[PATCH] powerpc: Fix handling of fpscr on 64-bit

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

diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 563d445..51fd78d 100644 (file)
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -48,7 +48,7 @@ _GLOBAL(load_up_fpu)
        addi    r4,r4,THREAD            /* want last_task_used_math->thread */
        SAVE_32FPRS(0, r4)
        mffs    fr0
-       stfd    fr0,THREAD_FPSCR-4(r4)
+       stfd    fr0,THREAD_FPSCR(r4)
        LDL     r5,PT_REGS(r4)
        tophys(r5,r5)
        LDL     r4,_MSR-STACK_FRAME_OVERHEAD(r5)
@@ -71,7 +71,7 @@ _GLOBAL(load_up_fpu)
        or      r12,r12,r4
        std     r12,_MSR(r1)
 #endif
-       lfd     fr0,THREAD_FPSCR-4(r5)
+       lfd     fr0,THREAD_FPSCR(r5)
        mtfsf   0xff,fr0
        REST_32FPRS(0, r5)
 #ifndef CONFIG_SMP
@@ -104,7 +104,7 @@ _GLOBAL(giveup_fpu)
        CMPI    0,r5,0
        SAVE_32FPRS(0, r3)
        mffs    fr0
-       stfd    fr0,THREAD_FPSCR-4(r3)
+       stfd    fr0,THREAD_FPSCR(r3)
        beq     1f
        LDL     r4,_MSR-STACK_FRAME_OVERHEAD(r5)
        li      r3,MSR_FP|MSR_FE0|MSR_FE1
@@ -117,3 +117,28 @@ _GLOBAL(giveup_fpu)
        STL     r5,OFF(last_task_used_math)(r4)
 #endif /* CONFIG_SMP */
        blr
+
+/*
+ * These are used in the alignment trap handler when emulating
+ * single-precision loads and stores.
+ * We restore and save the fpscr so the task gets the same result
+ * and exceptions as if the cpu had performed the load or store.
+ */
+
+_GLOBAL(cvt_fd)
+       lfd     0,THREAD_FPSCR(r5)      /* load up fpscr value */
+       mtfsf   0xff,0
+       lfs     0,0(r3)
+       stfd    0,0(r4)
+       mffs    0
+       stfd    0,THREAD_FPSCR(r5)      /* save new fpscr value */
+       blr
+
+_GLOBAL(cvt_df)
+       lfd     0,THREAD_FPSCR(r5)      /* load up fpscr value */
+       mtfsf   0xff,0
+       lfd     0,0(r3)
+       stfs    0,0(r4)
+       mffs    0
+       stfd    0,THREAD_FPSCR(r5)      /* save new fpscr value */
+       blr