2 * Thunderbolt Cactus Ridge driver - control channel and configuration commands
4 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
7 #include <linux/crc32.h>
8 #include <linux/slab.h>
10 #include <linux/dmapool.h>
11 #include <linux/workqueue.h>
12 #include <linux/kfifo.h>
20 struct ring_frame frame;
23 #define TB_CTL_RX_PKG_COUNT 10
26 * struct tb_cfg - thunderbolt control channel
33 struct dma_pool *frame_pool;
34 struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];
35 DECLARE_KFIFO(response_fifo, struct ctl_pkg*, 16);
36 struct completion response_ready;
43 #define tb_ctl_WARN(ctl, format, arg...) \
44 dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)
46 #define tb_ctl_err(ctl, format, arg...) \
47 dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)
49 #define tb_ctl_warn(ctl, format, arg...) \
50 dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)
52 #define tb_ctl_info(ctl, format, arg...) \
53 dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
55 /* utility functions */
57 static u64 get_route(struct tb_cfg_header header)
59 return (u64) header.route_hi << 32 | header.route_lo;
62 static struct tb_cfg_header make_header(u64 route)
64 struct tb_cfg_header header = {
65 .route_hi = route >> 32,
68 /* check for overflow, route_hi is not 32 bits! */
69 WARN_ON(get_route(header) != route);
73 static int check_header(struct ctl_pkg *pkg, u32 len, enum tb_cfg_pkg_type type,
76 struct tb_cfg_header *header = pkg->buffer;
78 /* check frame, TODO: frame flags */
79 if (WARN(len != pkg->frame.size,
80 "wrong framesize (expected %#x, got %#x)\n",
81 len, pkg->frame.size))
83 if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",
84 type, pkg->frame.eof))
86 if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",
91 if (WARN(header->unknown != 1 << 9,
92 "header->unknown is %#x\n", header->unknown))
94 if (WARN(route != get_route(*header),
95 "wrong route (expected %llx, got %llx)",
96 route, get_route(*header)))
101 static int check_config_address(struct tb_cfg_address addr,
102 enum tb_cfg_space space, u32 offset,
105 if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))
107 if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",
110 if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",
111 offset, addr.offset))
113 if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",
114 length, addr.length))
116 if (WARN(addr.seq, "addr.seq is %#x\n", addr.seq))
119 * We cannot check addr->port as it is set to the upstream port of the
125 static struct tb_cfg_result decode_error(struct ctl_pkg *response)
127 struct cfg_error_pkg *pkg = response->buffer;
128 struct tb_cfg_result res = { 0 };
129 res.response_route = get_route(pkg->header);
130 res.response_port = 0;
131 res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,
132 get_route(pkg->header));
136 WARN(pkg->zero1, "pkg->zero1 is %#x\n", pkg->zero1);
137 WARN(pkg->zero2, "pkg->zero1 is %#x\n", pkg->zero1);
138 WARN(pkg->zero3, "pkg->zero1 is %#x\n", pkg->zero1);
140 res.tb_error = pkg->error;
141 res.response_port = pkg->port;
146 static struct tb_cfg_result parse_header(struct ctl_pkg *pkg, u32 len,
147 enum tb_cfg_pkg_type type, u64 route)
149 struct tb_cfg_header *header = pkg->buffer;
150 struct tb_cfg_result res = { 0 };
152 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
153 return decode_error(pkg);
155 res.response_port = 0; /* will be updated later for cfg_read/write */
156 res.response_route = get_route(*header);
157 res.err = check_header(pkg, len, type, route);
161 static void tb_cfg_print_error(struct tb_ctl *ctl,
162 const struct tb_cfg_result *res)
164 WARN_ON(res->err != 1);
165 switch (res->tb_error) {
166 case TB_CFG_ERROR_PORT_NOT_CONNECTED:
167 /* Port is not connected. This can happen during surprise
168 * removal. Do not warn. */
170 case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
172 * Invalid cfg_space/offset/length combination in
173 * cfg_read/cfg_write.
176 "CFG_ERROR(%llx:%x): Invalid config space or offset\n",
177 res->response_route, res->response_port);
179 case TB_CFG_ERROR_NO_SUCH_PORT:
181 * - The route contains a non-existent port.
182 * - The route contains a non-PHY port (e.g. PCIe).
183 * - The port in cfg_read/cfg_write does not exist.
