blob: ad5b9c676fd8b59ce19bea29313b3f4ee7aa8cf5 [file] [log] [blame]
/*
* Copyright 2008 Advanced Micro Devices, Inc.
* Copyright 2008 Red Hat Inc.
* Copyright 2009 Jerome Glisse.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: Dave Airlie
* Alex Deucher
* Jerome Glisse
*/
#include <linux/ktime.h>
#include <drm/drmP.h>
#include <drm/amdgpu_drm.h>
#include "amdgpu.h"
void amdgpu_gem_object_free(struct drm_gem_object *gobj)
{
struct amdgpu_bo *robj = gem_to_amdgpu_bo(gobj);
if (robj) {
if (robj->gem_base.import_attach)
drm_prime_gem_destroy(&robj->gem_base, robj->tbo.sg);
amdgpu_bo_unref(&robj);
}
}
int amdgpu_gem_object_create(struct amdgpu_device *adev, unsigned long size,
int alignment, u32 initial_domain,
u64 flags, bool kernel,
struct drm_gem_object **obj)
{
struct amdgpu_bo *robj;
unsigned long max_size;
int r;
*obj = NULL;
/* At least align on page size */
if (alignment < PAGE_SIZE) {
alignment = PAGE_SIZE;
}
if (!(initial_domain & (AMDGPU_GEM_DOMAIN_GDS | AMDGPU_GEM_DOMAIN_GWS | AMDGPU_GEM_DOMAIN_OA))) {
/* Maximum bo size is the unpinned gtt size since we use the gtt to
* handle vram to system pool migrations.
*/
max_size = adev->mc.gtt_size - adev->gart_pin_size;
if (size > max_size) {
DRM_DEBUG("Allocation size %ldMb bigger than %ldMb limit\n",
size >> 20, max_size >> 20);
return -ENOMEM;
}
}
retry:
r = amdgpu_bo_create(adev, size, alignment, kernel, initial_domain, flags, NULL, &robj);
if (r) {
if (r != -ERESTARTSYS) {
if (initial_domain == AMDGPU_GEM_DOMAIN_VRAM) {
initial_domain |= AMDGPU_GEM_DOMAIN_GTT;
goto retry;
}
DRM_ERROR("Failed to allocate GEM object (%ld, %d, %u, %d)\n",
size, initial_domain, alignment, r);
}
return r;
}
*obj = &robj->gem_base;
robj->pid = task_pid_nr(current);
mutex_lock(&adev->gem.mutex);
list_add_tail(&robj->list, &adev->gem.objects);
mutex_unlock(&adev->gem.mutex);
return 0;
}
int amdgpu_gem_init(struct amdgpu_device *adev)
{
INIT_LIST_HEAD(&adev->gem.objects);
return 0;
}
void amdgpu_gem_fini(struct amdgpu_device *adev)
{
amdgpu_bo_force_delete(adev);
}
/*
* Call from drm_gem_handle_create which appear in both new and open ioctl
* case.
