/*
* sync.c
*
* Copyright 2012 Google, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <fcntl.h>
#include <malloc.h>
#include <poll.h>
#include <stdatomic.h>
#include <stdint.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <android/sync.h>
/* Legacy Sync API */
struct sync_legacy_merge_data {
int32_t fd2;
char name[32];
int32_t fence;
};
/**
* DOC: SYNC_IOC_MERGE - merge two fences
*
* Takes a struct sync_merge_data. Creates a new fence containing copies of
* the sync_pts in both the calling fd and sync_merge_data.fd2. Returns the
* new fence's fd in sync_merge_data.fence
*
* This is the legacy version of the Sync API before the de-stage that happened
* on Linux kernel 4.7.
*/
#define SYNC_IOC_LEGACY_MERGE _IOWR(SYNC_IOC_MAGIC, 1, \
struct sync_legacy_merge_data)
/**
* DOC: SYNC_IOC_LEGACY_FENCE_INFO - get detailed information on a fence
*
* Takes a struct sync_fence_info_data with extra space allocated for pt_info.
* Caller should write the size of the buffer into len. On return, len is
* updated to reflect the total size of the sync_fence_info_data including
* pt_info.
*
* pt_info is a buffer containing sync_pt_infos for every sync_pt in the fence.
* To iterate over the sync_pt_infos, use the sync_pt_info.len field.
*
* This is the legacy version of the Sync API before the de-stage that happened
* on Linux kernel 4.7.
*/
#define SYNC_IOC_LEGACY_FENCE_INFO _IOWR(SYNC_IOC_MAGIC, 2,\
struct sync_fence_info_data)
/* SW Sync API */
struct sw_sync_create_fence_data {
__u32 value;
char name[32];
__s32 fence;
};
#define SW_SYNC_IOC_MAGIC 'W'
#define SW_SYNC_IOC_CREATE_FENCE _IOWR(SW_SYNC_IOC_MAGIC, 0, struct sw_sync_create_fence_data)
#define SW_SYNC_IOC_INC _IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
// ---------------------------------------------------------------------------
// Support for caching the sync uapi version.
//
// This library supports both legacy (android/staging) uapi and modern
// (mainline) sync uapi. Library calls first try one uapi, and if that fails,
// try the other. Since any given kernel only supports one uapi version, after
// the first successful syscall we know what the kernel supports and can skip
// trying the other.
enum uapi_version {
UAPI_UNKNOWN,
UAPI_MODERN,
UAPI_LEGACY
};
static atomic_int g_uapi_version = ATOMIC_VAR_INIT(UAPI_UNKNOWN);
// ---------------------------------------------------------------------------
int sync_wait(int fd, int timeout)
{
struct pollfd fds;
int ret;
if (fd < 0) {
errno = EINVAL;
return -1;
}
fds.fd = fd;
fds.events = POLLIN;
do {
ret = poll(&fds, 1, timeout);
if (ret > 0) {
if (fds.revents & (POLLERR | POLLNVAL)) {
errno = EINVAL;
return -1;
}
return 0;
} else if (ret == 0) {
errno = ETIME;
return -1;
}
} while (ret == -1 && (errno == EINTR || errno == EAGAIN));
return ret;
}
static int legacy_sync_merge(const char *name, int fd1, int fd2)
{
struct sync_legacy_merge_data data;
int ret;
data.fd2 = fd2;
strlcpy(data.name, name, sizeof(data.name));
ret = ioctl(fd1, SYNC_IOC_LEGACY_MERGE, &data);
if (ret < 0)
return ret;
return data.fence;
}
static int modern_sync_merge(const char *name, int fd1, int fd2)
