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>
This commit is contained in:
Suresh Siddha
2008-03-10 15:28:04 -07:00
committed by Ingo Molnar
parent fa5c463941
commit 61c4628b53
16 changed files with 161 additions and 90 deletions

View File

@@ -1180,8 +1180,8 @@ u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *d)
control_word |= 0xffff0040;
partial_status = status_word() | 0xffff0000;
fpu_tag_word |= 0xffff0000;
I387.soft.fcs &= ~0xf8000000;
I387.soft.fos |= 0xffff0000;
I387->soft.fcs &= ~0xf8000000;
I387->soft.fos |= 0xffff0000;
#endif /* PECULIAR_486 */
if (__copy_to_user(d, &control_word, 7 * 4))
FPU_abort;