// SPDX-License-Identifier: GPL-2.0-only
/*
 * The test validates both the virtual and physical timer IRQs using
 * CVAL and TVAL registers.
 *
 * Copyright (c) 2021, Google LLC.
 */
#include "arch_timer.h"
#include "delay.h"
#include "gic.h"
#include "processor.h"
#include "timer_test.h"
#include "ucall_common.h"
#include "vgic.h"

enum guest_stage {
        GUEST_STAGE_VTIMER_CVAL = 1,
        GUEST_STAGE_VTIMER_TVAL,
        GUEST_STAGE_PTIMER_CVAL,
        GUEST_STAGE_PTIMER_TVAL,
        GUEST_STAGE_MAX,
};

static int vtimer_irq, ptimer_irq;

static void
guest_configure_timer_action(struct test_vcpu_shared_data *shared_data)
{
        switch (shared_data->guest_stage) {
        case GUEST_STAGE_VTIMER_CVAL:
                timer_set_next_cval_ms(VIRTUAL, test_args.timer_period_ms);
                shared_data->xcnt = timer_get_cntct(VIRTUAL);
                timer_set_ctl(VIRTUAL, CTL_ENABLE);
                break;
        case GUEST_STAGE_VTIMER_TVAL:
                timer_set_next_tval_ms(VIRTUAL, test_args.timer_period_ms);
                shared_data->xcnt = timer_get_cntct(VIRTUAL);
                timer_set_ctl(VIRTUAL, CTL_ENABLE);
                break;
        case GUEST_STAGE_PTIMER_CVAL:
                timer_set_next_cval_ms(PHYSICAL, test_args.timer_period_ms);
                shared_data->xcnt = timer_get_cntct(PHYSICAL);
                timer_set_ctl(PHYSICAL, CTL_ENABLE);
                break;
        case GUEST_STAGE_PTIMER_TVAL:
                timer_set_next_tval_ms(PHYSICAL, test_args.timer_period_ms);
                shared_data->xcnt = timer_get_cntct(PHYSICAL);
                timer_set_ctl(PHYSICAL, CTL_ENABLE);
                break;
        default:
                GUEST_ASSERT(0);
        }
}

static void guest_validate_irq(unsigned int intid,
                                struct test_vcpu_shared_data *shared_data)
{
        enum guest_stage stage = shared_data->guest_stage;
        uint64_t xcnt = 0, xcnt_diff_us, cval = 0;
        unsigned long xctl = 0;
        unsigned int timer_irq = 0;
        unsigned int accessor;

        if (intid == IAR_SPURIOUS)
                return;

        switch (stage) {
        case GUEST_STAGE_VTIMER_CVAL:
        case GUEST_STAGE_VTIMER_TVAL:
                accessor = VIRTUAL;
                timer_irq = vtimer_irq;
                break;
        case GUEST_STAGE_PTIMER_CVAL:
        case GUEST_STAGE_PTIMER_TVAL:
                accessor = PHYSICAL;
                timer_irq = ptimer_irq;
                break;
        default:
                GUEST_ASSERT(0);
                return;
        }

        xctl = timer_get_ctl(accessor);
        if ((xctl & CTL_IMASK) || !(xctl & CTL_ENABLE))
                return;

        timer_set_ctl(accessor, CTL_IMASK);
        xcnt = timer_get_cntct(accessor);
        cval = timer_get_cval(accessor);

        xcnt_diff_us = cycles_to_usec(xcnt - shared_data->xcnt);

        /* Make sure we are dealing with the correct timer IRQ */
        GUEST_ASSERT_EQ(intid, timer_irq);

        /* Basic 'timer condition met' check */
        __GUEST_ASSERT(xcnt >= cval,
                       "xcnt = 0x%lx, cval = 0x%lx, xcnt_diff_us = 0x%lx",
                       xcnt, cval, xcnt_diff_us);
        __GUEST_ASSERT(xctl & CTL_ISTATUS, "xctl = 0x%lx", xctl);

