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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drm_scatter.c (5445B)


      1/*
      2 * \file drm_scatter.c
      3 * IOCTLs to manage scatter/gather memory
      4 *
      5 * \author Gareth Hughes <gareth@valinux.com>
      6 */
      7
      8/*
      9 * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
     10 *
     11 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
     12 * All Rights Reserved.
     13 *
     14 * Permission is hereby granted, free of charge, to any person obtaining a
     15 * copy of this software and associated documentation files (the "Software"),
     16 * to deal in the Software without restriction, including without limitation
     17 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     18 * and/or sell copies of the Software, and to permit persons to whom the
     19 * Software is furnished to do so, subject to the following conditions:
     20 *
     21 * The above copyright notice and this permission notice (including the next
     22 * paragraph) shall be included in all copies or substantial portions of the
     23 * Software.
     24 *
     25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     28 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
     29 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     30 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     31 * DEALINGS IN THE SOFTWARE.
     32 */
     33
     34#include <linux/mm.h>
     35#include <linux/slab.h>
     36#include <linux/vmalloc.h>
     37
     38#include <drm/drm.h>
     39#include <drm/drm_drv.h>
     40#include <drm/drm_print.h>
     41
     42#include "drm_legacy.h"
     43
     44#define DEBUG_SCATTER 0
     45
     46static void drm_sg_cleanup(struct drm_sg_mem * entry)
     47{
     48	struct page *page;
     49	int i;
     50
     51	for (i = 0; i < entry->pages; i++) {
     52		page = entry->pagelist[i];
     53		if (page)
     54			ClearPageReserved(page);
     55	}
     56
     57	vfree(entry->virtual);
     58
     59	kfree(entry->busaddr);
     60	kfree(entry->pagelist);
     61	kfree(entry);
     62}
     63
     64void drm_legacy_sg_cleanup(struct drm_device *dev)
     65{
     66	if (drm_core_check_feature(dev, DRIVER_SG) && dev->sg &&
     67	    drm_core_check_feature(dev, DRIVER_LEGACY)) {
     68		drm_sg_cleanup(dev->sg);
     69		dev->sg = NULL;
     70	}
     71}
     72#ifdef _LP64
     73# define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
     74#else
     75# define ScatterHandle(x) (unsigned int)(x)
     76#endif
     77
     78int drm_legacy_sg_alloc(struct drm_device *dev, void *data,
     79			struct drm_file *file_priv)
     80{
     81	struct drm_scatter_gather *request = data;
     82	struct drm_sg_mem *entry;
     83	unsigned long pages, i, j;
     84
     85	DRM_DEBUG("\n");
     86
     87	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
     88		return -EOPNOTSUPP;
     89
     90	if (!drm_core_check_feature(dev, DRIVER_SG))
     91		return -EOPNOTSUPP;
     92
     93	if (request->size > SIZE_MAX - PAGE_SIZE)
     94		return -EINVAL;
     95
     96	if (dev->sg)
     97		return -EINVAL;
     98
     99	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
    100	if (!entry)
    101		return -ENOMEM;
    102
    103	pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE;
    104	DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages);
    105
    106	entry->pages = pages;
    107	entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL);
    108	if (!entry->pagelist) {
    109		kfree(entry);
    110		return -ENOMEM;
    111	}
    112
    113	entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL);
    114	if (!entry->busaddr) {
    115		kfree(entry->pagelist);
    116		kfree(entry);
    117		return -ENOMEM;
    118	}
    119
    120	entry->virtual = vmalloc_32(pages << PAGE_SHIFT);
    121	if (!entry->virtual) {
    122		kfree(entry->busaddr);
    123		kfree(entry->pagelist);
    124		kfree(entry);
    125		return -ENOMEM;
    126	}
    127
    128	/* This also forces the mapping of COW pages, so our page list
    129	 * will be valid.  Please don't remove it...
    130	 */
    131	memset(entry->virtual, 0, pages << PAGE_SHIFT);
    132
    133	entry->handle = ScatterHandle((unsigned long)entry->virtual);
    134
    135	DRM_DEBUG("handle  = %08lx\n", entry->handle);
    136	DRM_DEBUG("virtual = %p\n", entry->virtual);
    137
    138	for (i = (unsigned long)entry->virtual, j = 0; j < pages;
    139	     i += PAGE_SIZE, j++) {
    140		entry->pagelist[j] = vmalloc_to_page((void *)i);
    141		if (!entry->pagelist[j])
    142			goto failed;
    143		SetPageReserved(entry->pagelist[j]);
    144	}
    145
    146	request->handle = entry->handle;
    147
    148	dev->sg = entry;
    149
    150#if DEBUG_SCATTER
    151	/* Verify that each page points to its virtual address, and vice
    152	 * versa.
    153	 */
    154	{
    155		int error = 0;
    156
    157		for (i = 0; i < pages; i++) {
    158			unsigned long *tmp;
    159
    160			tmp = page_address(entry->pagelist[i]);
    161			for (j = 0;
    162			     j < PAGE_SIZE / sizeof(unsigned long);
    163			     j++, tmp++) {
    164				*tmp = 0xcafebabe;
    165			}
    166			tmp = (unsigned long *)((u8 *) entry->virtual +
    167						(PAGE_SIZE * i));
    168			for (j = 0;
    169			     j < PAGE_SIZE / sizeof(unsigned long);
    170			     j++, tmp++) {
    171				if (*tmp != 0xcafebabe && error == 0) {
    172					error = 1;
    173					DRM_ERROR("Scatter allocation error, "
    174						  "pagelist does not match "
    175						  "virtual mapping\n");
    176				}
    177			}
    178			tmp = page_address(entry->pagelist[i]);
    179			for (j = 0;
    180			     j < PAGE_SIZE / sizeof(unsigned long);
    181			     j++, tmp++) {
    182				*tmp = 0;
    183			}
    184		}
    185		if (error == 0)
    186			DRM_ERROR("Scatter allocation matches pagelist\n");
    187	}
    188#endif
    189
    190	return 0;
    191
    192      failed:
    193	drm_sg_cleanup(entry);
    194	return -ENOMEM;
    195}
    196
    197int drm_legacy_sg_free(struct drm_device *dev, void *data,
    198		       struct drm_file *file_priv)
    199{
    200	struct drm_scatter_gather *request = data;
    201	struct drm_sg_mem *entry;
    202
    203	if (!drm_core_check_feature(dev, DRIVER_LEGACY))
    204		return -EOPNOTSUPP;
    205
    206	if (!drm_core_check_feature(dev, DRIVER_SG))
    207		return -EOPNOTSUPP;
    208
    209	entry = dev->sg;
    210	dev->sg = NULL;
    211
    212	if (!entry || entry->handle != request->handle)
    213		return -EINVAL;
    214
    215	DRM_DEBUG("virtual  = %p\n", entry->virtual);
    216
    217	drm_sg_cleanup(entry);
    218
    219	return 0;
    220}