Commit 27248fe1 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
Browse files

arm64: assembler: remove conditional NEON yield macros 



The users of the conditional NEON yield macros have all been switched to
the simplified cond_yield macro, and so the NEON specific ones can be
removed.

Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Acked-by: default avatarWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210302090118.30666-2-ardb@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 1e28eed1

arch/arm64/include/asm/assembler.h

+0 −70
Original line number Diff line number Diff line
@@ -692,76 +692,6 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU 
	isb

.endm



/*

 * Check whether to yield to another runnable task from kernel mode NEON code

 * (which runs with preemption disabled).

 *

 * if_will_cond_yield_neon

 *        // pre-yield patchup code

 * do_cond_yield_neon

 *        // post-yield patchup code

 * endif_yield_neon    <label>

 *

 * where <label> is optional, and marks the point where execution will resume

 * after a yield has been performed. If omitted, execution resumes right after

 * the endif_yield_neon invocation. Note that the entire sequence, including

 * the provided patchup code, will be omitted from the image if

 * CONFIG_PREEMPTION is not defined.

 *

 * As a convenience, in the case where no patchup code is required, the above

 * sequence may be abbreviated to

 *

 * cond_yield_neon <label>

 *

 * Note that the patchup code does not support assembler directives that change

 * the output section, any use of such directives is undefined.

 *

 * The yield itself consists of the following:

 * - Check whether the preempt count is exactly 1 and a reschedule is also

 *   needed. If so, calling of preempt_enable() in kernel_neon_end() will

 *   trigger a reschedule. If it is not the case, yielding is pointless.

 * - Disable and re-enable kernel mode NEON, and branch to the yield fixup

 *   code.

 *

 * This macro sequence may clobber all CPU state that is not guaranteed by the

 * AAPCS to be preserved across an ordinary function call.

 */



	.macro		cond_yield_neon, lbl

	if_will_cond_yield_neon

	do_cond_yield_neon

	endif_yield_neon	\lbl

	.endm



	.macro		if_will_cond_yield_neon

#ifdef CONFIG_PREEMPTION

	get_current_task	x0

	ldr		x0, [x0, #TSK_TI_PREEMPT]

	sub		x0, x0, #PREEMPT_DISABLE_OFFSET

	cbz		x0, .Lyield_\@

	/* fall through to endif_yield_neon */

	.subsection	1

.Lyield_\@ :

#else

	.section	".discard.cond_yield_neon", "ax"

#endif

	.endm



	.macro		do_cond_yield_neon

	bl		kernel_neon_end

	bl		kernel_neon_begin

	.endm



	.macro		endif_yield_neon, lbl

	.ifnb		\lbl

	b		\lbl

	.else

	b		.Lyield_out_\@

	.endif

	.previous

.Lyield_out_\@ :

	.endm



	/*

	 * Check whether preempt-disabled code should yield as soon as it

	 * is able. This is the case if re-enabling preemption a single