        WRITE_ONCE(shared_data->nr_iter, shared_data->nr_iter + 1);
}

static void guest_irq_handler(struct ex_regs *regs)
{
        unsigned int intid = gic_get_and_ack_irq();
        uint32_t cpu = guest_get_vcpuid();
        struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];

        guest_validate_irq(intid, shared_data);

        gic_set_eoi(intid);
}

static void guest_run_stage(struct test_vcpu_shared_data *shared_data,
                                enum guest_stage stage)
{
        uint32_t irq_iter, config_iter;

        shared_data->guest_stage = stage;
        shared_data->nr_iter = 0;

        for (config_iter = 0; config_iter < test_args.nr_iter; config_iter++) {
                /* Setup the next interrupt */
                guest_configure_timer_action(shared_data);

                /* Setup a timeout for the interrupt to arrive */
                udelay(msecs_to_usecs(test_args.timer_period_ms) +
                        test_args.timer_err_margin_us);

                irq_iter = READ_ONCE(shared_data->nr_iter);
                __GUEST_ASSERT(config_iter + 1 == irq_iter,
                                "config_iter + 1 = 0x%x, irq_iter = 0x%x.\n"
                                "  Guest timer interrupt was not triggered within the specified\n"
                                "  interval, try to increase the error margin by [-e] option.\n",
                                config_iter + 1, irq_iter);
        }
}

static void guest_code(void)
{
        uint32_t cpu = guest_get_vcpuid();
        struct test_vcpu_shared_data *shared_data = &vcpu_shared_data[cpu];

        local_irq_disable();

        gic_init(GIC_V3, test_args.nr_vcpus);

        timer_set_ctl(VIRTUAL, CTL_IMASK);
        timer_set_ctl(PHYSICAL, CTL_IMASK);

        gic_irq_enable(vtimer_irq);
        gic_irq_enable(ptimer_irq);
        local_irq_enable();

        guest_run_stage(shared_data, GUEST_STAGE_VTIMER_CVAL);
        guest_run_stage(shared_data, GUEST_STAGE_VTIMER_TVAL);
        guest_run_stage(shared_data, GUEST_STAGE_PTIMER_CVAL);
        guest_run_stage(shared_data, GUEST_STAGE_PTIMER_TVAL);

        GUEST_DONE();
}

static void test_init_timer_irq(struct kvm_vm *vm)
{
        /* Timer initid should be same for all the vCPUs, so query only vCPU-0 */
        ptimer_irq = vcpu_get_ptimer_irq(vcpus[0]);
        vtimer_irq = vcpu_get_vtimer_irq(vcpus[0]);

        sync_global_to_guest(vm, ptimer_irq);
        sync_global_to_guest(vm, vtimer_irq);

        pr_debug("ptimer_irq: %d; vtimer_irq: %d\n", ptimer_irq, vtimer_irq);
}

struct kvm_vm *test_vm_create(void)
{
        struct kvm_vm *vm;
        unsigned int i;
        int nr_vcpus = test_args.nr_vcpus;

        TEST_REQUIRE(kvm_supports_vgic_v3());

        vm = vm_create_with_vcpus(nr_vcpus, guest_code, vcpus);

        vm_init_descriptor_tables(vm);
        vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT, guest_irq_handler);

        if (!test_args.reserved) {
                if (kvm_has_cap(KVM_CAP_COUNTER_OFFSET)) {
                        struct kvm_arm_counter_offset offset = {
                                .counter_offset = test_args.counter_offset,
                                .reserved = 0,
                        };
                        vm_ioctl(vm, KVM_ARM_SET_COUNTER_OFFSET, &offset);
                } else
                        TEST_FAIL("no support for global offset");
        }

        for (i = 0; i < nr_vcpus; i++)
                vcpu_init_descriptor_tables(vcpus[i]);

        test_init_timer_irq(vm);

        /* Make all the test's cmdline args visible to the guest */
        sync_global_to_guest(vm, test_args);

        return vm;
}

void test_vm_cleanup(struct kvm_vm *vm)
{
        kvm_vm_free(vm);
}