148 строки
3.1 KiB
C
148 строки
3.1 KiB
C
/*
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* Thunderbolt Cactus Ridge driver - bus logic (NHI independent)
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*
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* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
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*/
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#include <linux/slab.h>
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#include <linux/errno.h>
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#include <linux/delay.h>
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#include "tb.h"
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#include "tb_regs.h"
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/* hotplug handling */
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struct tb_hotplug_event {
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struct work_struct work;
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struct tb *tb;
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u64 route;
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u8 port;
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bool unplug;
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};
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/**
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* tb_handle_hotplug() - handle hotplug event
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*
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* Executes on tb->wq.
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*/
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static void tb_handle_hotplug(struct work_struct *work)
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{
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struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
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struct tb *tb = ev->tb;
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mutex_lock(&tb->lock);
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if (!tb->hotplug_active)
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goto out; /* during init, suspend or shutdown */
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/* do nothing for now */
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out:
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mutex_unlock(&tb->lock);
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kfree(ev);
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}
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/**
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* tb_schedule_hotplug_handler() - callback function for the control channel
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*
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* Delegates to tb_handle_hotplug.
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*/
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static void tb_schedule_hotplug_handler(void *data, u64 route, u8 port,
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bool unplug)
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{
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struct tb *tb = data;
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struct tb_hotplug_event *ev = kmalloc(sizeof(*ev), GFP_KERNEL);
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if (!ev)
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return;
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INIT_WORK(&ev->work, tb_handle_hotplug);
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ev->tb = tb;
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ev->route = route;
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ev->port = port;
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ev->unplug = unplug;
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queue_work(tb->wq, &ev->work);
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}
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/**
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* thunderbolt_shutdown_and_free() - shutdown everything
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*
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* Free all switches and the config channel.
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*
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* Used in the error path of thunderbolt_alloc_and_start.
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*/
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void thunderbolt_shutdown_and_free(struct tb *tb)
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{
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mutex_lock(&tb->lock);
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if (tb->root_switch)
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tb_switch_free(tb->root_switch);
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tb->root_switch = NULL;
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if (tb->ctl) {
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tb_ctl_stop(tb->ctl);
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tb_ctl_free(tb->ctl);
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}
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tb->ctl = NULL;
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tb->hotplug_active = false; /* signal tb_handle_hotplug to quit */
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/* allow tb_handle_hotplug to acquire the lock */
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mutex_unlock(&tb->lock);
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if (tb->wq) {
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flush_workqueue(tb->wq);
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destroy_workqueue(tb->wq);
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tb->wq = NULL;
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}
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mutex_destroy(&tb->lock);
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kfree(tb);
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}
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/**
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* thunderbolt_alloc_and_start() - setup the thunderbolt bus
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*
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* Allocates a tb_cfg control channel, initializes the root switch, enables
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* plug events and activates pci devices.
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*
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* Return: Returns NULL on error.
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*/
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struct tb *thunderbolt_alloc_and_start(struct tb_nhi *nhi)
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{
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struct tb *tb;
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BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4);
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BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4);
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BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4);
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tb = kzalloc(sizeof(*tb), GFP_KERNEL);
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if (!tb)
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return NULL;
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tb->nhi = nhi;
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mutex_init(&tb->lock);
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mutex_lock(&tb->lock);
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tb->wq = alloc_ordered_workqueue("thunderbolt", 0);
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if (!tb->wq)
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goto err_locked;
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tb->ctl = tb_ctl_alloc(tb->nhi, tb_schedule_hotplug_handler, tb);
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if (!tb->ctl)
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goto err_locked;
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/*
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* tb_schedule_hotplug_handler may be called as soon as the config
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* channel is started. Thats why we have to hold the lock here.
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*/
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tb_ctl_start(tb->ctl);
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tb->root_switch = tb_switch_alloc(tb, 0);
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if (!tb->root_switch)
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goto err_locked;
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/* Allow tb_handle_hotplug to progress events */
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tb->hotplug_active = true;
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mutex_unlock(&tb->lock);
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return tb;
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err_locked:
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mutex_unlock(&tb->lock);
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thunderbolt_shutdown_and_free(tb);
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return NULL;
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}
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