x86/fpu: Clean up xstate feature reservation

Put MPX support into its separate high level structure, and
also replace the fixed YMM, LWP and MPX structures in
xregs_state with just reservations - their exact offsets
in the structure will depend on the CPU and no code actually
relies on those fields.

No change in functionality.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
index 4c4eceb08a4212bad30d2333ef9336a2efe4ca70..02241c2a10e9cd2700e4f839129ab427e71b2b0a 100644 (file)
--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -145,12 +145,21 @@ struct bndcsr {
        u64                             bndstatus;
 } __packed;
 
+struct mpx_struct {
+       struct bndreg                   bndreg[4];
+       struct bndcsr                   bndcsr;
+};
+
 struct xstate_header {
        u64                             xfeatures;
        u64                             xcomp_bv;
        u64                             reserved[6];
 } __attribute__((packed));
 
+/* New processor state extensions should be added here: */
+#define XSTATE_RESERVE                 (sizeof(struct ymmh_struct) + \
+                                        sizeof(struct lwp_struct)  + \
+                                        sizeof(struct mpx_struct)  )
 /*
  * This is our most modern FPU state format, as saved by the XSAVE
  * and restored by the XRSTOR instructions.
@@ -162,11 +171,7 @@ struct xstate_header {
 struct xregs_state {
        struct fxregs_state             i387;
        struct xstate_header            header;
-       struct ymmh_struct              ymmh;
-       struct lwp_struct               lwp;
-       struct bndreg                   bndreg[4];
-       struct bndcsr                   bndcsr;
-       /* New processor state extensions will go here. */
+       u8                              __reserved[XSTATE_RESERVE];
 } __attribute__ ((packed, aligned (64)));
 
 /*