[MIPS] FPU affinity for MT ASE.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/asm-mips/system.h b/include/asm-mips/system.h
index 39026690d9e4..261f71d16a07 100644
--- a/include/asm-mips/system.h
+++ b/include/asm-mips/system.h
@@ -155,6 +155,37 @@ extern asmlinkage void *resume(void *last, void *next, void *next_ti);
 
 struct task_struct;
 
+#ifdef CONFIG_MIPS_MT_FPAFF
+
+/*
+ * Handle the scheduler resume end of FPU affinity management.  We do this
+ * inline to try to keep the overhead down. If we have been forced to run on
+ * a "CPU" with an FPU because of a previous high level of FP computation,
+ * but did not actually use the FPU during the most recent time-slice (CU1
+ * isn't set), we undo the restriction on cpus_allowed.
+ *
+ * We're not calling set_cpus_allowed() here, because we have no need to
+ * force prompt migration - we're already switching the current CPU to a
+ * different thread.
+ */
+
+#define switch_to(prev,next,last)                                       \
+do {                                                                    \
+        if (cpu_has_fpu &&                                              \
+            (prev->thread.mflags & MF_FPUBOUND) &&                      \
+             (!(KSTK_STATUS(prev) & ST0_CU1))) {                        \
+                prev->thread.mflags &= ~MF_FPUBOUND;                    \
+                prev->cpus_allowed = prev->thread.user_cpus_allowed;    \
+        }                                                               \
+        if (cpu_has_dsp)                                                \
+                __save_dsp(prev);                                       \
+        next->thread.emulated_fp = 0;                                   \
+        (last) = resume(prev, next, next->thread_info);                 \
+        if (cpu_has_dsp)                                                \
+                __restore_dsp(current);                                 \
+} while(0)
+
+#else
 #define switch_to(prev,next,last)                                       \
 do {                                                                    \
         if (cpu_has_dsp)                                                \
@@ -163,6 +194,7 @@ do {									\
         if (cpu_has_dsp)                                                \
                 __restore_dsp(current);                                 \
 } while(0)
+#endif
 
 /*
  * On SMP systems, when the scheduler does migration-cost autodetection,