cregit-Linux how code gets into the kernel

Release 4.11 drivers/pci/hotplug/cpci_hotplug_core.c

/*
 * CompactPCI Hot Plug Driver
 *
 * Copyright (C) 2002,2005 SOMA Networks, Inc.
 * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
 * Copyright (C) 2001 IBM Corp.
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <scottm@somanetworks.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/atomic.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include "cpci_hotplug.h"


#define DRIVER_AUTHOR	"Scott Murray <scottm@somanetworks.com>"

#define DRIVER_DESC	"CompactPCI Hot Plug Core"


#define MY_NAME	"cpci_hotplug"


#define dbg(format, arg...)					\
	do {                                                    \
                if (cpci_debug)                                 \
                        printk(KERN_DEBUG "%s: " format "\n",   \
                                MY_NAME, ## arg);               \
        } while (0)

#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)

#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)

#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)

/* local variables */
static DECLARE_RWSEM(list_rwsem);
static LIST_HEAD(slot_list);

static int slots;

static atomic_t extracting;

int cpci_debug;

static struct cpci_hp_controller *controller;

static struct task_struct *cpci_thread;

static int thread_finished;

static int enable_slot(struct hotplug_slot *slot);
static int disable_slot(struct hotplug_slot *slot);
static int set_attention_status(struct hotplug_slot *slot, u8 value);
static int get_power_status(struct hotplug_slot *slot, u8 *value);
static int get_attention_status(struct hotplug_slot *slot, u8 *value);
static int get_adapter_status(struct hotplug_slot *slot, u8 *value);
static int get_latch_status(struct hotplug_slot *slot, u8 *value);


static struct hotplug_slot_ops cpci_hotplug_slot_ops = {
	.enable_slot = enable_slot,
	.disable_slot = disable_slot,
	.set_attention_status = set_attention_status,
	.get_power_status = get_power_status,
	.get_attention_status = get_attention_status,
	.get_adapter_status = get_adapter_status,
	.get_latch_status = get_latch_status,
};


static int update_latch_status(struct hotplug_slot *hotplug_slot, u8 value) { struct hotplug_slot_info info; memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info)); info.latch_status = value; return pci_hp_change_slot_info(hotplug_slot, &info); }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray49100.00%1100.00%
Total49100.00%1100.00%


static int update_adapter_status(struct hotplug_slot *hotplug_slot, u8 value) { struct hotplug_slot_info info; memcpy(&info, hotplug_slot->info, sizeof(struct hotplug_slot_info)); info.adapter_status = value; return pci_hp_change_slot_info(hotplug_slot, &info); }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray49100.00%1100.00%
Total49100.00%1100.00%


static int enable_slot(struct hotplug_slot *hotplug_slot) { struct slot *slot = hotplug_slot->private; int retval = 0; dbg("%s - physical_slot = %s", __func__, slot_name(slot)); if (controller->ops->set_power) retval = controller->ops->set_power(slot, 1); return retval; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray5488.52%125.00%
Alexander Chiang46.56%125.00%
Rolf Eike Beer23.28%125.00%
Harvey Harrison11.64%125.00%
Total61100.00%4100.00%


static int disable_slot(struct hotplug_slot *hotplug_slot) { struct slot *slot = hotplug_slot->private; int retval = 0; dbg("%s - physical_slot = %s", __func__, slot_name(slot)); down_write(&list_rwsem); /* Unconfigure device */ dbg("%s - unconfiguring slot %s", __func__, slot_name(slot)); retval = cpci_unconfigure_slot(slot); if (retval) { err("%s - could not unconfigure slot %s", __func__, slot_name(slot)); goto disable_error; } dbg("%s - finished unconfiguring slot %s", __func__, slot_name(slot)); /* Clear EXT (by setting it) */ if (cpci_clear_ext(slot)) { err("%s - could not clear EXT for slot %s", __func__, slot_name(slot)); retval = -ENODEV; goto disable_error; } cpci_led_on(slot); if (controller->ops->set_power) { retval = controller->ops->set_power(slot, 0); if (retval) goto disable_error; } if (update_adapter_status(slot->hotplug_slot, 0)) warn("failure to update adapter file"); if (slot->extracting) { slot->extracting = 0; atomic_dec(&extracting); } disable_error: up_write(&list_rwsem); return retval; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray17584.13%342.86%
Alexander Chiang167.69%114.29%
Quentin Lambert104.81%114.29%
Harvey Harrison52.40%114.29%
Rolf Eike Beer20.96%114.29%
Total208100.00%7100.00%