185 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
186 res->response_route, res->response_port);
188 case TB_CFG_ERROR_LOOP:
189 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
190 res->response_route, res->response_port);
193 /* 5,6,7,9 and 11 are also valid error codes */
194 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
195 res->response_route, res->response_port);
200 static void cpu_to_be32_array(__be32 *dst, const u32 *src, size_t len)
203 for (i = 0; i < len; i++)
204 dst[i] = cpu_to_be32(src[i]);
207 static void be32_to_cpu_array(u32 *dst, __be32 *src, size_t len)
210 for (i = 0; i < len; i++)
211 dst[i] = be32_to_cpu(src[i]);
214 static __be32 tb_crc(void *data, size_t len)
216 return cpu_to_be32(~__crc32c_le(~0, data, len));
219 static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
222 dma_pool_free(pkg->ctl->frame_pool,
223 pkg->buffer, pkg->frame.buffer_phy);
228 static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
230 struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);
234 pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,
235 &pkg->frame.buffer_phy);
246 static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
249 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
250 tb_ctl_pkg_free(pkg);
254 * tb_cfg_tx() - transmit a packet on the control channel
256 * len must be a multiple of four.
258 * Return: Returns 0 on success or an error code on failure.
260 static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,
261 enum tb_cfg_pkg_type type)
265 if (len % 4 != 0) { /* required for le->be conversion */
266 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
269 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
270 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
271 len, TB_FRAME_SIZE - 4);
274 pkg = tb_ctl_pkg_alloc(ctl);
277 pkg->frame.callback = tb_ctl_tx_callback;
278 pkg->frame.size = len + 4;
279 pkg->frame.sof = type;
280 pkg->frame.eof = type;
281 cpu_to_be32_array(pkg->buffer, data, len / 4);
282 *(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len);
284 res = ring_tx(ctl->tx, &pkg->frame);
285 if (res) /* ring is stopped */
286 tb_ctl_pkg_free(pkg);
291 * tb_ctl_handle_plug_event() - acknowledge a plug event, invoke ctl->callback
293 static void tb_ctl_handle_plug_event(struct tb_ctl *ctl,
294 struct ctl_pkg *response)
296 struct cfg_event_pkg *pkg = response->buffer;
297 u64 route = get_route(pkg->header);
299 if (check_header(response, sizeof(*pkg), TB_CFG_PKG_EVENT, route)) {
300 tb_ctl_warn(ctl, "malformed TB_CFG_PKG_EVENT\n");
304 if (tb_cfg_error(ctl, route, pkg->port, TB_CFG_ERROR_ACK_PLUG_EVENT))
305 tb_ctl_warn(ctl, "could not ack plug event on %llx:%x\n",
307 WARN(pkg->zero, "pkg->zero is %#x\n", pkg->zero);
308 ctl->callback(ctl->callback_data, route, pkg->port, pkg->unplug);
311 static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
313 ring_rx(pkg->ctl->rx, &pkg->frame); /*
314 * We ignore failures during stop.
315 * All rx packets are referenced
316 * from ctl->rx_packets, so we do
321 static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
324 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
328 * ring is stopped, packet is referenced from
332 if (frame->size < 4 || frame->size % 4 != 0) {
333 tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
338 frame->size -= 4; /* remove checksum */
339 if (*(__be32 *) (pkg->buffer + frame->size)
340 != tb_crc(pkg->buffer, frame->size)) {
342 "RX: checksum mismatch, dropping packet\n");
345 be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
347 if (frame->eof == TB_CFG_PKG_EVENT) {
348 tb_ctl_handle_plug_event(pkg->ctl, pkg);
351 if (!kfifo_put(&pkg->ctl->response_fifo, pkg)) {
352 tb_ctl_err(pkg->ctl, "RX: fifo is full\n");
355 complete(&pkg->ctl->response_ready);
358 tb_ctl_rx_submit(pkg);
362 * tb_ctl_rx() - receive a packet from the control channel
364 static struct tb_cfg_result tb_ctl_rx(struct tb_ctl *ctl, void *buffer,
365 size_t length, int timeout_msec,
366 u64 route, enum tb_cfg_pkg_type type)
368 struct tb_cfg_result res;
371 if (!wait_for_completion_timeout(&ctl->response_ready,
372 msecs_to_jiffies(timeout_msec))) {
373 tb_ctl_WARN(ctl, "RX: timeout\n");
374 return (struct tb_cfg_result) { .err = -ETIMEDOUT };
376 if (!kfifo_get(&ctl->response_fifo, &pkg)) {
377 tb_ctl_WARN(ctl, "empty kfifo\n");
378 return (struct tb_cfg_result) { .err = -EIO };
381 res = parse_header(pkg, length, type, route);
383 memcpy(buffer, pkg->buffer, length);
384 tb_ctl_rx_submit(pkg);
389 /* public interface, alloc/start/stop/free */
392 * tb_ctl_alloc() - allocate a control channel
394 * cb will be invoked once for every hot plug event.
396 * Return: Returns a pointer on success or NULL on failure.
