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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: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210302090118.30666-2-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Ard Biesheuvel 2021-03-02 10:01:10 +01:00 committed by Catalin Marinas
parent 1e28eed176
commit 27248fe1ab
1 changed files with 0 additions and 70 deletions
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70
arch/arm64/include/asm/assembler.h
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@ -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