powerpc: Remove UP only lazy floating point and vector optimisations

[cascardo/linux.git] / arch / powerpc / kernel / fpu.S

diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index f7f5b8b..50d2352 100644 (file)
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -73,13 +73,25 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
        MTFSF_L(fr0)
        REST_32FPVSRS(0, R4, R7)
 
-       /* FP/VSX off again */
-       MTMSRD(r6)
-       SYNC
-
        blr
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
+/*
+ * Enable use of the FPU, and VSX if possible, for the caller.
+ */
+_GLOBAL(fp_enable)
+       mfmsr   r3
+       ori     r3,r3,MSR_FP
+#ifdef CONFIG_VSX
+BEGIN_FTR_SECTION
+       oris    r3,r3,MSR_VSX@h
+END_FTR_SECTION_IFSET(CPU_FTR_VSX)
+#endif
+       SYNC
+       MTMSRD(r3)
+       isync                   /* (not necessary for arch 2.02 and later) */
+       blr
+
 /*
  * Load state from memory into FP registers including FPSCR.
  * Assumes the caller has enabled FP in the MSR.
@@ -120,31 +132,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
        SYNC
        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
-       LOAD_REG_ADDRBASE(r3, last_task_used_math)
-       toreal(r3)
-       PPC_LL  r4,ADDROFF(last_task_used_math)(r3)
-       PPC_LCMPI       0,r4,0
-       beq     1f
-       toreal(r4)
-       addi    r4,r4,THREAD            /* want last_task_used_math->thread */
-       addi    r10,r4,THREAD_FPSTATE
-       SAVE_32FPVSRS(0, R5, R10)
-       mffs    fr0
-       stfd    fr0,FPSTATE_FPSCR(r10)
-       PPC_LL  r5,PT_REGS(r4)
-       toreal(r5)
-       PPC_LL  r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-       li      r10,MSR_FP|MSR_FE0|MSR_FE1
-       andc    r4,r4,r10               /* disable FP for previous task */
-       PPC_STL r4,_MSR-STACK_FRAME_OVERHEAD(r5)
-1:
-#endif /* CONFIG_SMP */
        /* enable use of FP after return */
 #ifdef CONFIG_PPC32
        mfspr   r5,SPRN_SPRG_THREAD     /* current task's THREAD (phys) */
@@ -163,11 +150,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
        lfd     fr0,FPSTATE_FPSCR(r10)
        MTFSF_L(fr0)
        REST_32FPVSRS(0, R4, R10)
-#ifndef CONFIG_SMP
-       subi    r4,r5,THREAD
-       fromreal(r4)
-       PPC_STL r4,ADDROFF(last_task_used_math)(r3)
-#endif /* CONFIG_SMP */
        /* restore registers and return */
        /* we haven't used ctr or xer or lr */
        blr
@@ -214,11 +196,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
        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_math)
-       PPC_STL r5,ADDROFF(last_task_used_math)(r4)
-#endif /* CONFIG_SMP */
        blr
 
 /*