diff options
Diffstat (limited to 'drivers/thunderbolt/tunnel.c')
| -rw-r--r-- | drivers/thunderbolt/tunnel.c | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c new file mode 100644 index 000000000000..31d0234837e4 --- /dev/null +++ b/drivers/thunderbolt/tunnel.c @@ -0,0 +1,691 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Thunderbolt driver - Tunneling support + * + * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> + * Copyright (C) 2019, Intel Corporation + */ + +#include <linux/slab.h> +#include <linux/list.h> + +#include "tunnel.h" +#include "tb.h" + +/* PCIe adapters use always HopID of 8 for both directions */ +#define TB_PCI_HOPID 8 + +#define TB_PCI_PATH_DOWN 0 +#define TB_PCI_PATH_UP 1 + +/* DP adapters use HopID 8 for AUX and 9 for Video */ +#define TB_DP_AUX_TX_HOPID 8 +#define TB_DP_AUX_RX_HOPID 8 +#define TB_DP_VIDEO_HOPID 9 + +#define TB_DP_VIDEO_PATH_OUT 0 +#define TB_DP_AUX_PATH_OUT 1 +#define TB_DP_AUX_PATH_IN 2 + +#define TB_DMA_PATH_OUT 0 +#define TB_DMA_PATH_IN 1 + +static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA" }; + +#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...) \ + do { \ + struct tb_tunnel *__tunnel = (tunnel); \ + level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt, \ + tb_route(__tunnel->src_port->sw), \ + __tunnel->src_port->port, \ + tb_route(__tunnel->dst_port->sw), \ + __tunnel->dst_port->port, \ + tb_tunnel_names[__tunnel->type], \ + ## arg); \ + } while (0) + +#define tb_tunnel_WARN(tunnel, fmt, arg...) \ + __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg) +#define tb_tunnel_warn(tunnel, fmt, arg...) \ + __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg) +#define tb_tunnel_info(tunnel, fmt, arg...) \ + __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg) +#define tb_tunnel_dbg(tunnel, fmt, arg...) \ + __TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg) + +static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths, + enum tb_tunnel_type type) +{ + struct tb_tunnel *tunnel; + + tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL); + if (!tunnel) + return NULL; + + tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL); + if (!tunnel->paths) { + tb_tunnel_free(tunnel); + return NULL; + } + + INIT_LIST_HEAD(&tunnel->list); + tunnel->tb = tb; + tunnel->npaths = npaths; + tunnel->type = type; + + return tunnel; +} + +static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate) +{ + int res; + + res = tb_pci_port_enable(tunnel->src_port, activate); + if (res) + return res; + + if (tb_port_is_pcie_up(tunnel->dst_port)) + return tb_pci_port_enable(tunnel->dst_port, activate); + + return 0; +} + +static void tb_pci_init_path(struct tb_path *path) +{ + path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL; + path->egress_shared_buffer = TB_PATH_NONE; + path->ingress_fc_enable = TB_PATH_ALL; + path->ingress_shared_buffer = TB_PATH_NONE; + path->priority = 3; + path->weight = 1; + path->drop_packages = 0; + path->nfc_credits = 0; + path->hops[0].initial_credits = 7; + path->hops[1].initial_credits = 16; +} + +/** + * tb_tunnel_discover_pci() - Discover existing PCIe tunnels + * @tb: Pointer to the domain structure + * @down: PCIe downstream adapter + * + * If @down adapter is active, follows the tunnel to the PCIe upstream + * adapter and back. Returns the discovered tunnel or %NULL if there was + * no tunnel. + */ +struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down) +{ + struct tb_tunnel *tunnel; + struct tb_path *path; + + if (!tb_pci_port_is_enabled(down)) + return NULL; + + tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI); + if (!tunnel) + return NULL; + + tunnel->activate = tb_pci_activate; + tunnel->src_port = down; + + /* + * Discover both paths even if they are not complete. We will + * clean them up by calling tb_tunnel_deactivate() below in that + * case. + */ + path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1, + &tunnel->dst_port, "PCIe Up"); + if (!path) { + /* Just disable the downstream port */ + tb_pci_port_enable(down, false); + goto err_free; + } + tunnel->paths[TB_PCI_PATH_UP] = path; + tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]); + + path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL, + "PCIe Down"); + if (!path) + goto err_deactivate; + tunnel->paths[TB_PCI_PATH_DOWN] = path; + tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]); + + /* Validate that the tunnel is