[PATCH 5.16 0870/1017] powerpc: Fix build errors with newer binutils

Greg Kroah-Hartman
2022-04-05T10:17:50Z

From: Anders Roxell <anders.roxell@linaro.org>

commit 8667d0d64dd1f84fd41b5897fd87fa9113ae05e3 upstream.

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 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>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
[mpe: Make commit subject more descriptive]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-2-anders.roxell@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/include/asm/io.h | 40 ++++++++++++++++++++++++++++-------
arch/powerpc/include/asm/uaccess.h | 3 ++
arch/powerpc/platforms/powernv/rng.c | 6 ++++-
3 files changed, 40 insertions(+), 9 deletions(-)

--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -359,25 +359,37 @@ static inline void __raw_writeq_be(unsig
*/
static inline void __raw_rm_writeb(u8 val, volatile void __iomem *paddr)
{
- __asm__ __volatile__("stbcix %0,0,%1"
+ __asm__ __volatile__(".machine push; \
+ .machine power6; \
+ stbcix %0,0,%1; \
+ .machine pop;"
: : "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; \
+ .machine power6; \
+ sthcix %0,0,%1; \
+ .machine pop;"
: : "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; \
+ .machine power6; \
+ stwcix %0,0,%1; \
+ .machine pop;"
: : "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; \
+ .machine power6; \
+ stdcix %0,0,%1; \
+ .machine pop;"
: : "r" (val), "r" (paddr) : "memory");
}

@@ -389,7 +401,10 @@ static inline void __raw_rm_writeq_be(u6
static inline u8 __raw_rm_readb(volatile void __iomem *paddr)
{
u8 ret;
- __asm__ __volatile__("lbzcix %0,0, %1"
+ __asm__ __volatile__(".machine push; \
+ .machine power6; \
+ lbzcix %0,0, %1; \
+ .machine pop;"
: "=r" (ret) : "r" (paddr) : "memory");
return ret;
}
@@ -397,7 +412,10 @@ static inline u8 __raw_rm_readb(volatile
static inline u16 __raw_rm_readw(volatile void __iomem *paddr)
{
u16 ret;
- __asm__ __volatile__("lhzcix %0,0, %1"
+ __asm__ __volatile__(".machine push; \
+ .machine power6; \
+ lhzcix %0,0, %1; \
+ .machine pop;"
: "=r" (ret) : "r" (paddr) : "memory");
return ret;
}
@@ -405,7 +423,10 @@ static inline u16 __raw_rm_readw(volatil
static inline u32 __raw_rm_readl(volatile void __iomem *paddr)
{
u32 ret;
- __asm__ __volatile__("lwzcix %0,0, %1"
+ __asm__ __volatile__(".machine push; \
+ .machine power6; \
+ lwzcix %0,0, %1; \
+ .machine pop;"
: "=r" (ret) : "r" (paddr) : "memory");
return ret;
}
@@ -413,7 +434,10 @@ static inline u32 __raw_rm_readl(volatil
static inline u64 __raw_rm_readq(volatile void __iomem *paddr)
{
u64 ret;
- __asm__ __volatile__("ldcix %0,0, %1"
+ __asm__ __volatile__(".machine push; \
+ .machine power6; \
+ ldcix %0,0, %1; \
+ .machine pop;"
: "=r" (ret) : "r" (paddr) : "memory");
return ret;
}
--- 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" \
--- a/arch/powerpc/platforms/powernv/rng.c
+++ b/arch/powerpc/platforms/powernv/rng.c
@@ -43,7 +43,11 @@ static unsigned long rng_whiten(struct p
unsigned long parity;

/* Calculate the parity of the value */
- asm ("popcntd %0,%1" : "=r" (parity) : "r" (val));
+ asm (".machine push; \
+ .machine power7; \
+ popcntd %0,%1; \
+ .machine pop;"
+ : "=r" (parity) : "r" (val));

/* xor our value with the previous mask */
val ^= rng->mask;