Add a few functions to apic.c to make it easier to enable and disable
the local apic timer.
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
lib/x86/apic.c | 37 +++++++++++++++++++++++++++++++++++++
lib/x86/apic.h | 6 ++++++
2 files changed, 43 insertions(+)
diff --git a/lib/x86/apic.c b/lib/x86/apic.c
index 5131525a..dc6d3862 100644
--- a/lib/x86/apic.c
+++ b/lib/x86/apic.c
@@ -256,3 +256,40 @@ void init_apic_map(void)
id_map[j++] = i;
}
}
+
+void apic_setup_timer(int vector, bool periodic)
+{
+ /* APIC runs with 'CPU core clock' divided by value in APIC_TDCR */
+
+ u32 lvtt = vector |
+ (periodic ? APIC_LVT_TIMER_PERIODIC : APIC_LVT_TIMER_ONESHOT);
+
+ apic_cleanup_timer();
+ apic_write(APIC_TDCR, APIC_TDR_DIV_1);
+ apic_write(APIC_LVTT, lvtt);
+}
+
+void apic_start_timer(u32 counter)
+{
+ apic_write(APIC_TMICT, counter);
+}
+
+void apic_stop_timer(void)
+{
+ apic_write(APIC_TMICT, 0);
+}
+
+void apic_cleanup_timer(void)
+{
+ u32 lvtt = apic_read(APIC_LVTT);
+
+ // stop the counter
+ apic_stop_timer();
+
+ // mask the timer interrupt
+ apic_write(APIC_LVTT, lvtt | APIC_LVT_MASKED);
+
+ // ensure that a pending timer is serviced
+ irq_enable();
+ irq_disable();
+}
diff --git a/lib/x86/apic.h b/lib/x86/apic.h
index 6d27f047..db691e2a 100644
--- a/lib/x86/apic.h
+++ b/lib/x86/apic.h
@@ -58,6 +58,12 @@ void disable_apic(void);
void reset_apic(void);
void init_apic_map(void);
+void apic_cleanup_timer(void);
+void apic_setup_timer(int vector, bool periodic);
+
+void apic_start_timer(u32 counter);
+void apic_stop_timer(void);
+
/* Converts byte-addressable APIC register offset to 4-byte offset. */
static inline u32 apic_reg_index(u32 reg)
{
--
2.26.3
