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-rw-r--r--nanosec.c109
1 files changed, 0 insertions, 109 deletions
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);
-}