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| 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/mpc8260ads/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/mpc8260ads/irq')
| -rw-r--r-- | c/src/lib/libbsp/powerpc/mpc8260ads/irq/irq_asm.S | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/c/src/lib/libbsp/powerpc/mpc8260ads/irq/irq_asm.S b/c/src/lib/libbsp/powerpc/mpc8260ads/irq/irq_asm.S index a8971f5b1d..a0aa73abc0 100644 --- a/c/src/lib/libbsp/powerpc/mpc8260ads/irq/irq_asm.S +++ b/c/src/lib/libbsp/powerpc/mpc8260ads/irq/irq_asm.S @@ -12,6 +12,9 @@ * Modifications to store nesting level in global _ISR_Nest_level * variable instead of SPRG0. Andy Dachs <a.dachs@sstl.co.uk> * + * Till Straumann <strauman@slac.stanford.edu>, 2005/4: + * - DONT enable FP across user ISR since fpregs are never saved!! + * * $Id$ */ @@ -92,11 +95,7 @@ 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 @@ -297,6 +296,27 @@ 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: |