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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-04 13:52:53 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-10-04 14:13:29 -0700 |
| commit | 40138249c3b7a0762155216b963ec7fd4d09b5b4 (patch) | |
| tree | be0a2441aa7f7b3245e6de70cc4a8055031742f8 /arch/sparc/kernel | |
| parent | ecefbd94b834fa32559d854646d777c56749ef1c (diff) | |
| download | linux-40138249c3b7a0762155216b963ec7fd4d09b5b4.tar.bz2 | |
sparc64: Rearrange thread info to cheaply clear syscall noerror state.
After fixing a couple of brainos, it even seems to work. What's done here
is move of ->syscall_noerror right before FPDEPTH byte in ->flags and
using sth to [%g6 + TI_SYS_NOERROR] instead of stb to [%g6 + TI_FPDEPTH] in
both branches of etrap_save. AFAICS, that ought to be solid. Again,
deciding what to do with now unused delay slot of branch on ->syscall_noerror
and dealing with the order of tests in ret_from_sys is a separate question,
but at least that way we don't have to clean ->syscall_noerror in there at
all. AFAICS, it ought to be a clear win - sth is not going to cost more than
stb on etrap_64.S side of things, and we are losing write on syscalls.S one.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel')
| -rw-r--r-- | arch/sparc/kernel/etrap_64.S | 8 | ||||
| -rw-r--r-- | arch/sparc/kernel/syscalls.S | 4 | ||||
| -rw-r--r-- | arch/sparc/kernel/traps_64.c | 2 |
3 files changed, 8 insertions, 6 deletions
diff --git a/arch/sparc/kernel/etrap_64.S b/arch/sparc/kernel/etrap_64.S index 786b185e6e3f..1276ca2567ba 100644 --- a/arch/sparc/kernel/etrap_64.S +++ b/arch/sparc/kernel/etrap_64.S @@ -92,8 +92,10 @@ etrap_save: save %g2, -STACK_BIAS, %sp rdpr %wstate, %g2 wrpr %g0, 0, %canrestore sll %g2, 3, %g2 + + /* Set TI_SYS_FPDEPTH to 1 and clear TI_SYS_NOERROR. */ mov 1, %l5 - stb %l5, [%l6 + TI_FPDEPTH] + sth %l5, [%l6 + TI_SYS_NOERROR] wrpr %g3, 0, %otherwin wrpr %g2, 0, %wstate @@ -152,7 +154,9 @@ etrap_save: save %g2, -STACK_BIAS, %sp add %l6, TI_FPSAVED + 1, %l4 srl %l5, 1, %l3 add %l5, 2, %l5 - stb %l5, [%l6 + TI_FPDEPTH] + + /* Set TI_SYS_FPDEPTH to %l5 and clear TI_SYS_NOERROR. */ + sth %l5, [%l6 + TI_SYS_NOERROR] ba,pt %xcc, 2b stb %g0, [%l4 + %l3] nop diff --git a/arch/sparc/kernel/syscalls.S b/arch/sparc/kernel/syscalls.S index 1d7e274f3f2b..ed277e2fdfc8 100644 --- a/arch/sparc/kernel/syscalls.S +++ b/arch/sparc/kernel/syscalls.S @@ -221,8 +221,8 @@ ret_sys_call: * was invoked. */ ldub [%g6 + TI_SYS_NOERROR], %l2 - brnz,a,pn %l2, 80f - stb %g0, [%g6 + TI_SYS_NOERROR] + brnz,pn %l2, 80f + nop cmp %o0, -ERESTART_RESTARTBLOCK bgeu,pn %xcc, 1f diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c index fa1f1d375ffc..82af591fe43f 100644 --- a/arch/sparc/kernel/traps_64.c +++ b/arch/sparc/kernel/traps_64.c @@ -2547,8 +2547,6 @@ void __init trap_init(void) TI_PRE_COUNT != offsetof(struct thread_info, preempt_count) || TI_NEW_CHILD != offsetof(struct thread_info, new_child) || - TI_SYS_NOERROR != offsetof(struct thread_info, - syscall_noerror) || TI_RESTART_BLOCK != offsetof(struct thread_info, restart_block) || TI_KUNA_REGS != offsetof(struct thread_info, |