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From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@alien8.de>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Brian Gerst <brgerst@gmail.com>
Subject: [PATCH v2 09/10] x86/percpu: Clean up percpu_stable_op()
Date: Sat, 30 May 2020 18:11:26 -0400	[thread overview]
Message-ID: <20200530221127.459704-10-brgerst@gmail.com> (raw)
In-Reply-To: <20200530221127.459704-1-brgerst@gmail.com>

Use __pcpu_size_call_return() to simplify this_cpu_read_stable().
Also remove __bad_percpu_size() which is now unused.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
---
 arch/x86/include/asm/percpu.h | 41 ++++++++++-------------------------
 1 file changed, 12 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 7efc0b5c4ff0..cf2b9c2a241e 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -85,7 +85,6 @@
 
 /* For arch-specific code, we can use direct single-insn ops (they
  * don't give an lvalue though). */
-extern void __bad_percpu_size(void);
 
 #define __pcpu_type_1 u8
 #define __pcpu_type_2 u16
@@ -167,33 +166,13 @@ do {									\
 	(typeof(_var))(unsigned long) pfo_val__;			\
 })
 
-#define percpu_stable_op(op, var)			\
-({							\
-	typeof(var) pfo_ret__;				\
-	switch (sizeof(var)) {				\
-	case 1:						\
-		asm(op "b "__percpu_arg(P1)",%0"	\
-		    : "=q" (pfo_ret__)			\
-		    : "p" (&(var)));			\
-		break;					\
-	case 2:						\
-		asm(op "w "__percpu_arg(P1)",%0"	\
-		    : "=r" (pfo_ret__)			\
-		    : "p" (&(var)));			\
-		break;					\
-	case 4:						\
-		asm(op "l "__percpu_arg(P1)",%0"	\
-		    : "=r" (pfo_ret__)			\
-		    : "p" (&(var)));			\
-		break;					\
-	case 8:						\
-		asm(op "q "__percpu_arg(P1)",%0"	\
-		    : "=r" (pfo_ret__)			\
-		    : "p" (&(var)));			\
-		break;					\
-	default: __bad_percpu_size();			\
-	}						\
-	pfo_ret__;					\
+#define percpu_stable_op(size, op, _var)				\
+({									\
+	__pcpu_type_##size pfo_val__;					\
+	asm(__pcpu_op2_##size(op, __percpu_arg(P[var]), "%[val]")	\
+	    : [val] __pcpu_reg_##size("=", pfo_val__)			\
+	    : [var] "p" (&(_var)));					\
+	(typeof(_var))(unsigned long) pfo_val__;			\
 })
 
 /*
@@ -258,7 +237,11 @@ do {									\
  * per-thread variables implemented as per-cpu variables and thus
  * stable for the duration of the respective task.
  */
-#define this_cpu_read_stable(var)	percpu_stable_op("mov", var)
+#define this_cpu_read_stable_1(pcp)	percpu_stable_op(1, "mov", pcp)
+#define this_cpu_read_stable_2(pcp)	percpu_stable_op(2, "mov", pcp)
+#define this_cpu_read_stable_4(pcp)	percpu_stable_op(4, "mov", pcp)
+#define this_cpu_read_stable_8(pcp)	percpu_stable_op(8, "mov", pcp)
+#define this_cpu_read_stable(pcp)	__pcpu_size_call_return(this_cpu_read_stable_, pcp)
 
 #define raw_cpu_read_1(pcp)		percpu_from_op(1, , "mov", pcp)
 #define raw_cpu_read_2(pcp)		percpu_from_op(2, , "mov", pcp)
-- 
2.25.4


  parent reply	other threads:[~2020-05-30 22:12 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-30 22:11 [PATCH v2 00/10] x86: Clean up percpu operations Brian Gerst
2020-05-30 22:11 ` [PATCH v2 01/10] x86/percpu: Introduce size abstraction macros Brian Gerst
2020-06-01 20:48   ` Nick Desaulniers
2020-05-30 22:11 ` [PATCH v2 02/10] x86/percpu: Clean up percpu_to_op() Brian Gerst
2020-07-09 10:30   ` Peter Zijlstra
2020-07-10  4:38     ` Brian Gerst
2020-07-10  8:53       ` Peter Zijlstra
2020-07-10 16:56         ` Nick Desaulniers
2020-05-30 22:11 ` [PATCH v2 03/10] x86/percpu: Clean up percpu_from_op() Brian Gerst
2020-05-30 22:11 ` [PATCH v2 04/10] x86/percpu: Clean up percpu_add_op() Brian Gerst
2020-06-01 20:18   ` Nick Desaulniers
2020-05-30 22:11 ` [PATCH v2 05/10] x86/percpu: Remove "e" constraint from XADD Brian Gerst
2020-06-01 18:50   ` Nick Desaulniers
2020-05-30 22:11 ` [PATCH v2 06/10] x86/percpu: Clean up percpu_add_return_op() Brian Gerst
2020-06-01 19:47   ` Nick Desaulniers
2020-05-30 22:11 ` [PATCH v2 07/10] x86/percpu: Clean up percpu_xchg_op() Brian Gerst
2020-05-30 22:11 ` [PATCH v2 08/10] x86/percpu: Clean up percpu_cmpxchg_op() Brian Gerst
2020-05-30 22:11 ` Brian Gerst [this message]
2020-06-01 20:43   ` [PATCH v2 09/10] x86/percpu: Clean up percpu_stable_op() Nick Desaulniers
2020-06-02 14:19     ` Brian Gerst
2020-07-09 10:25       ` Peter Zijlstra
2020-05-30 22:11 ` [PATCH v2 10/10] x86/percpu: Remove unused PER_CPU() macro Brian Gerst
2020-06-01 20:26   ` Nick Desaulniers
2020-06-01 21:00 ` [PATCH v2 00/10] x86: Clean up percpu operations Nick Desaulniers
2020-07-08 19:36   ` Nick Desaulniers
2020-07-09 20:02     ` Nick Desaulniers
2020-07-13 22:24     ` Nick Desaulniers
2020-07-13 22:40       ` Linus Torvalds
2020-07-13 22:58         ` Nick Desaulniers
2020-07-14  0:31           ` Nick Desaulniers
2020-07-14  1:29             ` Linus Torvalds
2020-07-09 10:30 ` Peter Zijlstra

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