/* * Thunderbolt Cactus Ridge driver - control channel and configuration commands * * Copyright (c) 2014 Andreas Noever */ #include #include #include #include #include #include #include "ctl.h" struct ctl_pkg { struct tb_ctl *ctl; void *buffer; struct ring_frame frame; }; #define TB_CTL_RX_PKG_COUNT 10 /** * struct tb_cfg - thunderbolt control channel */ struct tb_ctl { struct tb_nhi *nhi; struct tb_ring *tx; struct tb_ring *rx; struct dma_pool *frame_pool; struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT]; DECLARE_KFIFO(response_fifo, struct ctl_pkg*, 16); struct completion response_ready; hotplug_cb callback; void *callback_data; }; #define tb_ctl_WARN(ctl, format, arg...) \ dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg) #define tb_ctl_err(ctl, format, arg...) \ dev_err(&(ctl)->nhi->pdev->dev, format, ## arg) #define tb_ctl_warn(ctl, format, arg...) \ dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg) #define tb_ctl_info(ctl, format, arg...) \ dev_info(&(ctl)->nhi->pdev->dev, format, ## arg) /* configuration packets definitions */ enum tb_cfg_pkg_type { TB_CFG_PKG_READ = 1, TB_CFG_PKG_WRITE = 2, TB_CFG_PKG_ERROR = 3, TB_CFG_PKG_NOTIFY_ACK = 4, TB_CFG_PKG_EVENT = 5, TB_CFG_PKG_XDOMAIN_REQ = 6, TB_CFG_PKG_XDOMAIN_RESP = 7, TB_CFG_PKG_OVERRIDE = 8, TB_CFG_PKG_RESET = 9, TB_CFG_PKG_PREPARE_TO_SLEEP = 0xd, }; /* common header */ struct tb_cfg_header { u32 route_hi:22; u32 unknown:10; /* highest order bit is set on replies */ u32 route_lo; } __packed; /* additional header for read/write packets */ struct tb_cfg_address { u32 offset:13; /* in dwords */ u32 length:6; /* in dwords */ u32 port:6; enum tb_cfg_space space:2; u32 seq:2; /* sequence number */ u32 zero:3; } __packed; /* TB_CFG_PKG_READ, response for TB_CFG_PKG_WRITE */ struct cfg_read_pkg { struct tb_cfg_header header; struct tb_cfg_address addr; } __packed; /* TB_CFG_PKG_WRITE, response for TB_CFG_PKG_READ */ struct cfg_write_pkg { struct tb_cfg_header header; struct tb_cfg_address addr; u32 data[64]; /* maximum size, tb_cfg_address.length has 6 bits */ } __packed; /* TB_CFG_PKG_ERROR */ struct cfg_error_pkg { struct tb_cfg_header header; enum tb_cfg_error error:4; u32 zero1:4; u32 port:6; u32 zero2:2; /* Both should be zero, still they are different fields. */ u32 zero3:16; } __packed; /* TB_CFG_PKG_EVENT */ struct cfg_event_pkg { struct tb_cfg_header header; u32 port:6; u32 zero:25; bool unplug:1; } __packed; /* TB_CFG_PKG_RESET */ struct cfg_reset_pkg { struct tb_cfg_header header; } __packed; /* TB_CFG_PKG_PREPARE_TO_SLEEP */ struct cfg_pts_pkg { struct tb_cfg_header header; u32 data; } __packed; /* utility functions */ static u64 get_route(struct tb_cfg_header header) { return (u64) header.route_hi << 32 | header.route_lo; } static struct tb_cfg_header make_header(u64 route) { struct tb_cfg_header header = { .route_hi = route >> 32, .route_lo = route, }; /* check for overflow, route_hi is not 32 bits! */ WARN_ON(get_route(header) != route); return header; } static int check_header(struct ctl_pkg *pkg, u32 len, enum tb_cfg_pkg_type type, u64 route) { struct tb_cfg_header *header = pkg->buffer; /* check frame, TODO: frame flags */ if (WARN(len != pkg->frame.size, "wrong framesize (expected %#x, got %#x)\n", len, pkg->frame.size)) return -EIO; if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n", type, pkg->frame.eof)) return -EIO; if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n", pkg->frame.sof)) return -EIO; /* check header */ if (WARN(header->unknown != 1 << 9, "header->unknown is %#x\n", header->unknown)) return -EIO; if (WARN(route != get_route(*header), "wrong route (expected %llx, got %llx)", route, get_route(*header))) return -EIO; return 0; } static int check_config_address(struct tb_cfg_address addr, enum tb_cfg_space space, u32 offset, u32 length) { if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero)) return -EIO; if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)", space, addr.space)) return -EIO; if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)", offset, addr.offset)) return -EIO; if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)", length, addr.length)) return -EIO; if (WARN(addr.seq, "addr.seq is %#x\n", addr.seq)) return -EIO; /* * We cannot check addr->port as it is set