/* * Thunderbolt Cactus Ridge driver - path/tunnel functionality * * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> */ #include <linux/slab.h>#include <linux/errno.h> #include "tb.h"  static void tb_dump_hop(struct tb_port *port, struct tb_regs_hop *hop){	tb_port_info(port, " Hop through port %d to hop %d (%s)\n",		     hop->out_port, hop->next_hop,		     hop->enable ? "enabled" : "disabled");	tb_port_info(port, "  Weight: %d Priority: %d Credits: %d Drop: %d\n",		     hop->weight, hop->priority,		     hop->initial_credits, hop->drop_packages);	tb_port_info(port, "   Counter enabled: %d Counter index: %d\n",		     hop->counter_enable, hop->counter);	tb_port_info(port, "  Flow Control (In/Eg): %d/%d Shared Buffer (In/Eg): %d/%d\n",		     hop->ingress_fc, hop->egress_fc,		     hop->ingress_shared_buffer, hop->egress_shared_buffer);	tb_port_info(port, "  Unknown1: %#x Unknown2: %#x Unknown3: %#x\n",		     hop->unknown1, hop->unknown2, hop->unknown3);} /** * tb_path_alloc() - allocate a thunderbolt path * * Return: Returns a tb_path on success or NULL on failure. */struct tb_path *tb_path_alloc(struct tb *tb, int num_hops){	struct tb_path *path = kzalloc(sizeof(*path), GFP_KERNEL);	if (!path)		return NULL;	path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);	if (!path->hops) {		kfree(path);		return NULL;	}	path->tb = tb;	path->path_length = num_hops;	return path;} /** * tb_path_free() - free a deactivated path */void tb_path_free(struct tb_path *path){	if (path->activated) {		tb_WARN(path->tb, "trying to free an activated path\n")		return;	}	kfree(path->hops);	kfree(path);} static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop){	int i, res;	for (i = first_hop; i < path->path_length; i++) {		res = tb_port_add_nfc_credits(path->hops[i].in_port,					      -path->nfc_credits);		if (res)			tb_port_warn(path->hops[i].in_port,				     "nfc credits deallocation failed for hop %d\n",				     i);	}} static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop){	int i, res;	struct tb_regs_hop hop = { };	for (i = first_hop; i < path->path_length; i++) {		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,				    2 * path->hops[i].in_hop_index, 2);		if (res)			tb_port_warn(path->hops[i].in_port,				     "hop deactivation failed for hop %d, index %d\n",				     i, path->hops[i].in_hop_index);	}} void tb_path_deactivate(struct tb_path *path){	if (!path->activated) {		tb_WARN(path->tb, "trying to deactivate an inactive path\n");		return;	}	tb_info(path->tb,		"deactivating path from %llx:%x to %llx:%x\n",		tb_route(path->hops[0].in_port->sw),		path->hops[0].in_port->port,		tb_route(path->hops[path->path_length - 1].out_port->sw),		path->hops[path->path_length - 1].out_port->port);	__tb_path_deactivate_hops(path, 0);	__tb_path_deallocate_nfc(path, 0);	path->activated = false;} /** * tb_path_activate() - activate a path * * Activate a path starting with the last hop and iterating backwards. The * caller must fill path->hops before calling tb_path_activate(). * * Return: Returns 0 on success or an error code on failure. */int tb_path_activate(struct tb_path *path){	int i, res;	enum tb_path_port out_mask, in_mask;	if (path->activated) {		tb_WARN(path->tb, "trying to activate already activated path\n");		return -EINVAL;	} 	tb_info(path->tb,		"activating path from %llx:%x to %llx:%x\n",		tb_route(path->hops[0].in_port->sw),		path->hops[0].in_port->port,		tb_route(path->hops[path->path_length - 1].out_port->sw),		path->hops[path->path_length - 1].out_port->port); 	/* Clear counters. */	for (i = path->path_length - 1; i >= 0; i--) {		if (path->hops[i].in_counter_index == -1)			continue;		res = tb_port_clear_counter(path->hops[i].in_port,					    path->hops[i].in_counter_index);		if (res)			goto err;	} 	/* Add non flow controlled credits. */	for (i = path->path_length - 1; i >= 0; i--) {		res = tb_port_add_nfc_credits(path->hops[i].in_port,					      path->nfc_credits);		if (res) {			__tb_path_deallocate_nfc(path, i);			goto err;		}	} 	/* Activate hops. */	for (i = path->path_length - 1; i >= 0; i--) {		struct tb_regs_hop hop = { 0 }; 		/*		 * We do (currently) not tear down paths setup by the firmeware.		 * If a firmware device is unplugged and plugged in again then		 * it can happen that we reuse some of the hops from the (now		 * defunct) firmeware path. This causes the hotplug operation to		 * fail (the pci device does not show up). Clearing the hop		 * before overwriting it fixes the problem.		 *		 * Should be removed once we discover and tear down firmeware		 * paths.		 */		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,				    2 * path->hops[i].in_hop_index, 2);		if (res) {			__tb_path_deactivate_hops(path, i);			__tb_path_deallocate_nfc(path, 0);			goto err;		} 		/* dword 0 */		hop.next_hop = path->hops[i].next_hop_index;		hop.out_port = path->hops[i].out_port->port;		/* TODO: figure out why these are good values */		hop.initial_credits = (i == path->path_length - 1) ? 16 : 7;		hop.unknown1 = 0;		hop.enable = 1; 		/* dword 1 */		out_mask = (i == path->path_length - 1) ?				TB_PATH_DESTINATION : TB_PATH_INTERNAL;		in_mask = (i == 0) ? TB_PATH_SOURCE : TB_PATH_INTERNAL;		hop.weight = path->weight;		hop.unknown2 = 0;		hop.priority = path->priority;		hop.drop_packages = path->drop_packages;		hop.counter = path->hops[i].in_counter_index;		hop.counter_enable = path->hops[i].in_counter_index != -1;		hop.ingress_fc = path->ingress_fc_enable & in_mask;		hop.egress_fc = path->egress_fc_enable & out_mask;		hop.ingress_shared_buffer = path->ingress_shared_buffer					    & in_mask;		hop.egress_shared_buffer = path->egress_shared_buffer					    & out_mask;		hop.unknown3 = 0; 		tb_port_info(path->hops[i].in_port, "Writing hop %d, index %d",			     i, path->hops[i].in_hop_index);		tb_dump_hop(path->hops[i].in_port, &hop);		res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,				    2 * path->hops[i].in_hop_index, 2);		if (res) {			__tb_path_deactivate_hops(path, i);			__tb_path_deallocate_nfc(path, 0);			goto err;		}	}	path->activated = true;	tb_info(path->tb, "path activation complete\n");	return 0;err:	tb_WARN(path->tb, "path activation failed\n");	return res;} /** * tb_path_is_invalid() - check whether any ports on the path are invalid * * Return: Returns true if the path is invalid, false otherwise. */bool tb_path_is_invalid(struct tb_path *path){	int i = 0;	for (i = 0; i < path->path_length; i++) {		if (path->hops[i].in_port->sw->is_unplugged)			return true;		if (path->hops[i].out_port->sw->is_unplugged)			return true;	}	return false;}