diff options
author | 2015-08-04 12:17:53 -0700 | |
---|---|---|
committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/thunderbolt/tb.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/thunderbolt/tb.c')
-rw-r--r-- | kernel/drivers/thunderbolt/tb.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/kernel/drivers/thunderbolt/tb.c b/kernel/drivers/thunderbolt/tb.c new file mode 100644 index 000000000..d2c3fe346 --- /dev/null +++ b/kernel/drivers/thunderbolt/tb.c @@ -0,0 +1,436 @@ +/* + * Thunderbolt Cactus Ridge driver - bus logic (NHI independent) + * + * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> + */ + +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/delay.h> + +#include "tb.h" +#include "tb_regs.h" +#include "tunnel_pci.h" + + +/* enumeration & hot plug handling */ + + +static void tb_scan_port(struct tb_port *port); + +/** + * tb_scan_switch() - scan for and initialize downstream switches + */ +static void tb_scan_switch(struct tb_switch *sw) +{ + int i; + for (i = 1; i <= sw->config.max_port_number; i++) + tb_scan_port(&sw->ports[i]); +} + +/** + * tb_scan_port() - check for and initialize switches below port + */ +static void tb_scan_port(struct tb_port *port) +{ + struct tb_switch *sw; + if (tb_is_upstream_port(port)) + return; + if (port->config.type != TB_TYPE_PORT) + return; + if (port->dual_link_port && port->link_nr) + return; /* + * Downstream switch is reachable through two ports. + * Only scan on the primary port (link_nr == 0). + */ + if (tb_wait_for_port(port, false) <= 0) + return; + if (port->remote) { + tb_port_WARN(port, "port already has a remote!\n"); + return; + } + sw = tb_switch_alloc(port->sw->tb, tb_downstream_route(port)); + if (!sw) + return; + port->remote = tb_upstream_port(sw); + tb_upstream_port(sw)->remote = port; + tb_scan_switch(sw); +} + +/** + * tb_free_invalid_tunnels() - destroy tunnels of devices that have gone away + */ +static void tb_free_invalid_tunnels(struct tb *tb) +{ + struct tb_pci_tunnel *tunnel; + struct tb_pci_tunnel *n; + list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list) + { + if (tb_pci_is_invalid(tunnel)) { + tb_pci_deactivate(tunnel); + tb_pci_free(tunnel); + } + } +} + +/** + * tb_free_unplugged_children() - traverse hierarchy and free unplugged switches + */ +static void tb_free_unplugged_children(struct tb_switch *sw) +{ + int i; + for (i = 1; i <= sw->config.max_port_number; i++) { + struct tb_port *port = &sw->ports[i]; + if (tb_is_upstream_port(port)) + continue; + if (!port->remote) + continue; + if (port->remote->sw->is_unplugged) { + tb_switch_free(port->remote->sw); + port->remote = NULL; + } else { + tb_free_unplugged_children(port->remote->sw); + } + } +} + + +/** + * find_pci_up_port() - return the first PCIe up port on @sw or NULL + */ +static struct tb_port *tb_find_pci_up_port(struct tb_switch *sw) +{ + int i; + for (i = 1; i <= sw->config.max_port_number; i++) + if (sw->ports[i].config.type == TB_TYPE_PCIE_UP) + return &sw->ports[i]; + return NULL; +} + +/** + * find_unused_down_port() - return the first inactive PCIe down port on @sw + */ +static struct tb_port *tb_find_unused_down_port(struct tb_switch *sw) +{ + int i; + int cap; + int res; + int data; + for (i = 1; i <= sw->config.max_port_number; i++) { + if (tb_is_upstream_port(&sw->ports[i])) + continue; + if (sw->ports[i].config.type != TB_TYPE_PCIE_DOWN) + continue; + cap = tb_find_cap(&sw->ports[i], TB_CFG_PORT, TB_CAP_PCIE); + if (cap <= 0) + continue; + res = tb_port_read(&sw->ports[i], &data, TB_CFG_PORT, cap, 1); + if (res < 0) + continue; + if (data & 0x80000000) + continue; + return &sw->ports[i]; + } + return NULL; +} + +/** + * tb_activate_pcie_devices() - scan for and activate PCIe devices + * + * This method is somewhat ad hoc. For