drivers/net/ethernet/mellanox/mlx5/core/uar.c

   1 /*
   2  * Copyright (c) 2013-2015, Mellanox Technologies. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <linux/kernel.h>
  34 #include <linux/module.h>
  35 #include <linux/io-mapping.h>
  36 #include <linux/mlx5/driver.h>
  37 #include "mlx5_core.h"
  38
  39 int mlx5_cmd_alloc_uar(struct mlx5_core_dev *dev, u32 *uarn)
  40 {
  41         u32 out[MLX5_ST_SZ_DW(alloc_uar_out)] = {};
  42         u32 in[MLX5_ST_SZ_DW(alloc_uar_in)] = {};
  43         int err;
  44
  45         MLX5_SET(alloc_uar_in, in, opcode, MLX5_CMD_OP_ALLOC_UAR);
  46         err = mlx5_cmd_exec_inout(dev, alloc_uar, in, out);
  47         if (!err)
  48                 *uarn = MLX5_GET(alloc_uar_out, out, uar);
  49         return err;
  50 }
  51 EXPORT_SYMBOL(mlx5_cmd_alloc_uar);
  52
  53 int mlx5_cmd_free_uar(struct mlx5_core_dev *dev, u32 uarn)
  54 {
  55         u32 in[MLX5_ST_SZ_DW(dealloc_uar_in)] = {};
  56
  57         MLX5_SET(dealloc_uar_in, in, opcode, MLX5_CMD_OP_DEALLOC_UAR);
  58         MLX5_SET(dealloc_uar_in, in, uar, uarn);
  59         return mlx5_cmd_exec_in(dev, dealloc_uar, in);
  60 }
  61 EXPORT_SYMBOL(mlx5_cmd_free_uar);
  62
  63 static int uars_per_sys_page(struct mlx5_core_dev *mdev)
  64 {
  65         if (MLX5_CAP_GEN(mdev, uar_4k))
  66                 return MLX5_CAP_GEN(mdev, num_of_uars_per_page);
  67
  68         return 1;
  69 }
  70
  71 static u64 uar2pfn(struct mlx5_core_dev *mdev, u32 index)
  72 {
  73         u32 system_page_index;
  74
  75         if (MLX5_CAP_GEN(mdev, uar_4k))
  76                 system_page_index = index >> (PAGE_SHIFT - MLX5_ADAPTER_PAGE_SHIFT);
  77         else
  78                 system_page_index = index;
  79
  80         return (mdev->bar_addr >> PAGE_SHIFT) + system_page_index;
  81 }
  82
  83 static void up_rel_func(struct kref *kref)
  84 {
  85         struct mlx5_uars_page *up = container_of(kref, struct mlx5_uars_page, ref_count);
  86
  87         list_del(&up->list);
  88         iounmap(up->map);
  89         if (mlx5_cmd_free_uar(up->mdev, up->index))
  90                 mlx5_core_warn(up->mdev, "failed to free uar index %d\n", up->index);
  91         bitmap_free(up->reg_bitmap);
  92         bitmap_free(up->fp_bitmap);
  93         kfree(up);
  94 }
  95
  96 static struct mlx5_uars_page *alloc_uars_page(struct mlx5_core_dev *mdev,
  97                                               bool map_wc)
  98 {
  99         struct mlx5_uars_page *up;
 100         int err = -ENOMEM;
 101         phys_addr_t pfn;
 102         int bfregs;
 103         int i;
 104
 105         bfregs = uars_per_sys_page(mdev) * MLX5_BFREGS_PER_UAR;
 106         up = kzalloc(sizeof(*up), GFP_KERNEL);
 107         if (!up)
 108                 return ERR_PTR(err);
 109
 110         up->mdev = mdev;
 111         up->reg_bitmap = bitmap_zalloc(bfregs, GFP_KERNEL);
 112         if (!up->reg_bitmap)
 113                 goto error1;
 114
 115         up->fp_bitmap = bitmap_zalloc(bfregs, GFP_KERNEL);
 116         if (!up->fp_bitmap)
 117                 goto error1;
 118
 119         for (i = 0; i < bfregs; i++)
 120                 if ((i % MLX5_BFREGS_PER_UAR) < MLX5_NON_FP_BFREGS_PER_UAR)
 121                         set_bit(i, up->reg_bitmap);
 122                 else
 123                         set_bit(i, up->fp_bitmap);
 124
 125         up->bfregs = bfregs;
 126         up->fp_avail = bfregs * MLX5_FP_BFREGS_PER_UAR / MLX5_BFREGS_PER_UAR;
 127         up->reg_avail = bfregs * MLX5_NON_FP_BFREGS_PER_UAR / MLX5_BFREGS_PER_UAR;
 128
 129         err = mlx5_cmd_alloc_uar(mdev, &up->index);
 130         if (err) {
