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linux/arch/powerpc/kernel/vector.S
Stephen Rothwell 46f5221049 powerpc: Remove second definition of STACK_FRAME_OVERHEAD 
Since STACK_FRAME_OVERHEAD is defined in asm/ptrace.h and that
is ASSEMBER safe, we can just include that instead of going via
asm-offsets.h.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-11-29 15:48:23 +11:00

408 lines
8.5 KiB
ArmAsm
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#include <asm/processor.h>
#include <asm/ppc_asm.h>
#include <asm/reg.h>
#include <asm/asm-offsets.h>
#include <asm/cputable.h>
#include <asm/thread_info.h>
#include <asm/page.h>
#include <asm/ptrace.h>
/*
* load_up_altivec(unused, unused, tsk)
* Disable VMX for the task which had it previously,
* and save its vector registers in its thread_struct.
* Enables the VMX for use in the kernel on return.
* On SMP we know the VMX is free, since we give it up every
* switch (ie, no lazy save of the vector registers).
*/
_GLOBAL(load_up_altivec)
mfmsr r5 /* grab the current MSR */
oris r5,r5,MSR_VEC@h
MTMSRD(r5) /* enable use of AltiVec now */
isync
/*
* For SMP, we don't do lazy VMX switching because it just gets too
* horrendously complex, especially when a task switches from one CPU
* to another. Instead we call giveup_altvec in switch_to.
* VRSAVE isn't dealt with here, that is done in the normal context
* switch code. Note that we could rely on vrsave value to eventually
* avoid saving all of the VREGs here...
*/
#ifndef CONFIG_SMP
LOAD_REG_ADDRBASE(r3, last_task_used_altivec)
toreal(r3)
PPC_LL r4,ADDROFF(last_task_used_altivec)(r3)
PPC_LCMPI 0,r4,0
beq 1f
/* Save VMX state to last_task_used_altivec's THREAD struct */
toreal(r4)
addi r4,r4,THREAD
SAVE_32VRS(0,r5,r4)
mfvscr vr0
li r10,THREAD_VSCR
stvx vr0,r10,r4
/* Disable VMX for last_task_used_altivec */
PPC_LL r5,PT_REGS(r4)
toreal(r5)
PPC_LL r4,_MSR-STACK_FRAME_OVERHEAD(r5)
lis r10,MSR_VEC@h
andc r4,r4,r10
PPC_STL r4,_MSR-STACK_FRAME_OVERHEAD(r5)
1:
#endif /* CONFIG_SMP */
/* Hack: if we get an altivec unavailable trap with VRSAVE
* set to all zeros, we assume this is a broken application
* that fails to set it properly, and thus we switch it to
* all 1's
*/
mfspr r4,SPRN_VRSAVE
cmpwi 0,r4,0
bne+ 1f
li r4,-1
mtspr SPRN_VRSAVE,r4
1:
/* enable use of VMX after return */
#ifdef CONFIG_PPC32
mfspr r5,SPRN_SPRG_THREAD /* current task's THREAD (phys) */
oris r9,r9,MSR_VEC@h
#else
ld r4,PACACURRENT(r13)
addi r5,r4,THREAD /* Get THREAD */
oris r12,r12,MSR_VEC@h
std r12,_MSR(r1)
#endif
li r4,1
li r10,THREAD_VSCR
stw r4,THREAD_USED_VR(r5)
lvx vr0,r10,r5
mtvscr vr0
REST_32VRS(0,r4,r5)
#ifndef CONFIG_SMP
/* Update last_task_used_altivec to 'current' */
subi r4,r5,THREAD /* Back to 'current' */
fromreal(r4)
PPC_STL r4,ADDROFF(last_task_used_altivec)(r3)
#endif /* CONFIG_SMP */
/* restore registers and return */
blr
/*
* giveup_altivec(tsk)
* Disable VMX for the task given as the argument,
* and save the vector registers in its thread_struct.
* Enables the VMX for use in the kernel on return.
