diff options
| author | David S. Miller <davem@davemloft.net> | 2012-05-13 23:09:04 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-05-14 13:31:38 -0700 |
| commit | c68e5d39a502d01421cbc70d25c377e9215facef (patch) | |
| tree | 9135a68681381d94a929b57a28a1878df0134ff7 /arch/sparc/kernel/entry.S | |
| parent | 5d83d66635bb1642f3c6a3690c28ff4afdf1ae5f (diff) | |
sparc32: Implement hard_smp_processor_id() via instruction patching.
This is the last non-trivial user of btfixup.
Like sparc64, use a special patch section to resolve the various
implementations of how to read the current CPU's ID when we don't
have current_thread_info()->cpu necessarily available.
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Diffstat (limited to 'arch/sparc/kernel/entry.S')
| -rw-r--r-- | arch/sparc/kernel/entry.S | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/sparc/kernel/entry.S b/arch/sparc/kernel/entry.S index d7143ba6a8ff..773f3f05bf26 100644 --- a/arch/sparc/kernel/entry.S +++ b/arch/sparc/kernel/entry.S @@ -7,6 +7,7 @@ * Copyright (C) 1997 Anton Blanchard (anton@progsoc.uts.edu.au) */ +#include <linux/linkage.h> #include <linux/errno.h> #include <asm/head.h> @@ -1347,4 +1348,26 @@ flushw_all: ret restore +#ifdef CONFIG_SMP +ENTRY(hard_smp_processor_id) +661: rd %tbr, %g1 + srl %g1, 12, %o0 + and %o0, 3, %o0 + .section .cpuid_patch, "ax" + /* Instruction location. */ + .word 661b + /* SUN4D implementation. */ + lda [%g0] ASI_M_VIKING_TMP1, %o0 + nop + nop + /* LEON implementation. */ + rd %asr17, %o0 + srl %o0, 0x1c, %o0 + nop + .previous + retl + nop +ENDPROC(hard_smp_processor_id) +#endif + /* End of entry.S */ |