linux-toradex.git/arch/xtensa/kernel, branch v3.12.20 Linux kernel for Apalis and Colibri modules xtensa: introduce spill_registers_kernel macro 2014-03-05T16:13:53+00:00 Max Filippov jcmvbkbc@gmail.com 2014-01-22T04:04:43+00:00 d33ee5e7f8c3de1a6f407e3568ece84ec51db042 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: Jiri Slaby <jslaby@suse.cz> 
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: Jiri Slaby <jslaby@suse.cz>
xtensa: save current register frame in fast_syscall_spill_registers_fixup 2014-03-05T16:13:52+00:00 Max Filippov jcmvbkbc@gmail.com 2013-10-30T12:18:25+00:00 38848e0b02a239b01e5d974a84b8a6b85bcaf48a commit 3251f1e27a5a17f0efd436cfd1e7b9896cfab0a0 upstream. We need it saved because it contains a3 where we track which register windows we still need to spill, and fixup handler may call C exception handlers. Also fix comments. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> 
commit 3251f1e27a5a17f0efd436cfd1e7b9896cfab0a0 upstream.

We need it saved because it contains a3 where we track which register
windows we still need to spill, and fixup handler may call C exception
handlers. Also fix comments.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
xtensa: don't use alternate signal stack on threads 2013-10-15T20:39:16+00:00 Baruch Siach baruch@tkos.co.il 2013-10-14T22:22:43+00:00 cba9a90053e3b7973eff4f1946f33032e98eeed5 According to create_thread(3): "The new thread does not inherit the creating thread's alternate signal stack". Since commit f9a3879a (Fix sigaltstack corruption among cloned threads), current->sas_ss_size is set to 0 for cloned processes sharing VM with their parent. Don't use the (nonexistent) alternate signal stack in this case. This has been broken since commit 29c4dfd9 ([XTENSA] Remove non-rt signal handling). Fixes the SA_ONSTACK part of the nptl/tst-cancel20 test from uClibc. Cc: <stable@vger.kernel.org> Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net> 
According to create_thread(3): "The new thread does not inherit the creating
thread's alternate signal stack". Since commit f9a3879a (Fix sigaltstack
corruption among cloned threads), current->sas_ss_size is set to 0 for cloned
processes sharing VM with their parent. Don't use the (nonexistent) alternate
signal stack in this case. This has been broken since commit 29c4dfd9 ([XTENSA]
Remove non-rt signal handling).

Fixes the SA_ONSTACK part of the nptl/tst-cancel20 test from uClibc.

Cc: <stable@vger.kernel.org>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
xtensa: fix fast_syscall_spill_registers_fixup 2013-10-15T20:39:06+00:00 Max Filippov jcmvbkbc@gmail.com 2013-10-14T22:22:42+00:00 244066f4be8ce2dc2d2d60f01bceeba55c71a783 fast_syscall_spill_registers_fixup was not correctly updated by the 'keep a3 and excsave1 on entry to exception handlers' patch: it doesn't preserve a3 that it gets on entry, breaking _spill_registers in case of page fault on stack during register spilling, leading to unhandled exception in kernel mode. Preserve a3 by saving it in the original _spill_registers stack frame's a3 during exception handling and restoring it afterwards. Also fix comments and function bounds annotations. Reported-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Tested-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Chris Zankel <chris@zankel.net> 
fast_syscall_spill_registers_fixup was not correctly updated by the
'keep a3 and excsave1 on entry to exception handlers' patch: it doesn't
preserve a3 that it gets on entry, breaking _spill_registers in case of
page fault on stack during register spilling, leading to unhandled
exception in kernel mode.

Preserve a3 by saving it in the original _spill_registers stack frame's
a3 during exception handling and restoring it afterwards.

Also fix comments and function bounds annotations.

Reported-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Chris Zankel <chris@zankel.net>
Merge tag 'xtensa-next-20130912' of git://github.com/czankel/xtensa-linux 2013-09-13T17:57:48+00:00 Linus Torvalds torvalds@linux-foundation.org 2013-09-13T17:57:48+00:00 67002151403350b497c1efc8d36450974dfca023 Pull Xtensa updates from Chris Zankel. * tag 'xtensa-next-20130912' of git://github.com/czankel/xtensa-linux: xtensa: Fix broken allmodconfig build xtensa: remove CCOUNT_PER_JIFFY xtensa: fix !CONFIG_XTENSA_CALIBRATE_CCOUNT build failure xtensa: don't use echo -e needlessly xtensa: new fast_alloca handler xtensa: keep a3 and excsave1 on entry to exception handlers xtensa: enable kernel preemption xtensa: check thread flags atomically on return from user exception 
Pull Xtensa updates from Chris Zankel.

