[PATCH 3/3] x86/asm: use _ASM_BYTES() in <asm/nops.h>

From: H. Peter Anvin
Date: Mon May 10 2021 - 05:10:37 EST


From: "H. Peter Anvin (Intel)" <hpa@xxxxxxxxx>

Use the new generalized _ASM_BYTES() macro from <asm/asm.h> instead of
the "home grown" _ASM_MK_NOP() in <asm/nops.h>.

Add <asm/asm.h> and update <asm/nops.h> in the tools directory...

Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
---
arch/x86/include/asm/nops.h | 24 ++--
tools/arch/x86/include/asm/asm.h | 189 ++++++++++++++++++++++++++++++
tools/arch/x86/include/asm/nops.h | 24 ++--
3 files changed, 209 insertions(+), 28 deletions(-)
create mode 100644 tools/arch/x86/include/asm/asm.h

diff --git a/arch/x86/include/asm/nops.h b/arch/x86/include/asm/nops.h
index c1e5e818ba16..c5573eaa5bb9 100644
--- a/arch/x86/include/asm/nops.h
+++ b/arch/x86/include/asm/nops.h
@@ -2,6 +2,8 @@
#ifndef _ASM_X86_NOPS_H
#define _ASM_X86_NOPS_H

+#include <asm/asm.h>
+
/*
* Define nops for use with alternative() and for tracing.
*/
@@ -57,20 +59,14 @@

#endif /* CONFIG_64BIT */

-#ifdef __ASSEMBLY__
-#define _ASM_MK_NOP(x) .byte x
-#else
-#define _ASM_MK_NOP(x) ".byte " __stringify(x) "\n"
-#endif
-
-#define ASM_NOP1 _ASM_MK_NOP(BYTES_NOP1)
-#define ASM_NOP2 _ASM_MK_NOP(BYTES_NOP2)
-#define ASM_NOP3 _ASM_MK_NOP(BYTES_NOP3)
-#define ASM_NOP4 _ASM_MK_NOP(BYTES_NOP4)
-#define ASM_NOP5 _ASM_MK_NOP(BYTES_NOP5)
-#define ASM_NOP6 _ASM_MK_NOP(BYTES_NOP6)
-#define ASM_NOP7 _ASM_MK_NOP(BYTES_NOP7)
-#define ASM_NOP8 _ASM_MK_NOP(BYTES_NOP8)
+#define ASM_NOP1 _ASM_BYTES(BYTES_NOP1)
+#define ASM_NOP2 _ASM_BYTES(BYTES_NOP2)
+#define ASM_NOP3 _ASM_BYTES(BYTES_NOP3)
+#define ASM_NOP4 _ASM_BYTES(BYTES_NOP4)
+#define ASM_NOP5 _ASM_BYTES(BYTES_NOP5)
+#define ASM_NOP6 _ASM_BYTES(BYTES_NOP6)
+#define ASM_NOP7 _ASM_BYTES(BYTES_NOP7)
+#define ASM_NOP8 _ASM_BYTES(BYTES_NOP8)