complete */ + if (!tb_port_is_pcie_up(tunnel->dst_port)) { + tb_port_warn(tunnel->dst_port, + "path does not end on a PCIe adapter, cleaning up\n"); + goto err_deactivate; + } + + if (down != tunnel->src_port) { + tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n"); + goto err_deactivate; + } + + if (!tb_pci_port_is_enabled(tunnel->dst_port)) { + tb_tunnel_warn(tunnel, + "tunnel is not fully activated, cleaning up\n"); + goto err_deactivate; + } + + tb_tunnel_dbg(tunnel, "discovered\n"); + return tunnel; + +err_deactivate: + tb_tunnel_deactivate(tunnel); +err_free: + tb_tunnel_free(tunnel); + + return NULL; +} + +/** + * tb_tunnel_alloc_pci() - allocate a pci tunnel + * @tb: Pointer to the domain structure + * @up: PCIe upstream adapter port + * @down: PCIe downstream adapter port + * + * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and + * TB_TYPE_PCIE_DOWN. + * + * Return: Returns a tb_tunnel on success or NULL on failure. + */ +struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up, + struct tb_port *down) +{ + struct tb_tunnel *tunnel; + struct tb_path *path; + + tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI); + if (!tunnel) + return NULL; + + tunnel->activate = tb_pci_activate; + tunnel->src_port = down; + tunnel->dst_port = up; + + path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0, + "PCIe Down"); + if (!path) { + tb_tunnel_free(tunnel); + return NULL; + } + tb_pci_init_path(path); + tunnel->paths[TB_PCI_PATH_UP] = path; + + path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0, + "PCIe Up"); + if (!path) { + tb_tunnel_free(tunnel); + return NULL; + } + tb_pci_init_path(path); + tunnel->paths[TB_PCI_PATH_DOWN] = path; + + return tunnel; +} + +static int tb_dp_xchg_caps(struct tb_tunnel *tunnel) +{ + struct tb_port *out = tunnel->dst_port; + struct tb_port *in = tunnel->src_port; + u32 in_dp_cap, out_dp_cap; + int ret; + + /* + * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for + * newer generation hardware. + */ + if (in->sw->generation < 2 || out->sw->generation < 2) + return 0; + + /* Read both DP_LOCAL_CAP registers */ + ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT, + in->cap_adap + TB_DP_LOCAL_CAP, 1); + if (ret) + return ret; + + ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT, + out->cap_adap + TB_DP_LOCAL_CAP, 1); + if (ret) + return ret; + + /* Write IN local caps to OUT remote caps */ + ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT, + out->cap_adap + TB_DP_REMOTE_CAP, 1); + if (ret) + return ret; + + return tb_port_write(in, &out_dp_cap, TB_CFG_PORT, + in->cap_adap + TB_DP_REMOTE_CAP, 1); +} + +static int tb_dp_activate(struct tb_tunnel *tunnel, bool active) +{ + int ret; + + if (active) { + struct tb_path **paths; + int last; + + paths = tunnel->paths; + last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1; + + tb_dp_port_set_hops(tunnel->src_port, + paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index, + paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index, + paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index); + + tb_dp_port_set_hops(tunnel->dst_port, + paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index, + paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index, + paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index); + } else { + tb_dp_port_hpd_clear(tunnel->src_port); + tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0); + if (tb_port_is_dpout(tunnel->dst_port)) + tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0); + } + + ret = tb_dp_port_enable(tunnel->src_port, active); + if (ret) + return ret; + + if (tb_port_is_dpout(tunnel->dst_port)) + return tb_dp_port_enable(tunnel->dst_port, active); + + return 0; +} + +static void tb_dp_init_aux_path(struct tb_path *path) +{ + int i; + + path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL; + path->egress_shared_buffer = TB_PATH_NONE; + path->ingress_fc_enable = TB_PATH_ALL; + path->ingress_shared_buffer = TB_PATH_NONE; + path->priority = 2; + path->weight = 1; + + for (i = 0; i < path->path_length; i++) + path->hops[i].initial_credits = 1; +} + +static void tb_dp_init_video_path(struct tb_path *path, bool discover) +{ + u32 nfc_credits = path->hops[0].in_port->config.nfc_credits; + + path->egress_fc_enable = TB_PATH_NONE; + path->egress_shared_buffer = TB_PATH_NONE; + path->ingress_fc_enable = TB_PATH_NONE; + path->ingress_shared_buffer = TB_PATH_NONE; + path->priority = 1; + path->weight = 1; + + if (discover) { + path->nfc_credits = nfc_credits & TB_PORT_NFC_CREDITS_MASK; + } else { + u32 max_credits; + + max_credits = (nfc_credits & TB_PORT_MAX_CREDITS_MASK) >> + TB_PORT_MAX_CREDITS_SHIFT; + /* Leave some credits for AUX path */ + path->nfc_credits = min(max_credits - 2, 12U); + } +} + +/** + * tb_tunnel_discover_dp() - Discover existing Display Port tunnels + * @tb: Pointer to the domain structure + * @in: DP in adapter + * + * If @in adapter is active, follows the tunnel to the DP out adapter + * and back. Returns the discovered tunnel or %NULL if there was no + * tunnel. + * + * Return: DP tunnel or %NULL if no tunnel found. + */ +struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in) +{ + struct tb_tunnel *tunnel; + struct tb_port *port; + struct tb_path *path; + + if (!tb_dp_port_is_enabled(in)) + return NULL; + + tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP); + if (!tunnel) + return NULL; + + tunnel->init = tb_dp_xchg_caps; + tunnel->activate = tb_dp_activate; + tunnel->src_port = in; + + path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1, + &tunnel->dst_port, "Video"); + if (!path) { + /* Just disable the DP IN port */ + tb_dp_port_enable(in, false); + goto err_free; + } + tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path; + tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], true); + + path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX"); + if (!path) + goto err_deactivate; + tunnel->paths[TB_DP_AUX_PATH_OUT] = path; + tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]); + + path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID, + &port, "AUX RX"); + if (!path) + goto err_deactivate; + tunnel->paths[TB_DP_AUX_PATH_IN] = path; + tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]); + + /* Validate that the tunnel is complete */ + if (!tb_port_is_dpout(tunnel->dst_port)) { + tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n"); + goto err_deactivate; + } + + if (!tb_dp_port_is_enabled(tunnel->dst_port)) + goto err_deactivate; + + if (!tb_dp_port_hpd_is_active(tunnel->dst_port)) + goto err_deactivate; + + if (port != tunnel->src_port) { + tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n"); + goto err_deactivate; + } + + tb_tunnel_dbg(tunnel, "discovered\n"); + return tunnel; + +err_deactivate: + tb_tunnel_deactivate(tunnel); +err_free: + tb_tunnel_free(tunnel); + + return NULL; +} + +/** + * tb_tunnel_alloc_dp() - allocate a Display Port tunnel + * @tb: Pointer to the domain structure + * @in: DP in adapter port + * @out: DP out adapter port + * + * Allocates a tunnel between @in and @out that is capable of tunneling + * Display Port traffic. + * + * Return: Returns a tb_tunnel on success or NULL on failure. + */ +struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in, + struct tb_port *out) +{ + struct tb_tunnel *tunnel; + struct tb_path **paths; + struct tb_path *path; + + if (WARN_ON(!in->cap_adap || !out->cap_adap)) + return NULL; + + tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP); + if (!tunnel) + return NULL; + + tunnel->init = tb_dp_xchg_caps; + tunnel->activate = tb_dp_activate; + tunnel->src_port = in; + tunnel->dst_port = out; + + paths = tunnel->paths; + + path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID, + 1, "Video"); + if (!path) + goto err_free; + tb_dp_init_video_path(path, false); + paths[TB_DP_VIDEO_PATH_OUT] = path; + + path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out, + TB_DP_AUX_TX_HOPID, 1, "AUX TX"); + if (!path) + goto err_free; + tb_dp_init_aux_path(path); + paths[TB_DP_AUX_PATH_OUT] = path; + + path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in, + TB_DP_AUX_RX_HOPID, 1, "AUX RX"); + if (!path) + goto err_free; + tb_dp_init_aux_path(path); + paths[TB_DP_AUX_PATH_IN] = path; + + return tunnel; + +err_free: + tb_tunnel_free(tunnel); + return NULL; +} + +static u32 tb_dma_credits(struct tb_port *nhi) +{ + u32 max_credits; + + max_credits = (nhi->config.nfc_credits & TB_PORT_MAX_CREDITS_MASK) >> + TB_PORT_MAX_CREDITS_SHIFT; + return min(max_credits, 13U); +} + +static int tb_dma_activate(struct tb_tunnel *tunnel, bool active) +{ + struct tb_port *nhi = tunnel->src_port; + u32 credits; + + credits = active ? tb_dma_credits(nhi) : 0; + return tb_port_set_initial_credits(nhi, credits); +} + +static void tb_dma_init_path(struct tb_path *path, unsigned