diff options
Diffstat (limited to 'arch/ppc/kernel/head.S')
| -rw-r--r-- | arch/ppc/kernel/head.S | 234 |
1 files changed, 163 insertions, 71 deletions
diff --git a/arch/ppc/kernel/head.S b/arch/ppc/kernel/head.S index 8b56c635c..dd16b8c27 100644 --- a/arch/ppc/kernel/head.S +++ b/arch/ppc/kernel/head.S @@ -460,8 +460,24 @@ SystemCall: STD_EXCEPTION(0xd00, SingleStep, SingleStepException) STD_EXCEPTION(0xe00, Trap_0e, UnknownException) -#ifdef CONFIG_ALTIVEC - STD_EXCEPTION(0xf20, AltiVec, AltiVecUnavailable) +#ifndef CONFIG_ALTIVEC + STD_EXCEPTION(0xf00, Trap_0f, UnknownException) +#else +/* + * The Altivec unavailable trap is at 0x0f20. Foo. + * We effectively remap it to 0x3000. + */ + . = 0xf00 + b Trap_0f +trap_0f_cont: + addi r3,r1,STACK_FRAME_OVERHEAD + li r20,MSR_KERNEL + bl transfer_to_handler + .long UnknownException + .long ret_from_except + + . = 0xf20 + b AltiVecUnavailable #endif /* CONFIG_ALTIVEC */ /* @@ -674,6 +690,21 @@ DataStoreTLBMiss: . = 0x3000 +#ifdef CONFIG_ALTIVEC +AltiVecUnavailable: + EXCEPTION_PROLOG + bne load_up_altivec /* if from user, just load it up */ + li r20,MSR_KERNEL + bl transfer_to_handler /* if from kernel, take a trap */ + .long KernelAltiVec + .long ret_from_except + +/* here are the bits of trap 0xf00 which got displaced */ +Trap_0f: + EXCEPTION_PROLOG + b trap_0f_cont +#endif /* CONFIG_ALTIVEC */ + /* * This code finishes saving the registers to the exception frame * and jumps to the appropriate handler for the exception, turning @@ -813,72 +844,134 @@ KernelFP: 86: .string "floating point used in kernel (task=%p, pc=%x)\n" .align 4 +#ifdef CONFIG_ALTIVEC +/* Note that the AltiVec support is closely modeled after the FP + * support. Changes to one are likely to be applicable to the + * other! */ +load_up_altivec: /* - * Take away the altivec regs. - * - * For now, ignore the vrsave regs and save them all - * -- Cort + * Disable AltiVec for the task which had AltiVec previously, + * and save its AltiVec registers in its thread_struct. + * Enables AltiVec for use in the kernel on return. + * On SMP we know the AltiVec units are free, since we give it up every + * switch. -- Kumar */ - .globl giveup_altivec -giveup_altivec: -#ifdef CONFIG_ALTIVEC - /* check for altivec */ - mfspr r4,PVR - srwi r4,r4,16 - cmpi 0,r4,12 - bnelr - - /* enable altivec so we can save */ - mfmsr r4 - oris r4,r4,MSR_VEC@h - mtmsr r4 + mfmsr r5 + oris r5,r5,MSR_VEC@h + SYNC + mtmsr r5 /* enable use of AltiVec now */ + SYNC +/* + * For SMP, we don't do lazy AltiVec switching because it just gets too + * horrendously complex, especially when a task switches from one CPU + * to another. Instead we call giveup_altivec in switch_to. + */ +#ifndef __SMP__ +#ifndef CONFIG_APUS + lis r6,-KERNELBASE@h +#else + lis r6,CYBERBASEp@h + lwz r6,0(r6) +#endif + addis r3,r6,last_task_used_altivec@ha + lwz r4,last_task_used_altivec@l(r3) + cmpi 0,r4,0 + beq 1f + add r4,r4,r6 + addi r4,r4,THREAD /* want THREAD of last_task_used_altivec */ + SAVE_32VR(0,r20,r4) + MFVSCR(vr0) + li r20,THREAD_VSCR + STVX(vr0,r20,r4) + lwz r5,PT_REGS(r4) + add r5,r5,r6 + lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5) + lis r20,MSR_VEC@h + andc r4,r4,r20 /* disable altivec for previous task */ + stw r4,_MSR-STACK_FRAME_OVERHEAD(r5) +1: +#endif /* __SMP__ */ + /* enable use of