freebsd-nq/sys/amd64/ia32/ia32_reg.c
Konstantin Belousov 8c6f8f3d5b Add support for the extended FPU states on amd64, both for native
64bit and 32bit ABIs.  As a side-effect, it enables AVX on capable
CPUs.

In particular:

- Query the CPU support for XSAVE, list of the supported extensions
  and the required size of FPU save area. The hw.use_xsave tunable is
  provided for disabling XSAVE, and hw.xsave_mask may be used to
  select the enabled extensions.

- Remove the FPU save area from PCB and dynamically allocate the
  (run-time sized) user save area on the top of the kernel stack,
  right above the PCB. Reorganize the thread0 PCB initialization to
  postpone it after BSP is queried for save area size.

- The dumppcb, stoppcbs and susppcbs now do not carry the FPU state as
  well. FPU state is only useful for suspend, where it is saved in
  dynamically allocated suspfpusave area.

- Use XSAVE and XRSTOR to save/restore FPU state, if supported and
  enabled.

- Define new mcontext_t flag _MC_HASFPXSTATE, indicating that
  mcontext_t has a valid pointer to out-of-struct extended FPU
  state. Signal handlers are supplied with stack-allocated fpu
  state. The sigreturn(2) and setcontext(2) syscall honour the flag,
  allowing the signal handlers to inspect and manipilate extended
  state in the interrupted context.

- The getcontext(2) never returns extended state, since there is no
  place in the fixed-sized mcontext_t to place variable-sized save
  area. And, since mcontext_t is embedded into ucontext_t, makes it
  impossible to fix in a reasonable way.  Instead of extending
  getcontext(2) syscall, provide a sysarch(2) facility to query
  extended FPU state.

- Add ptrace(2) support for getting and setting extended state; while
  there, implement missed PT_I386_{GET,SET}XMMREGS for 32bit binaries.

- Change fpu_kern KPI to not expose struct fpu_kern_ctx layout to
  consumers, making it opaque. Internally, struct fpu_kern_ctx now
  contains a space for the extended state. Convert in-kernel consumers
  of fpu_kern KPI both on i386 and amd64.

First version of the support for AVX was submitted by Tim Bird
<tim.bird am sony com> on behalf of Sony. This version was written
from scratch.

Tested by:	pho (previous version), Yamagi Burmeister <lists yamagi org>
MFC after:	1 month
2012-01-21 17:45:27 +00:00

