8534 Want AVX-512 Support

8535 kernel cpuid support for new processors
8536 xsave area should size dynamically, based on CPU features
8537 rtld needs to learn about AVX512
8538 add support for xsaveopt for improved context switching
8539 better handling for AMD-specifc *save_ctxt FP exceptions
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Approved by: Richard Lowe <richlowe@richlowe.net>

1 files changed, 54 insertions, 11 deletions

diff --git a/usr/src/uts/intel/sys/fp.h b/usr/src/uts/intel/sys/fp.h
index 3373484dec..e6d482fdd8 100644
--- a/usr/src/uts/intel/sys/fp.h
+++ b/usr/src/uts/intel/sys/fp.h
@@ -20,6 +20,7 @@
  */
 /*
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright 2017 Joyent, Inc.
  *
  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
  */
@@ -229,27 +230,59 @@ struct fxsave_state {
 };	/* 512 bytes */
 
 /*
- * This structure is written to memory by an 'xsave' instruction.
- * First 512 byte is compatible with the format of an 'fxsave' area.
+ * This structure is written to memory by one of the 'xsave' instruction
+ * variants. The first 512 bytes are compatible with the format of the 'fxsave'
+ * area. The header portion of the xsave layout is documented in section
+ * 13.4.2 of the Intel 64 and IA-32 Architectures Software Developer’s Manual,
+ * Volume 1 (IASDv1). The extended portion is documented in section 13.4.3.
+ *
+ * Our size is at least AVX_XSAVE_SIZE (832 bytes), asserted in fpnoextflt().
+ * Enabling additional xsave-related CPU features requires an increase in the
+ * size. We dynamically allocate the per-lwp xsave area at runtime, based on
+ * the size needed for the CPU-specific features. This xsave_state structure
+ * simply defines our historical layout for the beginning of the xsave area. The
+ * locations and size of new, extended, components is determined dynamically by
+ * querying the CPU. See the xsave_info structure in cpuid.c.
+ *
+ * xsave component usage is tracked using bits in the xs_xstate_bv field. The
+ * components are documented in section 13.1 of IASDv1. For easy reference,
+ * this is a summary of the currently defined component bit definitions:
+ *	x87			0x0001
+ *	SSE			0x0002
+ *	AVX			0x0004
+ *	bndreg (MPX)		0x0008
+ *	bndcsr (MPX)		0x0010
+ *	opmask (AVX512)		0x0020
+ *	zmm hi256 (AVX512)	0x0040
+ *	zmm hi16 (AVX512)	0x0080
+ *	PT			0x0100
+ *	PKRU			0x0200
+ * When xsaveopt_ctxt is being used to save into the xsave_state area, the
+ * xs_xstate_bv field is updated by the xsaveopt instruction to indicate which
+ * elements of the xsave area are active.
+ *
+ * xs_xcomp_bv should always be 0, since we do not currently use the compressed
+ * form of xsave (xsavec).
  */
 struct xsave_state {
-	struct fxsave_state	xs_fxsave;
-	uint64_t		xs_xstate_bv;	/* 512 */
-	uint64_t		xs_rsv_mbz[2];
-	uint64_t		xs_reserved[5];
-	upad128_t		xs_ymm[16];	/* avx - 576 */
-};	/* 832 bytes, asserted in fpnoextflt() */
+	struct fxsave_state	xs_fxsave;	/* 0-511 legacy region */
+	uint64_t		xs_xstate_bv;	/* 512-519 start xsave header */
+	uint64_t		xs_xcomp_bv;	/* 520-527 */
+	uint64_t		xs_reserved[6];	/* 528-575 end xsave header */
+	upad128_t		xs_ymm[16];	/* 576 AVX component */
+};
 
 /*
  * Kernel's FPU save area
  */
 typedef struct {
 	union _kfpu_u {
-		struct fxsave_state kfpu_fx;
+		void *kfpu_generic;
+		struct fxsave_state *kfpu_fx;
 #if defined(__i386)
-		struct fnsave_state kfpu_fn;
+		struct fnsave_state *kfpu_fn;
 #endif
-		struct xsave_state kfpu_xs;
+		struct xsave_state *kfpu_xs;
 	} kfpu_u;
 	uint32_t kfpu_status;		/* saved at #mf exception */
 	uint32_t kfpu_xstatus;		/* saved at #xm exception */
@@ -273,7 +306,12 @@ extern int fpu_probe_pentium_fdivbug(void);
 extern void fpnsave_ctxt(void *);
 extern void fpxsave_ctxt(void *);
 extern void xsave_ctxt(void *);
+extern void xsaveopt_ctxt(void *);
+extern void fpxsave_excp_clr_ctxt(void *);
+extern void xsave_excp_clr_ctxt(void *);
+extern void xsaveopt_excp_clr_ctxt(void *);
 extern void (*fpsave_ctxt)(void *);
+extern void (*xsavep)(struct xsave_state *, uint64_t);
 
 extern void fxsave_insn(struct fxsave_state *);
 extern void fpsave(struct fnsave_state *);
@@ -281,6 +319,7 @@ extern void fprestore(struct fnsave_state *);
 extern void fpxsave(struct fxsave_state *);
 extern void fpxrestore(struct fxsave_state *);
 extern void xsave(struct xsave_state *, uint64_t);
+extern void xsaveopt(struct xsave_state *, uint64_t);
 extern void xrestore(struct xsave_state *, uint64_t);
 
 extern void fpenable(void);
@@ -299,6 +338,10 @@ extern int fpextovrflt(struct regs *);
 extern int fpexterrflt(struct regs *);
 extern int fpsimderrflt(struct regs *);
 extern void fpsetcw(uint16_t, uint32_t);
+struct _klwp;
+extern void fp_lwp_init(struct _klwp *);
+extern void fp_lwp_cleanup(struct _klwp *);
+extern void fp_lwp_dup(struct _klwp *);
 
 #endif	/* _KERNEL */