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path: root/drivers/thunderbolt/tunnel_pci.c
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-rw-r--r--drivers/thunderbolt/tunnel_pci.c232
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 000000000000..baf1cd370446
--- /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);
+}
+