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>
diff --git a/arch/x86/math-emu/fpu_system.h b/arch/x86/math-emu/fpu_system.h
index a3ae28c..13488fa 100644
--- a/arch/x86/math-emu/fpu_system.h
+++ b/arch/x86/math-emu/fpu_system.h
@@ -35,8 +35,8 @@
#define SEG_EXPAND_DOWN(s) (((s).b & ((1 << 11) | (1 << 10))) \
== (1 << 10))
-#define I387 (current->thread.i387)
-#define FPU_info (I387.soft.info)
+#define I387 (current->thread.xstate)
+#define FPU_info (I387->soft.info)
#define FPU_CS (*(unsigned short *) &(FPU_info->___cs))
#define FPU_SS (*(unsigned short *) &(FPU_info->___ss))
@@ -46,25 +46,25 @@
#define FPU_EIP (FPU_info->___eip)
#define FPU_ORIG_EIP (FPU_info->___orig_eip)
-#define FPU_lookahead (I387.soft.lookahead)
+#define FPU_lookahead (I387->soft.lookahead)
/* nz if ip_offset and cs_selector are not to be set for the current
instruction. */
-#define no_ip_update (*(u_char *)&(I387.soft.no_update))
-#define FPU_rm (*(u_char *)&(I387.soft.rm))
+#define no_ip_update (*(u_char *)&(I387->soft.no_update))
+#define FPU_rm (*(u_char *)&(I387->soft.rm))
/* Number of bytes of data which can be legally accessed by the current
instruction. This only needs to hold a number <= 108, so a byte will do. */
-#define access_limit (*(u_char *)&(I387.soft.alimit))
+#define access_limit (*(u_char *)&(I387->soft.alimit))
-#define partial_status (I387.soft.swd)
-#define control_word (I387.soft.cwd)
-#define fpu_tag_word (I387.soft.twd)
-#define registers (I387.soft.st_space)
-#define top (I387.soft.ftop)
+#define partial_status (I387->soft.swd)
+#define control_word (I387->soft.cwd)
+#define fpu_tag_word (I387->soft.twd)
+#define registers (I387->soft.st_space)
+#define top (I387->soft.ftop)
-#define instruction_address (*(struct address *)&I387.soft.fip)
-#define operand_address (*(struct address *)&I387.soft.foo)
+#define instruction_address (*(struct address *)&I387->soft.fip)
+#define operand_address (*(struct address *)&I387->soft.foo)
#define FPU_access_ok(x,y,z) if ( !access_ok(x,y,z) ) \
math_abort(FPU_info,SIGSEGV)