/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright IBM Corp. 2007
 *
 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
 *          Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
 */

#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/hrtimer.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <asm/cputable.h>
#include <asm/uaccess.h>
#include <asm/kvm_ppc.h>
#include <asm/tlbflush.h>
#include "timing.h"
#include "../mm/mmu_decl.h"

#define CREATE_TRACE_POINTS
#include "trace.h"

int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
        return !(v->arch.shared->msr & MSR_WE) ||
               !!(v->arch.pending_exceptions);
}

int kvmppc_kvm_pv(struct kvm_vcpu *vcpu)
{
        int nr = kvmppc_get_gpr(vcpu, 11);
        int r;
        unsigned long __maybe_unused param1 = kvmppc_get_gpr(vcpu, 3);
        unsigned long __maybe_unused param2 = kvmppc_get_gpr(vcpu, 4);
        unsigned long __maybe_unused param3 = kvmppc_get_gpr(vcpu, 5);
        unsigned long __maybe_unused param4 = kvmppc_get_gpr(vcpu, 6);
        unsigned long r2 = 0;

        if (!(vcpu->arch.shared->msr & MSR_SF)) {
                /* 32 bit mode */
                param1 &= 0xffffffff;
                param2 &= 0xffffffff;
                param3 &= 0xffffffff;
                param4 &= 0xffffffff;
        }

        switch (nr) {
        case HC_VENDOR_KVM | KVM_HC_PPC_MAP_MAGIC_PAGE:
        {
                vcpu->arch.magic_page_pa = param1;
                vcpu->arch.magic_page_ea = param2;

                r2 = KVM_MAGIC_FEAT_SR;

                r = HC_EV_SUCCESS;
                break;
        }
        case HC_VENDOR_KVM | KVM_HC_FEATURES:
                r = HC_EV_SUCCESS;
#if defined(CONFIG_PPC_BOOK3S) /* XXX Missing magic page on BookE */
                r2 |= (1 << KVM_FEATURE_MAGIC_PAGE);
#endif

                /* Second return value is in r4 */
                break;
        default:
                r = HC_EV_UNIMPLEMENTED;
                break;
        }

        kvmppc_set_gpr(vcpu, 4, r2);

        return r;
}

int kvmppc_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
        enum emulation_result er;
        int r;

        er = kvmppc_emulate_instruction(run, vcpu);
        switch (er) {
        case EMULATE_DONE:
                /* Future optimization: only reload non-volatiles if they were
                 * actually modified. */
                r = RESUME_GUEST_NV;
                break;
        case EMULATE_DO_MMIO:
                run->exit_reason = KVM_EXIT_MMIO;
                /* We must reload nonvolatiles because "update" load/store
                 * instructions modify register state. */
                /* Future optimization: only reload non-volatiles if they were
                 * actually modified. */
                r = RESUME_HOST_NV;
                break;
        case EMULATE_FAIL:
                /* XXX Deliver Program interrupt to guest. */
                printk(KERN_EMERG "%s: emulation failed (%08x)\n", __func__,
                       kvmppc_get_last_inst(vcpu));
                r = RESUME_HOST;
                break;
        default:
                BUG();
        }

        return r;
}

int kvm_arch_hardware_enable(void *garbage)
{
        return 0;
}

void kvm_arch_hardware_disable(void *garbage)
{
}

int kvm_arch_hardware_setup(void)
{
        return 0;
}

void kvm_arch_hardware_unsetup(void)
{
}

void kvm_arch_check_processor_compat(void *rtn)
{
        *(int *)rtn = kvmppc_core_check_processor_compat();
}

int kvm_arch_init_vm(struct kvm *kvm)
{
        return 0;
}

void kvm_arch_destroy_vm(struct kvm *kvm)
{
        unsigned int i;
        struct kvm_vcpu *vcpu;

        kvm_for_each_vcpu(i, vcpu, kvm)
                kvm_arch_vcpu_free(vcpu);

        mutex_lock(&kvm->lock);
        for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
                kvm->vcpus[i] = NULL;

        atomic_set(&kvm->online_vcpus, 0);
        mutex_unlock(&kvm->lock);
}

void kvm_arch_sync_events(struct kvm *kvm)
{
}

int kvm_dev_ioctl_check_extension(long ext)
{
        int r;