static u8 cpci_get_power_status(struct slot *slot) { u8 power = 1; if (controller->ops->get_power) power = controller->ops->get_power(slot); return power; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray38100.00%1100.00%
Total38100.00%1100.00%


static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value) { struct slot *slot = hotplug_slot->private; *value = cpci_get_power_status(slot); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray3394.29%150.00%
Rolf Eike Beer25.71%150.00%
Total35100.00%2100.00%


static int get_attention_status(struct hotplug_slot *hotplug_slot, u8 *value) { struct slot *slot = hotplug_slot->private; *value = cpci_get_attention_status(slot); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray3394.29%150.00%
Rolf Eike Beer25.71%150.00%
Total35100.00%2100.00%


static int set_attention_status(struct hotplug_slot *hotplug_slot, u8 status) { return cpci_set_attention_status(hotplug_slot->private, status); }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray2083.33%150.00%
Rolf Eike Beer416.67%150.00%
Total24100.00%2100.00%


static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value) { *value = hotplug_slot->info->adapter_status; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray27100.00%1100.00%
Total27100.00%1100.00%


static int get_latch_status(struct hotplug_slot *hotplug_slot, u8 *value) { *value = hotplug_slot->info->latch_status; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray27100.00%1100.00%
Total27100.00%1100.00%


static void release_slot(struct hotplug_slot *hotplug_slot) { struct slot *slot = hotplug_slot->private; kfree(slot->hotplug_slot->info); kfree(slot->hotplug_slot); pci_dev_put(slot->dev); kfree(slot); }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman3981.25%133.33%
Scott Murray714.58%133.33%
Rolf Eike Beer24.17%133.33%
Total48100.00%3100.00%

#define SLOT_NAME_SIZE 6
int cpci_hp_register_bus(struct pci_bus *bus, u8 first, u8 last) { struct slot *slot; struct hotplug_slot *hotplug_slot; struct hotplug_slot_info *info; char name[SLOT_NAME_SIZE]; int status; int i; if (!(controller && bus)) return -ENODEV; /* * Create a structure for each slot, and register that slot * with the pci_hotplug subsystem. */ for (i = first; i <= last; ++i) { slot = kzalloc(sizeof(struct slot), GFP_KERNEL); if (!slot) { status = -ENOMEM; goto error; } hotplug_slot = kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL); if (!hotplug_slot) { status = -ENOMEM; goto error_slot; } slot->hotplug_slot = hotplug_slot; info = kzalloc(sizeof(struct hotplug_slot_info), GFP_KERNEL); if (!info) { status = -ENOMEM; goto error_hpslot; } hotplug_slot->info = info; slot->bus = bus; slot->number = i; slot->devfn = PCI_DEVFN(i, 0); snprintf(name, SLOT_NAME_SIZE, "%02x:%02x", bus->number, i); hotplug_slot->private = slot; hotplug_slot->release = &release_slot; hotplug_slot->ops = &cpci_hotplug_slot_ops; /* * Initialize the slot info structure with some known * good values. */ dbg("initializing slot %s", name); info->power_status = cpci_get_power_status(slot); info->attention_status = cpci_get_attention_status(slot); dbg("registering slot %s", name); status = pci_hp_register(slot->hotplug_slot, bus, i, name); if (status) { err("pci_hp_register failed with error %d", status); goto error_info; } dbg("slot registered with name: %s", slot_name(slot)); /* Add slot to our internal list */ down_write(&list_rwsem); list_add(&slot->slot_list, &slot_list); slots++; up_write(&list_rwsem); } return 0; error_info: kfree(info); error_hpslot: kfree(hotplug_slot); error_slot: kfree(slot); error: return status; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray25371.07%222.22%
Rolf Eike Beer3710.39%111.11%
Alexander Chiang359.83%333.33%
Julia Lawall215.90%111.11%
Greg Kroah-Hartman71.97%111.11%
Eric Sesterhenn / Snakebyte30.84%111.11%
Total356100.00%9100.00%

