diff options
Diffstat (limited to 'drivers/thunderbolt/tunnel_pci.c')
| -rw-r--r-- | drivers/thunderbolt/tunnel_pci.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/thunderbolt/tunnel_pci.c b/drivers/thunderbolt/tunnel_pci.c new file mode 100644 index 00000000000..baf1cd37044 --- /dev/null +++ b/drivers/thunderbolt/tunnel_pci.c @@ -0,0 +1,232 @@ +/* + * Thunderbolt Cactus Ridge driver - PCIe tunnel + * + * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> + */ + +#include <linux/slab.h> +#include <linux/list.h> + +#include "tunnel_pci.h" +#include "tb.h" + +#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...) \ + do { \ + struct tb_pci_tunnel *__tunnel = (tunnel); \ + level(__tunnel->tb, "%llx:%x <-> %llx:%x (PCI): " fmt, \ + tb_route(__tunnel->down_port->sw), \ + __tunnel->down_port->port, \ + tb_route(__tunnel->up_port->sw), \ + __tunnel->up_port->port, \ + ## 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) + +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; +} + +/** + * tb_pci_alloc() - allocate a pci tunnel + * + * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and + * TB_TYPE_PCIE_DOWN. + * + * Currently only paths consisting of two hops are supported (that is the + * ports must be on "adjacent" switches). + * + * The paths are hard-coded to use hop 8 (the only working hop id available on + * my thunderbolt devices). Therefore at most ONE path per device may be + * activated. + * + * Return: Returns a tb_pci_tunnel on success or NULL on failure. + */ +struct tb_pci_tunnel *tb_pci_alloc(struct tb *tb, struct tb_port *up, + struct tb_port *down) +{ + struct tb_pci_tunnel *tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL); + if (!tunnel) + goto err; + tunnel->tb = tb; + tunnel->down_port = down; + tunnel->up_port = up; + INIT_LIST_HEAD(&tunnel->list); + tunnel->path_to_up = tb_path_alloc(up->sw->tb, 2); + if (!tunnel->path_to_up) + goto err; + tunnel->path_to_down = tb_path_alloc(up->sw->tb, 2); + if (!tunnel->path_to_down) + goto err; + tb_pci_init_path(tunnel->path_to_up); + tb_pci_init_path(tunnel->path_to_down); + + tunnel->path_to_up->hops[0].in_port = down; + tunnel->path_to_up->hops[0].in_hop_index = 8; + tunnel->path_to_up->hops[0].in_counter_index = -1; + tunnel->path_to_up->hops[0].out_port = tb_upstream_port(up->sw)->remote; + tunnel->path_to_up->hops[0].next_hop_index = 8; + + tunnel->path_to_up->hops[1].in_port = tb_upstream_port(up->sw); + tunnel->path_to_up->hops[1].in_hop_index = 8; + tunnel->path_to_up->hops[1].in_counter_index = -1; + tunnel->path_to_up->hops[1].out_port = up; + tunnel->path_to_up->hops[1].next_hop_index = 8; + + tunnel->path_to_down->hops[0].in_port = up; + tunnel->path_to_down->hops[0].in_hop_index = 8; + tunnel->path_to_down->hops[0].in_counter_index = -1; + tunnel->path_to_down->hops[0].out_port = tb_upstream_port(up->sw); + tunnel->path_to_down->hops[0].next_hop_index = 8; + + tunnel->path_to_down->hops[1].in_port = + tb_upstream_port(up->sw)->remote; + tunnel->path_to_down->hops[1].in_hop_index = 8; + tunnel->path_to_down->hops[1].in_counter_index = -1; + tunnel->path_to_down->hops[1].out_port = down; + tunnel->path_to_down->hops[1].next_hop_index = 8; + return tunnel; + +err: + if (tunnel) { + if (tunnel->path_to_down) + tb_path_free(tunnel->path_to_down); + if (tunnel->path_to_up) + tb_path_free(tunnel->path_to_up); + kfree(tunnel); + } + return NULL; +} + +/** + * tb_pci_free() - free a tunnel + * + * The tunnel must have been deactivated. + */ +void tb_pci_free(struct tb_pci_tunnel *tunnel) +{ + if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) { + tb_tunnel_WARN(tunnel, "trying to free an activated tunnel\n"); + return; + } + tb_path_free(tunnel->path_to_up); + tb_path_free(tunnel->path_to_down); + kfree(tunnel); +} + +/** + * tb_pci_is_invalid - check whether an activated path is still valid + */ +bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel) +{ + WARN_ON(!tunnel->path_to_up->activated); + WARN_ON(!tunnel->path_to_down->activated); + + return tb_path_is_invalid(tunnel->path_to_up) + || tb_path_is_invalid(tunnel->path_to_down); +} + +/** + * tb_pci_port_active() - activate/deactivate PCI capability + * + * Return: Returns 0 on success or an error code on failure. + */ +static int tb_pci_port_active(struct tb_port *port, bool active) +{ + u32 word = active ? 0x80000000 : 0x0; + int cap = tb_find_cap(port, TB_CFG_PORT, TB_CAP_PCIE); + if (cap <= 0) { + tb_port_warn(port, "TB_CAP_PCIE not found: %d\n", cap); + return cap ? cap : -ENXIO; + } + return tb_port_write(port, &word, TB_CFG_PORT, cap, 1); +} + +/** + * tb_pci_restart() - activate a tunnel after a hardware reset + */ +int tb_pci_restart(struct tb_pci_tunnel *tunnel) +{ + int res; + tunnel->path_to_up->activated = false; + tunnel->path_to_down->activated = false; + + tb_tunnel_info(tunnel, "activating\n"); + + res = tb_path_activate(tunnel->path_to_up); + if (res) + goto err; + res = tb_path_activate(tunnel->path_to_down); + if (res) + goto err; + + res = tb_pci_port_active(tunnel->down_port, true); + if (res) + goto err; + + res = tb_pci_port_active(tunnel->up_port, true); + if (res) + goto err; + return 0; +err: + tb_tunnel_warn(tunnel, "activation failed\n"); + tb_pci_deactivate(tunnel); + return res; +} + +/** + * tb_pci_activate() - activate a tunnel + * + * Return: Returns 0 on success or an error code on failure. + */ +int tb_pci_activate(struct tb_pci_tunnel *tunnel) +{ + int res; + if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) { + tb_tunnel_WARN(tunnel, + "trying to activate an already activated tunnel\n"); + return -EINVAL; + } + + res = tb_pci_restart(tunnel); + if (res) + return res; + + list_add(&tunnel->list, &tunnel->tb->tunnel_list); + return 0; +} + + + +/** + * tb_pci_deactivate() - deactivate a tunnel + */ +void tb_pci_deactivate(struct tb_pci_tunnel *tunnel) +{ + tb_tunnel_info(tunnel, "deactivating\n"); + /* + * TODO: enable reset by writing 0x04000000 to TB_CAP_PCIE + 1 on up + * port. Seems to have no effect? + */ + tb_pci_port_active(tunnel->up_port, false); + tb_pci_port_active(tunnel->down_port, false); + if (tunnel->path_to_down->activated) + tb_path_deactivate(tunnel->path_to_down); + if (tunnel->path_to_up->activated) + tb_path_deactivate(tunnel->path_to_up); + list_del_init(&tunnel->list); +} + |