From 675aa84403f98776a7d463e1cc5f9bd41cdbab92 Mon Sep 17 00:00:00 2001
From: rodri <rgl@antares-labs.eu>
Date: Sat, 25 Nov 2023 10:34:41 +0000
Subject: cleaned things up and improved the organization a bit.

---
 nanosec.c | 109 --------------------------------------------------------------
 1 file changed, 109 deletions(-)
 delete mode 100644 nanosec.c

(limited to 'nanosec.c')

diff --git a/nanosec.c b/nanosec.c
deleted file mode 100644
index f82d47a..0000000
--- a/nanosec.c
+++ /dev/null
@@ -1,109 +0,0 @@
-#include <u.h>
-#include <libc.h>
-#include <tos.h>
-
-/*
- * This code is a mixture of cpuid(1) and the nanosec() found in vmx,
- * in order to force the use of nsec(2) in case we are running in a
- * virtualized environment where the clock is mis-bhyve-ing.
- */
-
-typedef struct Res {
-	ulong ax, bx, cx, dx;
-} Res;
-
-static uchar _cpuid[] = {
-	0x5E,			/* POP SI (PC) */
-	0x5D,			/* POP BP (Res&) */
-	0x58,			/* POP AX */
-	0x59,			/* POP CX */
-
-	0x51,			/* PUSH CX */
-	0x50,			/* PUSH AX */
-	0x55,			/* PUSH BP */
-	0x56,			/* PUSH SI */
-
-	0x31, 0xDB,		/* XOR BX, BX */
-	0x31, 0xD2,		/* XOR DX, DX */
-
-	0x0F, 0xA2,		/* CPUID */
-
-	0x89, 0x45, 0x00,	/* MOV AX, 0(BP) */
-	0x89, 0x5d, 0x04,	/* MOV BX, 4(BP) */
-	0x89, 0x4d, 0x08,	/* MOV CX, 8(BP) */
-	0x89, 0x55, 0x0C,	/* MOV DX, 12(BP) */
-	0xC3,			/* RET */
-};
-
-static Res (*cpuid)(ulong ax, ulong cx) = (Res(*)(ulong, ulong)) _cpuid;
-
-/*
- * nsec() is wallclock and can be adjusted by timesync
- * so need to use cycles() instead, but fall back to
- * nsec() in case we can't
- */
-uvlong
-nanosec(void)
-{
-	static uvlong fasthz, xstart;
-	char buf[13], path[128];
-	ulong w;
-	uvlong x, div;
-	int fd;
-	Res r;
-
-	if(fasthz == ~0ULL)
-		return nsec() - xstart;
-
-	if(fasthz == 0){
-		/* first long in a.out header */
-		snprint(path, sizeof path, "/proc/%d/text", getpid());
-		fd = open(path, OREAD);
-		if(fd < 0)
-			goto Wallclock;
-		if(read(fd, buf, 4) != 4){
-			close(fd);
-			goto Wallclock;
-		}
-		close(fd);
-
-		w = ((ulong *) buf)[0];
-
-		switch(w){
-		default:
-			goto Wallclock;
-		case 0x978a0000:	/* amd64 */
-			/* patch out POP BP -> POP AX */
-			_cpuid[1] = 0x58;
-		case 0xeb010000:	/* 386 */
-			break;
-		}
-		segflush(_cpuid, sizeof(_cpuid));
-
-		r = cpuid(0x40000000, 0);
-		((ulong *) buf)[0] = r.bx;
-		((ulong *) buf)[1] = r.cx;
-		((ulong *) buf)[2] = r.dx;
-		buf[12] = 0;
-
-		if(strstr(buf, "bhyve") != nil)
-			goto Wallclock;
-
-		if(_tos->cyclefreq){
-			fasthz = _tos->cyclefreq;
-			cycles(&xstart);
-		} else {
-Wallclock:
-			fasthz = ~0ULL;
-			xstart = nsec();
-		}
-		return 0;
-	}
-	cycles(&x);
-	x -= xstart;
-
-	/* this is ugly */
-	for(div = 1000000000ULL; x < 0x1999999999999999ULL && div > 1 ; div /= 10ULL, x *= 10ULL);
-
-	return x / (fasthz / div);
-}
-- 
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