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>
This commit is contained in:
David S. Miller 2012-05-13 23:09:04 -07:00
parent 5d83d66635
commit c68e5d39a5
10 changed files with 99 additions and 175 deletions

View file

@ -103,37 +103,24 @@
st %scratch, [%cur_reg + TI_W_SAVED];
#ifdef CONFIG_SMP
/* Results of LOAD_CURRENT() after BTFIXUP for SUN4M, SUN4D & LEON (comments) */
#define LOAD_CURRENT4M(dest_reg, idreg) \
rd %tbr, %idreg; \
sethi %hi(current_set), %dest_reg; \
srl %idreg, 10, %idreg; \
or %dest_reg, %lo(current_set), %dest_reg; \
and %idreg, 0xc, %idreg; \
ld [%idreg + %dest_reg], %dest_reg;
#define LOAD_CURRENT4D(dest_reg, idreg) \
lda [%g0] ASI_M_VIKING_TMP1, %idreg; \
sethi %hi(C_LABEL(current_set)), %dest_reg; \
sll %idreg, 2, %idreg; \
or %dest_reg, %lo(C_LABEL(current_set)), %dest_reg; \
ld [%idreg + %dest_reg], %dest_reg;
#define LOAD_CURRENT_LEON(dest_reg, idreg) \
rd %asr17, %idreg; \
sethi %hi(current_set), %dest_reg; \
srl %idreg, 0x1c, %idreg; \
or %dest_reg, %lo(current_set), %dest_reg; \
sll %idreg, 0x2, %idreg; \
ld [%idreg + %dest_reg], %dest_reg;
/* Blackbox - take care with this... - check smp4m and smp4d before changing this. */
#define LOAD_CURRENT(dest_reg, idreg) \
sethi %hi(___b_load_current), %idreg; \
sethi %hi(current_set), %dest_reg; \
sethi %hi(boot_cpu_id4), %idreg; \
or %dest_reg, %lo(current_set), %dest_reg; \
ldub [%idreg + %lo(boot_cpu_id4)], %idreg; \
#define LOAD_CURRENT(dest_reg, idreg) \
661: rd %tbr, %idreg; \
srl %idreg, 10, %idreg; \
and %idreg, 0xc, %idreg; \
.section .cpuid_patch, "ax"; \
/* Instruction location. */ \
.word 661b; \
/* SUN4D implementation. */ \
lda [%g0] ASI_M_VIKING_TMP1, %idreg; \
sll %idreg, 2, %idreg; \
nop; \
/* LEON implementation. */ \
rd %asr17, %idreg; \
srl %idreg, 0x1c, %idreg; \
sll %idreg, 0x02, %idreg; \
.previous; \
sethi %hi(current_set), %dest_reg; \
or %dest_reg, %lo(current_set), %dest_reg;\
ld [%idreg + %dest_reg], %dest_reg;
#else
#define LOAD_CURRENT(dest_reg, idreg) \