-/*
- * load_up_fpu(unused, unused, tsk)
- * Disable FP for the task which had the FPU previously,
- * and save its floating-point registers in its thread_struct.
- * Enables the FPU for use in the kernel on return.
- * On SMP we know the fpu is free, since we give it up every
- * switch (ie, no lazy save of the FP registers).
- * On entry: r13 == 'current' && last_task_used_math != 'current'
- */
-_STATIC(load_up_fpu)
- mfmsr r5 /* grab the current MSR */
- ori r5,r5,MSR_FP
- mtmsrd r5 /* enable use of fpu now */
- isync
-/*
- * For SMP, we don't do lazy FPU switching because it just gets too
- * horrendously complex, especially when a task switches from one CPU
- * to another. Instead we call giveup_fpu in switch_to.
- *
- */
-#ifndef CONFIG_SMP
- ld r3,last_task_used_math@got(r2)
- ld r4,0(r3)
- cmpdi 0,r4,0
- beq 1f
- /* Save FP state to last_task_used_math's THREAD struct */
- addi r4,r4,THREAD
- SAVE_32FPRS(0, r4)
- mffs fr0
- stfd fr0,THREAD_FPSCR(r4)
- /* Disable FP for last_task_used_math */
- ld r5,PT_REGS(r4)
- ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
- li r6,MSR_FP|MSR_FE0|MSR_FE1
- andc r4,r4,r6
- std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-1:
-#endif /* CONFIG_SMP */
- /* enable use of FP after return */
- ld r4,PACACURRENT(r13)
- addi r5,r4,THREAD /* Get THREAD */
- ld r4,THREAD_FPEXC_MODE(r5)
- ori r12,r12,MSR_FP
- or r12,r12,r4
- std r12,_MSR(r1)
- lfd fr0,THREAD_FPSCR(r5)
- mtfsf 0xff,fr0
- REST_32FPRS(0, r5)
-#ifndef CONFIG_SMP
- /* Update last_task_used_math to 'current' */
- subi r4,r5,THREAD /* Back to 'current' */
- std r4,0(r3)
-#endif /* CONFIG_SMP */
- /* restore registers and return */
- b fast_exception_return
-
-/*
- * disable_kernel_fp()
- * Disable the FPU.
- */
-_GLOBAL(disable_kernel_fp)
- mfmsr r3
- rldicl r0,r3,(63-MSR_FP_LG),1
- rldicl r3,r0,(MSR_FP_LG+1),0
- mtmsrd r3 /* disable use of fpu now */
- isync
- blr
-
-/*
- * giveup_fpu(tsk)
- * Disable FP for the task given as the argument,
- * and save the floating-point registers in its thread_struct.
- * Enables the FPU for use in the kernel on return.
- */
-_GLOBAL(giveup_fpu)
- mfmsr r5
- ori r5,r5,MSR_FP
- mtmsrd r5 /* enable use of fpu 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
- SAVE_32FPRS(0, r3)
- mffs fr0
- stfd fr0,THREAD_FPSCR(r3)
- beq 1f
- ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
- li r3,MSR_FP|MSR_FE0|MSR_FE1
- andc r4,r4,r3 /* disable FP for previous task */
- std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-1:
-#ifndef CONFIG_SMP
- li r5,0
- ld r4,last_task_used_math@got(r2)
- std r5,0(r4)
-#endif /* CONFIG_SMP */
- blr
-
-
-#ifdef CONFIG_ALTIVEC
-
-/*
- * 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).
- * On entry: r13 == 'current' && last_task_used_altivec != 'current'
- */
-_STATIC(load_up_altivec)
- mfmsr r5 /* grab the current MSR */
- oris r5,r5,MSR_VEC@h
- mtmsrd r5 /* enable use of VMX 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
- ld r3,last_task_used_altivec@got(r2)
- ld r4,0(r3)
- cmpdi 0,r4,0
- beq 1f
- /* Save VMX state to last_task_used_altivec's THREAD struct */
- 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 */
- ld r5,PT_REGS(r4)
- ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
- lis r6,MSR_VEC@h
- andc r4,r4,r6
- std 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
- cmpdi 0,r4,0
- bne+ 1f
- li r4,-1
- mtspr SPRN_VRSAVE,r4
-1:
- /* enable use of VMX after return */
- ld r4,PACACURRENT(r13)
- addi r5,r4,THREAD /* Get THREAD */
- oris r12,r12,MSR_VEC@h
- std r12,_MSR(r1)
- 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_math to 'current' */
- subi r4,r5,THREAD /* Back to 'current' */
- std r4,0(r3)
-#endif /* CONFIG_SMP */
- /* restore registers and return */
- b fast_exception_return
-
-/*
- * disable_kernel_altivec()
- * Disable the VMX.
- */
-_GLOBAL(disable_kernel_altivec)
- mfmsr r3
- rldicl r0,r3,(63-MSR_VEC_LG),1
- rldicl r3,r0,(MSR_VEC_LG+1),0
- mtmsrd r3 /* disable use of VMX now */
- isync
- 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
- mtmsrd r5 /* enable use of VMX 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
- SAVE_32VRS(0,r4,r3)
- mfvscr vr0
- li r4,THREAD_VSCR
- stvx vr0,r4,r3
- beq 1f
- ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
- lis r3,MSR_VEC@h
- andc r4,r4,r3 /* disable FP for previous task */
- std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-1:
-#ifndef CONFIG_SMP
- li r5,0
- ld r4,last_task_used_altivec@got(r2)
- std r5,0(r4)
-#endif /* CONFIG_SMP */
- blr
-
-#endif /* CONFIG_ALTIVEC */
-