#define ASM_NOP_MAX 8

diff --git a/tools/arch/x86/include/asm/asm.h b/tools/arch/x86/include/asm/asm.h
new file mode 100644
index 000000000000..1a1e22297867
--- /dev/null
+++ b/tools/arch/x86/include/asm/asm.h
@@ -0,0 +1,189 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_ASM_H
+#define _ASM_X86_ASM_H
+
+#ifdef __ASSEMBLY__
+# define __ASM_FORM(x, ...) x,## __VA_ARGS__
+# define __ASM_FORM_RAW(x, ...) x,## __VA_ARGS__
+# define __ASM_FORM_COMMA(x, ...) x,## __VA_ARGS__,
+#else
+#include <linux/stringify.h>
+# define __ASM_FORM(x, ...) " " __stringify(x,##__VA_ARGS__) " "
+# define __ASM_FORM_RAW(x, ...) __stringify(x,##__VA_ARGS__)
+# define __ASM_FORM_COMMA(x, ...) " " __stringify(x,##__VA_ARGS__) ","
+#endif
+
+#define _ASM_BYTES(x, ...) __ASM_FORM(.byte x,##__VA_ARGS__ ;)
+
+#ifndef __x86_64__
+/* 32 bit */
+# define __ASM_SEL(a,b) __ASM_FORM(a)
+# define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(a)
+#else
+/* 64 bit */
+# define __ASM_SEL(a,b) __ASM_FORM(b)
+# define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(b)
+#endif
+
+#define __ASM_SIZE(inst, ...) __ASM_SEL(inst##l##__VA_ARGS__, \
+ inst##q##__VA_ARGS__)
+#define __ASM_REG(reg) __ASM_SEL_RAW(e##reg, r##reg)
+
+#define _ASM_PTR __ASM_SEL(.long, .quad)
+#define _ASM_ALIGN __ASM_SEL(.balign 4, .balign 8)
+
+#define _ASM_MOV __ASM_SIZE(mov)
+#define _ASM_INC __ASM_SIZE(inc)
+#define _ASM_DEC __ASM_SIZE(dec)
+#define _ASM_ADD __ASM_SIZE(add)
+#define _ASM_SUB __ASM_SIZE(sub)
+#define _ASM_XADD __ASM_SIZE(xadd)
+#define _ASM_MUL __ASM_SIZE(mul)
+
+#define _ASM_AX __ASM_REG(ax)
+#define _ASM_BX __ASM_REG(bx)
+#define _ASM_CX __ASM_REG(cx)
+#define _ASM_DX __ASM_REG(dx)
+#define _ASM_SP __ASM_REG(sp)
+#define _ASM_BP __ASM_REG(bp)
+#define _ASM_SI __ASM_REG(si)
+#define _ASM_DI __ASM_REG(di)
+
+#ifndef __x86_64__
+/* 32 bit */
+
+#define _ASM_ARG1 _ASM_AX
+#define _ASM_ARG2 _ASM_DX
+#define _ASM_ARG3 _ASM_CX
+
+#define _ASM_ARG1L eax
+#define _ASM_ARG2L edx
+#define _ASM_ARG3L ecx
+
+#define _ASM_ARG1W ax
+#define _ASM_ARG2W dx
+#define _ASM_ARG3W cx
+
+#define _ASM_ARG1B al
+#define _ASM_ARG2B dl
+#define _ASM_ARG3B cl
+
+#else
+/* 64 bit */
+
+#define _ASM_ARG1 _ASM_DI
+#define _ASM_ARG2 _ASM_SI
+#define _ASM_ARG3 _ASM_DX
+#define _ASM_ARG4 _ASM_CX
+#define _ASM_ARG5 r8
+#define _ASM_ARG6 r9
+
+#define _ASM_ARG1Q rdi
+#define _ASM_ARG2Q rsi
+#define _ASM_ARG3Q rdx
+#define _ASM_ARG4Q rcx
+#define _ASM_ARG5Q r8
+#define _ASM_ARG6Q r9
+
+#define _ASM_ARG1L edi
+#define _ASM_ARG2L esi
+#define _ASM_ARG3L edx
+#define _ASM_ARG4L ecx
+#define _ASM_ARG5L r8d
+#define _ASM_ARG6L r9d
+
+#define _ASM_ARG1W di
+#define _ASM_ARG2W si
+#define _ASM_ARG3W dx
+#define _ASM_ARG4W cx
+#define _ASM_ARG5W r8w
+#define _ASM_ARG6W r9w
+
+#define _ASM_ARG1B dil
+#define _ASM_ARG2B sil
+#define _ASM_ARG3B dl
+#define _ASM_ARG4B cl
+#define _ASM_ARG5B r8b
+#define _ASM_ARG6B r9b
+
+#endif
+
+/*
+ * Macros to generate condition code outputs from inline assembly,
+ * The output operand must be type "bool".
+ */
+#ifdef __GCC_ASM_FLAG_OUTPUTS__
+# define CC_SET(c) "\n\t/* output condition code " #c "*/\n"
+# define CC_OUT(c) "=@cc" #c
+#else
+# define CC_SET(c) "\n\tset" #c " %[_cc_" #c "]\n"
+# define CC_OUT(c) [_cc_ ## c] "=qm"
+#endif
+
+/* Exception table entry */
+#ifdef __ASSEMBLY__
+# define _ASM_EXTABLE_HANDLE(from, to, handler) \
+ .pushsection "__ex_table","a" ; \
+ .balign 4 ; \
+ .long (from) - . ; \
+ .long (to) - . ; \
+ .long (handler) - . ; \
+ .popsection
+
+# define _ASM_EXTABLE(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
+
+# define _ASM_EXTABLE_UA(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess)
+
+# define _ASM_EXTABLE_CPY(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_copy)
+
+# define _ASM_EXTABLE_FAULT(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
+
+# ifdef CONFIG_KPROBES
+# define _ASM_NOKPROBE(entry) \
+ .pushsection "_kprobe_blacklist","aw" ; \
+ _ASM_ALIGN ; \
+ _ASM_PTR (entry); \
+ .popsection
+# else
+# define _ASM_NOKPROBE(entry)
+# endif
+
+#else /* ! __ASSEMBLY__ */
+# define _EXPAND_EXTABLE_HANDLE(x) #x
+# define _ASM_EXTABLE_HANDLE(from, to, handler) \
+ " .pushsection \"__ex_table\",\"a\"\n" \
+ " .balign 4\n" \
+ " .long (" #from ") - .\n" \
+ " .long (" #to ") - .\n" \
+ " .long (" _EXPAND_EXTABLE_HANDLE(handler) ") - .\n" \
+ " .popsection\n"
+
+# define _ASM_EXTABLE(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
+
+# define _ASM_EXTABLE_UA(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_uaccess)
+
+# define _ASM_EXTABLE_CPY(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_copy)
+
+# define _ASM_EXTABLE_FAULT(from, to) \
+ _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
+
+/* For C file, we already have NOKPROBE_SYMBOL macro */
+
+/*
+ * This output constraint should be used for any inline asm which has a "call"
+ * instruction. Otherwise the asm may be inserted before the frame pointer
+ * gets set up by the containing function. If you forget to do this, objtool
+ * may print a "call without frame pointer save/setup" warning.
+ */
+register unsigned long current_stack_pointer asm(_ASM_SP);
+#define ASM_CALL_CONSTRAINT "+r" (current_stack_pointer)
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_X86_ASM_H */
diff --git a/tools/arch/x86/include/asm/nops.h b/tools/arch/x86/include/asm/nops.h
index c1e5e818ba16..c5573eaa5bb9 100644
--- a/tools/arch/x86/include/asm/nops.h
+++ b/tools/arch/x86/include/asm/nops.h
@@ -2,6 +2,8 @@
#ifndef _ASM_X86_NOPS_H
#define _ASM_X86_NOPS_H