 131                 mlx5_core_warn(mdev, "mlx5_cmd_alloc_uar() failed, %d\n", err);
 132                 goto error1;
 133         }
 134
 135         pfn = uar2pfn(mdev, up->index);
 136         if (map_wc) {
 137                 up->map = ioremap_wc(pfn << PAGE_SHIFT, PAGE_SIZE);
 138                 if (!up->map) {
 139                         err = -EAGAIN;
 140                         goto error2;
 141                 }
 142         } else {
 143                 up->map = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
 144                 if (!up->map) {
 145                         err = -ENOMEM;
 146                         goto error2;
 147                 }
 148         }
 149         kref_init(&up->ref_count);
 150         mlx5_core_dbg(mdev, "allocated UAR page: index %d, total bfregs %d\n",
 151                       up->index, up->bfregs);
 152         return up;
 153
 154 error2:
 155         if (mlx5_cmd_free_uar(mdev, up->index))
 156                 mlx5_core_warn(mdev, "failed to free uar index %d\n", up->index);
 157 error1:
 158         bitmap_free(up->fp_bitmap);
 159         bitmap_free(up->reg_bitmap);
 160         kfree(up);
 161         return ERR_PTR(err);
 162 }
 163
 164 struct mlx5_uars_page *mlx5_get_uars_page(struct mlx5_core_dev *mdev)
 165 {
 166         struct mlx5_uars_page *ret;
 167
 168         mutex_lock(&mdev->priv.bfregs.reg_head.lock);
 169         if (!list_empty(&mdev->priv.bfregs.reg_head.list)) {
 170                 ret = list_first_entry(&mdev->priv.bfregs.reg_head.list,
 171                                        struct mlx5_uars_page, list);
 172                 kref_get(&ret->ref_count);
 173                 goto out;
 174         }
 175         ret = alloc_uars_page(mdev, false);
 176         if (IS_ERR(ret))
 177                 goto out;
 178         list_add(&ret->list, &mdev->priv.bfregs.reg_head.list);
 179 out:
 180         mutex_unlock(&mdev->priv.bfregs.reg_head.lock);
 181
 182         return ret;
 183 }
 184 EXPORT_SYMBOL(mlx5_get_uars_page);
 185
 186 void mlx5_put_uars_page(struct mlx5_core_dev *mdev, struct mlx5_uars_page *up)
 187 {
 188         mutex_lock(&mdev->priv.bfregs.reg_head.lock);
 189         kref_put(&up->ref_count, up_rel_func);
 190         mutex_unlock(&mdev->priv.bfregs.reg_head.lock);
 191 }
 192 EXPORT_SYMBOL(mlx5_put_uars_page);
 193
 194 static unsigned long map_offset(struct mlx5_core_dev *mdev, int dbi)
 195 {
 196         /* return the offset in bytes from the start of the page to the
 197          * blue flame area of the UAR
 198          */
 199         return dbi / MLX5_BFREGS_PER_UAR * MLX5_ADAPTER_PAGE_SIZE +
 200                (dbi % MLX5_BFREGS_PER_UAR) *
 201                (1 << MLX5_CAP_GEN(mdev, log_bf_reg_size)) + MLX5_BF_OFFSET;
 202 }
 203
 204 static int alloc_bfreg(struct mlx5_core_dev *mdev, struct mlx5_sq_bfreg *bfreg,
 205                        bool map_wc, bool fast_path)
 206 {
 207         struct mlx5_bfreg_data *bfregs;
 208         struct mlx5_uars_page *up;
 209         struct list_head *head;
 210         unsigned long *bitmap;
 211         unsigned int *avail;
 212         struct mutex *lock;  /* pointer to right mutex */
 213         int dbi;
 214
 215         bfregs = &mdev->priv.bfregs;
 216         if (map_wc) {
 217                 head = &bfregs->wc_head.list;
 218                 lock = &bfregs->wc_head.lock;
 219         } else {
 220                 head = &bfregs->reg_head.list;
 221                 lock = &bfregs->reg_head.lock;
 222         }
 223         mutex_lock(lock);
 224         if (list_empty(head)) {
 225                 up = alloc_uars_page(mdev, map_wc);
