1 /*- 2 * Copyright (c) 2011 The FreeBSD Foundation 3 * Copyright (c) 2014-2020 François Tigeot <ftigeot@wolfpond.org> 4 * All rights reserved. 5 * 6 * Portions of this software were developed by Konstantin Belousov 7 * under sponsorship from the FreeBSD Foundation. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 #include <vm/vm.h> 33 #include <vm/vm_page.h> 34 #include <vm/vm_page2.h> 35 #include <vm/vm_pager.h> 36 #include <vm/vm_extern.h> 37 38 #include <linux/err.h> 39 #include <linux/shmem_fs.h> 40 41 /* 42 * This code is typically called with a normal VM object to access 43 * data from a userspace shared memory mapping. However, handle the 44 * case where it might be called with OBJT_MGTDEVICE anyway. 45 */ 46 struct page * 47 shmem_read_mapping_page(vm_object_t object, vm_pindex_t pindex) 48 { 49 vm_page_t m; 50 int rv; 51 52 VM_OBJECT_LOCK(object); 53 if (object->type == OBJT_MGTDEVICE) { 54 m = NULL; 55 rv = vm_pager_get_page(object, pindex, &m, 1); 56 if (m == NULL) 57 return ERR_PTR(-ENOMEM); 58 if (rv != VM_PAGER_OK) { 59 vm_page_free(m); 60 return ERR_PTR(-ENOMEM); 61 } 62 } else { 63 m = vm_page_grab(object, pindex, 64 VM_ALLOC_NORMAL | VM_ALLOC_RETRY); 65 if (m->valid != VM_PAGE_BITS_ALL) { 66 if (vm_pager_has_page(object, pindex)) { 67 rv = vm_pager_get_page(object, pindex, &m, 1); 68 m = vm_page_lookup(object, pindex); 69 if (m == NULL) 70 return ERR_PTR(-ENOMEM); 71 if (rv != VM_PAGER_OK) { 72 vm_page_free(m); 73 return ERR_PTR(-ENOMEM); 74 } 75 } else { 76 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 77 m->valid = VM_PAGE_BITS_ALL; 78 m->dirty = 0; 79 } 80 } 81 } 82 vm_page_wire(m); /* put_page() undoes this */ 83 vm_page_wakeup(m); 84 VM_OBJECT_UNLOCK(object); 85 86 return (struct page *)m; 87 } 88 89 struct page * 90 shmem_read_mapping_page_gfp(struct vm_object *mapping, 91 pgoff_t index, gfp_t gfp_mask) 92 { 93 return shmem_read_mapping_page(mapping, index); 94 } 95 96 #include <linux/fs.h> 97 98 int 99 pagecache_write_begin(struct vm_object *obj, struct address_space *mapping, 100 loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) 101 { 102 *pagep = shmem_read_mapping_page(obj, OFF_TO_IDX(pos)); 103 104 return 0; 105 } 106 107 /* This is really shmem_write_end() for the i915 gem code */ 108 int 109 pagecache_write_end(struct vm_object *obj, struct address_space *mapping, 110 loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) 111 { 112 set_page_dirty(page); 113 put_page(page); 114 115 return copied; 116 } 117 118 /* 119 * userptr support 120 */ 121 long 122 get_user_pages(unsigned long start, unsigned long nr_pages, 123 unsigned int gup_flags, struct page **pages, 124 struct vm_area_struct **vmas) 125 { 126 thread_t td; 127 vm_page_t m; 128 vm_map_t map; 129 long i; 130 int error; 131 int busied; 132 int fault_type = VM_PROT_READ; 133 134 /* returning related vmas not yet supported */ 135 td = curthread; 136 KKASSERT(vmas == NULL); 137 KKASSERT(td->td_proc == NULL); 138 map = &td->td_proc->p_vmspace->vm_map; 139 140 if (gup_flags) 141 fault_type |= VM_PROT_WRITE; 142 143 error = 0; 144 for (i = 0; i < nr_pages; ++i) { 145 m = vm_fault_page(map, start + i * PAGE_SIZE, 146 fault_type, VM_FAULT_NORMAL, 147 &error, &busied); 148 if (error) 149 break; 150 if (busied) { 151 vm_page_wire(m); 152 } else { 153 vm_page_busy_wait(m, TRUE, "drmgup"); 154 vm_page_wire(m); 155 vm_page_unhold(m); 156 } 157 vm_page_wakeup(m); 158 pages[i] = (void *)m; 159 } 160 if (error) { 161 while (--i >= 0) { 162 put_page(pages[i]); 163 pages[i] = NULL; 164 } 165 i = -error; 166 } 167 return i; 168 } 169 170 void 171 release_pages(struct page **pages, unsigned long nr_pages) 172 { 173 while (nr_pages > 0) { 174 --nr_pages; 175 put_page(pages[nr_pages]); 176 pages[nr_pages] = NULL; 177 } 178 } 179