{
struct sync_merge_data data;
int ret;
data.fd2 = fd2;
strlcpy(data.name, name, sizeof(data.name));
data.flags = 0;
data.pad = 0;
ret = ioctl(fd1, SYNC_IOC_MERGE, &data);
if (ret < 0)
return ret;
return data.fence;
}
int sync_merge(const char *name, int fd1, int fd2)
{
int uapi;
int ret;
uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire);
if (uapi == UAPI_MODERN || uapi == UAPI_UNKNOWN) {
ret = modern_sync_merge(name, fd1, fd2);
if (ret >= 0 || errno != ENOTTY) {
if (ret >= 0 && uapi == UAPI_UNKNOWN) {
atomic_store_explicit(&g_uapi_version, UAPI_MODERN,
memory_order_release);
}
return ret;
}
}
ret = legacy_sync_merge(name, fd1, fd2);
if (ret >= 0 && uapi == UAPI_UNKNOWN) {
atomic_store_explicit(&g_uapi_version, UAPI_LEGACY,
memory_order_release);
}
return ret;
}
static struct sync_fence_info_data *legacy_sync_fence_info(int fd)
{
struct sync_fence_info_data *legacy_info;
struct sync_pt_info *legacy_pt_info;
int err;
legacy_info = malloc(4096);
if (legacy_info == NULL)
return NULL;
legacy_info->len = 4096;
err = ioctl(fd, SYNC_IOC_LEGACY_FENCE_INFO, legacy_info);
if (err < 0) {
free(legacy_info);
return NULL;
}
return legacy_info;
}
static struct sync_file_info *modern_sync_file_info(int fd)
{
struct sync_file_info local_info;
struct sync_file_info *info;
int err;
memset(&local_info, 0, sizeof(local_info));
err = ioctl(fd, SYNC_IOC_FILE_INFO, &local_info);
if (err < 0)
return NULL;
info = calloc(1, sizeof(struct sync_file_info) +
local_info.num_fences * sizeof(struct sync_fence_info));
if (!info)
return NULL;
info->sync_fence_info = (__u64)(uintptr_t)(info + 1);
err = ioctl(fd, SYNC_IOC_FILE_INFO, info);
if (err < 0) {
free(info);
return NULL;
}
return info;
}
static struct sync_fence_info_data *sync_file_info_to_legacy_fence_info(
const struct sync_file_info *info)
{
struct sync_fence_info_data *legacy_info;
struct sync_pt_info *legacy_pt_info;
const struct sync_fence_info *fence_info = sync_get_fence_info(info);
const uint32_t num_fences = info->num_fences;
legacy_info = malloc(4096);
if (legacy_info == NULL)
return NULL;
legacy_info->len = sizeof(*legacy_info) +
num_fences * sizeof(struct sync_pt_info);
strlcpy(legacy_info->name, info->name, sizeof(legacy_info->name));
legacy_info->status = info->status;
legacy_pt_info = (struct sync_pt_info *)legacy_info->pt_info;
for (uint32_t i = 0; i < num_fences; i++) {
legacy_pt_info[i].len = sizeof(*legacy_pt_info);
strlcpy(legacy_pt_info[i].obj_name, fence_info[i].obj_name,
sizeof(legacy_pt_info->obj_name));
strlcpy(legacy_pt_info[i].driver_name, fence_info[i].driver_name,
sizeof(legacy_pt_info->driver_name));
legacy_pt_info[i].status = fence_info[i].status;
legacy_pt_info[i].timestamp_ns = fence_info[i].timestamp_ns;
}
return legacy_info;
}
static struct sync_file_info* legacy_fence_info_to_sync_file_info(
struct sync_fence_info_data *legacy_info)
{
struct sync_file_info *info;
struct sync_pt_info *pt;
struct sync_fence_info *fence;
size_t num_fences;
int err;
pt = NULL;
num_fences = 0;
while ((pt = sync_pt_info(legacy_info, pt)) != NULL)
num_fences++;
info = calloc(1, sizeof(struct sync_file_info) +