*/
int amdgpu_gem_object_open(struct drm_gem_object *obj, struct drm_file *file_priv)
{
struct amdgpu_bo *rbo = gem_to_amdgpu_bo(obj);
struct amdgpu_device *adev = rbo->adev;
struct amdgpu_fpriv *fpriv = file_priv->driver_priv;
struct amdgpu_vm *vm = &fpriv->vm;
struct amdgpu_bo_va *bo_va;
int r;
r = amdgpu_bo_reserve(rbo, false);
if (r) {
return r;
}
bo_va = amdgpu_vm_bo_find(vm, rbo);
if (!bo_va) {
bo_va = amdgpu_vm_bo_add(adev, vm, rbo);
} else {
++bo_va->ref_count;
}
amdgpu_bo_unreserve(rbo);
return 0;
}
void amdgpu_gem_object_close(struct drm_gem_object *obj,
struct drm_file *file_priv)
{
struct amdgpu_bo *rbo = gem_to_amdgpu_bo(obj);
struct amdgpu_device *adev = rbo->adev;
struct amdgpu_fpriv *fpriv = file_priv->driver_priv;
struct amdgpu_vm *vm = &fpriv->vm;
struct amdgpu_bo_va *bo_va;
int r;
r = amdgpu_bo_reserve(rbo, true);
if (r) {
dev_err(adev->dev, "leaking bo va because "
"we fail to reserve bo (%d)\n", r);
return;
}
bo_va = amdgpu_vm_bo_find(vm, rbo);
if (bo_va) {
if (--bo_va->ref_count == 0) {
amdgpu_vm_bo_rmv(adev, bo_va);
}
}
amdgpu_bo_unreserve(rbo);
}
static int amdgpu_gem_handle_lockup(struct amdgpu_device *adev, int r)
{
if (r == -EDEADLK) {
r = amdgpu_gpu_reset(adev);
if (!r)
r = -EAGAIN;
}
return r;
}
/*
* GEM ioctls.
*/
int amdgpu_gem_create_ioctl(struct drm_device *dev, void *data,
struct drm_file *filp)
{
struct amdgpu_device *adev = dev->dev_private;
union drm_amdgpu_gem_create *args = data;
uint64_t size = args->in.bo_size;
struct drm_gem_object *gobj;
uint32_t handle;
bool kernel = false;
int r;
down_read(&adev->exclusive_lock);
/* create a gem object to contain this object in */
if (args->in.domains & (AMDGPU_GEM_DOMAIN_GDS |
AMDGPU_GEM_DOMAIN_GWS | AMDGPU_GEM_DOMAIN_OA)) {
kernel = true;
if (args->in.domains == AMDGPU_GEM_DOMAIN_GDS)
size = size << AMDGPU_GDS_SHIFT;
else if (args->in.domains == AMDGPU_GEM_DOMAIN_GWS)
size = size << AMDGPU_GWS_SHIFT;
else if (args->in.domains == AMDGPU_GEM_DOMAIN_OA)
size = size << AMDGPU_OA_SHIFT;
else {
r = -EINVAL;
goto error_unlock;
}
}
size = roundup(size, PAGE_SIZE);
r = amdgpu_gem_object_create(adev, size, args->in.alignment,
(u32)(0xffffffff & args->in.domains),
args->in.domain_flags,
kernel, &gobj);
if (r)
goto error_unlock;
r = drm_gem_handle_create(filp, gobj, &handle);
/* drop reference from allocate - handle holds it now */
drm_gem_object_unreference_unlocked(gobj);
if (r)
goto error_unlock;
memset(args, 0, sizeof(*args));
args->out.handle = handle;
up_read(&adev->exclusive_lock);
return 0;
error_unlock:
up_read(&adev->exclusive_lock);
r = amdgpu_gem_handle_lockup(adev, r);
return r;
}
int amdgpu_gem_userptr_ioctl(struct drm_device *dev, void *data,
struct drm_file *filp)
{
struct amdgpu_device *adev = dev->dev_private;
struct drm_amdgpu_gem_userptr *args = data;