to the upstream port of the * sender. */ return 0; } static struct tb_cfg_result decode_error(struct ctl_pkg *response) { struct cfg_error_pkg *pkg = response->buffer; struct tb_cfg_result res = { 0 }; res.response_route = get_route(pkg->header); res.response_port = 0; res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR, get_route(pkg->header)); if (res.err) return res; WARN(pkg->zero1, "pkg->zero1 is %#x\n", pkg->zero1); WARN(pkg->zero2, "pkg->zero1 is %#x\n", pkg->zero1); WARN(pkg->zero3, "pkg->zero1 is %#x\n", pkg->zero1); res.err = 1; res.tb_error = pkg->error; res.response_port = pkg->port; return res; } static struct tb_cfg_result parse_header(struct ctl_pkg *pkg, u32 len, enum tb_cfg_pkg_type type, u64 route) { struct tb_cfg_header *header = pkg->buffer; struct tb_cfg_result res = { 0 }; if (pkg->frame.eof == TB_CFG_PKG_ERROR) return decode_error(pkg); res.response_port = 0; /* will be updated later for cfg_read/write */ res.response_route = get_route(*header); res.err = check_header(pkg, len, type, route); return res; } static void tb_cfg_print_error(struct tb_ctl *ctl, const struct tb_cfg_result *res) { WARN_ON(res->err != 1); switch (res->tb_error) { case TB_CFG_ERROR_PORT_NOT_CONNECTED: /* Port is not connected. This can happen during surprise * removal. Do not warn. */ return; case TB_CFG_ERROR_INVALID_CONFIG_SPACE: /* * Invalid cfg_space/offset/length combination in * cfg_read/cfg_write. */ tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid config space of offset\n", res->response_route, res->response_port); return; case TB_CFG_ERROR_NO_SUCH_PORT: /* * - The route contains a non-existent port. * - The route contains a non-PHY port (e.g. PCIe). * - The port in cfg_read/cfg_write does not exist. */ tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n", res->response_route, res->response_port); return; case TB_CFG_ERROR_LOOP: tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n", res->response_route, res->response_port); return; default: /* 5,6,7,9 and 11 are also valid error codes */ tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n", res->response_route, res->response_port); return; } } static void cpu_to_be32_array(__be32 *dst, u32 *src, size_t len) { int i; for (i = 0; i < len; i++) dst[i] = cpu_to_be32(src[i]); } static void be32_to_cpu_array(u32 *dst, __be32 *src, size_t len) { int i; for (i = 0; i < len; i++) dst[i] = be32_to_cpu(src[i]); } static __be32 tb_crc(void *data, size_t len) { return cpu_to_be32(~__crc32c_le(~0, data, len)); } static void tb_ctl_pkg_free(struct ctl_pkg *pkg) { if (pkg) { dma_pool_free(pkg->ctl->frame_pool, pkg->buffer, pkg->frame.buffer_phy); kfree(pkg); } } static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl) { struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL); if (!pkg) return NULL; pkg->ctl = ctl; pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL, &pkg->frame.buffer_phy); if (!pkg->buffer) { kfree(pkg); return NULL; } return pkg; } /* RX/TX handling */ static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame, bool canceled) { struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); tb_ctl_pkg_free(pkg); } /** * tb_cfg_tx() - transmit a packet on the control channel * * len must be a multiple of four. * * Return: Returns 0 on success or an error code on failure. */ static int tb_ctl_tx(struct tb_ctl *ctl, void *data, size_t len, enum tb_cfg_pkg_type type) { int res; struct ctl_pkg *pkg; if (len % 4 != 0) { /* required for le->be conversion */ tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len); return -EINVAL; } if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */ tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n", len, TB_FRAME_SIZE - 4); return -EINVAL; } pkg = tb_ctl_pkg_alloc(ctl); if (!pkg) return -ENOMEM; pkg->frame.callback = tb_ctl_tx_callback; pkg->frame.size = len + 4; pkg->frame.sof = type; pkg->frame.eof = type; cpu_to_be32_array(pkg->buffer, data, len / 4); *(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len); res = ring_tx(ctl->tx, &pkg->frame); if (res) /* ring is stopped */ tb_ctl_pkg_free(pkg); return res; } /** * tb_ctl_handle_plug_event() - acknowledge a plug event, invoke ctl->callback */ static void tb_ctl_handle_plug_event(struct tb_ctl *ctl, struct ctl_pkg *response) { struct cfg_event_pkg *pkg = response->buffer; u64 route = get_route(pkg->header); if (check_header(response, sizeof(*pkg), TB_CFG_PKG_EVENT, route)) { tb_ctl_warn(ctl, "malformed TB_CFG_PKG_EVENT\n"); return; } if (tb_cfg_error(ctl, route, pkg->port, TB_CFG_ERROR_ACK_PLUG_EVENT)) tb_ctl_warn(ctl, "could not ack plug event on %llx:%x\n", route, pkg->port); WARN(pkg->zero, "pkg->zero is %#x\n", pkg->zero); ctl->callback(ctl->callback_data, route, pkg->port, pkg->unplug); } static void tb_ctl_rx_submit(struct ctl_pkg *pkg) { ring_rx(pkg->ctl->rx, &pkg->frame); /* * We ignore failures during stop. * All rx packets are referenced * from ctl->rx_packets, so we do * not loose them. */ } static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame, bool canceled) { struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); if (canceled) return; /* * ring is stopped, packet is referenced from * ctl->rx_packets. */ if (frame->size < 4 || frame->size % 4 != 0) { tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n", frame->size); goto rx; } frame->size -= 4; /* remove checksum */ if (*(__be32 *) (pkg->buffer + frame->size) != tb_crc(pkg->buffer, frame->size)) { tb_ctl_err(pkg->ctl, "RX: checksum mismatch, dropping packet\n"); goto rx; } be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4); if (frame->eof == TB_CFG_PKG_EVENT) { tb_ctl_handle_plug_event(pkg->ctl, pkg); goto rx; } if (!kfifo_put(&pkg->ctl->response_fifo, pkg)) { tb_ctl_err(pkg->ctl, "RX: fifo is full\n"); goto rx; } complete(&pkg->ctl->response_ready); return; rx: tb_ctl_rx_submit(pkg); } /** * tb_ctl_rx() - receive a packet from the control channel */ static struct tb_cfg_result tb_ctl_rx(struct tb_ctl *ctl, void *buffer, size_t length, int timeout_msec, u64 route, enum tb_cfg_pkg_type type) { struct tb_cfg_result res; struct ctl_pkg *pkg; if (!wait_for_completion_timeout(&ctl->response_ready, msecs_to_jiffies(timeout_msec))) { tb_ctl_WARN(ctl, "RX: timeout\n"); return (struct tb_cfg_result) { .err = -ETIMEDOUT }; } if (!kfifo_get(&ctl->response_fifo, &pkg)) { tb_ctl_WARN(ctl, "empty kfifo\n"); return (struct tb_cfg_result) { .err = -EIO }; } res = parse_header(pkg, length, type, route); if (!res.err) memcpy(buffer, pkg->buffer, length); tb_ctl_rx_submit(pkg); return res; } /* public interface, alloc/start/stop/free */ /** * tb_ctl_alloc() - allocate a control channel * * cb will be invoked once for every hot plug event. * * Return: Returns a pointer on success or NULL on failure. */ struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, hotplug_cb cb, void *cb_data) { int i; struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL); if (!ctl) return NULL; ctl->nhi = nhi; ctl->callback = cb; ctl->callback_data = cb_data; init_completion(&ctl->response_ready); INIT_KFIFO(ctl->response_fifo); ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev, TB_FRAME_SIZE, 4, 0); if (!ctl->frame_pool) goto err; ctl->tx = ring_alloc_tx(nhi, 0, 10); if (!ctl->tx) goto err; ctl->rx = ring_alloc_rx(nhi, 0, 10); if (!ctl->rx) goto err; for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) { ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl); if (!ctl->rx_packets[i]) goto err; ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback; } tb_ctl_info(ctl, "control channel created\n"); return ctl; err: tb_ctl_free(ctl); return NULL; } /** * tb_ctl_free() - free a control channel * * Must be called after tb_ctl_stop. * * Must NOT be called from ctl->callback. */ void tb_ctl_free(struct tb_ctl *ctl) { int i; if (ctl->rx) ring_free(ctl->rx); if (ctl->tx) ring_free(ctl->tx); /* free RX packets */ for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) tb_ctl_pkg_free(ctl->rx_packets[i]); if (ctl->frame_pool) dma_pool_destroy(ctl->frame_pool); kfree(ctl); } /** * tb_cfg_start() - start/resume the control channel */ void tb_ctl_start(struct tb_ctl *ctl) { int i; tb_ctl_info(ctl, "control channel starting...