num_fences * sizeof(struct sync_fence_info));
if (!info) {
free(legacy_info);
return NULL;
}
info->sync_fence_info = (__u64)(uintptr_t)(info + 1);
strlcpy(info->name, legacy_info->name, sizeof(info->name));
info->status = legacy_info->status;
info->num_fences = num_fences;
pt = NULL;
fence = sync_get_fence_info(info);
while ((pt = sync_pt_info(legacy_info, pt)) != NULL) {
strlcpy(fence->obj_name, pt->obj_name, sizeof(fence->obj_name));
strlcpy(fence->driver_name, pt->driver_name,
sizeof(fence->driver_name));
fence->status = pt->status;
fence->timestamp_ns = pt->timestamp_ns;
fence++;
}
return info;
}
struct sync_fence_info_data *sync_fence_info(int fd)
{
struct sync_fence_info_data *legacy_info;
int uapi;
uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire);
if (uapi == UAPI_LEGACY || uapi == UAPI_UNKNOWN) {
legacy_info = legacy_sync_fence_info(fd);
if (legacy_info || errno != ENOTTY) {
if (legacy_info && uapi == UAPI_UNKNOWN) {
atomic_store_explicit(&g_uapi_version, UAPI_LEGACY,
memory_order_release);
}
return legacy_info;
}
}
struct sync_file_info* file_info;
file_info = modern_sync_file_info(fd);
if (!file_info)
return NULL;
if (uapi == UAPI_UNKNOWN) {
atomic_store_explicit(&g_uapi_version, UAPI_MODERN,
memory_order_release);
}
legacy_info = sync_file_info_to_legacy_fence_info(file_info);
sync_file_info_free(file_info);
return legacy_info;
}
struct sync_file_info* sync_file_info(int32_t fd)
{
struct sync_file_info *info;
int uapi;
uapi = atomic_load_explicit(&g_uapi_version, memory_order_acquire);
if (uapi == UAPI_MODERN || uapi == UAPI_UNKNOWN) {
info = modern_sync_file_info(fd);
if (info || errno != ENOTTY) {
if (info && uapi == UAPI_UNKNOWN) {
atomic_store_explicit(&g_uapi_version, UAPI_MODERN,
memory_order_release);
}
return info;
}
}
struct sync_fence_info_data *legacy_info;
legacy_info = legacy_sync_fence_info(fd);
if (!legacy_info)
return NULL;
if (uapi == UAPI_UNKNOWN) {
atomic_store_explicit(&g_uapi_version, UAPI_LEGACY,
memory_order_release);
}
info = legacy_fence_info_to_sync_file_info(legacy_info);
sync_fence_info_free(legacy_info);
return info;
}
struct sync_pt_info *sync_pt_info(struct sync_fence_info_data *info,
struct sync_pt_info *itr)
{
if (itr == NULL)
itr = (struct sync_pt_info *) info->pt_info;
else
itr = (struct sync_pt_info *) ((__u8 *)itr + itr->len);
if ((__u8 *)itr - (__u8 *)info >= (int)info->len)
return NULL;
return itr;
}
void sync_fence_info_free(struct sync_fence_info_data *info)
{
free(info);
}
void sync_file_info_free(struct sync_file_info *info)
{
free(info);
}
int sw_sync_timeline_create(void)
{
int ret;
ret = open("/sys/kernel/debug/sync/sw_sync", O_RDWR);
if (ret < 0)
ret = open("/dev/sw_sync", O_RDWR);
return ret;
}
int sw_sync_timeline_inc(int fd, unsigned count)
{
__u32 arg = count;
return ioctl(fd, SW_SYNC_IOC_INC, &arg);
}
int sw_sync_fence_create(int fd, const char *name, unsigned value)
{
struct sw_sync_create_fence_data data;
int err;
data.value = value;
strlcpy(data.name, name, sizeof(data.name));
err = ioctl(fd, SW_SYNC_IOC_CREATE_FENCE, &data);
if (err < 0)
return err;
return data.fence;
}