diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2023-04-08 12:17:49 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-04-20 12:54:22 +1000 |
| commit | dc5dac748af9087e9240bd2ae6ae7db48d5360ae (patch) | |
| tree | 59998f55199668c054226f3bc29fc4963fc35741 /arch/powerpc/include/asm/uaccess.h | |
| parent | b270bebd34e36fb69363d65e24b00a9d148903e8 (diff) | |
powerpc/64: Add support to build with prefixed instructions
Add an option to build kernel and module with prefixed instructions if
the CPU and toolchain support it.
This is not related to kernel support for userspace execution of
prefixed instructions.
Building with prefixed instructions breaks some extended inline asm
memory addressing, for example it will provide immediates that exceed
the range of simple load/store displacement. Whether this is a
toolchain or a kernel asm problem remains to be seen. For now, these
are replaced with simpler and less efficient direct register addressing
when compiling with prefixed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-4-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include/asm/uaccess.h')
| -rw-r--r-- | arch/powerpc/include/asm/uaccess.h | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 52378e641d38..a2d255aa9627 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -71,14 +71,26 @@ __pu_failed: \ * because we do not write to any memory gcc knows about, so there * are no aliasing issues. */ +/* -mprefixed can generate offsets beyond range, fall back hack */ +#ifdef CONFIG_PPC_KERNEL_PREFIXED +#define __put_user_asm_goto(x, addr, label, op) \ + asm_volatile_goto( \ + "1: " op " %0,0(%1) # put_user\n" \ + EX_TABLE(1b, %l2) \ + : \ + : "r" (x), "b" (addr) \ + : \ + : label) +#else #define __put_user_asm_goto(x, addr, label, op) \ asm_volatile_goto( \ "1: " op "%U1%X1 %0,%1 # put_user\n" \ EX_TABLE(1b, %l2) \ : \ - : "r" (x), "m<>" (*addr) \ + : "r" (x), "m<>" (*addr) \ : \ : label) +#endif #ifdef __powerpc64__ #define __put_user_asm2_goto(x, ptr, label) \ @@ -131,14 +143,26 @@ do { \ #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +/* -mprefixed can generate offsets beyond range, fall back hack */ +#ifdef CONFIG_PPC_KERNEL_PREFIXED +#define __get_user_asm_goto(x, addr, label, op) \ + asm_volatile_goto( \ + "1: "op" %0,0(%1) # get_user\n" \ + EX_TABLE(1b, %l2) \ + : "=r" (x) \ + : "b" (addr) \ + : \ + : label) +#else #define __get_user_asm_goto(x, addr, label, op) \ asm_volatile_goto( \ "1: "op"%U1%X1 %0, %1 # get_user\n" \ EX_TABLE(1b, %l2) \ : "=r" (x) \ - : "m<>" (*addr) \ + : "m<>" (*addr) \ : \ : label) +#endif #ifdef __powerpc64__ #define __get_user_asm2_goto(x, addr, label) \ |