EXPORT_SYMBOL_GPL(cpci_hp_register_bus);
int cpci_hp_unregister_bus(struct pci_bus *bus) { struct slot *slot; struct slot *tmp; int status = 0; down_write(&list_rwsem); if (!slots) { up_write(&list_rwsem); return -1; } list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { if (slot->bus == bus) { list_del(&slot->slot_list); slots--; dbg("deregistering slot %s", slot_name(slot)); status = pci_hp_deregister(slot->hotplug_slot); if (status) { err("pci_hp_deregister failed with error %d", status); break; } } } up_write(&list_rwsem); return status; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray11996.75%360.00%
Alexander Chiang32.44%120.00%
Greg Kroah-Hartman10.81%120.00%
Total123100.00%5100.00%

EXPORT_SYMBOL_GPL(cpci_hp_unregister_bus); /* This is the interrupt mode interrupt handler */
static irqreturn_t cpci_hp_intr(int irq, void *data) { dbg("entered cpci_hp_intr"); /* Check to see if it was our interrupt */ if ((controller->irq_flags & IRQF_SHARED) && !controller->ops->check_irq(controller->dev_id)) { dbg("exited cpci_hp_intr, not our interrupt"); return IRQ_NONE; } /* Disable ENUM interrupt */ controller->ops->disable_irq(); /* Trigger processing by the event thread */ wake_up_process(cpci_thread); return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray5986.76%240.00%
Andrew Morton710.29%120.00%
Thomas Gleixner11.47%120.00%
Greg Kroah-Hartman11.47%120.00%
Total68100.00%5100.00%

/* * According to PICMG 2.1 R2.0, section 6.3.2, upon * initialization, the system driver shall clear the * INS bits of the cold-inserted devices. */
static int init_slots(int clear_ins) { struct slot *slot; struct pci_dev *dev; dbg("%s - enter", __func__); down_read(&list_rwsem); if (!slots) { up_read(&list_rwsem); return -1; } list_for_each_entry(slot, &slot_list, slot_list) { dbg("%s - looking at slot %s", __func__, slot_name(slot)); if (clear_ins && cpci_check_and_clear_ins(slot)) dbg("%s - cleared INS for slot %s", __func__, slot_name(slot)); dev = pci_get_slot(slot->bus, PCI_DEVFN(slot->number, 0)); if (dev) { if (update_adapter_status(slot->hotplug_slot, 1)) warn("failure to update adapter file"); if (update_latch_status(slot->hotplug_slot, 1)) warn("failure to update latch file"); slot->dev = dev; } } up_read(&list_rwsem); dbg("%s - exit", __func__); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray16094.12%360.00%
Alexander Chiang63.53%120.00%
Harvey Harrison42.35%120.00%
Total170100.00%5100.00%


