[PATCH 2/3] powerpc: fix build errors

Anders Roxell
2022-02-23T13:58:55Z

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