diff options
Diffstat (limited to 'drivers/staging/cdv/drv/psb_socket.c')
-rw-r--r-- | drivers/staging/cdv/drv/psb_socket.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/staging/cdv/drv/psb_socket.c b/drivers/staging/cdv/drv/psb_socket.c new file mode 100644 index 000000000000..7cc9a7b386e6 --- /dev/null +++ b/drivers/staging/cdv/drv/psb_socket.c @@ -0,0 +1,374 @@ +/* + * Copyright (c) 2011, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. 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., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + * + * Copyright (C) 2004 Red Hat, Inc. All rights reserved. + * Copyright (C) 2004 Novell, Inc. All rights reserved. + * Copyright (C) 2004 IBM, Inc. All rights reserved. + * Copyright (C) 2011 Intel Corporation. All rights reserved. + * + * Licensed under the GNU GPL v2. + * + * Authors: + * Robert Love <rml@novell.com> + * Kay Sievers <kay.sievers@vrfy.org> + * Arjan van de Ven <arjanv@redhat.com> + * Greg Kroah-Hartman <greg@kroah.com> + * + * Notes: + * Adapted from existing kobj event socket code to enable + * mutlicast usermode communication for gfx driver to mutiple + * usermode threads via different socket broadcast groups. + * Original kobject uevent code does not allow for different + * broadcast groups. Due to the frequency of usermode events + * generated by some gfx subsystems it is necessary to open + * a new dedicated socket with multicast group support. In + * the future it is hoped that this code can be removed + * and either a new netlink protocol type added for graphics + * or conversely to simply enable group routing to be leveraged + * on the existing kobject uevent infrastructure. + */ + +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/kobject.h> +#include <linux/module.h> +#include <linux/socket.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <net/sock.h> +#include "psb_umevents.h" + +#define NETLINK_PSB_KOBJECT_UEVENT 31 + +u64 psb_uevent_seqnum; +char psb_uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH; +static DEFINE_SPINLOCK(sequence_lock); +#if defined(CONFIG_NET) +static struct sock *uevent_sock; +#endif + +/* the strings here must match the enum in include/linux/kobject.h */ +static const char *psb_kobject_actions[] = { + [KOBJ_ADD] = "add", + [KOBJ_REMOVE] = "remove", + [KOBJ_CHANGE] = "change", + [KOBJ_MOVE] = "move", + [KOBJ_ONLINE] = "online", + [KOBJ_OFFLINE] = "offline", +}; + +/** + * kobject_action_type - translate action string to numeric type + * + * @buf: buffer containing the action string, newline is ignored + * @len: length of buffer + * @type: pointer to the location to store the action type + * + * Returns 0 if the action string was recognized. + */ +int psb_kobject_action_type(const char *buf, size_t count, + enum kobject_action *type) +{ + enum kobject_action action; + int ret = -EINVAL; + + if (count && (buf[count-1] == '\n' || buf[count-1] == '\0')) + count--; + + if (!count) + goto out; + + for (action = 0; action < ARRAY_SIZE(psb_kobject_actions); action++) { + if (strncmp(psb_kobject_actions[action], buf, count) != 0) + continue; + if (psb_kobject_actions[action][count] != '\0') + continue; + *type = action; + ret = 0; + break; + } +out: + return ret; +} + +/** + * psb_kobject_uevent_env - send an uevent with environmental data + * + * @action: action that is happening + * @kobj: struct kobject that the action is happening to + * @envp_ext: pointer to environmental data + * + * Returns 0 if kobject_uevent() is completed with success or the + * corresponding error when it fails. + */ +int psb_kobject_uevent_env(struct kobject *kobj, enum kobject_action action, + char *envp_ext[], int dst_group_id) +{ + struct kobj_uevent_env *env; + const char *action_string = psb_kobject_actions[action]; + const char *devpath = NULL; + const char *subsystem; + struct kobject *top_kobj; + struct kset *kset; + struct kset_uevent_ops *uevent_ops; + u64 seq; + int i = 0; + int retval = 0; + + pr_debug("kobject: '%s' (%p): %s\n", + kobject_name(kobj), kobj, __func__); + + /* search the kset we belong to */ + top_kobj = kobj; + while (!top_kobj->kset && top_kobj->parent) + top_kobj = top_kobj->parent; + + if (!top_kobj->kset) { + pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " + "without kset!\n", kobject_name(kobj), kobj, + __func__); + return -EINVAL; + } + + kset = top_kobj->kset; + uevent_ops = (struct kset_uevent_ops *)kset->uevent_ops; + + /* skip the event, if uevent_suppress is set*/ + if (kobj->uevent_suppress) { + pr_debug("kobject: '%s' (%p): %s: uevent_suppress " + "caused the event to drop!\n", + kobject_name(kobj), kobj, __func__); + return 0; + } + /* skip the event, if the filter returns zero. */ + if (uevent_ops && uevent_ops->filter) + if (!uevent_ops->filter(kset, kobj)) { + pr_debug("kobject: '%s' (%p): %s: filter function " + "caused the event to drop!\n", + kobject_name(kobj), kobj, __func__); + return 0; + } + + /* originating subsystem */ + if (uevent_ops && uevent_ops->name) + subsystem = uevent_ops->name(kset, kobj); + else + subsystem = kobject_name(&kset->kobj); + if (!subsystem) { + pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " + "event to drop!