[PATCH v7 05/16] arm64: fpsimd: Generalise context saving for non-task contexts

[Catalin Marinas]

On Wed, May 09, 2018 at 05:12:54PM +0100, Dave P Martin wrote:
> In preparation for allowing non-task (i.e., KVM vcpu) FPSIMD
> contexts to be handled by the fpsimd common code, this patch adapts
> task_fpsimd_save() to save back the currently loaded context,
> removing the explicit dependency on current.
> 
> The relevant storage to write back to in memory is now found by
> examining the fpsimd_last_state percpu struct.
> 
> fpsimd_save() does nothing unless TIF_FOREIGN_FPSTATE is clear, and
> fpsimd_last_state is updated under local_bh_disable() or
> local_irq_disable() everywhere that TIF_FOREIGN_FPSTATE is cleared:
> thus, fpsimd_save() will write back to the correct storage for the
> loaded context.
> 
> No functional change.
> 
> Signed-off-by: Dave Martin <Dave.Martin at arm.com>
> Acked-by: Marc Zyngier <marc.zyngier at arm.com>

Acked-by: Catalin Marinas <catalin.marinas at arm.com>