arch: arm: cortex_m: Update APIs to save and restore FPU context #93057
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Added missing #include for used types uint32_t and bool in file fpu.h Signed-off-by: Michele Sardo <[email protected]>
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z_arm_save_fp_context and z_arm_restore_fp_context save and restore fpu context regardless of the CONFIG_FPU_SHARING setting. This modification is required to support suspend to ram use cases where save and restore of FPU state is needed to ensure proper bahaviour after wakeup. Signed-off-by: Michele Sardo <[email protected]>
Following changes to arch/arm/core/cortex_m/fpu.c, the dependency on CONFIG_FPU_SHARING is moved into this file. Signed-off-by: Michele Sardo <[email protected]>
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Update API to save and restore FPU context to address suspend to ram use case.
The API is updated as follow:
z_arm_save_fp_contextandz_arm_restore_fp_contexthave been changed to always save/restore FPU context regardless ofFPU_SHARINGsettingI also noticed by reading code and ARM documentation that the FPU context is preserved across threads by hardware on Cortex-M devices (via the FPCCR.ASPEN register field).
See also #90001, #92847 (comment)