398 struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, hotplug_cb cb, void *cb_data)
401 struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
406 ctl->callback_data = cb_data;
408 init_completion(&ctl->response_ready);
409 INIT_KFIFO(ctl->response_fifo);
410 ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
411 TB_FRAME_SIZE, 4, 0);
412 if (!ctl->frame_pool)
415 ctl->tx = ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);
419 ctl->rx = ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);
423 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
424 ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
425 if (!ctl->rx_packets[i])
427 ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
430 tb_ctl_info(ctl, "control channel created\n");
438 * tb_ctl_free() - free a control channel
440 * Must be called after tb_ctl_stop.
442 * Must NOT be called from ctl->callback.
444 void tb_ctl_free(struct tb_ctl *ctl)
456 /* free RX packets */
457 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
458 tb_ctl_pkg_free(ctl->rx_packets[i]);
462 dma_pool_destroy(ctl->frame_pool);
467 * tb_cfg_start() - start/resume the control channel
469 void tb_ctl_start(struct tb_ctl *ctl)
472 tb_ctl_info(ctl, "control channel starting...\n");
473 ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
475 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
476 tb_ctl_rx_submit(ctl->rx_packets[i]);
480 * control() - pause the control channel
482 * All invocations of ctl->callback will have finished after this method
485 * Must NOT be called from ctl->callback.
487 void tb_ctl_stop(struct tb_ctl *ctl)
492 if (!kfifo_is_empty(&ctl->response_fifo))
493 tb_ctl_WARN(ctl, "dangling response in response_fifo\n");
494 kfifo_reset(&ctl->response_fifo);
495 tb_ctl_info(ctl, "control channel stopped\n");
498 /* public interface, commands */
501 * tb_cfg_error() - send error packet
503 * Return: Returns 0 on success or an error code on failure.
505 int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port,
506 enum tb_cfg_error error)
508 struct cfg_error_pkg pkg = {
509 .header = make_header(route),
513 tb_ctl_info(ctl, "resetting error on %llx:%x.\n", route, port);
514 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
518 * tb_cfg_reset() - send a reset packet and wait for a response
520 * If the switch at route is incorrectly configured then we will not receive a
521 * reply (even though the switch will reset). The caller should check for
522 * -ETIMEDOUT and attempt to reconfigure the switch.
524 struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route,
528 struct cfg_reset_pkg request = { .header = make_header(route) };
529 struct tb_cfg_header reply;
531 err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_RESET);
533 return (struct tb_cfg_result) { .err = err };
535 return tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route,
540 * tb_cfg_read() - read from config space into buffer
542 * Offset and length are in dwords.
544 struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
545 u64 route, u32 port, enum tb_cfg_space space,
546 u32 offset, u32 length, int timeout_msec)
548 struct tb_cfg_result res = { 0 };
549 struct cfg_read_pkg request = {
550 .header = make_header(route),
558 struct cfg_write_pkg reply;
560 res.err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_READ);
564 res = tb_ctl_rx(ctl, &reply, 12 + 4 * length, timeout_msec, route,
569 res.response_port = reply.addr.port;
570 res.err = check_config_address(reply.addr, space, offset, length);
572 memcpy(buffer, &reply.data, 4 * length);
577 * tb_cfg_write() - write from buffer into config space
579 * Offset and length are in dwords.
581 struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,
582 u64 route, u32 port, enum tb_cfg_space space,
583 u32 offset, u32 length, int timeout_msec)
585 struct tb_cfg_result res = { 0 };
586 struct cfg_write_pkg request = {
587 .header = make_header(route),
595 struct cfg_read_pkg reply;
597 memcpy(&request.data, buffer, length * 4);
599 res.err = tb_ctl_tx(ctl, &request, 12 + 4 * length, TB_CFG_PKG_WRITE);
603 res = tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route,
608 res.response_port = reply.addr.port;
609 res.err = check_config_address(reply.addr, space, offset, length);
613 int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
614 enum tb_cfg_space space, u32 offset, u32 length)
616 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
617 space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
619 tb_cfg_print_error(ctl, &res);
622 WARN(res.err, "tb_cfg_read: %d\n", res.err);
626 int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
627 enum tb_cfg_space space, u32 offset, u32 length)
629 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
630 space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
632 tb_cfg_print_error(ctl, &res);
635 WARN(res.err, "tb_cfg_write: %d\n", res.err);
640 * tb_cfg_get_upstream_port() - get upstream port number of switch at route
642 * Reads the first dword from the switches TB_CFG_SWITCH config area and
643 * returns the port number from which the reply originated.
645 * Return: Returns the upstream port number on success or an error code on
648 int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
651 struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
653 TB_CFG_DEFAULT_TIMEOUT);
658 return res.response_port;