linux-kernel - [PATCH v2 4/4] locking/atomic: hexagon: arch_cmpxchg[64]

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Message-Id: <20231104091615.4884-5-wuqiang.matt@bytedance.com>
Date:   Sat,  4 Nov 2023 17:16:15 +0800
From:   "wuqiang.matt" <wuqiang.matt@...edance.com>
To:     vgupta@...nel.org, bcain@...cinc.com, jonas@...thpole.se,
        stefan.kristiansson@...nalahti.fi, shorne@...il.com,
        geert@...ux-m68k.org, andi.shyti@...ux.intel.com, mingo@...nel.org,
        palmer@...osinc.com, andrzej.hajda@...el.com, arnd@...db.de,
        peterz@...radead.orgm, mhiramat@...nel.org
Cc:     linux-snps-arc@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-hexagon@...r.kernel.org, linux-openrisc@...r.kernel.org,
        linux-trace-kernel@...r.kernel.org, mattwu@....com,
        linux@...ck-us.ne, "wuqiang.matt" <wuqiang.matt@...edance.com>,
        kernel test robot <lkp@...el.com>
Subject: [PATCH v2 4/4] locking/atomic: hexagon: arch_cmpxchg[64]_local undefined

For architectures that support native cmpxchg, we'd like to
implement arch_cmpxchg[64]_local with the native variants of
supported data size. If not, the generci_cmpxchg[64]_local
will be used.

Reported-by: kernel test robot <lkp@...el.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202310272207.tLPflya4-lkp@intel.com/

Signed-off-by: wuqiang.matt <wuqiang.matt@...edance.com>
---
 arch/hexagon/include/asm/cmpxchg.h | 51 +++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/arch/hexagon/include/asm/cmpxchg.h b/arch/hexagon/include/asm/cmpxchg.h
index bf6cf5579cf4..2b5e5bbaf807 100644
--- a/arch/hexagon/include/asm/cmpxchg.h
+++ b/arch/hexagon/include/asm/cmpxchg.h
@@ -8,6 +8,8 @@
 #ifndef _ASM_CMPXCHG_H
 #define _ASM_CMPXCHG_H
 
+#include <linux/build_bug.h>
+
 /*
  * __arch_xchg - atomically exchange a register and a memory location
  * @x: value to swap
@@ -51,13 +53,15 @@ __arch_xchg(unsigned long x, volatile void *ptr, int size)
  *  variable casting.
  */
 
-#define arch_cmpxchg(ptr, old, new)				\
+#define __cmpxchg_32(ptr, old, new)				\
 ({								\
 	__typeof__(ptr) __ptr = (ptr);				\
 	__typeof__(*(ptr)) __old = (old);			\
 	__typeof__(*(ptr)) __new = (new);			\
 	__typeof__(*(ptr)) __oldval = 0;			\
 								\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 4);			\
+								\
 	asm volatile(						\
 		"1:	%0 = memw_locked(%1);\n"		\
 		"	{ P0 = cmp.eq(%0,%2);\n"		\
@@ -72,4 +76,49 @@ __arch_xchg(unsigned long x, volatile void *ptr, int size)
 	__oldval;						\
 })
 
+#define __cmpxchg(ptr, old, val, size)				\
+({								\
+	__typeof__(*(ptr)) oldval;				\
+								\
+	switch (size) {						\
+	case 4:							\
+		oldval = __cmpxchg_32(ptr, old, val);		\
+		break;						\
+	default:						\
+		BUILD_BUG();					\
+		oldval = val;					\
+		break;						\
+	}							\
+								\
+	oldval;							\
+})
+
+#define arch_cmpxchg(ptr, o, n)	__cmpxchg((ptr), (o), (n), sizeof(*(ptr)))
+
+/*
+ * always make arch_cmpxchg[64]_local available, native cmpxchg
+ * will be used if available, then generic_cmpxchg[64]_local
+ */
+#include <asm-generic/cmpxchg-local.h>
+
+#define arch_cmpxchg_local(ptr, old, val)			\
+({								\
+	__typeof__(*(ptr)) retval;				\
+	int size = sizeof(*(ptr));				\
+								\
+	switch (size) {						\
+	case 4:							\
+		retval = __cmpxchg_32(ptr, old, val);		\
+		break;						\
+	default:						\
+		retval = __generic_cmpxchg_local(ptr, old,	\
+						 val, size);	\
+		break;						\
+	}							\
+								\
+	retval;							\
+})
+
+#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
+
 #endif /* _ASM_CMPXCHG_H */
-- 
2.40.1