*/
_GLOBAL(giveup_altivec)
mfmsr r5
oris r5,r5,MSR_VEC@h
SYNC
MTMSRD(r5) /* enable use of VMX now */
isync
PPC_LCMPI 0,r3,0
beqlr- /* if no previous owner, done */
addi r3,r3,THREAD /* want THREAD of task */
PPC_LL r5,PT_REGS(r3)
PPC_LCMPI 0,r5,0
SAVE_32VRS(0,r4,r3)
mfvscr vr0
li r4,THREAD_VSCR
stvx vr0,r4,r3
beq 1f
PPC_LL r4,_MSR-STACK_FRAME_OVERHEAD(r5)
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
lis r3,(MSR_VEC|MSR_VSX)@h
FTR_SECTION_ELSE
lis r3,MSR_VEC@h
ALT_FTR_SECTION_END_IFSET(CPU_FTR_VSX)
#else
lis r3,MSR_VEC@h
#endif
andc r4,r4,r3 /* disable FP for previous task */
PPC_STL r4,_MSR-STACK_FRAME_OVERHEAD(r5)
1:
#ifndef CONFIG_SMP
li r5,0
LOAD_REG_ADDRBASE(r4,last_task_used_altivec)
PPC_STL r5,ADDROFF(last_task_used_altivec)(r4)
#endif /* CONFIG_SMP */
blr
#ifdef CONFIG_VSX
#ifdef CONFIG_PPC32
#error This asm code isn't ready for 32-bit kernels
#endif
/*
* load_up_vsx(unused, unused, tsk)
* Disable VSX for the task which had it previously,
* and save its vector registers in its thread_struct.
* Reuse the fp and vsx saves, but first check to see if they have
* been saved already.
*/
_GLOBAL(load_up_vsx)
/* Load FP and VSX registers if they haven't been done yet */
andi. r5,r12,MSR_FP
beql+ load_up_fpu /* skip if already loaded */
andis. r5,r12,MSR_VEC@h
beql+ load_up_altivec /* skip if already loaded */
#ifndef CONFIG_SMP
ld r3,last_task_used_vsx@got(r2)
ld r4,0(r3)
cmpdi 0,r4,0
beq 1f
/* Disable VSX for last_task_used_vsx */
addi r4,r4,THREAD
ld r5,PT_REGS(r4)
ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
lis r6,MSR_VSX@h
andc r6,r4,r6
std r6,_MSR-STACK_FRAME_OVERHEAD(r5)
1:
#endif /* CONFIG_SMP */
ld r4,PACACURRENT(r13)
addi r4,r4,THREAD /* Get THREAD */
li r6,1
stw r6,THREAD_USED_VSR(r4) /* ... also set thread used vsr */
/* enable use of VSX after return */
oris r12,r12,MSR_VSX@h
std r12,_MSR(r1)
#ifndef CONFIG_SMP
/* Update last_task_used_vsx to 'current' */
ld r4,PACACURRENT(r13)
std r4,0(r3)
#endif /* CONFIG_SMP */
b fast_exception_return
/*
* __giveup_vsx(tsk)
* Disable VSX for the task given as the argument.
* Does NOT save vsx registers.
* Enables the VSX for use in the kernel on return.
*/
_GLOBAL(__giveup_vsx)
mfmsr r5
oris r5,r5,MSR_VSX@h
mtmsrd r5 /* enable use of VSX now */
isync
cmpdi 0,r3,0
beqlr- /* if no previous owner, done */
addi r3,r3,THREAD /* want THREAD of task */
ld r5,PT_REGS(r3)
cmpdi 0,r5,0
beq 1f
ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
lis r3,MSR_VSX@h
andc r4,r4,r3 /* disable VSX for previous task */
std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
1:
#ifndef CONFIG_SMP
li r5,0
ld r4,last_task_used_vsx@got(r2)
std r5,0(r4)
#endif /* CONFIG_SMP */
blr
#endif /* CONFIG_VSX */
/*
* The routines below are in assembler so we can closely control the
* usage of floating-point registers. These routines must be called
* with preempt disabled.
*/
#ifdef CONFIG_PPC32
.data
fpzero:
.long 0
fpone:
.long 0x3f800000 /* 1.0 in single-precision FP */
fphalf:
.long 0x3f000000 /* 0.5 in single-precision FP */
#define LDCONST(fr, name) \
lis r11,name@ha; \
lfs fr,name@l(r11)
#else
.section ".toc","aw"
fpzero:
.tc FD_0_0[TC],0
fpone:
.tc FD_3ff00000_0[TC],0x3ff0000000000000 /* 1.0 */
fphalf:
.tc FD_3fe00000_0[TC],0x3fe0000000000000 /* 0.5 */
#define LDCONST(fr, name) \
lfd fr,name@toc(r2)
#endif
.text
/*
* Internal routine to enable floating point and set FPSCR to 0.
* Don't call it from C; it doesn't use the normal calling convention.
