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| author | Andrea Shepard <andrea@persephoneslair.org> | 2008-10-20 08:33:03 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-10-23 06:53:40 +0200 |
| commit | e0037df3852b4b60edbe01f70f4968e4a9fdb272 (patch) | |
| tree | 44b1c67b743ba4b36bf22a7b4044b2a9b9d1b35a /arch/sparc64/kernel | |
| parent | binfmt_elf_fdpic: Update for cputime changes. (diff) | |
| download | linux-e0037df3852b4b60edbe01f70f4968e4a9fdb272.tar.xz linux-e0037df3852b4b60edbe01f70f4968e4a9fdb272.zip | |
sparc64: Fix race in arch/sparc64/kernel/trampoline.S
Make arch/sparc64/kernel/trampoline.S in 2.6.27.1 lock prom_entry_lock
when calling the PROM. This prevents a race condition that I observed
causing a hang on startup on a 12-CPU E4500.
I am not subscribed to this list, so please CC me on replies.
Signed-off-by: Andrea Shepard <andrea@persephoneslair.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64/kernel')
| -rw-r--r-- | arch/sparc64/kernel/trampoline.S | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/sparc64/kernel/trampoline.S b/arch/sparc64/kernel/trampoline.S index 704a3afcfd06..83abd5ae88a4 100644 --- a/arch/sparc64/kernel/trampoline.S +++ b/arch/sparc64/kernel/trampoline.S @@ -328,6 +328,12 @@ after_lock_tlb: wrpr %g0, 0, %wstate + sethi %hi(prom_entry_lock), %g2 +1: ldstub [%g2 + %lo(prom_entry_lock)], %g1 + membar #StoreLoad | #StoreStore + brnz,pn %g1, 1b + nop + /* As a hack, put &init_thread_union into %g6. * prom_world() loads from here to restore the %asi * register. @@ -337,7 +343,7 @@ after_lock_tlb: sethi %hi(is_sun4v), %o0 lduw [%o0 + %lo(is_sun4v)], %o0 - brz,pt %o0, 1f + brz,pt %o0, 2f nop TRAP_LOAD_TRAP_BLOCK(%g2, %g3) @@ -369,10 +375,10 @@ after_lock_tlb: call %o1 add %sp, (2047 + 128), %o0 - ba,pt %xcc, 2f + ba,pt %xcc, 3f nop -1: sethi %hi(sparc64_ttable_tl0), %o0 +2: sethi %hi(sparc64_ttable_tl0), %o0 set prom_set_trap_table_name, %g2 stx %g2, [%sp + 2047 + 128 + 0x00] mov 1, %g2 @@ -386,7 +392,11 @@ after_lock_tlb: call %o1 add %sp, (2047 + 128), %o0 -2: ldx [%l0], %g6 +3: sethi %hi(prom_entry_lock), %g2 + stb %g0, [%g2 + %lo(prom_entry_lock)] + membar #StoreStore | #StoreLoad + + ldx [%l0], %g6 ldx [%g6 + TI_TASK], %g4 mov 1, %g5 |