MFamd64: Add support for extended FPU states on i386. This includes

support for AVX on i386.
- Similar to amd64, move the FPU save area out of the PCB and instead
  store saved FPU state in a variable-sized buffer after the PCB on the
  stack.
- To support the variable PCB location, alter the locore code to only use
  the bottom-most page of proc0stack for init386().  init386() returns
  the correct stack pointer to locore which adjusts the stack for thread0
  before calling mi_startup().
- Don't bother setting cr3 in thread0's pcb in locore before calling
  init386().  It wasn't used (init386() overwrote it at the end) and
  it doesn't work with the variable-sized FPU save area.
- Remove the new-bus attachment from npx.  This was only ever useful for
  external co-processors using IRQ13, but those have not been supported
  for several years.  npxinit() is now called much earlier during boot
  (init386()) similar to amd64.
- Implement PT_{GET,SET}XSTATE and I386_GET_XFPUSTATE.
- npxsave() is now only called from context switch contexts so it can
  use XSAVEOPT.

Differential Revision:	https://reviews.freebsd.org/D1058
Reviewed by:	kib
Tested on:	FreeBSD/i386 VM under bhyve on Intel i5-2520

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/i386/linux/linux_ptrace.c b/sys/i386/linux/linux_ptrace.c
index 1074d21..46a1169 100644
--- a/sys/i386/linux/linux_ptrace.c
+++ b/sys/i386/linux/linux_ptrace.c
@@ -225,7 +225,7 @@ linux_proc_read_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
 	if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
 		return (EIO);
-	bcopy(&td->td_pcb->pcb_user_save.sv_xmm, fpxregs, sizeof(*fpxregs));
+	bcopy(&get_pcb_user_save_td(td)->sv_xmm, fpxregs, sizeof(*fpxregs));
 	return (0);
 }
 
@@ -236,7 +236,7 @@ linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs)
 	PROC_LOCK_ASSERT(td->td_proc, MA_OWNED);
 	if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0)
 		return (EIO);
-	bcopy(fpxregs, &td->td_pcb->pcb_user_save.sv_xmm, sizeof(*fpxregs));
+	bcopy(fpxregs, &get_pcb_user_save_td(td)->sv_xmm, sizeof(*fpxregs));
 	return (0);
 }
 #endif