Quelle  vmwgfx_gmrid_manager.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0 OR MIT
/**************************************************************************
 *
 * Copyright 2007-2010 VMware, Inc., Palo Alto, CA., USA
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
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 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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 *
 **************************************************************************/
/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */

#include "vmwgfx_drv.h"
#include <drm/ttm/ttm_placement.h>
#include <linux/idr.h>
#include <linux/spinlock.h>
#include <linux/kernel.h>

struct vmwgfx_gmrid_man {
 struct ttm_resource_manager manager;
 spinlock_t lock;
 struct ida gmr_ida;
 uint32_t max_gmr_ids;
 uint32_t max_gmr_pages;
 uint32_t used_gmr_pages;
 uint8_t type;
};

static struct vmwgfx_gmrid_man *to_gmrid_manager(struct ttm_resource_manager *man)
{
 return container_of(man, struct vmwgfx_gmrid_man, manager);
}

static int vmw_gmrid_man_get_node(struct ttm_resource_manager *man,
      struct ttm_buffer_object *bo,
      const struct ttm_place *place,
      struct ttm_resource **res)
{
 struct vmwgfx_gmrid_man *gman = to_gmrid_manager(man);
 int id;

 *res = kmalloc(sizeof(**res), GFP_KERNEL);
 if (!*res)
  return -ENOMEM;

 ttm_resource_init(bo, place, *res);

 id = ida_alloc_max(&gman->gmr_ida, gman->max_gmr_ids - 1, GFP_KERNEL);
 if (id < 0) {
  ttm_resource_fini(man, *res);
  kfree(*res);
  return id;
 }

 spin_lock(&gman->lock);

 if (gman->max_gmr_pages > 0) {
  gman->used_gmr_pages += PFN_UP((*res)->size);
  /*
 * Because the graphics memory is a soft limit we can try to
 * expand it instead of letting the userspace apps crash.
 * We're just going to have a sane limit (half of RAM)
 * on the number of MOB's that we create and will try to keep
 * the system running until we reach that.
 */
  if (unlikely(gman->used_gmr_pages > gman->max_gmr_pages)) {
   const unsigned long max_graphics_pages = totalram_pages() / 2;
   uint32_t new_max_pages = 0;

   DRM_WARN("vmwgfx: mob memory overflow. Consider increasing guest RAM and graphicsMemory.\n");
   vmw_host_printf("vmwgfx, warning: mob memory overflow. Consider increasing guest RAM and graphicsMemory.\n");

   if (gman->max_gmr_pages > (max_graphics_pages / 2)) {
    DRM_WARN("vmwgfx: guest requires more than half of RAM for graphics.\n");
    new_max_pages = max_graphics_pages;
   } else
    new_max_pages = gman->max_gmr_pages * 2;
   if (new_max_pages > gman->max_gmr_pages && new_max_pages >= gman->used_gmr_pages) {
    DRM_WARN("vmwgfx: increasing guest mob limits to %u KiB.\n",
      ((new_max_pages) << (PAGE_SHIFT - 10)));

    gman->max_gmr_pages = new_max_pages;
   } else {
    char buf[256];
    snprintf(buf, sizeof(buf),
      "vmwgfx, error: guest graphics is out of memory (mob limit at: %u KiB).\n",
      ((gman->max_gmr_pages) << (PAGE_SHIFT - 10)));
    vmw_host_printf(buf);
    DRM_WARN("%s", buf);
    goto nospace;
   }
  }
 }

 (*res)->start = id;

 spin_unlock(&gman->lock);
 return 0;

nospace:
 gman->used_gmr_pages -= PFN_UP((*res)->size);
 spin_unlock(&gman->lock);
 ida_free(&gman->gmr_ida, id);
 ttm_resource_fini(man, *res);
 kfree(*res);
 return -ENOSPC;
}

static void vmw_gmrid_man_put_node(struct ttm_resource_manager *man,
       struct ttm_resource *res)
{
 struct vmwgfx_gmrid_man *gman = to_gmrid_manager(man);

 ida_free(&gman->gmr_ida, res->start);
 spin_lock(&gman->lock);
 gman->used_gmr_pages -= PFN_UP(res->size);
 spin_unlock(&gman->lock);
 ttm_resource_fini(man, res);
 kfree(res);
}

static void vmw_gmrid_man_debug(struct ttm_resource_manager *man,
    struct drm_printer *printer)
{
 struct vmwgfx_gmrid_man *gman = to_gmrid_manager(man);

 BUG_ON(gman->type != VMW_PL_GMR && gman->type != VMW_PL_MOB);

 drm_printf(printer, "%s's used: %u pages, max: %u pages, %u id's\n",
     (gman->type == VMW_PL_MOB) ? "Mob" : "GMR",
     gman->used_gmr_pages, gman->max_gmr_pages, gman->max_gmr_ids);
}

static const struct ttm_resource_manager_func vmw_gmrid_manager_func;

int vmw_gmrid_man_init(struct vmw_private *dev_priv, int type)
{
 struct ttm_resource_manager *man;
 struct vmwgfx_gmrid_man *gman =
  kzalloc(sizeof(*gman), GFP_KERNEL);

 if (unlikely(!gman))
  return -ENOMEM;

 man = &gman->manager;

 man->func = &vmw_gmrid_manager_func;
 man->use_tt = true;
 ttm_resource_manager_init(man, &dev_priv->bdev, 0);
 spin_lock_init(&gman->lock);
 gman->used_gmr_pages = 0;
 ida_init(&gman->gmr_ida);
 gman->type = type;

 switch (type) {
 case VMW_PL_GMR:
  gman->max_gmr_ids = dev_priv->max_gmr_ids;
  gman->max_gmr_pages = dev_priv->max_gmr_pages;
  break;
 case VMW_PL_MOB:
  gman->max_gmr_ids = VMWGFX_NUM_MOB;
  gman->max_gmr_pages = dev_priv->max_mob_pages;
  break;
 default:
  BUG();
 }
 ttm_set_driver_manager(&dev_priv->bdev, type, &gman->manager);
 ttm_resource_manager_set_used(man, true);
 return 0;
}

void vmw_gmrid_man_fini(struct vmw_private *dev_priv, int type)
{
 struct ttm_resource_manager *man = ttm_manager_type(&dev_priv->bdev, type);
 struct vmwgfx_gmrid_man *gman = to_gmrid_manager(man);

 ttm_resource_manager_set_used(man, false);

 ttm_resource_manager_evict_all(&dev_priv->bdev, man);

 ttm_resource_manager_cleanup(man);

 ttm_set_driver_manager(&dev_priv->bdev, type, NULL);
 ida_destroy(&gman->gmr_ida);
 kfree(gman);

}

static const struct ttm_resource_manager_func vmw_gmrid_manager_func = {
 .alloc = vmw_gmrid_man_get_node,
 .free = vmw_gmrid_man_put_node,
 .debug = vmw_gmrid_man_debug
};