptsMarc Gauthier2013-02-23
| | | | | | | | | | 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>
* xtensa: clean up files to make them code-style compliantChris Zankel2012-12-19
| | | | | | | 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>
* xtensa: provide proper assembler function boundaries with ENDPROC()Chris Zankel2012-12-19
| | | | | | Use ENDPROC() to mark the end of assembler functions. Signed-off-by: Chris Zankel <chris@zankel.net>
* xtensa: make DoubleExceptionVector literals fit the gapMax Filippov2012-12-19
| | | | | | | | | | | Manually load references to exc_table from the explicit literal in order to fit DoubleExceptionVector.literals into the available 16-byte gap before DoubleExceptionVector.text in the absence of link time relaxation. Without this fix DoubleExceptionVector.literal section overlaps DoubleExceptionVector.text section in the linked vmlinux image. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net>
* xtensa: reorganize SR referencingMax Filippov2012-10-16
| | | | | | | | | | - 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>
* xtensa: includecheck fix: vectors.SJaswinder Singh Rajput2010-05-25
| | | | | | | | | | | | fix the following 'make includecheck' warnings: arch/xtensa/kernel/vectors.S: asm/processor.h is included more than once. arch/xtensa/kernel/vectors.S: asm/ptrace.h is included more than once. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xtensa: nommu supportJohannes Weiner2009-04-03
| | | | | | | Add support for !CONFIG_MMU setups. Signed-off-by: Johannes Weiner <jw@emlix.com> Signed-off-by: Chris Zankel <chris@zankel.net>
* [PATCH] xtensa: remove extra header filesChris Zankel2006-12-10
| | | | | | | | | | | 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>
* kbuild: m68k,parisc,ppc,ppc64,s390,xtensa use generic asm-offsets.h supportSam Ravnborg2005-09-09
| | | | | | Delete obsoleted parts form arch makefiles and rename to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
* [PATCH] xtensa: Architecture support for Tensilica Xtensa Part 3Chris Zankel2005-06-24
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>