        switch (ext) {
        case KVM_CAP_PPC_SEGSTATE:
        case KVM_CAP_PPC_PAIRED_SINGLES:
        case KVM_CAP_PPC_UNSET_IRQ:
        case KVM_CAP_PPC_IRQ_LEVEL:
        case KVM_CAP_ENABLE_CAP:
        case KVM_CAP_PPC_OSI:
        case KVM_CAP_PPC_GET_PVINFO:
                r = 1;
                break;
        case KVM_CAP_COALESCED_MMIO:
                r = KVM_COALESCED_MMIO_PAGE_OFFSET;
                break;
        default:
                r = 0;
                break;
        }
        return r;

}

long kvm_arch_dev_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg)
{
        return -EINVAL;
}

int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                   struct kvm_memory_slot *memslot,
                                   struct kvm_memory_slot old,
                                   struct kvm_userspace_memory_region *mem,
                                   int user_alloc)
{
        return 0;
}

void kvm_arch_commit_memory_region(struct kvm *kvm,
               struct kvm_userspace_memory_region *mem,
               struct kvm_memory_slot old,
               int user_alloc)
{
       return;
}


void kvm_arch_flush_shadow(struct kvm *kvm)
{
}

struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
{
        struct kvm_vcpu *vcpu;
        vcpu = kvmppc_core_vcpu_create(kvm, id);
        if (!IS_ERR(vcpu))
                kvmppc_create_vcpu_debugfs(vcpu, id);
        return vcpu;
}

void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
        /* Make sure we're not using the vcpu anymore */
        hrtimer_cancel(&vcpu->arch.dec_timer);
        tasklet_kill(&vcpu->arch.tasklet);

        kvmppc_remove_vcpu_debugfs(vcpu);
        kvmppc_core_vcpu_free(vcpu);
}

void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
        kvm_arch_vcpu_free(vcpu);
}

int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
{
        return kvmppc_core_pending_dec(vcpu);
}

static void kvmppc_decrementer_func(unsigned long data)
{
        struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;

        kvmppc_core_queue_dec(vcpu);

        if (waitqueue_active(&vcpu->wq)) {
                wake_up_interruptible(&vcpu->wq);
                vcpu->stat.halt_wakeup++;
        }
}

/*
 * low level hrtimer wake routine. Because this runs in hardirq context
 * we schedule a tasklet to do the real work.
 */
enum hrtimer_restart kvmppc_decrementer_wakeup(struct hrtimer *timer)
{
        struct kvm_vcpu *vcpu;

        vcpu = container_of(timer, struct kvm_vcpu, arch.dec_timer);
        tasklet_schedule(&vcpu->arch.tasklet);

        return HRTIMER_NORESTART;
}

int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
        hrtimer_init(&vcpu->arch.dec_timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
        tasklet_init(&vcpu->arch.tasklet, kvmppc_decrementer_func, (ulong)vcpu);
        vcpu->arch.dec_timer.function = kvmppc_decrementer_wakeup;

        return 0;
}

void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
{
        kvmppc_mmu_destroy(vcpu);
}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
        kvmppc_core_vcpu_load(vcpu, cpu);
}

void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
        kvmppc_core_vcpu_put(vcpu);
}

int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
                                        struct kvm_guest_debug *dbg)
{
        return -EINVAL;
}

static void kvmppc_complete_dcr_load(struct kvm_vcpu *vcpu,
                                     struct kvm_run *run)
{
        kvmppc_set_gpr(vcpu, vcpu->arch.io_gpr, run->dcr.data);
}

static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
                                      struct kvm_run *run)
{
        u64 uninitialized_var(gpr);

        if (run->mmio.len > sizeof(gpr)) {
                printk(KERN_ERR "bad MMIO length: %d\n", run->mmio.len);
                return;
        }

        if (vcpu->arch.mmio_is_bigendian) {
                switch (run->mmio.len) {
                case 8: gpr = *(u64 *)run->mmio.data; break;
                case 4: gpr = *(u32 *)run->mmio.data; break;
                case 2: gpr = *(u16 *)run->mmio.data; break;
                case 1: gpr = *(u8 *)run->mmio.data; break;
                }
        } else {
                /* Convert BE data from userland back to LE. */
                switch (run->mmio.len) {
                case 4: gpr = ld_le32((u32 *)run->mmio.data); break;
                case 2: gpr = ld_le16((u16 *)run->mmio.data); break;
                case 1: gpr = *(u8 *)run->mmio.data; break;
                }
        }