int isb, + unsigned int efc, u32 credits) +{ + int i; + + path->egress_fc_enable = efc; + path->ingress_fc_enable = TB_PATH_ALL; + path->egress_shared_buffer = TB_PATH_NONE; + path->ingress_shared_buffer = isb; + path->priority = 5; + path->weight = 1; + path->clear_fc = true; + + for (i = 0; i < path->path_length; i++) + path->hops[i].initial_credits = credits; +} + +/** + * tb_tunnel_alloc_dma() - allocate a DMA tunnel + * @tb: Pointer to the domain structure + * @nhi: Host controller port + * @dst: Destination null port which the other domain is connected to + * @transmit_ring: NHI ring number used to send packets towards the + * other domain + * @transmit_path: HopID used for transmitting packets + * @receive_ring: NHI ring number used to receive packets from the + * other domain + * @reveive_path: HopID used for receiving packets + * + * Return: Returns a tb_tunnel on success or NULL on failure. + */ +struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi, + struct tb_port *dst, int transmit_ring, + int transmit_path, int receive_ring, + int receive_path) +{ + struct tb_tunnel *tunnel; + struct tb_path *path; + u32 credits; + + tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_DMA); + if (!tunnel) + return NULL; + + tunnel->activate = tb_dma_activate; + tunnel->src_port = nhi; + tunnel->dst_port = dst; + + credits = tb_dma_credits(nhi); + + path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0, "DMA RX"); + if (!path) { + tb_tunnel_free(tunnel); + return NULL; + } + tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL, + credits); + tunnel->paths[TB_DMA_PATH_IN] = path; + + path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0, "DMA TX"); + if (!path) { + tb_tunnel_free(tunnel); + return NULL; + } + tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits); + tunnel->paths[TB_DMA_PATH_OUT] = path; + + return tunnel; +} + +/** + * tb_tunnel_free() - free a tunnel + * @tunnel: Tunnel to be freed + * + * Frees a tunnel. The tunnel does not need to be deactivated. + */ +void tb_tunnel_free(struct tb_tunnel *tunnel) +{ + int i; + + if (!tunnel) + return; + + for (i = 0; i < tunnel->npaths; i++) { + if (tunnel->paths[i]) + tb_path_free(tunnel->paths[i]); + } + + kfree(tunnel->paths); + kfree(tunnel); +} + +/** + * tb_tunnel_is_invalid - check whether an activated path is still valid + * @tunnel: Tunnel to check + */ +bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel) +{ + int i; + + for (i = 0; i < tunnel->npaths; i++) { + WARN_ON(!tunnel->paths[i]->activated); + if (tb_path_is_invalid(tunnel->paths[i])) + return true; + } + + return false; +} + +/** + * tb_tunnel_restart() - activate a tunnel after a hardware reset + * @tunnel: Tunnel to restart + * + * Return: 0 on success and negative errno in case if failure + */ +int tb_tunnel_restart(struct tb_tunnel *tunnel) +{ + int res, i; + + tb_tunnel_dbg(tunnel, "activating\n"); + + /* + * Make sure all paths are properly disabled before enabling + * them again. + */ + for (i = 0; i < tunnel->npaths; i++) { + if (tunnel->paths[i]->activated) { + tb_path_deactivate(tunnel->paths[i]); + tunnel->paths[i]->activated = false; + } + } + + if (tunnel->init) { + res = tunnel->init(tunnel); + if (res) + return res; + } + + for (i = 0; i < tunnel->npaths; i++) { + res = tb_path_activate(tunnel->paths[i]); + if (res) + goto err; + } + + if (tunnel->activate) { + res = tunnel->activate(tunnel, true); + if (res) + goto err; + } + + return 0; + +err: + tb_tunnel_warn(tunnel, "activation failed\n"); + tb_tunnel_deactivate(tunnel); + return res; +} + +/** + * tb_tunnel_activate() - activate a tunnel + * @tunnel: Tunnel to activate + * + * Return: Returns 0 on success or an error code on failure. + */ +int tb_tunnel_activate(struct tb_tunnel *tunnel) +{ + int i; + + for (i = 0; i < tunnel->npaths; i++) { + if (tunnel->paths[i]->activated) { + tb_tunnel_WARN(tunnel, + "trying to activate an already activated tunnel\n"); + return -EINVAL; + } + } + + return tb_tunnel_restart(tunnel); +} + +/** + * tb_tunnel_deactivate() - deactivate a tunnel + * @tunnel: Tunnel to deactivate + */ +void tb_tunnel_deactivate(struct tb_tunnel *tunnel) +{ + int i; + + tb_tunnel_dbg(tunnel, "deactivating\n"); + + if (tunnel->activate) + tunnel->activate(tunnel, false); + + for (i = 0; i < tunnel->npaths; i++) { + if (tunnel->paths[i] && tunnel->paths[i]->activated) + tb_path_deactivate(tunnel->paths[i]); + } +} |