[PATCH v2 5/7] ARM: asm: import Linux adr_l/ldr_l assembler.h definitions

[Ahmad Fatoum]

These macros will come in handy to have loads in assembly routines not
generate relocation entries.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 arch/arm/include/asm/assembler.h | 211 +++++++++++++++++++++++++++++++
 1 file changed, 211 insertions(+)

diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 7f9281b9a1a1..5db0f692eec6 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -130,3 +130,214 @@
 #else
 #define CPU_LE(code...) code
 #endif
+
+#ifdef CONFIG_CPU_64
+/*
+ * 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
+	 */
+	.macro	adr_l, dst, sym
+	adrp	\dst, \sym
+	add	\dst, \dst, :lo12:\sym
+	.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
+
+#else
+
+	.macro		__adldst_l, op, reg, sym, tmp, c
+	.if		__LINUX_ARM_ARCH__ < 7
+	ldr\c		\tmp, .La\@
+	.subsection	1
+	.align		2
+.La\@:	.long		\sym - .Lpc\@
+	.previous
+	.else
+	.ifnb		\c
+ THUMB(	ittt		\c			)
+	.endif
+	movw\c		\tmp, #:lower16:\sym - .Lpc\@
+	movt\c		\tmp, #:upper16:\sym - .Lpc\@
+	.endif
+
+#ifndef CONFIG_THUMB2_BAREBOX
+	.set		.Lpc\@, . + 8			// PC bias
+	.ifc		\op, add
+	add\c		\reg, \tmp, pc
+	.else
+	\op\c		\reg, [pc, \tmp]
+	.endif
+#else
+.Lb\@:	add\c		\tmp, \tmp, pc
+	/*
+	 * In Thumb-2 builds, the PC bias depends on whether we are currently
+	 * emitting into a .arm or a .thumb section. The size of the add opcode
+	 * above will be 2 bytes when emitting in Thumb mode and 4 bytes when
+	 * emitting in ARM mode, so let's use this to account for the bias.
+	 */
+	.set		.Lpc\@, . + (. - .Lb\@)
+
+	.ifnc		\op, add
+	\op\c		\reg, [\tmp]
+	.endif
+#endif
+	.endm
+
+	/*
+	 * mov_l - move a constant value or [relocated] address into a register
+	 */
+	.macro		mov_l, dst:req, imm:req, cond
+	.if		__LINUX_ARM_ARCH__ < 7
+	ldr\cond	\dst, =\imm
+	.else
+	movw\cond	\dst, #:lower16:\imm
+	movt\cond	\dst, #:upper16:\imm
+	.endif
+	.endm
+
+	/*
+	 * adr_l - adr pseudo-op with unlimited range
+	 *
+	 * @dst: destination register
+	 * @sym: name of the symbol
+	 * @cond: conditional opcode suffix
+	 */
+	.macro		adr_l, dst:req, sym:req, cond
+	__adldst_l	add, \dst, \sym, \dst, \cond
+	.endm
+
+	/*
+	 * ldr_l - ldr <literal> pseudo-op with unlimited range
+	 *
+	 * @dst: destination register
+	 * @sym: name of the symbol
+	 * @cond: conditional opcode suffix
+	 */
+	.macro		ldr_l, dst:req, sym:req, cond
+	__adldst_l	ldr, \dst, \sym, \dst, \cond
+	.endm
+
+	/*
+	 * str_l - str <literal> pseudo-op with unlimited range
+	 *
+	 * @src: source register
+	 * @sym: name of the symbol
+	 * @tmp: mandatory scratch register
+	 * @cond: conditional opcode suffix
+	 */
+	.macro		str_l, src:req, sym:req, tmp:req, cond
+	__adldst_l	str, \src, \sym, \tmp, \cond
+	.endm
+
+	.macro		__ldst_va, op, reg, tmp, sym, cond, offset
+#if __LINUX_ARM_ARCH__ >= 7 || \
+    (defined(MODULE) && defined(CONFIG_ARM_MODULE_PLTS))
+	mov_l		\tmp, \sym, \cond
+#else
+	/*
+	 * Avoid a literal load, by emitting a sequence of ADD/LDR instructions
+	 * with the appropriate relocations. The combined sequence has a range
+	 * of -/+ 256 MiB, which should be sufficient for the core kernel and
+	 * for modules loaded into the module region.
+	 */
+	.globl		\sym
+	.reloc		.L0_\@, R_ARM_ALU_PC_G0_NC, \sym
+	.reloc		.L1_\@, R_ARM_ALU_PC_G1_NC, \sym
+	.reloc		.L2_\@, R_ARM_LDR_PC_G2, \sym
+.L0_\@: sub\cond	\tmp, pc, #8 - \offset
+.L1_\@: sub\cond	\tmp, \tmp, #4 - \offset
+.L2_\@:
+#endif
+	\op\cond	\reg, [\tmp, #\offset]
+	.endm
+
+	/*
+	 * ldr_va - load a 32-bit word from the virtual address of \sym
+	 */
+	.macro		ldr_va, rd:req, sym:req, cond, tmp, offset=0
+	.ifnb		\tmp
+	__ldst_va	ldr, \rd, \tmp, \sym, \cond, \offset
+	.else
+	__ldst_va	ldr, \rd, \rd, \sym, \cond, \offset
+	.endif
+	.endm
+
+	/*
+	 * str_va - store a 32-bit word to the virtual address of \sym
+	 */
+	.macro		str_va, rn:req, sym:req, tmp:req, cond
+	__ldst_va	str, \rn, \tmp, \sym, \cond, 0
+	.endm
+
+	/*
+	 * ldr_this_cpu - Load a 32-bit word from the per-CPU variable 'sym'
+	 *		  into register 'rd', which may be the stack pointer,
+	 *		  using 't1' and 't2' as general temp registers. These
+	 *		  are permitted to overlap with 'rd' if != sp
+	 */
+	.macro		ldr_this_cpu, rd:req, sym:req, t1:req, t2:req
+	ldr_va		\rd, \sym, tmp=\t1
+	.endm
+
+	/*
+	 * rev_l - byte-swap a 32-bit value
+	 *
+	 * @val: source/destination register
+	 * @tmp: scratch register
+	 */
+	.macro		rev_l, val:req, tmp:req
+	.if		__LINUX_ARM_ARCH__ < 6
+	eor		\tmp, \val, \val, ror #16
+	bic		\tmp, \tmp, #0x00ff0000
+	mov		\val, \val, ror #8
+	eor		\val, \val, \tmp, lsr #8
+	.else
+	rev		\val, \val
+	.endif
+	.endm
+
+	/*
+	 * bl_r - branch and link to register
+	 *
+	 * @dst: target to branch to
+	 * @c: conditional opcode suffix
+	 */
+	.macro		bl_r, dst:req, c
+	.if		__LINUX_ARM_ARCH__ < 6
+	mov\c		lr, pc
+	mov\c		pc, \dst
+	.else
+	blx\c		\dst
+	.endif
+	.endm
+#endif
-- 
2.39.2