/* increment the counter for # of contexts accessing the device. */
void gdev_access_start(struct gdev_device *gdev)
{
struct gdev_device *phys = gdev_phys_get(gdev);
retry:
if (phys) {
gdev_lock(&phys->global_lock);
if (phys->blocked) {
gdev_unlock(&phys->global_lock);
SCHED_YIELD();
goto retry;
}
phys->accessed++;
gdev_unlock(&phys->global_lock);
}
else {
gdev_lock(&gdev->global_lock);
if (gdev->blocked) {
gdev_unlock(&gdev->global_lock);
SCHED_YIELD();
goto retry;
}
gdev->accessed++;
gdev_unlock(&gdev->global_lock);
}
}
/* set the flag to block any access to the device. */
void gdev_block_start(struct gdev_device *gdev)
{
struct gdev_device *phys = gdev_phys_get(gdev);
/* we have to spin while some context is accessing the GPU. */
retry:
if (phys) {
gdev_lock(&phys->global_lock);
if (phys->accessed || phys->blocked) {
gdev_unlock(&phys->global_lock);
SCHED_YIELD();
goto retry;
}
phys->blocked++;
gdev_unlock(&phys->global_lock);
}
else {
gdev_lock(&gdev->global_lock);
if (gdev->accessed || gdev->blocked) {
gdev_unlock(&gdev->global_lock);
SCHED_YIELD();
goto retry;
}
gdev->blocked++;
gdev_unlock(&gdev->global_lock);
}
}
/* poll until the resource becomes available. */
int gdev_poll(struct gdev_ctx *ctx, uint32_t seq, struct gdev_time *timeout)
{
struct gdev_time time_start, time_now, time_elapse, time_relax;
struct gdev_vas *vas = ctx->vas;
struct gdev_device *gdev = vas->gdev;
struct gdev_compute *compute = gdev->compute;
gdev_time_stamp(&time_start);
gdev_time_ms(&time_relax, 100); /* relax polling when 100 ms elapsed. */
while (seq != compute->fence_read(ctx, seq)) {
gdev_time_stamp(&time_now);
/* time_elapse = time_now - time_start */
gdev_time_sub(&time_elapse, &time_now, &time_start);
/* relax polling after some time. */
if (gdev_time_ge(&time_elapse, &time_relax))
SCHED_YIELD();
/* check timeout. */
if (timeout && gdev_time_ge(&time_elapse, timeout))
return -ETIME;
}
compute->fence_reset(ctx, seq);
return 0;
}
void gdev_fifo_push(struct gdev_ctx *ctx, uint64_t base, uint32_t len, int flags)
{
uint64_t w = base | (uint64_t)len << 40 | (uint64_t)flags << 40;
while (((ctx->fifo.ib_put + 1) & ctx->fifo.ib_mask) == ctx->fifo.ib_get) {
uint32_t old = ctx->fifo.ib_get;
ctx->fifo.ib_get = __gdev_fifo_read_reg(ctx, 0x88);
if (old == ctx->fifo.ib_get) {
SCHED_YIELD();
}
}
ctx->fifo.ib_map[ctx->fifo.ib_put * 2] = w;
ctx->fifo.ib_map[ctx->fifo.ib_put * 2 + 1] = w >> 32;
ctx->fifo.ib_put++;
ctx->fifo.ib_put &= ctx->fifo.ib_mask;
MB(); /* is this needed? */
ctx->dummy = ctx->fifo.ib_map[0]; /* flush writes */
__gdev_fifo_write_reg(ctx, 0x8c, ctx->fifo.ib_put);
}
