From 0dfa1c12f300d06f95d861d2718ef198e37473a6 Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Fri, 20 May 2016 23:28:37 +0100
Subject: [PATCH] MIPS: Add inline asm encoding helpers
To allow simplification of macros which use inline assembly to
explicitly encode instructions, add a few simple abstractions to
mipsregs.h which expand to specific microMIPS or normal MIPS encodings
depending on what type of kernel is being built:
_ASM_INSN_IF_MIPS(_enc) : Emit a 32bit MIPS instruction if microMIPS is
not enabled.
_ASM_INSN32_IF_MM(_enc) : Emit a 32bit microMIPS instruction if enabled.
_ASM_INSN16_IF_MM(_enc) : Emit a 16bit microMIPS instruction if enabled.
The macros can be used one after another since the MIPS / microMIPS
macros are mutually exclusive, for example:
__asm__ __volatile__(
".set push\n\t"
".set noat\n\t"
"# mfgc0 $1, $%1, %2\n\t"
_ASM_INSN_IF_MIPS(0x40610000 | %1 << 11 | %2)
_ASM_INSN32_IF_MM(0x002004fc | %1 << 16 | %2 << 11)
"move %0, $1\n\t"
".set pop"
: "=r" (__res)
: "i" (source), "i" (sel));
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13310/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/include/asm/mipsregs.h | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 044219e741cc3..1ce2c72ab88db 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -1048,6 +1048,33 @@ static inline int mm_insn_16bit(u16 insn)
return (opcode >= 1 && opcode <= 3) ? 1 : 0;
}
+/*
+ * Helper macros for generating raw instruction encodings in inline asm.
+ */
+#ifdef CONFIG_CPU_MICROMIPS
+#define _ASM_INSN16_IF_MM(_enc) \
+ ".insn\n\t" \
+ ".hword (" #_enc ")\n\t"
+#define _ASM_INSN32_IF_MM(_enc) \
+ ".insn\n\t" \
+ ".hword ((" #_enc ") >> 16)\n\t" \
+ ".hword ((" #_enc ") & 0xffff)\n\t"
+#else
+#define _ASM_INSN_IF_MIPS(_enc) \
+ ".insn\n\t" \
+ ".word (" #_enc ")\n\t"
+#endif
+
+#ifndef _ASM_INSN16_IF_MM
+#define _ASM_INSN16_IF_MM(_enc)
+#endif
+#ifndef _ASM_INSN32_IF_MM
+#define _ASM_INSN32_IF_MM(_enc)
+#endif
+#ifndef _ASM_INSN_IF_MIPS
+#define _ASM_INSN_IF_MIPS(_enc)
+#endif
+
/*
* TLB Invalidate Flush
*/
--
GitLab