\n"); ring_start(ctl->tx); /* is used to ack hotplug packets, start first */ ring_start(ctl->rx); for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) tb_ctl_rx_submit(ctl->rx_packets[i]); } /** * control() - pause the control channel * * All invocations of ctl->callback will have finished after this method * returns. * * Must NOT be called from ctl->callback. */ void tb_ctl_stop(struct tb_ctl *ctl) { ring_stop(ctl->rx); ring_stop(ctl->tx); if (!kfifo_is_empty(&ctl->response_fifo)) tb_ctl_WARN(ctl, "dangling response in response_fifo\n"); kfifo_reset(&ctl->response_fifo); tb_ctl_info(ctl, "control channel stopped\n"); } /* public interface, commands */ /** * tb_cfg_error() - send error packet * * Return: Returns 0 on success or an error code on failure. */ int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port, enum tb_cfg_error error) { struct cfg_error_pkg pkg = { .header = make_header(route), .port = port, .error = error, }; tb_ctl_info(ctl, "resetting error on %llx:%x.\n", route, port); return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR); } /** * tb_cfg_reset() - send a reset packet and wait for a response * * If the switch at route is incorrectly configured then we will not receive a * reply (even though the switch will reset). The caller should check for * -ETIMEDOUT and attempt to reconfigure the switch. */ struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route, int timeout_msec) { int err; struct cfg_reset_pkg request = { .header = make_header(route) }; struct tb_cfg_header reply; err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_RESET); if (err) return (struct tb_cfg_result) { .err = err }; return tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route, TB_CFG_PKG_RESET); } /** * tb_cfg_read() - read from config space into buffer * * Offset and length are in dwords. */ struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, enum tb_cfg_space space, u32 offset, u32 length, int timeout_msec) { struct tb_cfg_result res = { 0 }; struct cfg_read_pkg request = { .header = make_header(route), .addr = { .port = port, .space = space, .offset = offset, .length = length, }, }; struct cfg_write_pkg reply; res.err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_READ); if (res.err) return res; res = tb_ctl_rx(ctl, &reply, 12 + 4 * length, timeout_msec, route, TB_CFG_PKG_READ); if (res.err) return res; res.response_port = reply.addr.port; res.err = check_config_address(reply.addr, space, offset, length); if (!res.err) memcpy(buffer, &reply.data, 4 * length); return res; } /** * tb_cfg_write() - write from buffer into config space * * Offset and length are in dwords. */ struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, enum tb_cfg_space space, u32 offset, u32 length, int timeout_msec) { struct tb_cfg_result res = { 0 }; struct cfg_write_pkg request = { .header = make_header(route), .addr = { .port = port, .space = space, .offset = offset, .length = length, }, }; struct cfg_read_pkg reply; memcpy(&request.data, buffer, length * 4); res.err = tb_ctl_tx(ctl, &request, 12 + 4 * length, TB_CFG_PKG_WRITE); if (res.err) return res; res = tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route, TB_CFG_PKG_WRITE); if (res.err) return res; res.response_port = reply.addr.port; res.err = check_config_address(reply.addr, space, offset, length); return res; } int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, enum tb_cfg_space space, u32 offset, u32 length) { struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port, space, offset, length, TB_CFG_DEFAULT_TIMEOUT); if (res.err == 1) { tb_cfg_print_error(ctl, &res); return -EIO; } WARN(res.err, "tb_cfg_read: %d\n", res.err); return res.err; } int tb_cfg_write(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, enum tb_cfg_space space, u32 offset, u32 length) { struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port, space, offset, length, TB_CFG_DEFAULT_TIMEOUT); if (res.err == 1) { tb_cfg_print_error(ctl, &res); return -EIO; } WARN(res.err, "tb_cfg_write: %d\n", res.err); return res.err; } /** * tb_cfg_get_upstream_port() - get upstream port number of switch at route * * Reads the first dword from the switches TB_CFG_SWITCH config area and * returns the port number from which the reply originated. * * Return: Returns the upstream port number on success or an error code on * failure. */ int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route) { u32 dummy; struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0, TB_CFG_SWITCH, 0, 1, TB_CFG_DEFAULT_TIMEOUT); if (res.err == 1) return -EIO; if (res.err) return res.err; return res.response_port; }