 226                 if (IS_ERR(up)) {
 227                         mutex_unlock(lock);
 228                         return PTR_ERR(up);
 229                 }
 230                 list_add(&up->list, head);
 231         } else {
 232                 up = list_entry(head->next, struct mlx5_uars_page, list);
 233                 kref_get(&up->ref_count);
 234         }
 235         if (fast_path) {
 236                 bitmap = up->fp_bitmap;
 237                 avail = &up->fp_avail;
 238         } else {
 239                 bitmap = up->reg_bitmap;
 240                 avail = &up->reg_avail;
 241         }
 242         dbi = find_first_bit(bitmap, up->bfregs);
 243         clear_bit(dbi, bitmap);
 244         (*avail)--;
 245         if (!(*avail))
 246                 list_del(&up->list);
 247
 248         bfreg->map = up->map + map_offset(mdev, dbi);
 249         bfreg->up = up;
 250         bfreg->wc = map_wc;
 251         bfreg->index = up->index + dbi / MLX5_BFREGS_PER_UAR;
 252         mutex_unlock(lock);
 253
 254         return 0;
 255 }
 256
 257 int mlx5_alloc_bfreg(struct mlx5_core_dev *mdev, struct mlx5_sq_bfreg *bfreg,
 258                      bool map_wc, bool fast_path)
 259 {
 260         int err;
 261
 262         err = alloc_bfreg(mdev, bfreg, map_wc, fast_path);
 263         if (!err)
 264                 return 0;
 265
 266         if (err == -EAGAIN && map_wc)
 267                 return alloc_bfreg(mdev, bfreg, false, fast_path);
 268
 269         return err;
 270 }
 271 EXPORT_SYMBOL(mlx5_alloc_bfreg);
 272
 273 static unsigned int addr_to_dbi_in_syspage(struct mlx5_core_dev *dev,
 274                                            struct mlx5_uars_page *up,
 275                                            struct mlx5_sq_bfreg *bfreg)
 276 {
 277         unsigned int uar_idx;
 278         unsigned int bfreg_idx;
 279         unsigned int bf_reg_size;
 280
 281         bf_reg_size = 1 << MLX5_CAP_GEN(dev, log_bf_reg_size);
 282
 283         uar_idx = (bfreg->map - up->map) >> MLX5_ADAPTER_PAGE_SHIFT;
 284         bfreg_idx = (((uintptr_t)bfreg->map % MLX5_ADAPTER_PAGE_SIZE) - MLX5_BF_OFFSET) / bf_reg_size;
 285
 286         return uar_idx * MLX5_BFREGS_PER_UAR + bfreg_idx;
 287 }
 288
 289 void mlx5_free_bfreg(struct mlx5_core_dev *mdev, struct mlx5_sq_bfreg *bfreg)
 290 {
 291         struct mlx5_bfreg_data *bfregs;
 292         struct mlx5_uars_page *up;
 293         struct mutex *lock; /* pointer to right mutex */
 294         unsigned int dbi;
 295         bool fp;
 296         unsigned int *avail;
 297         unsigned long *bitmap;
 298         struct list_head *head;
 299
 300         bfregs = &mdev->priv.bfregs;
 301         if (bfreg->wc) {
 302                 head = &bfregs->wc_head.list;
 303                 lock = &bfregs->wc_head.lock;
 304         } else {
 305                 head = &bfregs->reg_head.list;
 306                 lock = &bfregs->reg_head.lock;
 307         }
 308         up = bfreg->up;
 309         dbi = addr_to_dbi_in_syspage(mdev, up, bfreg);
 310         fp = (dbi % MLX5_BFREGS_PER_UAR) >= MLX5_NON_FP_BFREGS_PER_UAR;
 311         if (fp) {
 312                 avail = &up->fp_avail;
 313                 bitmap = up->fp_bitmap;
 314         } else {
 315                 avail = &up->reg_avail;
 316                 bitmap = up->reg_bitmap;
 317         }
 318         mutex_lock(lock);
 319         (*avail)++;
 320         set_bit(dbi, bitmap);
 321         if (*avail == 1)
 322                 list_add_tail(&up->list, head);
 323
 324         kref_put(&up->ref_count, up_rel_func);
 325         mutex_unlock(lock);
 326 }
 327 EXPORT_SYMBOL(mlx5_free_bfreg);