D21777.id62543.diff
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	Index: head/sys/x86/x86/tsc.c
	===================================================================
	--- head/sys/x86/x86/tsc.c
	+++ head/sys/x86/x86/tsc.c
	@@ -134,7 +134,11 @@

	/*
	* Calculate TSC frequency using information from the CPUID leaf 0x15
	- * 'Time Stamp Counter and Nominal Core Crystal Clock'. It should be
	+ * 'Time Stamp Counter and Nominal Core Crystal Clock'. If leaf 0x15
	+ * is not functional, as it is on Skylake/Kabylake, try 0x16 'Processor
	+ * Frequency Information'. Leaf 0x16 is described in the SDM as
	+ * informational only, but if 0x15 did not work, and TSC calibration
	+ * is disabled, it is the best we can get at all. It should still be
	* an improvement over the parsing of the CPU model name in
	* tsc_freq_intel(), when available.
	*/
	@@ -146,10 +150,20 @@
	if (cpu_high < 0x15)
	return (false);
	do_cpuid(0x15, regs);
	- if (regs[0] == 0 \|\| regs[1] == 0 \|\| regs[2] == 0)
	+ if (regs[0] != 0 && regs[1] != 0 && regs[2] != 0) {
	+ tsc_freq = (uint64_t)regs[2] * regs[1] / regs[0];
	+ return (true);
	+ }
	+
	+ if (cpu_high < 0x16)
	return (false);
	- tsc_freq = (uint64_t)regs[2] * regs[1] / regs[0];
	- return (true);
	+ do_cpuid(0x16, regs);
	+ if (regs[0] != 0) {
	+ tsc_freq = (uint64_t)regs[0] * 1000000;
	+ return (true);
	+ }
	+
	+ return (false);
	}

	static void