[PATCH 1/2][Aarch64][binutils] Add support for PAN architecture extension.

[PATCH 1/2][Aarch64][binutils] Add support for PAN architecture extension.

[Matthew Wahab]

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The ARMv8.1 architecture introduced the Privileged Access Never extension. This
adds a processor state field PSTATE.PAN which can be accessed using the MRS/MSR
instructions.

This patch adds support for the PAN architecture feature and processor state
field to binutils. A following patch will add support to GAS.
	
Tested for aarch64-none-linux-gnu with check-binutils and check-gas with no
failures.

Ok for trunk?

include/opcode
2015-05-20  Matthew Wahab  <matthew.wahab@arm.com>

	* aarch64.h (AARCH64_FEATURE_PAN): New.
	(aarch64_sys_reg_supported_p): Declare.
	(aarch64_pstatefield_supported_p): Declare.

opcodes/
2015-05-20  Matthew Wahab  <matthew.wahab@arm.com>
	* aarch64-opc.c (F_ARCHEXT): New.
	(aarch64_sys_regs): Add "pan".
	(aarch64_sys_reg_supported_p): New.
	(aarch64_pstatefields): Add "pan".
	(aarch64_pstatefield_supported_p): New.

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From f70d30b3797028f609aa8af8ce5a2e75eec17432 Mon Sep 17 00:00:00 2001
From: Matthew Wahab <matthew.wahab@arm.com>
Date: Wed, 6 May 2015 14:22:50 +0100
Subject: [PATCH 1/2] Add binutils support for PAN extension.

Change-Id: I8fc388bc9f5ce568805ae3045a1bd5a2f0e8321a
---
 include/opcode/aarch64.h |  5 +++++
 opcodes/aarch64-opc.c    | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/include/opcode/aarch64.h b/include/opcode/aarch64.h
index 7130d2d..8df82a1 100644
--- a/include/opcode/aarch64.h
+++ b/include/opcode/aarch64.h
@@ -39,6 +39,7 @@ typedef uint32_t aarch64_insn;
 #define AARCH64_FEATURE_SIMD	0x00040000	/* SIMD instructions.  */
 #define AARCH64_FEATURE_CRC	0x00080000	/* CRC instructions.  */
 #define AARCH64_FEATURE_LSE	0x00100000	/* LSE instructions.  */
+#define AARCH64_FEATURE_PAN	0x00200000	/* PAN instructions.  */
 
 /* Architectures are the sum of the base and extensions.  */
 #define AARCH64_ARCH_V8		AARCH64_FEATURE (AARCH64_FEATURE_V8, \
@@ -629,6 +630,10 @@ typedef struct
 extern const aarch64_sys_reg aarch64_sys_regs [];
 extern const aarch64_sys_reg aarch64_pstatefields [];
 extern bfd_boolean aarch64_sys_reg_deprecated_p (const aarch64_sys_reg *);
+extern bfd_boolean aarch64_sys_reg_supported_p (const aarch64_feature_set,
+						const aarch64_sys_reg *);
+extern bfd_boolean aarch64_pstatefield_supported_p (const aarch64_feature_set,
+						    const aarch64_sys_reg *);
 
 typedef struct
 {
diff --git a/opcodes/aarch64-opc.c b/opcodes/aarch64-opc.c
index 5ea1384..5c7ef86 100644
--- a/opcodes/aarch64-opc.c
+++ b/opcodes/aarch64-opc.c
@@ -2723,6 +2723,12 @@ aarch64_print_operand (char *buf, size_t size, bfd_vma pc,
 #endif
 #define F_DEPRECATED	0x1	/* Deprecated system register.  */
 
+#ifdef F_ARCHEXT
+#undef F_ARCHEXT
+#endif
+#define F_ARCHEXT	0x2	/* Architecture dependent system register.  */
+
+
 /* TODO there are two more issues need to be resolved
    1. handle read-only and write-only system registers
    2. handle cpu-implementation-defined system registers.  */
@@ -2734,6 +2740,7 @@ const aarch64_sys_reg aarch64_sys_regs [] =
   { "spsel",            CPEN_(0,C2,0),	0 },
   { "daif",             CPEN_(3,C2,1),	0 },
   { "currentel",        CPEN_(0,C2,2),	0 }, /* RO */
+  { "pan",		CPEN_(0,C2,3),	F_ARCHEXT },
   { "nzcv",             CPEN_(3,C2,0),	0 },
   { "fpcr",             CPEN_(3,C4,0),	0 },
   { "fpsr",             CPEN_(3,C4,1),	0 },
@@ -3043,14 +3050,45 @@ aarch64_sys_reg_deprecated_p (const aarch64_sys_reg *reg)
   return (reg->flags & F_DEPRECATED) != 0;
 }
 
+bfd_boolean
+aarch64_sys_reg_supported_p (const aarch64_feature_set features,
+			     const aarch64_sys_reg *reg)
+{
+  if (!(reg->flags & F_ARCHEXT))
+    return TRUE;
+
+  /* PAN.  Values are from aarch64_sys_regs.  */
+  if (reg->value == CPEN_(0,C2,3)
+      && !AARCH64_CPU_HAS_FEATURE (features, AARCH64_FEATURE_PAN))
+    return FALSE;
+
+  return TRUE;
+}
+
 const aarch64_sys_reg aarch64_pstatefields [] =
 {
   { "spsel",            0x05,	0 },
   { "daifset",          0x1e,	0 },
   { "daifclr",          0x1f,	0 },
+  { "pan",		0x04,	F_ARCHEXT },
   { 0,          CPENC(0,0,0,0,0), 0 },
 };
 
+bfd_boolean
+aarch64_pstatefield_supported_p (const aarch64_feature_set features,
+				 const aarch64_sys_reg *reg)
+{
+  if (!(reg->flags & F_ARCHEXT))
+    return TRUE;
+
+  /* PAN.  Values are from aarch64_pstatefields.  */
+  if (reg->value == 0x04
+      && !AARCH64_CPU_HAS_FEATURE (features, AARCH64_FEATURE_PAN))
+    return FALSE;
+
+  return TRUE;
+}
+
 const aarch64_sys_ins_reg aarch64_sys_regs_ic[] =
 {
     { "ialluis", CPENS(0,C7,C1,0), 0 },
-- 
1.9.1

Re: [PATCH 1/2][Aarch64][binutils] Add support for PAN architecture extension.

[Nicholas Clifton]

Hi Matthew,

> include/opcode
> 2015-05-20  Matthew Wahab  <matthew.wahab@arm.com>
>
>      * aarch64.h (AARCH64_FEATURE_PAN): New.
>      (aarch64_sys_reg_supported_p): Declare.
>      (aarch64_pstatefield_supported_p): Declare.
>
> opcodes/
> 2015-05-20  Matthew Wahab  <matthew.wahab@arm.com>
>      * aarch64-opc.c (F_ARCHEXT): New.
>      (aarch64_sys_regs): Add "pan".
>      (aarch64_sys_reg_supported_p): New.
>      (aarch64_pstatefields): Add "pan".
>      (aarch64_pstatefield_supported_p): New.

Approved - please apply.

Cheers
   Nick