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| author | Chris Zankel <chris@zankel.net> | 2013-02-24 07:35:57 +0400 |
|---|---|---|
| committer | Chris Zankel <chris@zankel.net> | 2013-02-24 07:35:57 +0400 |
| commit | c50842df47970eab459f13490c152aac85fc02f2 (patch) | |
| tree | d2933b4d9641067002ba6d662b0abf6ee3011375 /arch/xtensa/kernel/entry.S | |
| parent | b0c438e642699f8c47b84de957f30cf586cdbebd (diff) | |
| download | linux-c50842df47970eab459f13490c152aac85fc02f2.tar.xz | |
xtensa: add support for TLS
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>
Diffstat (limited to 'arch/xtensa/kernel/entry.S')
| -rw-r--r-- | arch/xtensa/kernel/entry.S | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 70d5a9e33573..63845f950792 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -130,6 +130,11 @@ _user_exception: s32i a3, a1, PT_SAR s32i a2, a1, PT_ICOUNTLEVEL +#if XCHAL_HAVE_THREADPTR + rur a2, threadptr + s32i a2, a1, PT_THREADPTR +#endif + /* Rotate ws so that the current windowbase is at bit0. */ /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */ @@ -510,6 +515,11 @@ user_exception_exit: * (if we have restored WSBITS-1 frames). */ +#if XCHAL_HAVE_THREADPTR + l32i a3, a1, PT_THREADPTR + wur a3, threadptr +#endif + 2: j common_exception_exit /* This is the kernel exception exit. @@ -1955,7 +1965,7 @@ ENTRY(_switch_to) s32i a6, a3, EXC_TABLE_FIXUP s32i a7, a3, EXC_TABLE_KSTK - /* restore context of the task that 'next' addresses */ + /* restore context of the task 'next' */ l32i a0, a13, THREAD_RA # restore return address l32i a1, a13, THREAD_SP # restore stack pointer |