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powerpc: Introduce toreal/fromreal assembly macros

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On 32-bit platforms, these convert from kernel virtual addresses
to real (physical addresses), like tophys/tovirt but they use
the same register for the source and destination.  On 64-bit
platforms, they do nothing because the hardware ignores the top
two bits of the address in real mode.

These new macros are used in fpu.S now.

Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Paul Mackerras
2005-10-27 22:44:39 +10:00
parent 80579e1f4a
commit 6316222ea0
2 changed files with 19 additions and 18 deletions
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8
arch/powerpc/kernel/fpu.S
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@ -40,17 +40,17 @@ _GLOBAL(load_up_fpu)
*/
#ifndef CONFIG_SMP
LOADBASE(r3, last_task_used_math)
tophys(r3,r3)
toreal(r3)
LDL r4,OFF(last_task_used_math)(r3)
CMPI 0,r4,0
beq 1f
tophys(r4,r4)
toreal(r4)
addi r4,r4,THREAD /* want last_task_used_math->thread */
SAVE_32FPRS(0, r4)
mffs fr0
stfd fr0,THREAD_FPSCR(r4)
LDL r5,PT_REGS(r4)
tophys(r5,r5)
toreal(r5)
LDL r4,_MSR-STACK_FRAME_OVERHEAD(r5)
li r10,MSR_FP|MSR_FE0|MSR_FE1
andc r4,r4,r10 /* disable FP for previous task */
@ -76,7 +76,7 @@ _GLOBAL(load_up_fpu)
REST_32FPRS(0, r5)
#ifndef CONFIG_SMP
subi r4,r5,THREAD
tovirt(r4,r4)
fromreal(r4)
STL r4,OFF(last_task_used_math)(r3)
#endif /* CONFIG_SMP */
/* restore registers and return */