From: Ard Biesheuvel
mainline inclusion
from mainline-v5.13-rc1
commit 27248fe1abb2
category: bugfix
issue: #I3ZXZF
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
-----------------------------------------------
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
Acked-by: Will Deacon
Link: https://lore.kernel.org/r/20210302090118.30666-2-ardb@kernel.org
Signed-off-by: Catalin Marinas
Signed-off-by: Wei Li
Reviewed-by: Jason Yan
Reviewed-by: Hanjun Guo
Signed-off-by: Chen Jun
Signed-off-by: Yu Changchun
---
arch/arm64/include/asm/assembler.h | 70 ------------------------------
1 file changed, 70 deletions(-)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index f1838bd93a40..2746aaa61438 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -675,76 +675,6 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU
.endif
.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
--
2.22.0
