[src/trunk]: src/sys/arch/x86/include Clean up the FPU headers.

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f62fedd20a11
branches:  trunk
changeset: 832676:f62fedd20a11
user:      maxv <maxv%NetBSD.org@localhost>
date:      Wed May 23 07:24:37 2018 +0000

description:
Clean up the FPU headers.

diffstat:

 sys/arch/x86/include/cpu_extended_state.h |  47 +++++++++++++++---------------
 sys/arch/x86/include/specialreg.h         |   8 +---
 2 files changed, 27 insertions(+), 28 deletions(-)

diffs (120 lines):

diff -r 78d83e84e691 -r f62fedd20a11 sys/arch/x86/include/cpu_extended_state.h
--- a/sys/arch/x86/include/cpu_extended_state.h Wed May 23 07:08:13 2018 +0000
+++ b/sys/arch/x86/include/cpu_extended_state.h Wed May 23 07:24:37 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpu_extended_state.h,v 1.15 2017/11/08 17:55:54 maxv Exp $     */
+/*     $NetBSD: cpu_extended_state.h,v 1.16 2018/05/23 07:24:37 maxv Exp $     */
 
 #ifndef _X86_CPU_EXTENDED_STATE_H_
 #define _X86_CPU_EXTENDED_STATE_H_
@@ -18,8 +18,8 @@
  * This includes registers (etc) used by SSE/SSE2/SSE3/SSSE3/SSE4 and the later
  * AVX instructions.
  *
- * The definitions are such that any future 'extended state' should be handled
- * (provided the kernel doesn't need to know the actual contents).
+ * The definitions are such that any future 'extended state' should be handled,
+ * provided the kernel doesn't need to know the actual contents.
  *
  * The actual structures the cpu accesses must be aligned to 16 bytes for FXSAVE
  * and 64 for XSAVE. The types aren't aligned because copies do not need extra
@@ -30,18 +30,18 @@
  * support the fxsave instruction.
  *
  * Associated save instructions:
- * FNSAVE:   Saves x87 state in 108 bytes (original i387 layout).
- *           Then reinitializes the fpu.
+ * FNSAVE:   Saves x87 state in 108 bytes (original i387 layout). Then
+ *           reinitializes the fpu.
  * FSAVE:    Encodes to FWAIT followed by FNSAVE.
- * FXSAVE:   Saves the x87 state and XMM (aka SSE) registers to the
- *           first 448 (max) bytes of a 512 byte area.
- *           This layout does not match that written by FNSAVE.
- * XSAVE:    Uses the same layout for the x87 and XMM registers,
- *           followed by a 64byte header and separate save areas
- *           for additional extended cpu state.
- *           The x87 state is always saved, the others conditionally.
- * XSAVEOPT: As XSAVE but only writes the registers blocks that have been
- *           modified.
+ * FXSAVE:   Saves the x87 state and XMM (aka SSE) registers to the first
+ *           448 (max) bytes of a 512 byte area. This layout does not match
+ *           that written by FNSAVE.
+ * XSAVE:    Uses the same layout for the x87 and XMM registers, followed by
+ *           a 64byte header and separate save areas for additional extended
+ *           cpu states. The x87 state is always saved, the others
+ *           conditionally.
+ * XSAVEOPT: Same as XSAVE but only writes the registers blocks that have
+ *           been modified.
  */
 
 /*
@@ -80,10 +80,11 @@
 };
 
 /*
- * Floating point unit registers (fsave instruction).
- * The s87_ac[] and fx_87_ac[] are relative to the stack top.
- * The 'tag word' contains 2 bits per register and refers to absolute register
- * numbers.
+ * Floating point unit registers (FSAVE instruction).
+ *
+ * The s87_ac[] and fx_87_ac[] are relative to the stack top. The 'tag word'
+ * contains 2 bits per register and refers to absolute register numbers.
+ *
  * The cpu sets the tag values 0b01 (zero) and 0b10 (special) when a value
  * is loaded. The software need only set 0b00 (used) and 0xb11 (unused).
  * The fxsave 'Abridged tag word' in inverted.
@@ -100,7 +101,7 @@
 __CTASSERT_NOLINT(sizeof(struct save87) == 108);
 
 /*
- * FPU/MMX/SSE/SSE2 context
+ * FPU/MMX/SSE/SSE2 context (FXSAVE instruction).
  */
 struct fxsave {
        uint16_t fx_cw;         /* FPU Control Word */
@@ -122,7 +123,7 @@
  * For XSAVE, a 64byte header follows the fxsave data.
  */
 struct xsave_header {
-       uint8_t xsh_fxsave[512];        /* to align in the union */
+       uint8_t xsh_fxsave[512];        /* struct fxsave */
        uint64_t xsh_xstate_bv;         /* bitmap of saved sub structures */
        uint64_t xsh_xcomp_bv;          /* bitmap of compact sub structures */
        uint8_t xsh_rsrvd[8];           /* must be zero */
@@ -145,10 +146,10 @@
  * NB: Some userspace stuff (eg firefox) uses it to parse ucontext.
  */
 union savefpu {
-       struct save87           sv_87;
-       struct fxsave           sv_xmm;
+       struct save87 sv_87;
+       struct fxsave sv_xmm;
 #ifdef _KERNEL
-       struct xsave_header     sv_xsave_hdr;
+       struct xsave_header sv_xsave_hdr;
 #endif
 };
 
diff -r 78d83e84e691 -r f62fedd20a11 sys/arch/x86/include/specialreg.h
--- a/sys/arch/x86/include/specialreg.h Wed May 23 07:08:13 2018 +0000
+++ b/sys/arch/x86/include/specialreg.h Wed May 23 07:24:37 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: specialreg.h,v 1.124 2018/05/22 17:14:46 maxv Exp $    */
+/*     $NetBSD: specialreg.h,v 1.125 2018/05/23 07:24:37 maxv Exp $    */
 
 /*-
  * Copyright (c) 1991 The Regents of the University of California.
@@ -104,10 +104,8 @@
 #define XCR0_Hi16_ZMM  0x00000080      /* AVX-512 512 bits upper registers */
 
 /*
- * Known fpu bits - only these get enabled
- * I think the XCR0_BNDREGS and XCR0_BNDCSR would need saving on
- * every context switch.
- * The save are is sized for all the fields below (max 2680 bytes).
+ * Known fpu bits - only these get enabled. The save area is sized for all the
+ * fields below (max 2680 bytes).
  */
 #define XCR0_FPU       (XCR0_X87 | XCR0_SSE | XCR0_YMM_Hi128 | \
                        XCR0_Opmask | XCR0_ZMM_Hi256 | XCR0_Hi16_ZMM)