linux/drivers/gpu/drm/nouveau/nvif/notify.c
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   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_fini(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_init(struct nvif_object *object, int (*func)(struct nvif_notify *),
 166                 bool work, u8 event, void *data, u32 size, u32 reply,
 167                 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->flags = 0;
 178        atomic_set(&notify->putcnt, 1);
 179        notify->func = func;
 180        notify->data = NULL;
 181        notify->size = reply;
 182        if (work) {
 183                INIT_WORK(&notify->work, nvif_notify_work);
 184                set_bit(NVIF_NOTIFY_WORK, &notify->flags);
 185                notify->data = kmalloc(notify->size, GFP_KERNEL);
 186                if (!notify->data)
 187                        goto done;
 188        }
 189
 190        if (!(args = kmalloc(sizeof(*args) + size, GFP_KERNEL)))
 191                goto done;
 192        args->ioctl.version = 0;
 193        args->ioctl.type = NVIF_IOCTL_V0_NTFY_NEW;
 194        args->ntfy.version = 0;
 195        args->ntfy.event = event;
 196        args->req.version = 0;
 197        args->req.reply = notify->size;
 198        args->req.route = 0;
 199        args->req.token = (unsigned long)(void *)notify;
 200
 201        memcpy(args->req.data, data, size);
 202        ret = nvif_object_ioctl(object, args, sizeof(*args) + size, NULL);
 203        notify->index = args->ntfy.index;
 204        kfree(args);
 205done:
 206        if (ret)
 207                nvif_notify_fini(notify);
 208        return ret;
 209}
 210