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-rw-r--r--arch/arm64/include/asm/assembler.h33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index bf125c591116..ca31594d3d6c 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -676,6 +676,23 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU
.endm
/*
+ * Set SCTLR_EL1 to the passed value, and invalidate the local icache
+ * in the process. This is called when setting the MMU on.
+ */
+.macro set_sctlr_el1, reg
+ msr sctlr_el1, \reg
+ isb
+ /*
+ * Invalidate the local I-cache so that any instructions fetched
+ * speculatively from the PoC are discarded, since they may have
+ * been dynamically patched at the PoU.
+ */
+ ic iallu
+ dsb nsh
+ isb
+.endm
+
+/*
* Check whether to yield to another runnable task from kernel mode NEON code
* (which runs with preemption disabled).
*
@@ -745,6 +762,22 @@ USER(\label, ic ivau, \tmp2) // invalidate I line PoU
.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
+ * time results in a preempt count of zero, and the TIF_NEED_RESCHED
+ * flag is set. (Note that the latter is stored negated in the
+ * top word of the thread_info::preempt_count field)
+ */
+ .macro cond_yield, lbl:req, tmp:req
+#ifdef CONFIG_PREEMPTION
+ get_current_task \tmp
+ ldr \tmp, [\tmp, #TSK_TI_PREEMPT]
+ sub \tmp, \tmp, #PREEMPT_DISABLE_OFFSET
+ cbz \tmp, \lbl
+#endif
+ .endm
+
/*
* This macro emits a program property note section identifying
* architecture features which require special handling, mainly for