237 lines
6.1 KiB
C

/*-
* Copyright (c) 2005 Peter Wemm
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/fcntl.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/mman.h>
#include <sys/namei.h>
#include <sys/pioctl.h>
#include <sys/proc.h>
#include <sys/procfs.h>
#include <sys/resourcevar.h>
#include <sys/systm.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_extern.h>
#include <compat/freebsd32/freebsd32_util.h>
#include <compat/freebsd32/freebsd32_proto.h>
#include <machine/fpu.h>
#include <compat/ia32/ia32_reg.h>
#include <machine/psl.h>
#include <machine/segments.h>
#include <machine/specialreg.h>
#include <machine/frame.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/cpufunc.h>
#define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
#define EFL_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
int
fill_regs32(struct thread *td, struct reg32 *regs)
{
struct pcb *pcb;
struct trapframe *tp;
tp = td->td_frame;
pcb = td->td_pcb;
if (tp->tf_flags & TF_HASSEGS) {
regs->r_gs = tp->tf_gs;
regs->r_fs = tp->tf_fs;
regs->r_es = tp->tf_es;
regs->r_ds = tp->tf_ds;
} else {
regs->r_gs = _ugssel;
regs->r_fs = _ufssel;
regs->r_es = _udatasel;
regs->r_ds = _udatasel;
}
regs->r_edi = tp->tf_rdi;
regs->r_esi = tp->tf_rsi;
regs->r_ebp = tp->tf_rbp;
regs->r_ebx = tp->tf_rbx;
regs->r_edx = tp->tf_rdx;
regs->r_ecx = tp->tf_rcx;
regs->r_eax = tp->tf_rax;
regs->r_eip = tp->tf_rip;
regs->r_cs = tp->tf_cs;
regs->r_eflags = tp->tf_rflags;
regs->r_esp = tp->tf_rsp;
regs->r_ss = tp->tf_ss;
return (0);
}
int
set_regs32(struct thread *td, struct reg32 *regs)
{
struct pcb *pcb;
struct trapframe *tp;
tp = td->td_frame;
if (!EFL_SECURE(regs->r_eflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
return (EINVAL);
pcb = td->td_pcb;
tp->tf_gs = regs->r_gs;
tp->tf_fs = regs->r_fs;
tp->tf_es = regs->r_es;
tp->tf_ds = regs->r_ds;
set_pcb_flags(pcb, PCB_FULL_IRET);
tp->tf_flags = TF_HASSEGS;
tp->tf_rdi = regs->r_edi;
tp->tf_rsi = regs->r_esi;
tp->tf_rbp = regs->r_ebp;
tp->tf_rbx = regs->r_ebx;
tp->tf_rdx = regs->r_edx;
tp->tf_rcx = regs->r_ecx;
tp->tf_rax = regs->r_eax;
tp->tf_rip = regs->r_eip;
tp->tf_cs = regs->r_cs;
tp->tf_rflags = regs->r_eflags;
tp->tf_rsp = regs->r_esp;
tp->tf_ss = regs->r_ss;
return (0);
}
int
fill_fpregs32(struct thread *td, struct fpreg32 *regs)
{
struct savefpu *sv_fpu;
struct save87 *sv_87;
struct env87 *penv_87;
struct envxmm *penv_xmm;
int i;
bzero(regs, sizeof(*regs));
sv_87 = (struct save87 *)regs;
penv_87 = &sv_87->sv_env;
fpugetregs(td);
sv_fpu = get_pcb_user_save_td(td);
penv_xmm = &sv_fpu->sv_env;
/* FPU control/status */
penv_87->en_cw = penv_xmm->en_cw;
penv_87->en_sw = penv_xmm->en_sw;
penv_87->en_tw = penv_xmm->en_tw;
/*
* XXX for en_fip/fcs/foo/fos, check if the fxsave format
* uses the old-style layout for 32 bit user apps. If so,
* read the ip and operand segment registers from there.
* For now, use the process's %cs/%ds.
*/
penv_87->en_fip = penv_xmm->en_rip;
penv_87->en_fcs = td->td_frame->tf_cs;
penv_87->en_opcode = penv_xmm->en_opcode;
penv_87->en_foo = penv_xmm->en_rdp;
/* Entry into the kernel always sets TF_HASSEGS */
penv_87->en_fos = td->td_frame->tf_ds;
/* FPU registers */
for (i = 0; i < 8; ++i)
sv_87->sv_ac[i] = sv_fpu->sv_fp[i].fp_acc;
return (0);
}
int
set_fpregs32(struct thread *td, struct fpreg32 *regs)
{
struct save87 *sv_87 = (struct save87 *)regs;
struct env87 *penv_87 = &sv_87->sv_env;
struct savefpu *sv_fpu = get_pcb_user_save_td(td);
struct envxmm *penv_xmm = &sv_fpu->sv_env;
int i;
/* FPU control/status */
penv_xmm->en_cw = penv_87->en_cw;
penv_xmm->en_sw = penv_87->en_sw;
penv_xmm->en_tw = penv_87->en_tw;
penv_xmm->en_rip = penv_87->en_fip;
/* penv_87->en_fcs and en_fos ignored, see above */
penv_xmm->en_opcode = penv_87->en_opcode;
penv_xmm->en_rdp = penv_87->en_foo;
/* FPU registers */
for (i = 0; i < 8; ++i)
sv_fpu->sv_fp[i].fp_acc = sv_87->sv_ac[i];
for (i = 8; i < 16; ++i)
bzero(&sv_fpu->sv_fp[i].fp_acc, sizeof(sv_fpu->sv_fp[i].fp_acc));
fpuuserinited(td);
return (0);
}
int
fill_dbregs32(struct thread *td, struct dbreg32 *regs)
{
struct dbreg dr;
int err, i;
err = fill_dbregs(td, &dr);
for (i = 0; i < 8; i++)
regs->dr[i] = dr.dr[i];
return (err);
}
int
set_dbregs32(struct thread *td, struct dbreg32 *regs)
{
struct dbreg dr;
int i;
for (i = 0; i < 8; i++)
dr.dr[i] = regs->dr[i];
for (i = 8; i < 16; i++)
dr.dr[i] = 0;
return (set_dbregs(td, &dr));
}