cpu/x86/lapic: Refactor timer_fsb()

Common apic_timer code in cpu/x86 should not depend on
intel header files.

Change-Id: Ib099921d4b8e561daea47219385762bb00fc4548
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34091
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/intel/common/fsb.c

@@ -11,12 +11,16 @@
  * GNU General Public License for more details.
  */
 
+#include <arch/early_variables.h>
 #include <cpu/cpu.h>
 #include <cpu/x86/msr.h>
 #include <cpu/intel/speedstep.h>
 #include <cpu/intel/fsb.h>
 #include <console/console.h>
 #include <commonlib/helpers.h>
+#include <delay.h>
+
+static u32 g_timer_fsb CAR_GLOBAL;
 
 static int get_fsb(void)
 {
@@ -67,16 +71,31 @@ static int get_fsb(void)
 	return ret;
 }
 
-int get_ia32_fsb(void)
+static int set_timer_fsb(void)
 {
-	int ret;
+	int ret = get_fsb();
 
-	ret = get_fsb();
+	if (ret > 0) {
+		car_set_var(g_timer_fsb, ret);
+		return 0;
+	}
 	if (ret == -1)
 		printk(BIOS_ERR, "FSB not found\n");
 	if (ret == -2)
 		printk(BIOS_ERR, "CPU not supported\n");
-	return ret;
+	return -1;
+}
+
+u32 get_timer_fsb(void)
+{
+	u32 fsb;
+
+	fsb = car_get_var(g_timer_fsb);
+	if (fsb > 0)
+		return fsb;
+
+	set_timer_fsb();
+	return car_get_var(g_timer_fsb);
 }
 
 /**
@@ -87,7 +106,7 @@ int get_ia32_fsb(void)
  */
 int get_ia32_fsb_x3(void)
 {
-	const int fsb = get_ia32_fsb();
+	const int fsb = get_timer_fsb();
 
 	if (fsb > 0)
 		return 100 * DIV_ROUND_CLOSEST(3 * fsb, 100);

src/cpu/x86/lapic/apic_timer.c

@@ -17,44 +17,8 @@
 #include <thread.h>
 #include <arch/cpu.h>
 #include <arch/early_variables.h>
-#include <cpu/intel/fsb.h>
 #include <cpu/x86/msr.h>
 #include <cpu/x86/lapic.h>
-#include <cpu/intel/speedstep.h>
-
-/* NOTE: This code uses global variables, so it can not be used during
- * memory init.
- */
-
-#if CONFIG_UDELAY_LAPIC_FIXED_FSB != 0
-static inline u32 get_timer_fsb(void)
-{
-	return CONFIG_UDELAY_LAPIC_FIXED_FSB;
-}
-
-static int set_timer_fsb(void)
-{
-	return 0;
-}
-#else
-static u32 g_timer_fsb CAR_GLOBAL;
-
-static int set_timer_fsb(void)
-{
-	int ia32_fsb = get_ia32_fsb();
-
-	if (ia32_fsb > 0) {
-		car_set_var(g_timer_fsb, ia32_fsb);
-		return 0;
-	}
-	return -1;
-}
-
-static inline u32 get_timer_fsb(void)
-{
-	return car_get_var(g_timer_fsb);
-}
-#endif
 
 void init_timer(void)
 {
@@ -66,9 +30,6 @@ void init_timer(void)
 
 	/* Set the initial counter to 0xffffffff */
 	lapic_write(LAPIC_TMICT, 0xffffffff);
-
-	/* Set FSB frequency to a reasonable value */
-	set_timer_fsb();
 }
 
 void udelay(u32 usecs)

src/include/cpu/intel/fsb.h

@@ -15,15 +15,7 @@
 #define CPU_INTEL_FSB_H
 
 /*
- * This function returns:
+ * This function returns round up 3 * get_timer_fsb()
- *	the system bus speed value in MHz
- *	-1 if FSB is not found
- *	-2 if the CPU is not supported
- */
-int get_ia32_fsb(void);
-
-/*
- * This function returns round up 3 * get_ia32_fsb()
  */
 int get_ia32_fsb_x3(void);
 

src/include/delay.h

@@ -1,6 +1,17 @@
 #ifndef DELAY_H
 #define DELAY_H
 
+#include <stdint.h>
+
+#if CONFIG_UDELAY_LAPIC_FIXED_FSB != 0
+static inline u32 get_timer_fsb(void)
+{
+	return CONFIG_UDELAY_LAPIC_FIXED_FSB;
+}
+#else
+u32 get_timer_fsb(void);
+#endif
+
 void init_timer(void);
 
 void udelay(unsigned int usecs);