+#include <asm/asm.h>
+
/*
* Define nops for use with alternative() and for tracing.
*/
@@ -57,20 +59,14 @@

#endif /* CONFIG_64BIT */

-#ifdef __ASSEMBLY__
-#define _ASM_MK_NOP(x) .byte x
-#else
-#define _ASM_MK_NOP(x) ".byte " __stringify(x) "\n"
-#endif
-
-#define ASM_NOP1 _ASM_MK_NOP(BYTES_NOP1)
-#define ASM_NOP2 _ASM_MK_NOP(BYTES_NOP2)
-#define ASM_NOP3 _ASM_MK_NOP(BYTES_NOP3)
-#define ASM_NOP4 _ASM_MK_NOP(BYTES_NOP4)
-#define ASM_NOP5 _ASM_MK_NOP(BYTES_NOP5)
-#define ASM_NOP6 _ASM_MK_NOP(BYTES_NOP6)
-#define ASM_NOP7 _ASM_MK_NOP(BYTES_NOP7)
-#define ASM_NOP8 _ASM_MK_NOP(BYTES_NOP8)
+#define ASM_NOP1 _ASM_BYTES(BYTES_NOP1)
+#define ASM_NOP2 _ASM_BYTES(BYTES_NOP2)
+#define ASM_NOP3 _ASM_BYTES(BYTES_NOP3)
+#define ASM_NOP4 _ASM_BYTES(BYTES_NOP4)
+#define ASM_NOP5 _ASM_BYTES(BYTES_NOP5)
+#define ASM_NOP6 _ASM_BYTES(BYTES_NOP6)
+#define ASM_NOP7 _ASM_BYTES(BYTES_NOP7)
+#define ASM_NOP8 _ASM_BYTES(BYTES_NOP8)

#define ASM_NOP_MAX 8

--
2.31.1