struct drm_gem_object *gobj;
struct amdgpu_bo *bo;
uint32_t handle;
int r;
if (offset_in_page(args->addr | args->size))
return -EINVAL;
/* reject unknown flag values */
if (args->flags & ~(AMDGPU_GEM_USERPTR_READONLY |
AMDGPU_GEM_USERPTR_ANONONLY | AMDGPU_GEM_USERPTR_VALIDATE |
AMDGPU_GEM_USERPTR_REGISTER))
return -EINVAL;
if (!(args->flags & AMDGPU_GEM_USERPTR_ANONONLY) ||
!(args->flags & AMDGPU_GEM_USERPTR_REGISTER)) {
/* if we want to write to it we must require anonymous
memory and install a MMU notifier */
return -EACCES;
}
down_read(&adev->exclusive_lock);
/* create a gem object to contain this object in */
r = amdgpu_gem_object_create(adev, args->size, 0,
AMDGPU_GEM_DOMAIN_CPU, 0,
0, &gobj);
if (r)
goto handle_lockup;
bo = gem_to_amdgpu_bo(gobj);
r = amdgpu_ttm_tt_set_userptr(bo->tbo.ttm, args->addr, args->flags);
if (r)
goto release_object;
if (args->flags & AMDGPU_GEM_USERPTR_REGISTER) {
r = amdgpu_mn_register(bo, args->addr);
if (r)
goto release_object;
}
if (args->flags & AMDGPU_GEM_USERPTR_VALIDATE) {
down_read(&current->mm->mmap_sem);
r = amdgpu_bo_reserve(bo, true);
if (r) {
up_read(&current->mm->mmap_sem);
goto release_object;
}
amdgpu_ttm_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
r = ttm_bo_validate(&bo->tbo, &bo->placement, true, false);
amdgpu_bo_unreserve(bo);
up_read(&current->mm->mmap_sem);
if (r)
goto release_object;
}
r = drm_gem_handle_create(filp, gobj, &handle);
/* drop reference from allocate - handle holds it now */
drm_gem_object_unreference_unlocked(gobj);
if (r)
goto handle_lockup;
args->handle = handle;
up_read(&adev->exclusive_lock);
return 0;
release_object:
drm_gem_object_unreference_unlocked(gobj);
handle_lockup:
up_read(&adev->exclusive_lock);
r = amdgpu_gem_handle_lockup(adev, r);
return r;
}
int amdgpu_mode_dumb_mmap(struct drm_file *filp,
struct drm_device *dev,
uint32_t handle, uint64_t *offset_p)
{
struct drm_gem_object *gobj;
struct amdgpu_bo *robj;
gobj = drm_gem_object_lookup(dev, filp, handle);
if (gobj == NULL) {
return -ENOENT;
}
robj = gem_to_amdgpu_bo(gobj);
if (amdgpu_ttm_tt_has_userptr(robj->tbo.ttm) ||
(robj->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)) {
drm_gem_object_unreference_unlocked(gobj);
return -EPERM;
}
*offset_p = amdgpu_bo_mmap_offset(robj);
drm_gem_object_unreference_unlocked(gobj);
return 0;
}
int amdgpu_gem_mmap_ioctl(struct drm_device *dev, void *data,
struct drm_file *filp)
{
union drm_amdgpu_gem_mmap *args = data;
uint32_t handle = args->in.handle;
memset(args, 0, sizeof(*args));
return amdgpu_mode_dumb_mmap(filp, dev, handle, &args->out.addr_ptr);
}
/**
* amdgpu_gem_timeout - calculate jiffies timeout from absolute value
*
* @timeout_ns: timeout in ns
*
* Calculate the timeout in jiffies from an absolute timeout in ns.
