x86, fpu: split FPU state from task struct - v5

Split the FPU save area from the task struct. This allows easy migration
of FPU context, and it's generally cleaner. It also allows the following
two optimizations:

1) only allocate when the application actually uses FPU, so in the first
lazy FPU trap. This could save memory for non-fpu using apps. Next patch
does this lazy allocation.

2) allocate the right size for the actual cpu rather than 512 bytes always.
Patches enabling xsave/xrstor support (coming shortly) will take advantage
of this.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/asm-x86/thread_info.h b/include/asm-x86/thread_info.h
index d5fd12f2abdb..407b88c170d3 100644
--- a/include/asm-x86/thread_info.h
+++ b/include/asm-x86/thread_info.h
@@ -1,5 +1,13 @@
+#ifndef _ASM_X86_THREAD_INFO_H
 #ifdef CONFIG_X86_32
 # include "thread_info_32.h"
 #else
 # include "thread_info_64.h"
 #endif
+
+#ifndef __ASSEMBLY__
+extern void arch_task_cache_init(void);
+extern void free_thread_info(struct thread_info *ti);
+extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
+#endif
+#endif /* _ASM_X86_THREAD_INFO_H */