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authorAtish Patra <atish.patra@wdc.com>2021-09-27 14:40:11 +0300
committerAnup Patel <anup@brainfault.org>2021-10-04 13:37:16 +0300
commit3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22 (patch)
treea15be60b9addd26c0fde559d2f2a80cad0bda612 /drivers/clocksource
parent9955371cc014e02a1ef2d13c4aaf743d18bd66aa (diff)
downloadlinux-3a9f66cb25e18a3eeca36c08d9f823a35b3ddc22.tar.xz
RISC-V: KVM: Add timer functionality
The RISC-V hypervisor specification doesn't have any virtual timer feature. Due to this, the guest VCPU timer will be programmed via SBI calls. The host will use a separate hrtimer event for each guest VCPU to provide timer functionality. We inject a virtual timer interrupt to the guest VCPU whenever the guest VCPU hrtimer event expires. This patch adds guest VCPU timer implementation along with ONE_REG interface to access VCPU timer state from user space. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Anup Patel <anup.patel@wdc.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/timer-riscv.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index c51c5ed15aa7..1767f8bf2013 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -13,10 +13,12 @@
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
+#include <linux/module.h>
#include <linux/sched_clock.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
+#include <clocksource/timer-riscv.h>
#include <asm/smp.h>
#include <asm/sbi.h>
#include <asm/timex.h>
@@ -79,6 +81,13 @@ static int riscv_timer_dying_cpu(unsigned int cpu)
return 0;
}
+void riscv_cs_get_mult_shift(u32 *mult, u32 *shift)
+{
+ *mult = riscv_clocksource.mult;
+ *shift = riscv_clocksource.shift;
+}
+EXPORT_SYMBOL_GPL(riscv_cs_get_mult_shift);
+
/* called directly from the low-level interrupt handler */
static irqreturn_t riscv_timer_interrupt(int irq, void *dev_id)
{