*/
unsigned long amdgpu_gem_timeout(uint64_t timeout_ns)
{
unsigned long timeout_jiffies;
ktime_t timeout;
/* clamp timeout if it's to large */
if (((int64_t)timeout_ns) < 0)
return MAX_SCHEDULE_TIMEOUT;
timeout = ktime_sub_ns(ktime_get(), timeout_ns);
if (ktime_to_ns(timeout) < 0)
return 0;
timeout_jiffies = nsecs_to_jiffies(ktime_to_ns(timeout));
/* clamp timeout to avoid unsigned-> signed overflow */
if (timeout_jiffies > MAX_SCHEDULE_TIMEOUT )
return MAX_SCHEDULE_TIMEOUT - 1;
return timeout_jiffies;
}
int amdgpu_gem_wait_idle_ioctl(struct drm_device *dev, void *data,
struct drm_file *filp)
{
struct amdgpu_device *adev = dev->dev_private;
union drm_amdgpu_gem_wait_idle *args = data;
struct drm_gem_object *gobj;
struct amdgpu_bo *robj;
uint32_t handle = args->in.handle;
unsigned long timeout = amdgpu_gem_timeout(args->in.timeout);
int r = 0;
long ret;
gobj = drm_gem_object_lookup(dev, filp, handle);
if (gobj == NULL) {
return -ENOENT;
}
robj = gem_to_amdgpu_bo(gobj);
if (timeout == 0)
ret = reservation_object_test_signaled_rcu(robj->tbo.resv, true);
else
ret = reservation_object_wait_timeout_rcu(robj->tbo.resv, true, true, timeout);
/* ret == 0 means not signaled,
* ret > 0 means signaled
* ret < 0 means interrupted before timeout
*/
if (ret >= 0) {
memset(args, 0, sizeof(*args));
args->out.status = (ret == 0);
} else
r = ret;
drm_gem_object_unreference_unlocked(gobj);
r = amdgpu_gem_handle_lockup(adev, r);
return r;
}
int amdgpu_gem_metadata_ioctl(struct drm_device *dev, void *data,
struct drm_file *filp)
{
struct drm_amdgpu_gem_metadata *args = data;
struct drm_gem_object *gobj;
struct amdgpu_bo *robj;
int r = -1;
DRM_DEBUG("%d \n", args->handle);
gobj = drm_gem_object_lookup(dev, filp, args->handle);
if (gobj == NULL)
return -ENOENT;
robj = gem_to_amdgpu_bo(gobj);
r = amdgpu_bo_reserve(robj, false);
if (unlikely(r != 0))
goto out;
if (args->op == AMDGPU_GEM_METADATA_OP_GET_METADATA) {
amdgpu_bo_get_tiling_flags(robj, &args->data.tiling_info);
r = amdgpu_bo_get_metadata(robj, args->data.data,
sizeof(args->data.data),
&args->data.data_size_bytes,
&args->data.flags);
} else if (args->op == AMDGPU_GEM_METADATA_OP_SET_METADATA) {
r = amdgpu_bo_set_tiling_flags(robj, args->data.tiling_info);
if (!r)
r = amdgpu_bo_set_metadata(robj, args->data.data,
args->data.data_size_bytes,
args->data.flags);
}
amdgpu_bo_unreserve(robj);
out:
drm_gem_object_unreference_unlocked(gobj);
return r;
}
/**
* amdgpu_gem_va_update_vm -update the bo_va in its VM
*
* @adev: amdgpu_device pointer
* @bo_va: bo_va to update
*
* Update the bo_va directly after setting it's address. Errors are not
* vital here, so they are not reported back to userspace.
*/
static void amdgpu_gem_va_update_vm(struct amdgpu_device *adev,
struct amdgpu_bo_va *bo_va)
{
struct ttm_validate_buffer tv, *entry;
struct amdgpu_bo_list_entry *vm_bos;
struct ww_acquire_ctx ticket;
struct list_head list;
unsigned domain;
int r;
INIT_LIST_HEAD(&list);
tv.bo = &bo_va->bo->tbo;
tv.shared = true;
list_add(&tv.head, &list);
vm_bos = amdgpu_vm_get_bos(adev, bo_va->vm, &list);
if (!vm_bos)
return;