* tag 'xtensa-next-20130912' of git://github.com/czankel/xtensa-linux:
  xtensa: Fix broken allmodconfig build
  xtensa: remove CCOUNT_PER_JIFFY
  xtensa: fix !CONFIG_XTENSA_CALIBRATE_CCOUNT build failure
  xtensa: don't use echo -e needlessly
  xtensa: new fast_alloca handler
  xtensa: keep a3 and excsave1 on entry to exception handlers
  xtensa: enable kernel preemption
  xtensa: check thread flags atomically on return from user exception
xtensa: Fix broken allmodconfig build 2013-09-06T16:50:56+00:00 Guenter Roeck linux@roeck-us.net 2013-08-28T04:06:37+00:00 8872366df396444d7655287c79ed182d8f47cba6 xtansa allmodbuild fails with: arch/xtensa/kernel/xtensa_ksyms.c:129:1: error: '_mcount' undeclared here (not in a function) make[2]: *** [arch/xtensa/kernel/xtensa_ksyms.o] Error 1 make[1]: *** [arch/xtensa/kernel] Error 2 The breakage is due to commit 478ba61af (xtensa: add static function tracer support) which exports _mcount without declaring it. Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Chris Zankel <chris@zankel.net> 
xtansa allmodbuild fails with:

arch/xtensa/kernel/xtensa_ksyms.c:129:1: error: '_mcount' undeclared here (not in a function)
make[2]: *** [arch/xtensa/kernel/xtensa_ksyms.o] Error 1
make[1]: *** [arch/xtensa/kernel] Error 2

The breakage is due to commit 478ba61af (xtensa: add static function tracer
support) which exports _mcount without declaring it.

Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Chris Zankel <chris@zankel.net>
xtensa: remove CCOUNT_PER_JIFFY 2013-09-06T16:48:59+00:00 Baruch Siach baruch@tkos.co.il 2013-07-15T05:24:22+00:00 8d5e1d8e62e87cd9eaecb4956261cce4320240fd Use ccount_freq directly to make the code a little more readable. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net> 
Use ccount_freq directly to make the code a little more readable.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
xtensa: fix !CONFIG_XTENSA_CALIBRATE_CCOUNT build failure 2013-09-06T16:48:51+00:00 Baruch Siach baruch@tkos.co.il 2013-07-15T04:03:38+00:00 fedc21dce814b500e2a9b3cc51f5f802d39e22e5 Commits 925f5532 (xtensa: ccount based clockevent implementation) and e3f43291 (xtensa: ccount based sched_clock) introduced users of ccount_freq. This variable doesn't exist when CONFIG_XTENSA_CALIBRATE_CCOUNT is disabled. Add ccount_freq definition in this case. Reported-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net> 
Commits 925f5532 (xtensa: ccount based clockevent implementation) and e3f43291
(xtensa: ccount based sched_clock) introduced users of ccount_freq. This
variable doesn't exist when CONFIG_XTENSA_CALIBRATE_CCOUNT is disabled. Add
ccount_freq definition in this case.

Reported-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
xtensa: new fast_alloca handler 2013-09-06T16:48:12+00:00 Max Filippov jcmvbkbc@gmail.com 2013-07-14T22:02:24+00:00 fff96d69f2af28f3243d1349341b6305f318f5a4 Instead of emulating movsp instruction in the kernel use window underflow handler to load missing register window and retry failed movsp. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Chris Zankel <chris@zankel.net> 
Instead of emulating movsp instruction in the kernel use window
underflow handler to load missing register window and retry failed
movsp.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
xtensa: keep a3 and excsave1 on entry to exception handlers 2013-09-06T16:47:41+00:00 Max Filippov jcmvbkbc@gmail.com 2013-07-03T16:23:28+00:00 99d5040ebc3cccc90dfe031f615ac3fbc79905b6 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> 
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>