diff options
Diffstat (limited to 'arch/arm/vfp/vfpmodule.c')
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 9f476a1be2c..7e1239041b3 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -377,6 +377,55 @@ static void vfp_pm_init(void) static inline void vfp_pm_init(void) { } #endif /* CONFIG_PM */ +/* + * Synchronise the hardware VFP state of a thread other than current with the + * saved one. This function is used by the ptrace mechanism. + */ +#ifdef CONFIG_SMP +void vfp_sync_state(struct thread_info *thread) +{ + /* + * On SMP systems, the VFP state is automatically saved at every + * context switch. We mark the thread VFP state as belonging to a + * non-existent CPU so that the saved one will be reloaded when + * needed. + */ + thread->vfpstate.hard.cpu = NR_CPUS; +} +#else +void vfp_sync_state(struct thread_info *thread) +{ + unsigned int cpu = get_cpu(); + u32 fpexc = fmrx(FPEXC); + + /* + * If VFP is enabled, the previous state was already saved and + * last_VFP_context updated. + */ + if (fpexc & FPEXC_EN) + goto out; + + if (!last_VFP_context[cpu]) + goto out; + + /* + * Save the last VFP state on this CPU. + */ + fmxr(FPEXC, fpexc | FPEXC_EN); + vfp_save_state(last_VFP_context[cpu], fpexc); + fmxr(FPEXC, fpexc); + + /* + * Set the context to NULL to force a reload the next time the thread + * uses the VFP. + */ + last_VFP_context[cpu] = NULL; + +out: + put_cpu(); +} +#endif + #include <linux/smp.h> /* |