1/* $NetBSD: huge_gem_object.c,v 1.2 2021/12/18 23:45:30 riastradh Exp $ */ 2 3/* 4 * SPDX-License-Identifier: MIT 5 * 6 * Copyright �� 2016 Intel Corporation 7 */ 8 9#include <sys/cdefs.h> 10__KERNEL_RCSID(0, "$NetBSD: huge_gem_object.c,v 1.2 2021/12/18 23:45:30 riastradh Exp $"); 11 12#include "i915_scatterlist.h" 13 14#include "huge_gem_object.h" 15 16static void huge_free_pages(struct drm_i915_gem_object *obj, 17 struct sg_table *pages) 18{ 19 unsigned long nreal = obj->scratch / PAGE_SIZE; 20 struct sgt_iter sgt_iter; 21 struct page *page; 22 23 for_each_sgt_page(page, sgt_iter, pages) { 24 __free_page(page); 25 if (!--nreal) 26 break; 27 } 28 29 sg_free_table(pages); 30 kfree(pages); 31} 32 33static int huge_get_pages(struct drm_i915_gem_object *obj) 34{ 35#define GFP (GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY) 36 const unsigned long nreal = obj->scratch / PAGE_SIZE; 37 const unsigned long npages = obj->base.size / PAGE_SIZE; 38 struct scatterlist *sg, *src, *end; 39 struct sg_table *pages; 40 unsigned long n; 41 42 pages = kmalloc(sizeof(*pages), GFP); 43 if (!pages) 44 return -ENOMEM; 45 46 if (sg_alloc_table(pages, npages, GFP)) { 47 kfree(pages); 48 return -ENOMEM; 49 } 50 51 sg = pages->sgl; 52 for (n = 0; n < nreal; n++) { 53 struct page *page; 54 55 page = alloc_page(GFP | __GFP_HIGHMEM); 56 if (!page) { 57 sg_mark_end(sg); 58 goto err; 59 } 60 61 sg_set_page(sg, page, PAGE_SIZE, 0); 62 sg = __sg_next(sg); 63 } 64 if (nreal < npages) { 65 for (end = sg, src = pages->sgl; sg; sg = __sg_next(sg)) { 66 sg_set_page(sg, sg_page(src), PAGE_SIZE, 0); 67 src = __sg_next(src); 68 if (src == end) 69 src = pages->sgl; 70 } 71 } 72 73 if (i915_gem_gtt_prepare_pages(obj, pages)) 74 goto err; 75 76 __i915_gem_object_set_pages(obj, pages, PAGE_SIZE); 77 78 return 0; 79 80err: 81 huge_free_pages(obj, pages); 82 return -ENOMEM; 83#undef GFP 84} 85 86static void huge_put_pages(struct drm_i915_gem_object *obj, 87 struct sg_table *pages) 88{ 89 i915_gem_gtt_finish_pages(obj, pages); 90 huge_free_pages(obj, pages); 91 92 obj->mm.dirty = false; 93} 94 95static const struct drm_i915_gem_object_ops huge_ops = { 96 .flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE | 97 I915_GEM_OBJECT_IS_SHRINKABLE, 98 .get_pages = huge_get_pages, 99 .put_pages = huge_put_pages, 100}; 101 102struct drm_i915_gem_object * 103huge_gem_object(struct drm_i915_private *i915, 104 phys_addr_t phys_size, 105 dma_addr_t dma_size) 106{ 107 static struct lock_class_key lock_class; 108 struct drm_i915_gem_object *obj; 109 unsigned int cache_level; 110 111 GEM_BUG_ON(!phys_size || phys_size > dma_size); 112 GEM_BUG_ON(!IS_ALIGNED(phys_size, PAGE_SIZE)); 113 GEM_BUG_ON(!IS_ALIGNED(dma_size, I915_GTT_PAGE_SIZE)); 114 115 if (overflows_type(dma_size, obj->base.size)) 116 return ERR_PTR(-E2BIG); 117 118 obj = i915_gem_object_alloc(); 119 if (!obj) 120 return ERR_PTR(-ENOMEM); 121 122 drm_gem_private_object_init(&i915->drm, &obj->base, dma_size); 123 i915_gem_object_init(obj, &huge_ops, &lock_class); 124 125 obj->read_domains = I915_GEM_DOMAIN_CPU; 126 obj->write_domain = I915_GEM_DOMAIN_CPU; 127 cache_level = HAS_LLC(i915) ? I915_CACHE_LLC : I915_CACHE_NONE; 128 i915_gem_object_set_cache_coherency(obj, cache_level); 129 obj->scratch = phys_size; 130 131 return obj; 132} 133