drivers/thunderbolt/tunnel_pci.c

   1 /*
   2  * Thunderbolt Cactus Ridge driver - PCIe tunnel
   3  *
   4  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
   5  */
   6
   7 #include <linux/slab.h>
   8 #include <linux/list.h>
   9
  10 #include "tunnel_pci.h"
  11 #include "tb.h"
  12
  13 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
  14         do {                                                            \
  15                 struct tb_pci_tunnel *__tunnel = (tunnel);              \
  16                 level(__tunnel->tb, "%llx:%x <-> %llx:%x (PCI): " fmt,  \
  17                       tb_route(__tunnel->down_port->sw),                \
  18                       __tunnel->down_port->port,                        \
  19                       tb_route(__tunnel->up_port->sw),                  \
  20                       __tunnel->up_port->port,                          \
  21                       ## arg);                                          \
  22         } while (0)
  23
  24 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
  25         __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
  26 #define tb_tunnel_warn(tunnel, fmt, arg...) \
  27         __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
  28 #define tb_tunnel_info(tunnel, fmt, arg...) \
  29         __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
  30
  31 static void tb_pci_init_path(struct tb_path *path)
  32 {
  33         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
  34         path->egress_shared_buffer = TB_PATH_NONE;
  35         path->ingress_fc_enable = TB_PATH_ALL;
  36         path->ingress_shared_buffer = TB_PATH_NONE;
  37         path->priority = 3;
  38         path->weight = 1;
  39         path->drop_packages = 0;
  40         path->nfc_credits = 0;
  41 }
  42
  43 /**
  44  * tb_pci_alloc() - allocate a pci tunnel
  45  *
  46  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
  47  * TB_TYPE_PCIE_DOWN.
  48  *
  49  * Currently only paths consisting of two hops are supported (that is the
  50  * ports must be on "adjacent" switches).
  51  *
  52  * The paths are hard-coded to use hop 8 (the only working hop id available on
  53  * my thunderbolt devices). Therefore at most ONE path per device may be
  54  * activated.
  55  *
  56  * Return: Returns a tb_pci_tunnel on success or NULL on failure.
  57  */
  58 struct tb_pci_tunnel *tb_pci_alloc(struct tb *tb, struct tb_port *up,
  59                                    struct tb_port *down)
  60 {
  61         struct tb_pci_tunnel *tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
  62         if (!tunnel)
  63                 goto err;
  64         tunnel->tb = tb;
  65         tunnel->down_port = down;
  66         tunnel->up_port = up;
  67         INIT_LIST_HEAD(&tunnel->list);
  68         tunnel->path_to_up = tb_path_alloc(up->sw->tb, 2);
  69         if (!tunnel->path_to_up)
  70                 goto err;
  71         tunnel->path_to_down = tb_path_alloc(up->sw->tb, 2);
  72         if (!tunnel->path_to_down)
  73                 goto err;
  74         tb_pci_init_path(tunnel->path_to_up);
  75         tb_pci_init_path(tunnel->path_to_down);
  76
  77         tunnel->path_to_up->hops[0].in_port = down;
  78         tunnel->path_to_up->hops[0].in_hop_index = 8;
  79         tunnel->path_to_up->hops[0].in_counter_index = -1;
  80         tunnel->path_to_up->hops[0].out_port = tb_upstream_port(up->sw)->remote;
  81         tunnel->path_to_up->hops[0].next_hop_index = 8;
  82
  83         tunnel->path_to_up->hops[1].in_port = tb_upstream_port(up->sw);
  84         tunnel->path_to_up->hops[1].in_hop_index = 8;
  85         tunnel->path_to_up->hops[1].in_counter_index = -1;
  86         tunnel->path_to_up->hops[1].out_port = up;
  87         tunnel->path_to_up->hops[1].next_hop_index = 8;
  88
  89         tunnel->path_to_down->hops[0].in_port = up;
  90         tunnel->path_to_down->hops[0].in_hop_index = 8;
  91         tunnel->path_to_down->hops[0].in_counter_index = -1;
  92         tunnel->path_to_down->hops[0].out_port = tb_upstream_port(up->sw);
  93         tunnel->path_to_down->hops[0].next_hop_index = 8;
  94
  95         tunnel->path_to_down->hops[1].in_port =
  96                 tb_upstream_port(up->sw)->remote;
  97         tunnel->path_to_down->hops[1].in_hop_index = 8;
  98         tunnel->path_to_down->hops[1].in_counter_index = -1;
  99         tunnel->path_to_down->hops[1].out_port = down;
 100         tunnel->path_to_down->hops[1].next_hop_index = 8;
 101         return tunnel;
 102
 103 err:
 104         if (tunnel) {
 105                 if (tunnel->path_to_down)
 106                         tb_path_free(tunnel->path_to_down);
 107                 if (tunnel->path_to_up)
 108                         tb_path_free(tunnel->path_to_up);
 109                 kfree(tunnel);
 110         }
 111         return NULL;
 112 }
 113
 114 /**
 115  * tb_pci_free() - free a tunnel
 116  *
 117  * The tunnel must have been deactivated.
