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From:   Anders Roxell <anders.roxell@linaro.org>
To:     mpe@ellerman.id.au
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        Anders Roxell <anders.roxell@linaro.org>,
        stable@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH 2/3] powerpc: fix build errors
Date:   Wed, 23 Feb 2022 14:58:19 +0100
Message-Id: <20220223135820.2252470-2-anders.roxell@linaro.org>
In-Reply-To: <20220223135820.2252470-1-anders.roxell@linaro.org>
References: <20220223135820.2252470-1-anders.roxell@linaro.org>
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Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:

 {standard input}: Assembler messages:
 {standard input}:1190: Error: unrecognized opcode: `stbcix'
 {standard input}:1433: Error: unrecognized opcode: `lwzcix'
 {standard input}:1453: Error: unrecognized opcode: `stbcix'
 {standard input}:1460: Error: unrecognized opcode: `stwcix'
 {standard input}:1596: Error: unrecognized opcode: `stbcix'
 ...

Rework to add assembler directives [1] around the instruction. Going
through the them one by one shows that the changes should be safe.  Like
__get_user_atomic_128_aligned() is only called in p9_hmi_special_emu(),
which according to the name is specific to power9.  And __raw_rm_read*()
are only called in things that are powernv or book3s_hv specific.

[1] https://sourceware.org/binutils/docs/as/PowerPC_002dPseudo.html#PowerPC_002dPseudo

Cc: <stable@vger.kernel.org>
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
---
 arch/powerpc/include/asm/io.h        | 46 +++++++++++++++++++++++-----
 arch/powerpc/include/asm/uaccess.h   |  3 ++
 arch/powerpc/platforms/powernv/rng.c |  6 +++-
 3 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index beba4979bff9..5ff6dec489f8 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -359,25 +359,37 @@ static inline void __raw_writeq_be(unsigned long v, volatile void __iomem *addr)
  */
 static inline void __raw_rm_writeb(u8 val, volatile void __iomem *paddr)
 {
-	__asm__ __volatile__("stbcix %0,0,%1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "stbcix %0,0,%1\n"
+			     ".machine \"pop\"\n"
 		: : "r" (val), "r" (paddr) : "memory");
 }
 
 static inline void __raw_rm_writew(u16 val, volatile void __iomem *paddr)
 {
-	__asm__ __volatile__("sthcix %0,0,%1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "sthcix %0,0,%1\n"
+			     ".machine \"pop\"\n"
 		: : "r" (val), "r" (paddr) : "memory");
 }
 
 static inline void __raw_rm_writel(u32 val, volatile void __iomem *paddr)
 {
-	__asm__ __volatile__("stwcix %0,0,%1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "stwcix %0,0,%1\n"
+			     ".machine \"pop\"\n"
 		: : "r" (val), "r" (paddr) : "memory");
 }
 
 static inline void __raw_rm_writeq(u64 val, volatile void __iomem *paddr)
 {
-	__asm__ __volatile__("stdcix %0,0,%1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "stdcix %0,0,%1\n"
+			     ".machine \"pop\"\n"
 		: : "r" (val), "r" (paddr) : "memory");
 }
 
@@ -389,7 +401,10 @@ static inline void __raw_rm_writeq_be(u64 val, volatile void __iomem *paddr)
 static inline u8 __raw_rm_readb(volatile void __iomem *paddr)
 {
 	u8 ret;
-	__asm__ __volatile__("lbzcix %0,0, %1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "lbzcix %0,0, %1\n"
+			     ".machine \"pop\"\n"
 			     : "=r" (ret) : "r" (paddr) : "memory");
 	return ret;
 }
@@ -397,7 +412,10 @@ static inline u8 __raw_rm_readb(volatile void __iomem *paddr)
 static inline u16 __raw_rm_readw(volatile void __iomem *paddr)
 {
 	u16 ret;
-	__asm__ __volatile__("lhzcix %0,0, %1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "lhzcix %0,0, %1\n"
+			     ".machine \"pop\"\n"
 			     : "=r" (ret) : "r" (paddr) : "memory");
 	return ret;
 }
@@ -405,7 +423,10 @@ static inline u16 __raw_rm_readw(volatile void __iomem *paddr)
 static inline u32 __raw_rm_readl(volatile void __iomem *paddr)
 {
 	u32 ret;
-	__asm__ __volatile__("lwzcix %0,0, %1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "lwzcix %0,0, %1\n"
+			     ".machine \"pop\"\n"
 			     : "=r" (ret) : "r" (paddr) : "memory");
 	return ret;
 }
@@ -413,7 +434,10 @@ static inline u32 __raw_rm_readl(volatile void __iomem *paddr)
 static inline u64 __raw_rm_readq(volatile void __iomem *paddr)
 {
 	u64 ret;
-	__asm__ __volatile__("ldcix %0,0, %1"
+	__asm__ __volatile__(".machine \"push\"\n"
+			     ".machine \"power6\"\n"
+			     "ldcix %0,0, %1\n"
+			     ".machine \"pop\"\n"
 			     : "=r" (ret) : "r" (paddr) : "memory");
 	return ret;
 }
@@ -441,7 +465,10 @@ static inline unsigned int name(unsigned int port)	\
 	unsigned int x;					\
 	__asm__ __volatile__(				\
 		"sync\n"				\
+		".machine \"push\"\n"			\
+		".machine \"power6\"\n"			\
 		"0:"	op "	%0,0,%1\n"		\
+		".machine \"pop\"\n"			\
 		"1:	twi	0,%0,0\n"		\
 		"2:	isync\n"			\
 		"3:	nop\n"				\
@@ -465,7 +492,10 @@ static inline void name(unsigned int val, unsigned int port) \
 {							\
 	__asm__ __volatile__(				\
 		"sync\n"				\
+		".machine \"push\"\n"			\
+		".machine \"power6\"\n"			\
 		"0:" op " %0,0,%1\n"			\
+		".machine \"pop\"\n"			\
 		"1:	sync\n"				\
 		"2:\n"					\
 		EX_TABLE(0b, 2b)			\
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 63316100080c..03ea552d535b 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -125,8 +125,11 @@ do {								\
  */
 #define __get_user_atomic_128_aligned(kaddr, uaddr, err)		\
 	__asm__ __volatile__(				\
+		".machine \"push\"\n"			\
+		".machine \"altivec\"\n"			\
 		"1:	lvx  0,0,%1	# get user\n"	\
 		" 	stvx 0,0,%2	# put kernel\n"	\
+		".machine \"pop\"\n"			\
 		"2:\n"					\
 		".section .fixup,\"ax\"\n"		\
 		"3:	li %0,%3\n"			\
diff --git a/arch/powerpc/platforms/powernv/rng.c b/arch/powerpc/platforms/powernv/rng.c
index b4386714494a..5bf30ef6d928 100644
--- a/arch/powerpc/platforms/powernv/rng.c
+++ b/arch/powerpc/platforms/powernv/rng.c
@@ -43,7 +43,11 @@ static unsigned long rng_whiten(struct powernv_rng *rng, unsigned long val)
 	unsigned long parity;
 
 	/* Calculate the parity of the value */
-	asm ("popcntd %0,%1" : "=r" (parity) : "r" (val));
+	asm (".machine \"push\"\n"
+	     ".machine \"power7\"\n"
+	     "popcntd %0,%1\n"
+	     ".machine \"pop\"\n"
+	     : "=r" (parity) : "r" (val));
 
 	/* xor our value with the previous mask */
 	val ^= rng->mask;
-- 
2.34.1