*/
fpenable:
#ifdef CONFIG_PPC32
stwu r1,-64(r1)
#else
stdu r1,-64(r1)
#endif
mfmsr r10
ori r11,r10,MSR_FP
mtmsr r11
isync
stfd fr0,24(r1)
stfd fr1,16(r1)
stfd fr31,8(r1)
LDCONST(fr1, fpzero)
mffs fr31
MTFSF_L(fr1)
blr
fpdisable:
mtlr r12
MTFSF_L(fr31)
lfd fr31,8(r1)
lfd fr1,16(r1)
lfd fr0,24(r1)
mtmsr r10
isync
addi r1,r1,64
blr
/*
* Vector add, floating point.
*/
_GLOBAL(vaddfp)
mflr r12
bl fpenable
li r0,4
mtctr r0
li r6,0
1: lfsx fr0,r4,r6
lfsx fr1,r5,r6
fadds fr0,fr0,fr1
stfsx fr0,r3,r6
addi r6,r6,4
bdnz 1b
b fpdisable
/*
* Vector subtract, floating point.
*/
_GLOBAL(vsubfp)
mflr r12
bl fpenable
li r0,4
mtctr r0
li r6,0
1: lfsx fr0,r4,r6
lfsx fr1,r5,r6
fsubs fr0,fr0,fr1
stfsx fr0,r3,r6
addi r6,r6,4
bdnz 1b
b fpdisable
/*
* Vector multiply and add, floating point.
*/
_GLOBAL(vmaddfp)
mflr r12
bl fpenable
stfd fr2,32(r1)
li r0,4
mtctr r0
li r7,0
1: lfsx fr0,r4,r7
lfsx fr1,r5,r7
lfsx fr2,r6,r7
fmadds fr0,fr0,fr2,fr1
stfsx fr0,r3,r7
addi r7,r7,4
bdnz 1b
lfd fr2,32(r1)
b fpdisable
/*
* Vector negative multiply and subtract, floating point.
*/
_GLOBAL(vnmsubfp)
mflr r12
bl fpenable
stfd fr2,32(r1)
li r0,4
mtctr r0
li r7,0
1: lfsx fr0,r4,r7
lfsx fr1,r5,r7
lfsx fr2,r6,r7
fnmsubs fr0,fr0,fr2,fr1
stfsx fr0,r3,r7
addi r7,r7,4
bdnz 1b
lfd fr2,32(r1)
b fpdisable
/*
* Vector reciprocal estimate. We just compute 1.0/x.
* r3 -> destination, r4 -> source.
*/
_GLOBAL(vrefp)
mflr r12
bl fpenable
li r0,4
LDCONST(fr1, fpone)
mtctr r0
li r6,0
1: lfsx fr0,r4,r6
fdivs fr0,fr1,fr0
stfsx fr0,r3,r6
addi r6,r6,4
bdnz 1b
b fpdisable
/*
* Vector reciprocal square-root estimate, floating point.
* We use the frsqrte instruction for the initial estimate followed
* by 2 iterations of Newton-Raphson to get sufficient accuracy.
* r3 -> destination, r4 -> source.
*/
_GLOBAL(vrsqrtefp)
mflr r12
bl fpenable
stfd fr2,32(r1)
stfd fr3,40(r1)
stfd fr4,48(r1)
stfd fr5,56(r1)
li r0,4
LDCONST(fr4, fpone)
LDCONST(fr5, fphalf)
mtctr r0
li r6,0
1: lfsx fr0,r4,r6
frsqrte fr1,fr0 /* r = frsqrte(s) */
fmuls fr3,fr1,fr0 /* r * s */
fmuls fr2,fr1,fr5 /* r * 0.5 */
fnmsubs fr3,fr1,fr3,fr4 /* 1 - s * r * r */
fmadds fr1,fr2,fr3,fr1 /* r = r + 0.5 * r * (1 - s * r * r) */
fmuls fr3,fr1,fr0 /* r * s */
fmuls fr2,fr1,fr5 /* r * 0.5 */
fnmsubs fr3,fr1,fr3,fr4 /* 1 - s * r * r */
fmadds fr1,fr2,fr3,fr1 /* r = r + 0.5 * r * (1 - s * r * r) */
stfsx fr1,r3,r6
addi r6,r6,4
bdnz 1b
lfd fr5,56(r1)
lfd fr4,48(r1)
lfd fr3,40(r1)
lfd fr2,32(r1)
b fpdisable
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