r = ttm_eu_reserve_buffers(&ticket, &list, true, NULL);
if (r)
goto error_free;
list_for_each_entry(entry, &list, head) {
domain = amdgpu_mem_type_to_domain(entry->bo->mem.mem_type);
/* if anything is swapped out don't swap it in here,
just abort and wait for the next CS */
if (domain == AMDGPU_GEM_DOMAIN_CPU)
goto error_unreserve;
}
mutex_lock(&bo_va->vm->mutex);
r = amdgpu_vm_clear_freed(adev, bo_va->vm);
if (r)
goto error_unlock;
r = amdgpu_vm_bo_update(adev, bo_va, &bo_va->bo->tbo.mem);
error_unlock:
mutex_unlock(&bo_va->vm->mutex);
error_unreserve:
ttm_eu_backoff_reservation(&ticket, &list);
error_free:
drm_free_large(vm_bos);
if (r)
DRM_ERROR("Couldn't update BO_VA (%d)\n", r);
}
int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
struct drm_file *filp)
{
union drm_amdgpu_gem_va *args = data;
struct drm_gem_object *gobj;
struct amdgpu_device *adev = dev->dev_private;
struct amdgpu_fpriv *fpriv = filp->driver_priv;
struct amdgpu_bo *rbo;
struct amdgpu_bo_va *bo_va;
uint32_t invalid_flags, va_flags = 0;
int r = 0;
if (!adev->vm_manager.enabled) {
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
return -ENOTTY;
}
if (args->in.va_address < AMDGPU_VA_RESERVED_SIZE) {
dev_err(&dev->pdev->dev,
"va_address 0x%lX is in reserved area 0x%X\n",
(unsigned long)args->in.va_address,
AMDGPU_VA_RESERVED_SIZE);
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
return -EINVAL;
}
invalid_flags = ~(AMDGPU_VM_PAGE_READABLE | AMDGPU_VM_PAGE_WRITEABLE |
AMDGPU_VM_PAGE_EXECUTABLE);
if ((args->in.flags & invalid_flags)) {
dev_err(&dev->pdev->dev, "invalid flags 0x%08X vs 0x%08X\n",
args->in.flags, invalid_flags);
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
return -EINVAL;
}
switch (args->in.operation) {
case AMDGPU_VA_OP_MAP:
case AMDGPU_VA_OP_UNMAP:
break;
default:
dev_err(&dev->pdev->dev, "unsupported operation %d\n",
args->in.operation);
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
return -EINVAL;
}
gobj = drm_gem_object_lookup(dev, filp, args->in.handle);
if (gobj == NULL) {
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
return -ENOENT;
}
rbo = gem_to_amdgpu_bo(gobj);
r = amdgpu_bo_reserve(rbo, false);
if (r) {
if (r != -ERESTARTSYS) {
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
}
drm_gem_object_unreference_unlocked(gobj);
return r;
}
bo_va = amdgpu_vm_bo_find(&fpriv->vm, rbo);
if (!bo_va) {
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
drm_gem_object_unreference_unlocked(gobj);
return -ENOENT;
}
switch (args->in.operation) {
case AMDGPU_VA_OP_MAP:
if (args->in.flags & AMDGPU_VM_PAGE_READABLE)
va_flags |= AMDGPU_PTE_READABLE;
if (args->in.flags & AMDGPU_VM_PAGE_WRITEABLE)
va_flags |= AMDGPU_PTE_WRITEABLE;
if (args->in.flags & AMDGPU_VM_PAGE_EXECUTABLE)
va_flags |= AMDGPU_PTE_EXECUTABLE;
r = amdgpu_vm_bo_map(adev, bo_va, args->in.va_address,
args->in.offset_in_bo, args->in.map_size,
va_flags);
break;
case AMDGPU_VA_OP_UNMAP:
r = amdgpu_vm_bo_unmap(adev, bo_va, args->in.va_address);
break;
default:
break;
}
if (!r) {
amdgpu_gem_va_update_vm(adev, bo_va);
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_OK;