\n", kobject_name(kobj), kobj, + __func__); + return 0; + } + + /* environment buffer */ + env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL); + if (!env) + return -ENOMEM; + + /* complete object path */ + devpath = kobject_get_path(kobj, GFP_KERNEL); + if (!devpath) { + retval = -ENOENT; + goto exit; + } + + /* default keys */ + retval = add_uevent_var(env, "ACTION=%s", action_string); + if (retval) + goto exit; + retval = add_uevent_var(env, "DEVPATH=%s", devpath); + if (retval) + goto exit; + retval = add_uevent_var(env, "SUBSYSTEM=%s", subsystem); + if (retval) + goto exit; + + /* keys passed in from the caller */ + if (envp_ext) { + for (i = 0; envp_ext[i]; i++) { + retval = add_uevent_var(env, "%s", envp_ext[i]); + if (retval) + goto exit; + } + } + + /* let the kset specific function add its stuff */ + if (uevent_ops && uevent_ops->uevent) { + retval = uevent_ops->uevent(kset, kobj, env); + if (retval) { + pr_debug("kobject: '%s' (%p): %s: uevent() returned " + "%d\n", kobject_name(kobj), kobj, + __func__, retval); + goto exit; + } + } + + /* + * Mark "add" and "remove" events in the object to ensure proper + * events to userspace during automatic cleanup. If the object did + * send an "add" event, "remove" will automatically generated by + * the core, if not already done by the caller. + */ + if (action == KOBJ_ADD) + kobj->state_add_uevent_sent = 1; + else if (action == KOBJ_REMOVE) + kobj->state_remove_uevent_sent = 1; + + /* we will send an event, so request a new sequence number */ + spin_lock(&sequence_lock); + seq = ++psb_uevent_seqnum; + spin_unlock(&sequence_lock); + retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq); + if (retval) + goto exit; + +#if defined(CONFIG_NET) + /* send netlink message */ + if (uevent_sock) { + struct sk_buff *skb; + size_t len; + + /* allocate message with the maximum possible size */ + len = strlen(action_string) + strlen(devpath) + 2; + skb = alloc_skb(len + env->buflen, GFP_KERNEL); + if (skb) { + char *scratch; + + /* add header */ + scratch = skb_put(skb, len); + sprintf(scratch, "%s@%s", action_string, devpath); + + /* copy keys to our continuous event payload buffer */ + for (i = 0; i < env->envp_idx; i++) { + len = strlen(env->envp[i]) + 1; + scratch = skb_put(skb, len); + strcpy(scratch, env->envp[i]); + } + + NETLINK_CB(skb).dst_group = dst_group_id; + retval = netlink_broadcast(uevent_sock, skb, 0, + dst_group_id, + GFP_KERNEL); + + /* ENOBUFS should be handled in userspace */ + if (retval == -ENOBUFS) + retval = 0; + } else + retval = -ENOMEM; + } +#endif + + /* call psb_uevent_helper, usually only enabled during early boot */ + if (psb_uevent_helper[0]) { + char *argv[3]; + + argv[0] = psb_uevent_helper; + argv[1] = (char *)subsystem; + argv[2] = NULL; + retval = add_uevent_var(env, "HOME=/"); + if (retval) + goto exit; + retval = add_uevent_var(env, + "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); + if (retval) + goto exit; + + retval = call_usermodehelper(argv[0], argv, + env->envp, UMH_WAIT_EXEC); + } + +exit: + kfree(devpath); + kfree(env); + return retval; +} +/*EXPORT_SYMBOL_GPL(psb_kobject_uevent_env); */ + +/** + * psb_kobject_uevent - notify userspace by ending an uevent + * + * @action: action that is happening + * @kobj: struct kobject that the action is happening to + * + * Returns 0 if psb_kobject_uevent() is completed with success or the + * corresponding error when it fails. + */ +int psb_kobject_uevent(struct kobject *kobj, enum kobject_action action, + int dst_group_id) +{ + return psb_kobject_uevent_env(kobj, action, NULL, dst_group_id); +} +/*EXPORT_SYMBOL_GPL(psb_kobject_uevent); */ + +/** + * psb_add_uevent_var - add key value string to the environment buffer + * @env: environment buffer structure + * @format: printf format for the key=value pair + * + * Returns 0 if environment variable was added successfully or -ENOMEM + * if no space was available. + */ +int psb_add_uevent_var(struct kobj_uevent_env *env, const char *format, ...) +{ + va_list args; + int len; + + if (env->envp_idx >= ARRAY_SIZE(env->envp)) { + WARN(1, KERN_ERR "psb_add_uevent_var: too many keys\n"); + return -ENOMEM; + } + + va_start(args, format); + len = vsnprintf(&env->buf[env->buflen], + sizeof(env->buf) - env->buflen, + format, args); + va_end(args); + + if (len >= (sizeof(env->buf) - env->buflen)) { + WARN(1, + KERN_ERR "psb_add_uevent_var: buffer size too small\n"); + return -ENOMEM; + } + + env->envp[env->envp_idx++] = &env->buf[env->buflen]; + env->buflen += len + 1; + return 0; +} +/*EXPORT_SYMBOL_GPL(psb_add_uevent_var);*/ + +#if defined(CONFIG_NET) +int psb_kobject_uevent_init(void) +{ + /* This should be the 15, but 3 seems to work better. Why? WHY!? */ + /* uevent_sock = netlink_kernel_create(&init_net, + NETLINK_PSB_KOBJECT_UEVENT, + DRM_GFX_SOCKET_GROUPS, + NULL, NULL, THIS_MODULE); */ + uevent_sock = netlink_kernel_create(&init_net, + NETLINK_PSB_KOBJECT_UEVENT, + 0x3, /* 3 is for hotplug & dpst */ + NULL, NULL, THIS_MODULE); + + if (!uevent_sock) { + printk(KERN_ERR "psb_kobject_uevent: failed create socket!\n"); + return -ENODEV; + } + netlink_set_nonroot(NETLINK_PSB_KOBJECT_UEVENT, NL_NONROOT_RECV); + + return 0; +} +#endif |