static int check_slots(void) { struct slot *slot; int extracted; int inserted; u16 hs_csr; down_read(&list_rwsem); if (!slots) { up_read(&list_rwsem); err("no slots registered, shutting down"); return -1; } extracted = inserted = 0; list_for_each_entry(slot, &slot_list, slot_list) { dbg("%s - looking at slot %s", __func__, slot_name(slot)); if (cpci_check_and_clear_ins(slot)) { /* * Some broken hardware (e.g. PLX 9054AB) asserts * ENUM# twice... */ if (slot->dev) { warn("slot %s already inserted", slot_name(slot)); inserted++; continue; } /* Process insertion */ dbg("%s - slot %s inserted", __func__, slot_name(slot)); /* GSM, debug */ hs_csr = cpci_get_hs_csr(slot); dbg("%s - slot %s HS_CSR (1) = %04x", __func__, slot_name(slot), hs_csr); /* Configure device */ dbg("%s - configuring slot %s", __func__, slot_name(slot)); if (cpci_configure_slot(slot)) { err("%s - could not configure slot %s", __func__, slot_name(slot)); continue; } dbg("%s - finished configuring slot %s", __func__, slot_name(slot)); /* GSM, debug */ hs_csr = cpci_get_hs_csr(slot); dbg("%s - slot %s HS_CSR (2) = %04x", __func__, slot_name(slot), hs_csr); if (update_latch_status(slot->hotplug_slot, 1)) warn("failure to update latch file"); if (update_adapter_status(slot->hotplug_slot, 1)) warn("failure to update adapter file"); cpci_led_off(slot); /* GSM, debug */ hs_csr = cpci_get_hs_csr(slot); dbg("%s - slot %s HS_CSR (3) = %04x", __func__, slot_name(slot), hs_csr); inserted++; } else if (cpci_check_ext(slot)) { /* Process extraction request */ dbg("%s - slot %s extracted", __func__, slot_name(slot)); /* GSM, debug */ hs_csr = cpci_get_hs_csr(slot); dbg("%s - slot %s HS_CSR = %04x", __func__, slot_name(slot), hs_csr); if (!slot->extracting) { if (update_latch_status(slot->hotplug_slot, 0)) warn("failure to update latch file"); slot->extracting = 1; atomic_inc(&extracting); } extracted++; } else if (slot->extracting) { hs_csr = cpci_get_hs_csr(slot); if (hs_csr == 0xffff) { /* * Hmmm, we're likely hosed at this point, should we * bother trying to tell the driver or not? */ err("card in slot %s was improperly removed", slot_name(slot)); if (update_adapter_status(slot->hotplug_slot, 0)) warn("failure to update adapter file"); slot->extracting = 0; atomic_dec(&extracting); } } } up_read(&list_rwsem); dbg("inserted=%d, extracted=%d, extracting=%d", inserted, extracted, atomic_read(&extracting)); if (inserted || extracted) return extracted; else if (!atomic_read(&extracting)) { err("cannot find ENUM# source, shutting down"); return -1; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray43290.38%360.00%
Alexander Chiang367.53%120.00%
Harvey Harrison102.09%120.00%
Total478100.00%5100.00%

/* This is the interrupt mode worker thread body */
static int event_thread(void *data) { int rc; dbg("%s - event thread started", __func__); while (1) { dbg("event thread sleeping"); set_current_state(TASK_INTERRUPTIBLE); schedule(); if (kthread_should_stop()) break; do { rc = check_slots(); if (rc > 0) { /* Give userspace a chance to handle extraction */ msleep(500); } else if (rc < 0) { dbg("%s - error checking slots", __func__); thread_finished = 1; goto out; } } while (atomic_read(&extracting) && !kthread_should_stop()); if (kthread_should_stop()) break; /* Re-enable ENUM# interrupt */ dbg("%s - re-enabling irq", __func__); controller->ops->enable_irq(); } out: return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray12496.12%466.67%
Harvey Harrison32.33%116.67%
Nishanth Aravamudan21.55%116.67%
Total129100.00%6100.00%

/* This is the polling mode worker thread body */
static int poll_thread(void *data) { int rc; while (1) { if (kthread_should_stop() || signal_pending(current)) break; if (controller->ops->query_enum()) { do { rc = check_slots(); if (rc > 0) { /* Give userspace a chance to handle extraction */ msleep(500); } else if (rc < 0) { dbg("%s - error checking slots", __func__); thread_finished = 1; goto out; } } while (atomic_read(&extracting) && !kthread_should_stop()); } msleep(100); } out: return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray10495.41%466.67%
Nishanth Aravamudan43.67%116.67%
Harvey Harrison10.92%116.67%
Total109100.00%6100.00%


static int cpci_start_thread(void) { if (controller->irq) cpci_thread = kthread_run(event_thread, NULL, "cpci_hp_eventd"); else cpci_thread = kthread_run(poll_thread, NULL, "cpci_hp_polld"); if (IS_ERR(cpci_thread)) { err("Can't start up our thread"); return PTR_ERR(cpci_thread); } thread_finished = 0; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray6296.88%266.67%
Al Viro23.12%133.33%
Total64100.00%3100.00%


