arm64: add macros for common adrp usages
The adrp instruction is mostly used in combination with either
an add, a ldr or a str instruction with the low bits of the
referenced symbol in the 12-bit immediate of the followup
instruction.
Introduce the macros adr_l, ldr_l and str_l that encapsulate
these common patterns.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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 750bac4..144b64a 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -159,4 +159,52 @@
orr \rd, \lbits, \hbits, lsl #32
.endm
+/*
+ * Pseudo-ops for PC-relative adr/ldr/str <reg>, <symbol> where
+ * <symbol> is within the range +/- 4 GB of the PC.
+ */
+ /*
+ * @dst: destination register (64 bit wide)
+ * @sym: name of the symbol
+ * @tmp: optional scratch register to be used if <dst> == sp, which
+ * is not allowed in an adrp instruction
+ */
+ .macro adr_l, dst, sym, tmp=
+ .ifb \tmp
+ adrp \dst, \sym
+ add \dst, \dst, :lo12:\sym
+ .else
+ adrp \tmp, \sym
+ add \dst, \tmp, :lo12:\sym
+ .endif
+ .endm
+
+ /*
+ * @dst: destination register (32 or 64 bit wide)
+ * @sym: name of the symbol
+ * @tmp: optional 64-bit scratch register to be used if <dst> is a
+ * 32-bit wide register, in which case it cannot be used to hold
+ * the address
+ */
+ .macro ldr_l, dst, sym, tmp=
+ .ifb \tmp
+ adrp \dst, \sym
+ ldr \dst, [\dst, :lo12:\sym]
+ .else
+ adrp \tmp, \sym
+ ldr \dst, [\tmp, :lo12:\sym]
+ .endif
+ .endm
+
+ /*
+ * @src: source register (32 or 64 bit wide)
+ * @sym: name of the symbol
+ * @tmp: mandatory 64-bit scratch register to calculate the address
+ * while <src> needs to be preserved.
+ */
+ .macro str_l, src, sym, tmp
+ adrp \tmp, \sym
+ str \src, [\tmp, :lo12:\sym]
+ .endm
+
#endif /* __ASM_ASSEMBLER_H */