        if (vcpu->arch.mmio_sign_extend) {
                switch (run->mmio.len) {
#ifdef CONFIG_PPC64
                case 4:
                        gpr = (s64)(s32)gpr;
                        break;
#endif
                case 2:
                        gpr = (s64)(s16)gpr;
                        break;
                case 1:
                        gpr = (s64)(s8)gpr;
                        break;
                }
        }

        kvmppc_set_gpr(vcpu, vcpu->arch.io_gpr, gpr);

        switch (vcpu->arch.io_gpr & KVM_REG_EXT_MASK) {
        case KVM_REG_GPR:
                kvmppc_set_gpr(vcpu, vcpu->arch.io_gpr, gpr);
                break;
        case KVM_REG_FPR:
                vcpu->arch.fpr[vcpu->arch.io_gpr & KVM_REG_MASK] = gpr;
                break;
#ifdef CONFIG_PPC_BOOK3S
        case KVM_REG_QPR:
                vcpu->arch.qpr[vcpu->arch.io_gpr & KVM_REG_MASK] = gpr;
                break;
        case KVM_REG_FQPR:
                vcpu->arch.fpr[vcpu->arch.io_gpr & KVM_REG_MASK] = gpr;
                vcpu->arch.qpr[vcpu->arch.io_gpr & KVM_REG_MASK] = gpr;
                break;
#endif
        default:
                BUG();
        }
}

int kvmppc_handle_load(struct kvm_run *run, struct kvm_vcpu *vcpu,
                       unsigned int rt, unsigned int bytes, int is_bigendian)
{
        if (bytes > sizeof(run->mmio.data)) {
                printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
                       run->mmio.len);
        }

        run->mmio.phys_addr = vcpu->arch.paddr_accessed;
        run->mmio.len = bytes;
        run->mmio.is_write = 0;

        vcpu->arch.io_gpr = rt;
        vcpu->arch.mmio_is_bigendian = is_bigendian;
        vcpu->mmio_needed = 1;
        vcpu->mmio_is_write = 0;
        vcpu->arch.mmio_sign_extend = 0;

        return EMULATE_DO_MMIO;
}

/* Same as above, but sign extends */
int kvmppc_handle_loads(struct kvm_run *run, struct kvm_vcpu *vcpu,
                        unsigned int rt, unsigned int bytes, int is_bigendian)
{
        int r;

        r = kvmppc_handle_load(run, vcpu, rt, bytes, is_bigendian);
        vcpu->arch.mmio_sign_extend = 1;

        return r;
}

int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
                        u64 val, unsigned int bytes, int is_bigendian)
{
        void *data = run->mmio.data;

        if (bytes > sizeof(run->mmio.data)) {
                printk(KERN_ERR "%s: bad MMIO length: %d\n", __func__,
                       run->mmio.len);
        }

        run->mmio.phys_addr = vcpu->arch.paddr_accessed;
        run->mmio.len = bytes;
        run->mmio.is_write = 1;
        vcpu->mmio_needed = 1;
        vcpu->mmio_is_write = 1;

        /* Store the value at the lowest bytes in 'data'. */
        if (is_bigendian) {
                switch (bytes) {
                case 8: *(u64 *)data = val; break;
                case 4: *(u32 *)data = val; break;
                case 2: *(u16 *)data = val; break;
                case 1: *(u8  *)data = val; break;
                }
        } else {
                /* Store LE value into 'data'. */
                switch (bytes) {
                case 4: st_le32(data, val); break;
                case 2: st_le16(data, val); break;
                case 1: *(u8 *)data = val; break;
                }
        }

        return EMULATE_DO_MMIO;
}

int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
        int r;
        sigset_t sigsaved;

