diff options
Diffstat (limited to 'arch/mips/kernel/r4k_switch.S')
| -rw-r--r-- | arch/mips/kernel/r4k_switch.S | 60 |
1 files changed, 42 insertions, 18 deletions
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S index cc78dd9a17c..abacac7c33e 100644 --- a/arch/mips/kernel/r4k_switch.S +++ b/arch/mips/kernel/r4k_switch.S @@ -29,18 +29,8 @@ #define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS) /* - * FPU context is saved iff the process has used it's FPU in the current - * time slice as indicated by _TIF_USEDFPU. In any case, the CU1 bit for user - * space STATUS register should be 0, so that a process *always* starts its - * userland with FPU disabled after each context switch. - * - * FPU will be enabled as soon as the process accesses FPU again, through - * do_cpu() trap. - */ - -/* * task_struct *resume(task_struct *prev, task_struct *next, - * struct thread_info *next_ti, int usedfpu) + * struct thread_info *next_ti, s32 fp_save) */ .align 5 LEAF(resume) @@ -50,23 +40,37 @@ LONG_S ra, THREAD_REG31(a0) /* - * check if we need to save FPU registers + * Check whether we need to save any FP context. FP context is saved + * iff the process has used the context with the scalar FPU or the MSA + * ASE in the current time slice, as indicated by _TIF_USEDFPU and + * _TIF_USEDMSA respectively. switch_to will have set fp_save + * accordingly to an FP_SAVE_ enum value. */ + beqz a3, 2f - beqz a3, 1f - - PTR_L t3, TASK_THREAD_INFO(a0) /* - * clear saved user stack CU1 bit + * We do. Clear the saved CU1 bit for prev, such that next time it is + * scheduled it will start in userland with the FPU disabled. If the + * task uses the FPU then it will be enabled again via the do_cpu trap. + * This allows us to lazily restore the FP context. */ + PTR_L t3, TASK_THREAD_INFO(a0) LONG_L t0, ST_OFF(t3) li t1, ~ST0_CU1 and t0, t0, t1 LONG_S t0, ST_OFF(t3) + /* Check whether we're saving scalar or vector context. */ + bgtz a3, 1f + + /* Save 128b MSA vector context. */ + msa_save_all a0 + b 2f + +1: /* Save 32b/64b scalar FP context. */ fpu_save_double a0 t0 t1 # c0_status passed in t0 # clobbers t1 -1: +2: #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP) PTR_LA t8, __stack_chk_guard @@ -141,6 +145,26 @@ LEAF(_restore_fp) jr ra END(_restore_fp) +#ifdef CONFIG_CPU_HAS_MSA + +/* + * Save a thread's MSA vector context. + */ +LEAF(_save_msa) + msa_save_all a0 + jr ra + END(_save_msa) + +/* + * Restore a thread's MSA vector context. + */ +LEAF(_restore_msa) + msa_restore_all a0 + jr ra + END(_restore_msa) + +#endif + /* * Load the FPU with signalling NANS. This bit pattern we're using has * the property that no matter whether considered as single or as double @@ -270,7 +294,7 @@ LEAF(_init_fpu) 1: .set pop #endif /* CONFIG_CPU_MIPS32_R2 */ #else - .set mips3 + .set arch=r4000 dmtc1 t1, $f0 dmtc1 t1, $f2 dmtc1 t1, $f4 |