} else {
memset(args, 0, sizeof(*args));
args->out.result = AMDGPU_VA_RESULT_ERROR;
}
drm_gem_object_unreference_unlocked(gobj);
return r;
}
int amdgpu_gem_op_ioctl(struct drm_device *dev, void *data,
struct drm_file *filp)
{
struct drm_amdgpu_gem_op *args = data;
struct drm_gem_object *gobj;
struct amdgpu_bo *robj;
int r;
gobj = drm_gem_object_lookup(dev, filp, args->handle);
if (gobj == NULL) {
return -ENOENT;
}
robj = gem_to_amdgpu_bo(gobj);
r = amdgpu_bo_reserve(robj, false);
if (unlikely(r))
goto out;
switch (args->op) {
case AMDGPU_GEM_OP_GET_GEM_CREATE_INFO: {
struct drm_amdgpu_gem_create_in info;
void __user *out = (void __user *)(long)args->value;
info.bo_size = robj->gem_base.size;
info.alignment = robj->tbo.mem.page_alignment << PAGE_SHIFT;
info.domains = robj->initial_domain;
info.domain_flags = robj->flags;
if (copy_to_user(out, &info, sizeof(info)))
r = -EFAULT;
break;
}
case AMDGPU_GEM_OP_SET_PLACEMENT:
if (amdgpu_ttm_tt_has_userptr(robj->tbo.ttm)) {
r = -EPERM;
break;
}
robj->initial_domain = args->value & (AMDGPU_GEM_DOMAIN_VRAM |
AMDGPU_GEM_DOMAIN_GTT |
AMDGPU_GEM_DOMAIN_CPU);
break;
default:
r = -EINVAL;
}
amdgpu_bo_unreserve(robj);
out:
drm_gem_object_unreference_unlocked(gobj);
return r;
}
int amdgpu_mode_dumb_create(struct drm_file *file_priv,
struct drm_device *dev,
struct drm_mode_create_dumb *args)
{
struct amdgpu_device *adev = dev->dev_private;
struct drm_gem_object *gobj;
uint32_t handle;
int r;
args->pitch = amdgpu_align_pitch(adev, args->width, args->bpp, 0) * ((args->bpp + 1) / 8);
args->size = args->pitch * args->height;
args->size = ALIGN(args->size, PAGE_SIZE);
r = amdgpu_gem_object_create(adev, args->size, 0,
AMDGPU_GEM_DOMAIN_VRAM,
0, ttm_bo_type_device,
&gobj);
if (r)
return -ENOMEM;
r = drm_gem_handle_create(file_priv, gobj, &handle);
/* drop reference from allocate - handle holds it now */
drm_gem_object_unreference_unlocked(gobj);
if (r) {
return r;
}
args->handle = handle;
return 0;
}
#if defined(CONFIG_DEBUG_FS)
static int amdgpu_debugfs_gem_info(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *)m->private;
struct drm_device *dev = node->minor->dev;
struct amdgpu_device *adev = dev->dev_private;
struct amdgpu_bo *rbo;
unsigned i = 0;
mutex_lock(&adev->gem.mutex);
list_for_each_entry(rbo, &adev->gem.objects, list) {
unsigned domain;
const char *placement;
domain = amdgpu_mem_type_to_domain(rbo->tbo.mem.mem_type);
switch (domain) {
case AMDGPU_GEM_DOMAIN_VRAM:
placement = "VRAM";
break;
case AMDGPU_GEM_DOMAIN_GTT:
placement = " GTT";
break;
case AMDGPU_GEM_DOMAIN_CPU:
default:
placement = " CPU";
break;
}
seq_printf(m, "bo[0x%08x] %8ldkB %8ldMB %s pid %8ld\n",
i, amdgpu_bo_size(rbo) >> 10, amdgpu_bo_size(rbo) >> 20,
placement, (unsigned long)rbo->pid);
i++;
}
mutex_unlock(&adev->gem.mutex);
return 0;
}
static struct drm_info_list amdgpu_debugfs_gem_list[] = {
{"amdgpu_gem_info", &amdgpu_debugfs_gem_info, 0, NULL},
};
#endif
int amdgpu_gem_debugfs_init(struct amdgpu_device *adev)
{
#if defined(CONFIG_DEBUG_FS)
return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_gem_list, 1);
#endif
return 0;
}