AltiVec after return */ + oris r23,r23,MSR_VEC@h + mfspr r5,SPRG3 /* current task's THREAD (phys) */ + li r20,THREAD_VSCR + LVX(vr0,r20,r5) + MTVSCR(vr0) + REST_32VR(0,r20,r5) +#ifndef __SMP__ + subi r4,r5,THREAD + sub r4,r4,r6 + stw r4,last_task_used_altivec@l(r3) +#endif /* __SMP__ */ + /* restore registers and return */ + lwz r3,_CCR(r21) + lwz r4,_LINK(r21) + mtcrf 0xff,r3 + mtlr r4 + REST_GPR(1, r21) + REST_4GPRS(3, r21) + /* we haven't used ctr or xer */ + mtspr SRR1,r23 + mtspr SRR0,r22 + REST_GPR(20, r21) + REST_2GPRS(22, r21) + lwz r21,GPR21(r21) + SYNC + rfi - /* make sure our tsk pointer is valid */ - cmpi 0,r3,0 - beqlr +/* + * AltiVec unavailable trap from kernel - print a message, but let + * the task use AltiVec in the kernel until it returns to user mode. + */ +KernelAltiVec: + lwz r3,_MSR(r1) + oris r3,r3,MSR_VEC@h + stw r3,_MSR(r1) /* enable use of AltiVec after return */ + lis r3,87f@h + ori r3,r3,87f@l + mr r4,r2 /* current */ + lwz r5,_NIP(r1) + bl printk + b ret_from_except +87: .string "AltiVec used in kernel (task=%p, pc=%x) \n" + .align 4 - /* save altivec regs */ - addi r4,r3,THREAD+THREAD_VRSAVE - mfspr r5,256 /* vrsave */ - stw r5,0(r4) - - /* get regs for the task */ - addi r4,r3,THREAD+PT_REGS - /* turn off the altivec bit in the tasks regs */ - lwz r5,_MSR(r4) - lis r6,MSR_VEC@h - andi. r5,r5,r6 - stw r5,_MSR(r4) - - /* we've given up the altivec - clear the pointer */ - li r3,0 - lis r4,last_task_used_altivec@h - stw r3,last_task_used_altivec@l(r4) -#endif /* CONFIG_ALTIVEC */ - blr - - .globl load_up_altivec -load_up_altivec: -#ifdef CONFIG_ALTIVEC - /* check for altivec */ - mfspr r4,PVR - srwi r4,r4,16 - cmpi 0,r4,12 - bnelr - - /* restore altivec regs */ - addi r4,r3,THREAD+THREAD_VRSAVE - lwz r5,0(r4) - mtspr 256,r5 /* vrsave */ - - /* get regs for the task */ - addi r4,r3,THREAD+PT_REGS - /* turn on the altivec bit in the tasks regs */ - lwz r5,_MSR(r4) +/* + * giveup_altivec(tsk) + * Disable AltiVec for the task given as the argument, + * and save the AltiVec registers in its thread_struct. + * Enables AltiVec for use in the kernel on return. + */ + + .globl giveup_altivec +giveup_altivec: + mfmsr r5 oris r5,r5,MSR_VEC@h - stw r5,_MSR(r4) -#endif /* CONFIG_ALTIVEC */ + SYNC + mtmsr r5 /* enable use of AltiVec now */ + SYNC + cmpi 0,r3,0 + beqlr- /* if no previous owner, done */ + addi r3,r3,THREAD /* want THREAD of task */ + lwz r5,PT_REGS(r3) + cmpi 0,r5,0 + SAVE_32VR(0, r4, r3) + MFVSCR(vr0) + li r4,THREAD_VSCR + STVX(vr0, r4, r3) + beq 1f + lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5) + lis r3,MSR_VEC@h + andc r4,r4,r3 /* disable AltiVec for previous task */ + stw r4,_MSR-STACK_FRAME_OVERHEAD(r5) +1: +#ifndef __SMP__ + li r5,0 + lis r4,last_task_used_altivec@ha + stw r5,last_task_used_altivec@l(r4) +#endif /* __SMP__ */ blr +#endif /* CONFIG_ALTIVEC */ /* * giveup_fpu(tsk) @@ -1437,17 +1530,16 @@ mmu_off: #if 0 /* That's useful debug stuff */ setup_screen_bat: + li r3,0 + mtspr DBAT1U,r3 + mtspr IBAT1U,r3 lis r3, 0x9100 -#ifdef __SMP__ - ori r3,r3,0x12 -#else - ori r3,r3,0x2 -#endif - mtspr DBAT1L, r3 - mtspr IBAT1L, r3 + ori r4,r3,0x2a + mtspr DBAT1L,r4 + mtspr IBAT1L,r4 ori r3,r3,(BL_8M<<2)|0x2 /* set up BAT registers for 604 */ - mtspr DBAT1U, r3 - mtspr IBAT1U, r3 + mtspr DBAT1U,r3 + mtspr IBAT1U,r3 blr #endif |