diff options
| author | Joel Sherrill <joel.sherrill@OARcorp.com> | 2005-10-06 19:36:41 +0000 |
|---|---|---|
| committer | Joel Sherrill <joel.sherrill@OARcorp.com> | 2005-10-06 19:36:41 +0000 |
| commit | 384ba7563aaede68c38be361b9b5edd8bf4b3d0e (patch) | |
| tree | 34cedbf5553935b6543aa91010157a09254f9adb /c/src/lib/libbsp/powerpc/mbx8xx/irq | |
| parent | 2005-10-06 Joel Sherrill <joel@OARcorp.com> (diff) | |
| download | rtems-384ba7563aaede68c38be361b9b5edd8bf4b3d0e.tar.bz2 | |
2005-10-06 Till Straumann <strauman@slac.stanford.edu>
PR 833/bsps
* irq/irq_asm.S: Currently, all (new exception) BSPs explicitely enable
the FPU across the user ISR but DONT save/restore the FPU context.
Any use of the FPU fron the user handler (e.g., due to GCC
optimizations) result in corruption. The fix results in an exception
in such cases (user ISR must explicitely save/enable/restore FPU).
Diffstat (limited to 'c/src/lib/libbsp/powerpc/mbx8xx/irq')
| -rw-r--r-- | c/src/lib/libbsp/powerpc/mbx8xx/irq/irq_asm.S | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/c/src/lib/libbsp/powerpc/mbx8xx/irq/irq_asm.S b/c/src/lib/libbsp/powerpc/mbx8xx/irq/irq_asm.S index 0e3ad7af7b..d94e9d2493 100644 --- a/c/src/lib/libbsp/powerpc/mbx8xx/irq/irq_asm.S +++ b/c/src/lib/libbsp/powerpc/mbx8xx/irq/irq_asm.S @@ -12,6 +12,8 @@ * Till Straumann <strauman@slac.stanford.edu>, 2003/7: * - store isr nesting level in _ISR_Nest_level rather than * SPRG0 - RTEMS relies on that variable. + * Till Straumann <strauman@slac.stanford.edu>, 2005/4: + * - DONT enable FP across user ISR since fpregs are never saved!! * * $Id$ */ @@ -126,11 +128,7 @@ SYM (shared_raw_irq_code_entry): * also, on CPUs with FP, enable FP so that FP context can be * saved and restored (using FP instructions) */ -#if (PPC_HAS_FPU == 0) ori r3, r3, MSR_RI | MSR_IR | MSR_DR -#else - ori r3, r3, MSR_RI | MSR_IR | MSR_DR | MSR_FP -#endif mtmsr r3 SYNC /* @@ -337,6 +335,27 @@ nested: rfi switch: +#if ( PPC_HAS_FPU != 0 ) +#if ! defined( CPU_USE_DEFERRED_FP_SWITCH ) +#error missing include file??? +#endif + mfmsr r4 +#if ( CPU_USE_DEFERRED_FP_SWITCH == TRUE ) + /* if the executing thread has FP enabled propagate + * this now so _Thread_Dispatch can save/restore the FPREGS + * NOTE: it is *crucial* to disable the FPU across the + * user ISR [independent of using the 'deferred' + * strategy or not]. We don't save FP regs across + * the user ISR and hence we prefer an exception to + * be raised rather than experiencing corruption. + */ + lwz r3, SRR1_FRAME_OFFSET(r1) + rlwimi r4, r3, 0, 18, 18 /* MSR_FP */ +#else + ori r4, r4, MSR_FP +#endif + mtmsr r4 +#endif bl SYM (_Thread_Dispatch) easy_exit: |