/** * \file drm_scatter.c * IOCTLs to manage scatter/gather memory * * \author Gareth Hughes <gareth@valinux.com> */ /* * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com * * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. * All Rights Reserved. * * 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, distribute, sublicense, * and/or sell copies of the Software, and to 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 NONINFRINGEMENT. IN NO EVENT SHALL * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ #include <linux/vmalloc.h> #include <linux/slab.h> #include <drm/drmP.h> #define DEBUG_SCATTER 0 static inline void *drm_vmalloc_dma(unsigned long size) { #if defined(__powerpc__) && defined(CONFIG_NOT_COHERENT_CACHE) return __vmalloc(size, GFP_KERNEL, PAGE_KERNEL | _PAGE_NO_CACHE); #else return vmalloc_32(size); #endif } void drm_sg_cleanup(struct drm_sg_mem * entry) { struct page *page; int i; for (i = 0; i < entry->pages; i++) { page = entry->pagelist[i]; if (page) ClearPageReserved(page); } vfree(entry->virtual); kfree(entry->busaddr); kfree(entry->pagelist); kfree(entry); } #ifdef _LP64 # define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1))) #else # define ScatterHandle(x) (unsigned int)(x) #endif int drm_sg_alloc(struct drm_device *dev, struct drm_scatter_gather * request) { struct drm_sg_mem *entry; unsigned long pages, i, j; DRM_DEBUG("\n"); if (!drm_core_check_feature(dev, DRIVER_SG)) return -EINVAL; if (dev->sg) return -EINVAL; entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (!entry) return -ENOMEM; pages = (request->size + PAGE_SIZE - 1) / PAGE_SIZE; DRM_DEBUG("size=%ld pages=%ld\n", request->size, pages); entry->pages = pages; entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL); if (!entry->pagelist) { kfree(entry); return -ENOMEM; } entry->busaddr = kcalloc(pages, sizeof(*entry->busaddr), GFP_KERNEL); if (!entry->busaddr) { kfree(entry->pagelist); kfree(entry); return -ENOMEM; } entry->virtual = drm_vmalloc_dma(pages << PAGE_SHIFT); if (!entry->virtual) { kfree(entry->busaddr); kfree(entry->pagelist); kfree(entry); return -ENOMEM; } /* This also forces the mapping of COW pages, so our page list * will be valid. Please don't remove it... */ memset(entry->virtual, 0, pages << PAGE_SHIFT); entry->handle = ScatterHandle((unsigned long)entry->virtual); DRM_DEBUG("handle = %08lx\n", entry->handle); DRM_DEBUG("virtual = %p\n", entry->virtual); for (i = (unsigned long)entry->virtual, j = 0; j < pages; i += PAGE_SIZE, j++) { entry->pagelist[j] = vmalloc_to_page((void *)i); if (!entry->pagelist[j]) goto failed; SetPageReserved(entry->pagelist[j]); } request->handle = entry->handle; dev->sg = entry; #if DEBUG_SCATTER /* Verify that each page points to its virtual address, and vice * versa. */ { int error = 0; for (i = 0; i < pages; i++) { unsigned long *tmp; tmp = page_address(entry->pagelist[i]); for (j = 0; j < PAGE_SIZE / sizeof(unsigned long); j++, tmp++) { *tmp = 0xcafebabe; } tmp = (unsigned long *)((u8 *) entry->virtual + (PAGE_SIZE * i)); for (j = 0; j < PAGE_SIZE / sizeof(unsigned long); j++, tmp++) { if (*tmp != 0xcafebabe && error == 0) { error = 1; DRM_ERROR("Scatter allocation error, " "pagelist does not match " "virtual mapping\n"); } } tmp = page_address(entry->pagelist[i]); for (j = 0; j < PAGE_SIZE / sizeof(unsigned long); j++, tmp++) { *tmp = 0; } } if (error == 0) DRM_ERROR("Scatter allocation matches pagelist\n"); } #endif return 0; failed: drm_sg_cleanup(entry); return -ENOMEM; } int drm_sg_alloc_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_scatter_gather *request = data; return drm_sg_alloc(dev, request); } int drm_sg_free(struct drm_device *dev, void *data, struct drm_file *file_priv) { struct drm_scatter_gather *request = data; struct drm_sg_mem *entry; if (!drm_core_check_feature(dev, DRIVER_SG)) return -EINVAL; entry = dev->sg; dev->sg = NULL; if (!entry || entry->handle != request->handle) return -EINVAL; DRM_DEBUG("virtual = %p\n", entry->virtual); drm_sg_cleanup(entry); return 0; }