diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2017-04-20 15:36:51 -0700 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2017-04-20 15:37:49 -0700 |
| commit | 3d5e80125a6e5649c6bdad8d5780e39ea422c67d (patch) | |
| tree | 5db65bfac17a6dbbff36d055b0292e9addeb8d90 /arch/arc/kernel | |
| parent | 6492f09e864417d382e22b922ae30693a7ce2982 (diff) | |
ARCv2: entry: save Accumulator register pair (r58:59) if present
Accumulator is present in configs with FPU and/or DSP MPY (mpy > 6)
Instead of doing this in pt_regs (and thus every kernel entry/exit),
this could have been done in context switch (and for user task only) as
currently kernel doesn't clobber these registers for its own accord.
However we will soon start using 64-bit multiply instructions for kernel
which can clobber these. Also gcc folks also plan to start using these
as GPRs, hence better to always save/restore them
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel')
| -rw-r--r-- | arch/arc/kernel/setup.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c index fa62404ba58f..fc8211f338ad 100644 --- a/arch/arc/kernel/setup.c +++ b/arch/arc/kernel/setup.c @@ -319,7 +319,8 @@ static char *arc_extn_mumbojumbo(int cpu_id, char *buf, int len) static void arc_chk_core_config(void) { struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()]; - int fpu_enabled; + int saved = 0, present = 0; + char *opt_nm = NULL;; if (!cpu->extn.timer0) panic("Timer0 is not present!\n"); @@ -346,17 +347,28 @@ static void arc_chk_core_config(void) /* * FP hardware/software config sanity - * -If hardware contains DPFP, kernel needs to save/restore FPU state + * -If hardware present, kernel needs to save/restore FPU state * -If not, it will crash trying to save/restore the non-existant regs - * - * (only DPDP checked since SP has no arch visible regs) */ - fpu_enabled = IS_ENABLED(CONFIG_ARC_FPU_SAVE_RESTORE); - if (cpu->extn.fpu_dp && !fpu_enabled) - pr_warn("CONFIG_ARC_FPU_SAVE_RESTORE needed for working apps\n"); - else if (!cpu->extn.fpu_dp && fpu_enabled) - panic("FPU non-existent, disable CONFIG_ARC_FPU_SAVE_RESTORE\n"); + if (is_isa_arcompact()) { + opt_nm = "CONFIG_ARC_FPU_SAVE_RESTORE"; + saved = IS_ENABLED(CONFIG_ARC_FPU_SAVE_RESTORE); + + /* only DPDP checked since SP has no arch visible regs */ + present = cpu->extn.fpu_dp; + } else { + opt_nm = "CONFIG_ARC_HAS_ACCL_REGS"; + saved = IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS); + + /* Accumulator Low:High pair (r58:59) present if DSP MPY or FPU */ + present = cpu->extn_mpy.dsp | cpu->extn.fpu_sp | cpu->extn.fpu_dp; + } + + if (present && !saved) + pr_warn("Enable %s for working apps\n", opt_nm); + else if (!present && saved) + panic("Disable %s, hardware NOT present\n", opt_nm); } /* |