MIPS: Tidy up FPU context switching
Rather than saving the scalar FP or vector context in the assembly
resume function, reuse the existing C code we have in fpu.h to do
exactly that. This reduces duplication, results in a much easier to read
resume function & should allow the compiler to optimise out more MSA
code due to is_msa_enabled()/cpu_has_msa being known-zero at compile
time for kernels without MSA support.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/10830/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
index 9733cd0..28b5d84a 100644
--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -16,29 +16,21 @@
#include <asm/watch.h>
#include <asm/dsp.h>
#include <asm/cop2.h>
-#include <asm/msa.h>
+#include <asm/fpu.h>
struct task_struct;
-enum {
- FP_SAVE_NONE = 0,
- FP_SAVE_VECTOR = -1,
- FP_SAVE_SCALAR = 1,
-};
-
/**
* resume - resume execution of a task
* @prev: The task previously executed.
* @next: The task to begin executing.
* @next_ti: task_thread_info(next).
- * @fp_save: Which, if any, FP context to save for prev.
*
* This function is used whilst scheduling to save the context of prev & load
* the context of next. Returns prev.
*/
extern asmlinkage struct task_struct *resume(struct task_struct *prev,
- struct task_struct *next, struct thread_info *next_ti,
- s32 fp_save);
+ struct task_struct *next, struct thread_info *next_ti);
extern unsigned int ll_bit;
extern struct task_struct *ll_task;
@@ -91,8 +83,8 @@
*/
#define switch_to(prev, next, last) \
do { \
- s32 __fpsave = FP_SAVE_NONE; \
__mips_mt_fpaff_switch_to(prev); \
+ lose_fpu_inatomic(1, prev); \
if (cpu_has_dsp) { \
__save_dsp(prev); \
__restore_dsp(next); \
@@ -111,15 +103,10 @@
clear_c0_status(ST0_CU2); \
} \
__clear_software_ll_bit(); \
- if (test_and_clear_tsk_thread_flag(prev, TIF_USEDFPU)) \
- __fpsave = FP_SAVE_SCALAR; \
- if (test_and_clear_tsk_thread_flag(prev, TIF_USEDMSA)) \
- __fpsave = FP_SAVE_VECTOR; \
if (cpu_has_userlocal) \
write_c0_userlocal(task_thread_info(next)->tp_value); \
__restore_watch(); \
- disable_msa(); \
- (last) = resume(prev, next, task_thread_info(next), __fpsave); \
+ (last) = resume(prev, next, task_thread_info(next)); \
} while (0)
#endif /* _ASM_SWITCH_TO_H */