arm64: Add this_cpu_ptr() assembler macro for use in entry.S
irq_stack is a per_cpu variable, that needs to be access from entry.S.
Use an assembler macro instead of the unreadable details.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 12eff92..bb7b727 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -193,6 +193,17 @@
str \src, [\tmp, :lo12:\sym]
.endm
+ /*
+ * @sym: The name of the per-cpu variable
+ * @reg: Result of per_cpu(sym, smp_processor_id())
+ * @tmp: scratch register
+ */
+ .macro this_cpu_ptr, sym, reg, tmp
+ adr_l \reg, \sym
+ mrs \tmp, tpidr_el1
+ add \reg, \reg, \tmp
+ .endm
+
/*
* Annotate a function as position independent, i.e., safe to be called before
* the kernel virtual mapping is activated.