There are several actions that need to be done on entry into the kernel. Currently these actions are performed in a mix of get_saved_sp and SAVE_SOME. This commit introduces a macro named setup_kernel_mode which will eventually contain all of the necessary steps to be taken on entry into the kernel from user mode. For a start, we need to set register $28 to its kernel conventional usage of the current thread info. Move this from SAVE_SOME into setup_kernel_mode and invoke it in its place. As part of the move, ensure that the Octeon code does not leave the .set mips64 active by adding a .set push & .set pop around it. Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxx> --- arch/mips/include/asm/stackframe.h | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/arch/mips/include/asm/stackframe.h b/arch/mips/include/asm/stackframe.h index 2161357cc68f..494fe41f5619 100644 --- a/arch/mips/include/asm/stackframe.h +++ b/arch/mips/include/asm/stackframe.h @@ -48,6 +48,19 @@ #define STATMASK 0x1f #endif + .macro setup_kernel_mode docfi=0 + + /* Set thread_info if we're coming from user mode */ + ori $28, sp, _THREAD_MASK + xori $28, _THREAD_MASK +#ifdef CONFIG_CPU_CAVIUM_OCTEON + .set push + .set mips64 + pref 0, 0($28) /* Prefetch the current pointer */ + .set pop +#endif + .endm + .macro SAVE_AT docfi=0 .set push .set noat @@ -273,17 +286,12 @@ cfi_st $25, PT_R25, \docfi cfi_st $28, PT_R28, \docfi - /* Set thread_info if we're coming from user mode */ + /* Set up kernel mode if we're coming from user */ mfc0 k0, CP0_STATUS sll k0, 3 /* extract cu0 bit */ bltz k0, 9f - ori $28, sp, _THREAD_MASK - xori $28, _THREAD_MASK -#ifdef CONFIG_CPU_CAVIUM_OCTEON - .set mips64 - pref 0, 0($28) /* Prefetch the current pointer */ -#endif + setup_kernel_mode \docfi 9: .set pop .endm -- 2.7.4
