thunderbolt: Discover preboot PCIe paths the boot firmware established

In Apple Macs the boot firmware (EFI) connects all devices automatically
when the system is started, before it hands over to the OS. Instead of
ignoring we discover all those PCIe tunnels and record them using our
internal structures, just like we do when a device is connected after
the OS is already up.

By doing this we can properly tear down tunnels when devices are
disconnected. Also this allows us to resume the existing tunnels after
system suspend/resume cycle.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 322bbdc00d95..a558adf6ff10 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -155,6 +155,8 @@ struct tb_port {
  * @in_counter_index: Used counter index (not used in the driver
  *		      currently, %-1 to disable)
  * @next_hop_index: HopID of the packet when it is routed out from @out_port
+ * @initial_credits: Number of initial flow control credits allocated for
+ *		     the path
  *
  * Hop configuration is always done on the IN port of a switch.
  * in_port and out_port have to be on the same switch. Packets arriving on
@@ -173,6 +175,7 @@ struct tb_path_hop {
 	int in_hop_index;
 	int in_counter_index;
 	int next_hop_index;
+	unsigned int initial_credits;
 };
 
 /**
@@ -230,6 +233,7 @@ struct tb_path {
 
 /* HopIDs 0-7 are reserved by the Thunderbolt protocol */
 #define TB_PATH_MIN_HOPID	8
+#define TB_PATH_MAX_HOPS	7
 
 /**
  * struct tb_cm_ops - Connection manager specific operations vector
@@ -346,6 +350,11 @@ static inline bool tb_port_has_remote(const struct tb_port *port)
 	return true;
 }
 
+static inline bool tb_port_is_pcie_up(const struct tb_port *port)
+{
+	return port && port->config.type == TB_TYPE_PCIE_UP;
+}
+
 static inline int tb_sw_read(struct tb_switch *sw, void *buffer,
 			     enum tb_cfg_space space, u32 offset, u32 length)
 {
@@ -508,6 +517,11 @@ static inline struct tb_switch *tb_to_switch(struct device *dev)
 	return NULL;
 }
 
+static inline struct tb_switch *tb_switch_parent(struct tb_switch *sw)
+{
+	return tb_to_switch(sw->dev.parent);
+}
+
 static inline bool tb_switch_is_lr(const struct tb_switch *sw)
 {
 	return sw->config.device_id == PCI_DEVICE_ID_INTEL_LIGHT_RIDGE;
@@ -531,8 +545,12 @@ struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
 int tb_switch_find_vse_cap(struct tb_switch *sw, enum tb_switch_vse_cap vsec);
 int tb_port_find_cap(struct tb_port *port, enum tb_port_cap cap);
 
+bool tb_pci_port_is_enabled(struct tb_port *port);
 int tb_pci_port_enable(struct tb_port *port, bool enable);
 
+struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
+				 struct tb_port *dst, int dst_hopid,
+				 struct tb_port **last, const char *name);
 struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
 			      struct tb_port *dst, int dst_hopid, int link_nr,
 			      const char *name);