now it only supports one device + * per port and only devices at depth 1. + */ +static void tb_activate_pcie_devices(struct tb *tb) +{ + int i; + int cap; + u32 data; + struct tb_switch *sw; + struct tb_port *up_port; + struct tb_port *down_port; + struct tb_pci_tunnel *tunnel; + /* scan for pcie devices at depth 1*/ + for (i = 1; i <= tb->root_switch->config.max_port_number; i++) { + if (tb_is_upstream_port(&tb->root_switch->ports[i])) + continue; + if (tb->root_switch->ports[i].config.type != TB_TYPE_PORT) + continue; + if (!tb->root_switch->ports[i].remote) + continue; + sw = tb->root_switch->ports[i].remote->sw; + up_port = tb_find_pci_up_port(sw); + if (!up_port) { + tb_sw_info(sw, "no PCIe devices found, aborting\n"); + continue; + } + + /* check whether port is already activated */ + cap = tb_find_cap(up_port, TB_CFG_PORT, TB_CAP_PCIE); + if (cap <= 0) + continue; + if (tb_port_read(up_port, &data, TB_CFG_PORT, cap, 1)) + continue; + if (data & 0x80000000) { + tb_port_info(up_port, + "PCIe port already activated, aborting\n"); + continue; + } + + down_port = tb_find_unused_down_port(tb->root_switch); + if (!down_port) { + tb_port_info(up_port, + "All PCIe down ports are occupied, aborting\n"); + continue; + } + tunnel = tb_pci_alloc(tb, up_port, down_port); + if (!tunnel) { + tb_port_info(up_port, + "PCIe tunnel allocation failed, aborting\n"); + continue; + } + + if (tb_pci_activate(tunnel)) { + tb_port_info(up_port, + "PCIe tunnel activation failed, aborting\n"); + tb_pci_free(tunnel); + } + + } +} + +/* hotplug handling */ + +struct tb_hotplug_event { + struct work_struct work; + struct tb *tb; + u64 route; + u8 port; + bool unplug; +}; + +/** + * tb_handle_hotplug() - handle hotplug event + * + * Executes on tb->wq. + */ +static void tb_handle_hotplug(struct work_struct *work) +{ + struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work); + struct tb *tb = ev->tb; + struct tb_switch *sw; + struct tb_port *port; + mutex_lock(&tb->lock); + if (!tb->hotplug_active) + goto out; /* during init, suspend or shutdown */ + + sw = get_switch_at_route(tb->root_switch, ev->route); + if (!sw) { + tb_warn(tb, + "hotplug event from non existent switch %llx:%x (unplug: %d)\n", + ev->route, ev->port, ev->unplug); + goto out; + } + if (ev->port > sw->config.max_port_number) { + tb_warn(tb, + "hotplug event from non existent port %llx:%x (unplug: %d)\n", + ev->route, ev->port, ev->unplug); + goto out; + } + port = &sw->ports[ev->port]; + if (tb_is_upstream_port(port)) { + tb_warn(tb, + "hotplug event for upstream port %llx:%x (unplug: %d)\n", + ev->route, ev->port, ev->unplug); + goto out; + } + if (ev->unplug) { + if (port->remote) { + tb_port_info(port, "unplugged\n"); + tb_sw_set_unpplugged(port->remote->sw); + tb_free_invalid_tunnels(tb); + tb_switch_free(port->remote->sw); + port->remote = NULL; + } else { + tb_port_info(port, + "got unplug event for disconnected port, ignoring\n"); + } + } else if (port->remote) { + tb_port_info(port, + "got plug event for connected port, ignoring\n"); + } else { + tb_port_info(port, "hotplug: scanning\n"); + tb_scan_port(port); + if (!port->remote) { + tb_port_info(port, "hotplug: no switch found\n"); + } else if (port->remote->sw->config.depth > 1) { + tb_sw_warn(port->remote->sw, + "hotplug: chaining not supported\n"); + } else { + tb_sw_info(port->remote->sw, + "hotplug: activating pcie devices\n"); + tb_activate_pcie_devices(tb); + } + } +out: + mutex_unlock(&tb->lock); + kfree(ev); +} + +/** + * tb_schedule_hotplug_handler() - callback function for the control channel + * + * Delegates to tb_handle_hotplug. + */ +static void tb_schedule_hotplug_handler(void *data, u64 route, u8 port, + bool unplug) +{ + struct tb *tb = data; + struct tb_hotplug_event *ev = kmalloc(sizeof(*ev), GFP_KERNEL); + if (!ev) + return; + INIT_WORK(&ev->work, tb_handle_hotplug); + ev->tb = tb; + ev->route = route; + ev->port = port; + ev->unplug = unplug; + queue_work(tb->wq, &ev->work); +} + +/** + * thunderbolt_shutdown_and_free() - shutdown everything + * + * Free all switches and the config channel. + * + * Used in the error path of thunderbolt_alloc_and_start. + */ +void thunderbolt_shutdown_and_free(struct tb *tb) +{ + struct tb_pci_tunnel *tunnel; + struct tb_pci_tunnel *n; + + mutex_lock(&tb->lock); + + /* tunnels are only present after everything has been initialized */ + list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list) { + tb_pci_deactivate(tunnel); + tb_pci_free(tunnel); + } + + if (tb->root_switch) + tb_switch_free(tb->root_switch); + tb->root_switch = NULL; + + if (tb->ctl) { + tb_ctl_stop(tb->ctl); + tb_ctl_free(tb->ctl); + } + tb->ctl = NULL; + tb->hotplug_active = false; /* signal tb_handle_hotplug to quit */ + + /* allow tb_handle_hotplug to acquire the lock */ + mutex_unlock(&tb->lock); + if (tb->wq) { + flush_workqueue(tb->wq); + destroy_workqueue(tb->wq); + tb->wq = NULL; + } + mutex_destroy(&tb->lock); + kfree(tb); +} + +/** + * thunderbolt_alloc_and_start() - setup the thunderbolt bus + * + * Allocates a tb_cfg control channel, initializes the root switch, enables + * plug events and activates pci devices. + * + * Return: Returns NULL on error. + */ +struct tb *thunderbolt_alloc_and_start(struct tb_nhi *nhi) +{ + struct tb *tb; + + BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4); + BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4); + BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4); + + tb = kzalloc(sizeof(*tb), GFP_KERNEL); + if (!tb) + return NULL; + + tb->nhi = nhi; + mutex_init(&tb->lock); + mutex_lock(&tb->lock); + INIT_LIST_HEAD(&tb->tunnel_list); + + tb->wq = alloc_ordered_workqueue("thunderbolt", 0); + if (!tb->wq) + goto err_locked; + + tb->ctl = tb_ctl_alloc(tb->nhi, tb_schedule_hotplug_handler, tb); + if (!tb->ctl) + goto err_locked; + /* + * tb_schedule_hotplug_handler may be called as soon as the config + * channel is started. Thats why we have to hold the lock here. + */ + tb_ctl_start(tb->ctl); + + tb->root_switch = tb_switch_alloc(tb, 0); + if (!tb->root_switch) + goto err_locked; + + /* Full scan to discover devices added before the driver was loaded. */ + tb_scan_switch(tb->root_switch); + tb_activate_pcie_devices(tb); + + /* Allow tb_handle_hotplug to progress events */ + tb->hotplug_active = true; + mutex_unlock(&tb->lock); + return tb; + +err_locked: + mutex_unlock(&tb->lock); + thunderbolt_shutdown_and_free(tb); + return NULL; +} + +void thunderbolt_suspend(struct tb *tb) +{ + tb_info(tb, "suspending...\n"); + mutex_lock(&tb->lock); + tb_switch_suspend(tb->root_switch); + tb_ctl_stop(tb->ctl); + tb->hotplug_active = false; /* signal tb_handle_hotplug to quit */ + mutex_unlock(&tb->lock); + tb_info(tb, "suspend finished\n"); +} + +void thunderbolt_resume(struct tb *tb) +{ + struct tb_pci_tunnel *tunnel, *n; + tb_info(tb, "resuming...\n"); + mutex_lock(&tb->lock); + tb_ctl_start(tb->ctl); + + /* remove any pci devices the firmware might have setup */ + tb_switch_reset(tb, 0); + + tb_switch_resume(tb->root_switch); + tb_free_invalid_tunnels(tb); + tb_free_unplugged_children(tb->root_switch); + list_for_each_entry_safe(tunnel, n, &tb->tunnel_list, list) + tb_pci_restart(tunnel); + if (!list_empty(&tb->tunnel_list)) { + /* + * the pcie links need some time to get going. + * 100ms works for me... + */ + tb_info(tb, "tunnels restarted, sleeping for 100ms\n"); + msleep(100); + } + /* Allow tb_handle_hotplug to progress events */ + tb->hotplug_active = true; + mutex_unlock(&tb->lock); + tb_info(tb, "resume finished\n"); +} |