static void cpci_stop_thread(void) { kthread_stop(cpci_thread); thread_finished = 1; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray17100.00%2100.00%
Total17100.00%2100.00%


int cpci_hp_register_controller(struct cpci_hp_controller *new_controller) { int status = 0; if (controller) return -1; if (!(new_controller && new_controller->ops)) return -EINVAL; if (new_controller->irq) { if (!(new_controller->ops->enable_irq && new_controller->ops->disable_irq)) status = -EINVAL; if (request_irq(new_controller->irq, cpci_hp_intr, new_controller->irq_flags, MY_NAME, new_controller->dev_id)) { err("Can't get irq %d for the hotplug cPCI controller", new_controller->irq); status = -ENODEV; } dbg("%s - acquired controller irq %d", __func__, new_controller->irq); } if (!status) controller = new_controller; return status; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray12799.22%266.67%
Harvey Harrison10.78%133.33%
Total128100.00%3100.00%

EXPORT_SYMBOL_GPL(cpci_hp_register_controller);
static void cleanup_slots(void) { struct slot *slot; struct slot *tmp; /* * Unregister all of our slots with the pci_hotplug subsystem, * and free up all memory that we had allocated. */ down_write(&list_rwsem); if (!slots) goto cleanup_null; list_for_each_entry_safe(slot, tmp, &slot_list, slot_list) { list_del(&slot->slot_list); pci_hp_deregister(slot->hotplug_slot); } cleanup_null: up_write(&list_rwsem); return; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray69100.00%2100.00%
Total69100.00%2100.00%


int cpci_hp_unregister_controller(struct cpci_hp_controller *old_controller) { int status = 0; if (controller) { if (!thread_finished) cpci_stop_thread(); if (controller->irq) free_irq(controller->irq, controller->dev_id); controller = NULL; cleanup_slots(); } else status = -ENODEV; return status; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray62100.00%2100.00%
Total62100.00%2100.00%

EXPORT_SYMBOL_GPL(cpci_hp_unregister_controller);
int cpci_hp_start(void) { static int first = 1; int status; dbg("%s - enter", __func__); if (!controller) return -ENODEV; down_read(&list_rwsem); if (list_empty(&slot_list)) { up_read(&list_rwsem); return -ENODEV; } up_read(&list_rwsem); status = init_slots(first); if (first) first = 0; if (status) return status; status = cpci_start_thread(); if (status) return status; dbg("%s - thread started", __func__); if (controller->irq) { /* Start enum interrupt processing */ dbg("%s - enabling irq", __func__); controller->ops->enable_irq(); } dbg("%s - exit", __func__); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray13497.10%375.00%
Harvey Harrison42.90%125.00%
Total138100.00%4100.00%

EXPORT_SYMBOL_GPL(cpci_hp_start);
int cpci_hp_stop(void) { if (!controller) return -ENODEV; if (controller->irq) { /* Stop enum interrupt processing */ dbg("%s - disabling irq", __func__); controller->ops->disable_irq(); } cpci_stop_thread(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray4497.78%266.67%
Harvey Harrison12.22%133.33%
Total45100.00%3100.00%

EXPORT_SYMBOL_GPL(cpci_hp_stop);
int __init cpci_hotplug_init(int debug) { cpci_debug = debug; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Scott Murray1062.50%150.00%
Greg Kroah-Hartman637.50%150.00%
Total16100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Scott Murray254388.54%517.86%
Alexander Chiang1003.48%310.71%
Greg Kroah-Hartman602.09%517.86%
Rolf Eike Beer511.78%310.71%
Harvey Harrison301.04%13.57%
Ryan Desfosses301.04%13.57%
Julia Lawall210.73%13.57%
Quentin Lambert100.35%13.57%
Andrew Morton70.24%13.57%
Nishanth Aravamudan60.21%13.57%
Bogicevic Sasa40.14%13.57%
Eric Sesterhenn / Snakebyte30.10%13.57%
Ingo Molnar30.10%13.57%
Al Viro20.07%13.57%
Arun Sharma10.03%13.57%
Thomas Gleixner10.03%13.57%
Total2872100.00%28100.00%
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