usb/xhci/xhci-trb.c

10 zx_status_t xhci_transfer_ring_init(xhci_transfer_ring_t* ring, zx_handle_t bti_handle, int count) {
11     zx_status_t status = io_buffer_init(&ring->buffer, bti_handle,
16     ring->start = io_buffer_virt(&ring->buffer);
17     ring->current = ring->start;
18     ring->dequeue_ptr = ring->start;
19     ring->full = false;
20     ring->size = count - 1;    // subtract 1 for LINK TRB at the end
21     ring->pcs = TRB_C;
24     trb_set_ptr(&ring->start[count - 1], (void *)io_buffer_phys(&ring->buffer));
25     trb_set_control(&ring->start[count - 1], TRB_LINK, TRB_TC);
29 void xhci_transfer_ring_free(xhci_transfer_ring_t* ring) {
30     io_buffer_release(&ring->buffer);
33 // return the number of free TRBs in the ring
34 size_t xhci_transfer_ring_free_trbs(xhci_transfer_ring_t* ring) {
35     xhci_trb_t* current = ring->current;
36     xhci_trb_t* dequeue_ptr = ring->dequeue_ptr;
38     if (ring->full) {
43     int size = ring->size;
53 zx_status_t xhci_event_ring_init(xhci_event_ring_t* ring, zx_handle_t bti_handle,
56     zx_status_t status = io_buffer_init(&ring->buffer, bti_handle,
61     ring->start = io_buffer_virt(&ring->buffer);
62     XHCI_WRITE64(&erst_array[0].ptr, io_buffer_phys(&ring->buffer));
65     ring->current = ring->start;
66     ring->end = ring->start + count;
67     ring->ccs = TRB_C;
71 void xhci_event_ring_free(xhci_event_ring_t* ring) {
72     io_buffer_release(&ring->buffer);
93 void* xhci_read_trb_ptr(xhci_transfer_ring_t* ring, xhci_trb_t* trb) {
96     ptr += ((uint8_t *)io_buffer_virt(&ring->buffer) - (uint8_t *)io_buffer_phys(&ring->buffer));
100 xhci_trb_t* xhci_get_next_trb(xhci_transfer_ring_t* ring, xhci_trb_t* trb) {
104         trb = xhci_read_trb_ptr(ring, trb);
109 void xhci_increment_ring(xhci_transfer_ring_t* ring) {
110     xhci_trb_t* trb = ring->current;
113     if (ring->pcs) {
114         XHCI_WRITE32(&trb->control, control | ring->pcs);
116     trb = ++ring->current;
121         control = (control & ~(TRB_CHAIN | TRB_C)) | chain | ring->pcs;
126             ring->pcs ^= TRB_C;
128         ring->current = xhci_read_trb_ptr(ring, trb);
131     if (ring->current == ring->dequeue_ptr) {
133         // the ring must be full.
134         ring->full = true;
138 void xhci_set_dequeue_ptr(xhci_transfer_ring_t* ring, xhci_trb_t* new_ptr) {
139     ring->dequeue_ptr = new_ptr;
140     ring->full = false;
143 xhci_trb_t* xhci_transfer_ring_phys_to_trb(xhci_transfer_ring_t* ring, zx_paddr_t phys) {
144     zx_paddr_t first_trb_phys = xhci_transfer_ring_start_phys(ring);
146     // ring->size does not include the LINK TRB at the end of the ring.
147     zx_paddr_t last_trb_phys = first_trb_phys + (ring->size * sizeof(xhci_trb_t));
152    return ring->start + ((phys - first_trb_phys) / sizeof(xhci_trb_t));