/*
 * 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/fs.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"

gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
{
        return gfn;
}

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


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__,
                       vcpu->arch.last_inst);
                r = RESUME_HOST;
                break;
        default:
                BUG();
        }

        return r;
}

void kvm_arch_hardware_enable(void *garbage)
{
}

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();
}

struct kvm *kvm_arch_create_vm(void)
{
        struct kvm *kvm;

        kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL);
        if (!kvm)
                return ERR_PTR(-ENOMEM);

        return kvm;
}

static void kvmppc_free_vcpus(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)
{
}

void kvm_arch_destroy_vm(struct kvm *kvm)
{
        kvmppc_free_vcpus(kvm);
        kvm_free_physmem(kvm);
        kfree(kvm);
}

int kvm_dev_ioctl_check_extension(long ext)
{
        int r;

        switch (ext) {
        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_set_memory_region(struct kvm *kvm,
                               struct kvm_userspace_memory_region *mem,
                               struct kvm_memory_slot old,
                               int user_alloc)
{
        return 0;
}

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);
        kvmppc_create_vcpu_debugfs(vcpu, id);
        return vcpu;
}

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

int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
{
        setup_timer(&vcpu->arch.dec_timer, kvmppc_decrementer_func,
                    (unsigned long)vcpu);

        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)
{
        ulong *gpr = &vcpu->arch.gpr[vcpu->arch.io_gpr];
        *gpr = run->dcr.data;
}

static void kvmppc_complete_mmio_load(struct kvm_vcpu *vcpu,
                                      struct kvm_run *run)
{
        ulong *gpr = &vcpu->arch.gpr[vcpu->arch.io_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 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;
                }
        }
}

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;

        return EMULATE_DO_MMIO;
}

int kvmppc_handle_store(struct kvm_run *run, struct kvm_vcpu *vcpu,
                        u32 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 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;

        vcpu_load(vcpu);

        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;
        }

        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);

        vcpu_put(vcpu);

        return r;
}

int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
{
        kvmppc_core_queue_external(vcpu, irq);

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

        return 0;
}

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);
                break;
        }
        default:
                r = -EINVAL;
        }

out:
        return r;
}

int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
{
        return -ENOTSUPP;
}

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

        switch (ioctl) {
        default:
                r = -EINVAL;
        }

        return r;
}

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

void kvm_arch_exit(void)
{
}