#include "hv/arch.h"
#include "hv/log.h"
#include "hv/psci.h"
#include "hv/string.h"
#include "hv/uart.h"

#define PSCI32_VERSION 0x84000000ull
#define PSCI32_CPU_SUSPEND 0x84000001ull
#define PSCI32_CPU_OFF 0x84000002ull
#define PSCI32_CPU_ON 0x84000003ull
#define PSCI32_AFFINITY_INFO 0x84000004ull
#define PSCI32_SYSTEM_OFF 0x84000008ull
#define PSCI32_SYSTEM_RESET 0x84000009ull
#define PSCI32_FEATURES 0x8400000aull
#define PSCI64_CPU_SUSPEND 0xc4000001ull
#define PSCI64_CPU_ON 0xc4000003ull
#define PSCI64_AFFINITY_INFO 0xc4000004ull

#define PSCI_RET_SUCCESS 0ull
#define PSCI_RET_NOT_SUPPORTED UINT64_MAX
#define PSCI_RET_INVALID_PARAMETERS (~0ull - 1ull)
#define PSCI_RET_DENIED (~0ull - 2ull)

static uint64_t g_calls;
static uint64_t g_denied_cpu_on;
static uint64_t g_last_function;

static void log_psci(struct vcpu *vcpu, uint64_t fid, uint64_t ret)
{
    struct log_event ev;
    hv_memset(&ev, 0, sizeof(ev));
    ev.kind = LOG_HVC;
    ev.vcpu = vcpu != (struct vcpu *)0 ? vcpu->id : UINT64_MAX;
    ev.operand = fid;
    ev.result = ret;
    ev.reason = 320u;
    ev.name = "psci";
    log_event_commit(&ev);
}

bool psci_handle_call(struct vcpu *vcpu, uint64_t function_id)
{
    uint64_t ret = PSCI_RET_NOT_SUPPORTED;

    if (vcpu == (struct vcpu *)0) {
        return false;
    }

    g_calls++;
    g_last_function = function_id;
    switch (function_id) {
    case PSCI32_VERSION:
        ret = 0x00010001ull;
        break;
    case PSCI32_FEATURES: {
        uint64_t query = vcpu_read_gpr(vcpu, 1u);
        if (query == PSCI32_VERSION || query == PSCI32_FEATURES ||
            query == PSCI32_AFFINITY_INFO || query == PSCI64_AFFINITY_INFO ||
            query == PSCI32_SYSTEM_OFF || query == PSCI32_SYSTEM_RESET) {
            ret = PSCI_RET_SUCCESS;
        }
        break;
    }
    case PSCI32_AFFINITY_INFO:
    case PSCI64_AFFINITY_INFO:
        ret = PSCI_RET_SUCCESS;
        break;
    case PSCI32_CPU_SUSPEND:
    case PSCI64_CPU_SUSPEND:
        ret = PSCI_RET_DENIED;
        break;
    case PSCI32_CPU_ON:
    case PSCI64_CPU_ON:
        g_denied_cpu_on++;
        ret = PSCI_RET_DENIED;
        break;
    case PSCI32_CPU_OFF:
        ret = PSCI_RET_DENIED;
        break;
    case PSCI32_SYSTEM_OFF:
    case PSCI32_SYSTEM_RESET:
        log_psci(vcpu, function_id, PSCI_RET_SUCCESS);
        uart_puts("psci power request function=");
        uart_put_hex64(function_id);
        uart_puts("; halting\n");
        arch_halt();
    default:
        ret = PSCI_RET_NOT_SUPPORTED;
        break;
    }

    vcpu_write_gpr(vcpu, 0u, ret);
    log_psci(vcpu, function_id, ret);
    arch_advance_guest_pc(vcpu);
    return true;
}

void psci_dump(void)
{
    uart_puts("psci calls=");
    uart_put_dec64(g_calls);
    uart_puts(" denied_cpu_on=");
    uart_put_dec64(g_denied_cpu_on);
    uart_puts(" last=");
    uart_put_hex64(g_last_function);
    uart_puts("\n");
}