cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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notify.c (5621B)


      1/*
      2 * Copyright 2014 Red Hat Inc.
      3 *
      4 * Permission is hereby granted, free of charge, to any person obtaining a
      5 * copy of this software and associated documentation files (the "Software"),
      6 * to deal in the Software without restriction, including without limitation
      7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      8 * and/or sell copies of the Software, and to permit persons to whom the
      9 * Software is furnished to do so, subject to the following conditions:
     10 *
     11 * The above copyright notice and this permission notice shall be included in
     12 * all copies or substantial portions of the Software.
     13 *
     14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
     18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     20 * OTHER DEALINGS IN THE SOFTWARE.
     21 *
     22 * Authors: Ben Skeggs <bskeggs@redhat.com>
     23 */
     24
     25#include <nvif/client.h>
     26#include <nvif/driver.h>
     27#include <nvif/notify.h>
     28#include <nvif/object.h>
     29#include <nvif/ioctl.h>
     30#include <nvif/event.h>
     31
     32static inline int
     33nvif_notify_put_(struct nvif_notify *notify)
     34{
     35	struct nvif_object *object = notify->object;
     36	struct {
     37		struct nvif_ioctl_v0 ioctl;
     38		struct nvif_ioctl_ntfy_put_v0 ntfy;
     39	} args = {
     40		.ioctl.type = NVIF_IOCTL_V0_NTFY_PUT,
     41		.ntfy.index = notify->index,
     42	};
     43
     44	if (atomic_inc_return(&notify->putcnt) != 1)
     45		return 0;
     46
     47	return nvif_object_ioctl(object, &args, sizeof(args), NULL);
     48}
     49
     50int
     51nvif_notify_put(struct nvif_notify *notify)
     52{
     53	if (likely(notify->object) &&
     54	    test_and_clear_bit(NVIF_NOTIFY_USER, &notify->flags)) {
     55		int ret = nvif_notify_put_(notify);
     56		if (test_bit(NVIF_NOTIFY_WORK, &notify->flags))
     57			flush_work(&notify->work);
     58		return ret;
     59	}
     60	return 0;
     61}
     62
     63static inline int
     64nvif_notify_get_(struct nvif_notify *notify)
     65{
     66	struct nvif_object *object = notify->object;
     67	struct {
     68		struct nvif_ioctl_v0 ioctl;
     69		struct nvif_ioctl_ntfy_get_v0 ntfy;
     70	} args = {
     71		.ioctl.type = NVIF_IOCTL_V0_NTFY_GET,
     72		.ntfy.index = notify->index,
     73	};
     74
     75	if (atomic_dec_return(&notify->putcnt) != 0)
     76		return 0;
     77
     78	return nvif_object_ioctl(object, &args, sizeof(args), NULL);
     79}
     80
     81int
     82nvif_notify_get(struct nvif_notify *notify)
     83{
     84	if (likely(notify->object) &&
     85	    !test_and_set_bit(NVIF_NOTIFY_USER, &notify->flags))
     86		return nvif_notify_get_(notify);
     87	return 0;
     88}
     89
     90static inline int
     91nvif_notify_func(struct nvif_notify *notify, bool keep)
     92{
     93	int ret = notify->func(notify);
     94	if (ret == NVIF_NOTIFY_KEEP ||
     95	    !test_and_clear_bit(NVIF_NOTIFY_USER, &notify->flags)) {
     96		if (!keep)
     97			atomic_dec(&notify->putcnt);
     98		else
     99			nvif_notify_get_(notify);
    100	}
    101	return ret;
    102}
    103
    104static void
    105nvif_notify_work(struct work_struct *work)
    106{
    107	struct nvif_notify *notify = container_of(work, typeof(*notify), work);
    108	nvif_notify_func(notify, true);
    109}
    110
    111int
    112nvif_notify(const void *header, u32 length, const void *data, u32 size)
    113{
    114	struct nvif_notify *notify = NULL;
    115	const union {
    116		struct nvif_notify_rep_v0 v0;
    117	} *args = header;
    118	int ret = NVIF_NOTIFY_DROP;
    119
    120	if (length == sizeof(args->v0) && args->v0.version == 0) {
    121		if (WARN_ON(args->v0.route))
    122			return NVIF_NOTIFY_DROP;
    123		notify = (void *)(unsigned long)args->v0.token;
    124	}
    125
    126	if (!WARN_ON(notify == NULL)) {
    127		struct nvif_client *client = notify->object->client;
    128		if (!WARN_ON(notify->size != size)) {
    129			atomic_inc(&notify->putcnt);
    130			if (test_bit(NVIF_NOTIFY_WORK, &notify->flags)) {
    131				memcpy((void *)notify->data, data, size);
    132				schedule_work(&notify->work);
    133				return NVIF_NOTIFY_DROP;
    134			}
    135			notify->data = data;
    136			ret = nvif_notify_func(notify, client->driver->keep);
    137			notify->data = NULL;
    138		}
    139	}
    140
    141	return ret;
    142}
    143
    144int
    145nvif_notify_dtor(struct nvif_notify *notify)
    146{
    147	struct nvif_object *object = notify->object;
    148	struct {
    149		struct nvif_ioctl_v0 ioctl;
    150		struct nvif_ioctl_ntfy_del_v0 ntfy;
    151	} args = {
    152		.ioctl.type = NVIF_IOCTL_V0_NTFY_DEL,
    153		.ntfy.index = notify->index,
    154	};
    155	int ret = nvif_notify_put(notify);
    156	if (ret >= 0 && object) {
    157		ret = nvif_object_ioctl(object, &args, sizeof(args), NULL);
    158		notify->object = NULL;
    159		kfree((void *)notify->data);
    160	}
    161	return ret;
    162}
    163
    164int
    165nvif_notify_ctor(struct nvif_object *object, const char *name,
    166		 int (*func)(struct nvif_notify *), bool work, u8 event,
    167		 void *data, u32 size, u32 reply, struct nvif_notify *notify)
    168{
    169	struct {
    170		struct nvif_ioctl_v0 ioctl;
    171		struct nvif_ioctl_ntfy_new_v0 ntfy;
    172		struct nvif_notify_req_v0 req;
    173	} *args;
    174	int ret = -ENOMEM;
    175
    176	notify->object = object;
    177	notify->name = name ? name : "nvifNotify";
    178	notify->flags = 0;
    179	atomic_set(&notify->putcnt, 1);
    180	notify->func = func;
    181	notify->data = NULL;
    182	notify->size = reply;
    183	if (work) {
    184		INIT_WORK(&notify->work, nvif_notify_work);
    185		set_bit(NVIF_NOTIFY_WORK, &notify->flags);
    186		notify->data = kmalloc(notify->size, GFP_KERNEL);
    187		if (!notify->data)
    188			goto done;
    189	}
    190
    191	if (!(args = kmalloc(sizeof(*args) + size, GFP_KERNEL)))
    192		goto done;
    193	args->ioctl.version = 0;
    194	args->ioctl.type = NVIF_IOCTL_V0_NTFY_NEW;
    195	args->ntfy.version = 0;
    196	args->ntfy.event = event;
    197	args->req.version = 0;
    198	args->req.reply = notify->size;
    199	args->req.route = 0;
    200	args->req.token = (unsigned long)(void *)notify;
    201
    202	memcpy(args->req.data, data, size);
    203	ret = nvif_object_ioctl(object, args, sizeof(*args) + size, NULL);
    204	notify->index = args->ntfy.index;
    205	kfree(args);
    206done:
    207	if (ret)
    208		nvif_notify_dtor(notify);
    209	return ret;
    210}