        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);

        if (vcpu->mmio_needed) {
                if (!vcpu->mmio_is_write)
                        kvmppc_complete_mmio_load(vcpu, run);
                vcpu->mmio_needed = 0;
        } else if (vcpu->arch.dcr_needed) {
                if (!vcpu->arch.dcr_is_write)
                        kvmppc_complete_dcr_load(vcpu, run);
                vcpu->arch.dcr_needed = 0;
        } else if (vcpu->arch.osi_needed) {
                u64 *gprs = run->osi.gprs;
                int i;

                for (i = 0; i < 32; i++)
                        kvmppc_set_gpr(vcpu, i, gprs[i]);
                vcpu->arch.osi_needed = 0;
        }

        kvmppc_core_deliver_interrupts(vcpu);

        local_irq_disable();
        kvm_guest_enter();
        r = __kvmppc_vcpu_run(run, vcpu);
        kvm_guest_exit();
        local_irq_enable();

        if (vcpu->sigset_active)
                sigprocmask(SIG_SETMASK, &sigsaved, NULL);

        return r;
}

int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
{
        if (irq->irq == KVM_INTERRUPT_UNSET)
                kvmppc_core_dequeue_external(vcpu, irq);
        else
                kvmppc_core_queue_external(vcpu, irq);

        if (waitqueue_active(&vcpu->wq)) {
                wake_up_interruptible(&vcpu->wq);
                vcpu->stat.halt_wakeup++;
        }

        return 0;
}

static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
                                     struct kvm_enable_cap *cap)
{
        int r;

        if (cap->flags)
                return -EINVAL;

        switch (cap->cap) {
        case KVM_CAP_PPC_OSI:
                r = 0;
                vcpu->arch.osi_enabled = true;
                break;
        default:
                r = -EINVAL;
                break;
        }

        return r;
}

int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        return -EINVAL;
}

int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        return -EINVAL;
}

long kvm_arch_vcpu_ioctl(struct file *filp,
                         unsigned int ioctl, unsigned long arg)
{
        struct kvm_vcpu *vcpu = filp->private_data;
        void __user *argp = (void __user *)arg;
        long r;

        switch (ioctl) {
        case KVM_INTERRUPT: {
                struct kvm_interrupt irq;
                r = -EFAULT;
                if (copy_from_user(&irq, argp, sizeof(irq)))
                        goto out;
                r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
                goto out;
        }

        case KVM_ENABLE_CAP:
        {
                struct kvm_enable_cap cap;
                r = -EFAULT;
                if (copy_from_user(&cap, argp, sizeof(cap)))
                        goto out;
                r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
                break;
        }
        default:
                r = -EINVAL;
        }

out:
        return r;
}

static int kvm_vm_ioctl_get_pvinfo(struct kvm_ppc_pvinfo *pvinfo)
{
        u32 inst_lis = 0x3c000000;
        u32 inst_ori = 0x60000000;
        u32 inst_nop = 0x60000000;
        u32 inst_sc = 0x44000002;
        u32 inst_imm_mask = 0xffff;

        /*
         * The hypercall to get into KVM from within guest context is as
         * follows:
         *
         *    lis r0, r0, KVM_SC_MAGIC_R0@h
         *    ori r0, KVM_SC_MAGIC_R0@l
         *    sc
         *    nop
         */
        pvinfo->hcall[0] = inst_lis | ((KVM_SC_MAGIC_R0 >> 16) & inst_imm_mask);
        pvinfo->hcall[1] = inst_ori | (KVM_SC_MAGIC_R0 & inst_imm_mask);
        pvinfo->hcall[2] = inst_sc;
        pvinfo->hcall[3] = inst_nop;

        return 0;
}

long kvm_arch_vm_ioctl(struct file *filp,
                       unsigned int ioctl, unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        long r;

        switch (ioctl) {
        case KVM_PPC_GET_PVINFO: {
                struct kvm_ppc_pvinfo pvinfo;
                memset(&pvinfo, 0, sizeof(pvinfo));
                r = kvm_vm_ioctl_get_pvinfo(&pvinfo);
                if (copy_to_user(argp, &pvinfo, sizeof(pvinfo))) {
                        r = -EFAULT;
                        goto out;
                }

                break;
        }
        default:
                r = -ENOTTY;
        }

out:
        return r;
}

int kvm_arch_init(void *opaque)
{
        return 0;
}

void kvm_arch_exit(void)
{
}