Commit 8884b7bd authored by Dave Martin's avatar Dave Martin Committed by Will Deacon
Browse files

arm64: fpsimd: Abstract out binding of task's fpsimd context to the cpu. 



There is currently some duplicate logic to associate current's
FPSIMD context with the cpu when loading FPSIMD state into the cpu
regs.

Subsequent patches will update that logic, so in order to ensure it
only needs to be done in one place, this patch factors the relevant
code out into a new function fpsimd_bind_to_cpu().

Signed-off-by: default avatarDave Martin <Dave.Martin@arm.com>
Reviewed-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent 071b6d4a

arch/arm64/kernel/fpsimd.c

+15 −10
Original line number Diff line number Diff line
@@ -991,6 +991,18 @@ void fpsimd_signal_preserve_current_state(void) 
		sve_to_fpsimd(current);

}



/*

 * Associate current's FPSIMD context with this cpu

 * Preemption must be disabled when calling this function.

 */

static void fpsimd_bind_to_cpu(void)

{

	struct fpsimd_state *st = &current->thread.fpsimd_state;



	__this_cpu_write(fpsimd_last_state, st);

	st->cpu = smp_processor_id();

}



/*

 * Load the userland FPSIMD state of 'current' from memory, but only if the

 * FPSIMD state already held in the registers is /not/ the most recent FPSIMD
@@ -1004,11 +1016,8 @@ void fpsimd_restore_current_state(void) 
	local_bh_disable();



	if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) {

		struct fpsimd_state *st = &current->thread.fpsimd_state;



		task_fpsimd_load();

		__this_cpu_write(fpsimd_last_state, st);

		st->cpu = smp_processor_id();

		fpsimd_bind_to_cpu();

	}



	local_bh_enable();
@@ -1032,12 +1041,8 @@ void fpsimd_update_current_state(struct fpsimd_state *state) 


	task_fpsimd_load();



	if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) {

		struct fpsimd_state *st = &current->thread.fpsimd_state;



		__this_cpu_write(fpsimd_last_state, st);

		st->cpu = smp_processor_id();

	}

	if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE))

		fpsimd_bind_to_cpu();



	local_bh_enable();

}

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