hv: timer: add calibrate tsc hz by cpuid 0x15

Get tsc hz by cpuid 0x15 if we supported, otherwise
calibrate tsc by pit timer.

Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

arch/x86/cpu.c

@@ -41,8 +41,6 @@
 extern uint32_t efi_physical_available_ap_bitmap;
 #endif
 
-uint64_t tsc_clock_freq = 1000000000;
-
 spinlock_t cpu_secondary_spinlock = {
 	.head = 0,
 	.tail = 0
@@ -494,8 +492,8 @@ void bsp_boot_init(void)
 	/* Make sure rdtsc is enabled */
 	check_tsc();
 
-	/* Calculate TSC Frequency */
+	/* Calibrate TSC Frequency */
-	tsc_clock_freq = tsc_cycles_in_period(1000) / 1000 * 1000000;
+	calibrate_tsc();
 
 	/* Enable logging */
 	init_logmsg(LOG_BUF_SIZE,

arch/x86/cpuid.c

@@ -170,7 +170,7 @@ static void init_vcpuid_entry(__unused struct vm *vm,
 	 * ECX, EDX: RESERVED (reserved fields are set to zero).
 	 */
 	case 0x40000010:
-		entry->eax = (uint32_t)(tsc_clock_freq / 1000);
+		entry->eax = (uint32_t)(tsc_hz / 1000);
 		entry->ebx = (128 * 1024 * 1024) / 1000;
 		entry->ecx = 0;
 		entry->edx = 0;

arch/x86/timer.c

@@ -34,7 +34,10 @@
 #include <hv_arch.h>
 #include <hv_debug.h>
 
-#define MAX_TIMER_ACTIONS 32
+#define MAX_TIMER_ACTIONS	32
+#define CAL_MS			10
+
+uint64_t tsc_hz = 1000000000;
 
 struct timer {
 	timer_handle_t	func;		/* callback if time reached */
@@ -421,21 +424,24 @@ void check_tsc(void)
 	CPU_CR_WRITE(cr4, (temp64 & ~CR4_TSD));
 }
 
-uint64_t tsc_cycles_in_period(uint16_t timer_period_in_us)
+static uint64_t pit_calibrate_tsc(uint16_t cal_ms)
 {
+#define PIT_TICK_RATE	1193182UL
+#define PIT_TARGET	0x3FFF
+#define PIT_MAX_COUNT	0xFFFF
+
 	uint16_t initial_pit;
 	uint16_t current_pit;
-	uint32_t current_tsc;
+	uint16_t max_cal_ms;
-#define PIT_TARGET          0x3FFF
+	uint64_t current_tsc;
 
-	if (timer_period_in_us < 1000)
+	max_cal_ms = (PIT_MAX_COUNT - PIT_TARGET) * 1000 / PIT_TICK_RATE;
-		pr_warn("Bad timer_period_in_us: %d\n",
+	cal_ms = min(cal_ms, max_cal_ms);
-				timer_period_in_us);
 
 	/* Assume the 8254 delivers 18.2 ticks per second when 16 bits fully
 	 * wrap.  This is about 1.193MHz or a clock period of 0.8384uSec
 	 */
-	initial_pit = (uint16_t)(timer_period_in_us*1193000UL/1000000);
+	initial_pit = (uint16_t)(cal_ms * PIT_TICK_RATE / 1000);
 	initial_pit += PIT_TARGET;
 
 	/* Port 0x43 ==> Control word write; Data 0x30 ==> Select Counter 0,
@@ -444,7 +450,7 @@ uint64_t tsc_cycles_in_period(uint16_t timer_period_in_us)
 
 	io_write_byte(0x30, 0x43);
 	io_write_byte(initial_pit & 0x00ff, 0x40);	/* Write LSB */
-	io_write_byte(initial_pit >> 8, 0x40);	/* Write MSB */
+	io_write_byte(initial_pit >> 8, 0x40);		/* Write MSB */
 
 	current_tsc = rdtsc();
 
@@ -461,6 +467,32 @@ uint64_t tsc_cycles_in_period(uint16_t timer_period_in_us)
 
 	current_tsc = rdtsc() - current_tsc;
 
-	return (uint64_t) current_tsc;
+	return current_tsc / cal_ms * 1000;
 }
 
+/*
+ * Determine TSC frequency via CPUID 0x15
+ */
+static uint64_t native_calibrate_tsc(void)
+{
+	if (boot_cpu_data.cpuid_level >= 0x15) {
+		uint32_t eax_denominator, ebx_numerator, ecx_hz, reserved;
+
+		cpuid(0x15, &eax_denominator, &ebx_numerator,
+			&ecx_hz, &reserved);
+
+		if (eax_denominator != 0 && ebx_numerator != 0)
+			return (uint64_t) ecx_hz *
+				ebx_numerator / eax_denominator;
+	}
+
+	return 0;
+}
+
+void calibrate_tsc(void)
+{
+	tsc_hz = native_calibrate_tsc();
+	if (!tsc_hz)
+		tsc_hz = pit_calibrate_tsc(CAL_MS);
+	printf("%s, tsc_hz=%lu\n", __func__, tsc_hz);
+}

include/arch/x86/cpu.h

@@ -258,8 +258,6 @@ extern struct cpuinfo_x86 boot_cpu_data;
 
 /* Function prototypes */
 void cpu_dead(uint32_t logical_id);
-uint64_t cpu_cycles_per_second(void);
-uint64_t tsc_cycles_in_period(uint16_t timer_period_in_us);
 void cpu_secondary_reset(void);
 int hv_main(int cpu_id);
 bool is_vapic_supported(void);

include/arch/x86/timer.h

@@ -42,5 +42,6 @@ int timer_softirq(int pcpu_id);
 void timer_init(void);
 void timer_cleanup(void);
 void check_tsc(void);
+void calibrate_tsc(void);
 
 #endif /* TIMER_H */

include/lib/rtl.h

@@ -65,12 +65,12 @@ void *memcpy_s(void *d, size_t dmax, const void *s, size_t slen);
 int udiv64(uint64_t dividend, uint64_t divisor, struct udiv_result *res);
 int udiv32(uint32_t dividend, uint32_t divisor, struct udiv_result *res);
 
-extern uint64_t tsc_clock_freq;
+extern uint64_t tsc_hz;
-#define US_TO_TICKS(x)	((x)*tsc_clock_freq/1000000UL)
+#define US_TO_TICKS(x)	((x) * tsc_hz / 1000000UL)
 #define CYCLES_PER_MS	US_TO_TICKS(1000UL)
 
-#define TICKS_TO_US(x)	((((x) * (1000000UL >> 8)) / tsc_clock_freq) << 8)
+#define TICKS_TO_US(x)	((((x) * (1000000UL >> 8)) / tsc_hz) << 8)
-#define TICKS_TO_MS(x)	(((x) * 1000UL) / tsc_clock_freq)
+#define TICKS_TO_MS(x)	(((x) * 1000UL) / tsc_hz)
 
 static inline uint64_t rdtsc(void)
 {