| From 97ae72869e28151235f53f5564b29e74cc5dc18b Mon Sep 17 00:00:00 2001 |
| From: Andrea Shepard <andrea@persephoneslair.org> |
| Date: Sun, 19 Oct 2008 23:33:03 -0700 |
| Subject: sparc64: Fix race in arch/sparc64/kernel/trampoline.S |
| |
| From: Andrea Shepard <andrea@persephoneslair.org> |
| |
| [ Upstream commit e0037df3852b4b60edbe01f70f4968e4a9fdb272 ] |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| arch/sparc64/kernel/trampoline.S | 18 ++++++++++++++---- |
| 1 file changed, 14 insertions(+), 4 deletions(-) |
| |
| --- 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 |