 118  */
 119 void tb_pci_free(struct tb_pci_tunnel *tunnel)
 120 {
 121         if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
 122                 tb_tunnel_WARN(tunnel, "trying to free an activated tunnel\n");
 123                 return;
 124         }
 125         tb_path_free(tunnel->path_to_up);
 126         tb_path_free(tunnel->path_to_down);
 127         kfree(tunnel);
 128 }
 129
 130 /**
 131  * tb_pci_is_invalid - check whether an activated path is still valid
 132  */
 133 bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel)
 134 {
 135         WARN_ON(!tunnel->path_to_up->activated);
 136         WARN_ON(!tunnel->path_to_down->activated);
 137
 138         return tb_path_is_invalid(tunnel->path_to_up)
 139                || tb_path_is_invalid(tunnel->path_to_down);
 140 }
 141
 142 /**
 143  * tb_pci_port_active() - activate/deactivate PCI capability
 144  *
 145  * Return: Returns 0 on success or an error code on failure.
 146  */
 147 static int tb_pci_port_active(struct tb_port *port, bool active)
 148 {
 149         u32 word = active ? 0x80000000 : 0x0;
 150         int cap = tb_find_cap(port, TB_CFG_PORT, TB_CAP_PCIE);
 151         if (cap <= 0) {
 152                 tb_port_warn(port, "TB_CAP_PCIE not found: %d\n", cap);
 153                 return cap ? cap : -ENXIO;
 154         }
 155         return tb_port_write(port, &word, TB_CFG_PORT, cap, 1);
 156 }
 157
 158 /**
 159  * tb_pci_restart() - activate a tunnel after a hardware reset
 160  */
 161 int tb_pci_restart(struct tb_pci_tunnel *tunnel)
 162 {
 163         int res;
 164         tunnel->path_to_up->activated = false;
 165         tunnel->path_to_down->activated = false;
 166
 167         tb_tunnel_info(tunnel, "activating\n");
 168
 169         res = tb_path_activate(tunnel->path_to_up);
 170         if (res)
 171                 goto err;
 172         res = tb_path_activate(tunnel->path_to_down);
 173         if (res)
 174                 goto err;
 175
 176         res = tb_pci_port_active(tunnel->down_port, true);
 177         if (res)
 178                 goto err;
 179
 180         res = tb_pci_port_active(tunnel->up_port, true);
 181         if (res)
 182                 goto err;
 183         return 0;
 184 err:
 185         tb_tunnel_warn(tunnel, "activation failed\n");
 186         tb_pci_deactivate(tunnel);
 187         return res;
 188 }
 189
 190 /**
 191  * tb_pci_activate() - activate a tunnel
 192  *
 193  * Return: Returns 0 on success or an error code on failure.
 194  */
 195 int tb_pci_activate(struct tb_pci_tunnel *tunnel)
 196 {
 197         int res;
 198         if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
 199                 tb_tunnel_WARN(tunnel,
 200                                "trying to activate an already activated tunnel\n");
 201                 return -EINVAL;
 202         }
 203
 204         res = tb_pci_restart(tunnel);
 205         if (res)
 206                 return res;
 207
 208         list_add(&tunnel->list, &tunnel->tb->tunnel_list);
 209         return 0;
 210 }
 211
 212
 213
 214 /**
 215  * tb_pci_deactivate() - deactivate a tunnel
 216  */
 217 void tb_pci_deactivate(struct tb_pci_tunnel *tunnel)
 218 {
 219         tb_tunnel_info(tunnel, "deactivating\n");
 220         /*
 221          * TODO: enable reset by writing 0x04000000 to TB_CAP_PCIE + 1 on up
 222          * port. Seems to have no effect?
 223          */
 224         tb_pci_port_active(tunnel->up_port, false);
 225         tb_pci_port_active(tunnel->down_port, false);
 226         if (tunnel->path_to_down->activated)
 227                 tb_path_deactivate(tunnel->path_to_down);
 228         if (tunnel->path_to_up->activated)
 229                 tb_path_deactivate(tunnel->path_to_up);
 230         list_del_init(&tunnel->list);
 231 }
 232