1 /* 2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $DragonFly: src/sys/kern/kern_xio.c,v 1.16 2008/05/09 07:24:45 dillon Exp $ 35 */ 36 /* 37 * Kernel XIO interface. An initialized XIO is basically a collection of 38 * appropriately held vm_page_t's. XIO buffers are vmspace agnostic and 39 * can represent userspace or kernelspace buffers, and can be passed to 40 * foreign threads outside of the originating vmspace. XIO buffers are 41 * not mapped into KVM and thus can be manipulated and passed around with 42 * very low overheads. 43 * 44 * The intent is for XIO to be used in the I/O path, VFS, CAPS, and other 45 * places that need to pass (possibly userspace) data between threads. 46 * 47 * TODO: check for busy page when modifying, check writeable. 48 */ 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/malloc.h> 53 #include <sys/proc.h> 54 #include <sys/vmmeter.h> 55 #include <sys/vnode.h> 56 #include <sys/xio.h> 57 #include <sys/sfbuf.h> 58 59 #include <vm/vm.h> 60 #include <vm/vm_param.h> 61 #include <sys/lock.h> 62 #include <vm/vm_kern.h> 63 #include <vm/pmap.h> 64 #include <vm/vm_map.h> 65 #include <vm/vm_object.h> 66 #include <vm/vm_page.h> 67 #include <vm/vm_pageout.h> 68 #include <vm/vm_pager.h> 69 #include <vm/vm_extern.h> 70 #include <vm/vm_page2.h> 71 72 /* 73 * Just do basic initialization of an empty XIO 74 */ 75 void 76 xio_init(xio_t xio) 77 { 78 xio->xio_flags = 0; 79 xio->xio_bytes = 0; 80 xio->xio_error = 0; 81 xio->xio_offset = 0; 82 xio->xio_npages = 0; 83 xio->xio_pages = xio->xio_internal_pages; 84 } 85 86 /* 87 * Initialize an XIO given a userspace buffer. 0 is returned on success, 88 * an error code on failure. The actual number of bytes that could be 89 * accomodated in the XIO will be stored in xio_bytes and the page offset 90 * will be stored in xio_offset. 91 */ 92 int 93 xio_init_ubuf(xio_t xio, void *ubase, size_t ubytes, int flags) 94 { 95 vm_offset_t addr; 96 vm_page_t m; 97 vm_page_t m0; 98 int error; 99 int i; 100 int n; 101 int vmprot; 102 103 addr = trunc_page((vm_offset_t)ubase); 104 xio->xio_flags = flags; 105 xio->xio_bytes = 0; 106 xio->xio_error = 0; 107 if (ubytes == 0) { 108 xio->xio_offset = 0; 109 xio->xio_npages = 0; 110 } else { 111 vmprot = (flags & XIOF_WRITE) ? VM_PROT_WRITE : VM_PROT_READ; 112 xio->xio_offset = (vm_offset_t)ubase & PAGE_MASK; 113 xio->xio_pages = xio->xio_internal_pages; 114 if ((n = PAGE_SIZE - xio->xio_offset) > ubytes) 115 n = ubytes; 116 m0 = NULL; 117 for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) { 118 m = vm_fault_page_quick(addr, vmprot, &error); 119 if (m == NULL) 120 break; 121 xio->xio_pages[i] = m; 122 ubytes -= n; 123 xio->xio_bytes += n; 124 if ((n = ubytes) > PAGE_SIZE) 125 n = PAGE_SIZE; 126 addr += PAGE_SIZE; 127 128 /* 129 * Check linearity, used by syslink to memory map DMA buffers. 130 */ 131 if (flags & XIOF_VMLINEAR) { 132 if (i == 0) { 133 m0 = m; 134 } else 135 if (m->object != m0->object || m->pindex != m0->pindex + i) { 136 error = EINVAL; 137 break; 138 } 139 } 140 } 141 xio->xio_npages = i; 142 143 /* 144 * If a failure occured clean out what we loaded and return EFAULT. 145 * Return 0 on success. Do not dirty the pages. 146 */ 147 if (i < XIO_INTERNAL_PAGES && n) { 148 xio->xio_flags &= ~XIOF_WRITE; 149 xio_release(xio); 150 xio->xio_error = EFAULT; 151 } 152 } 153 return(xio->xio_error); 154 } 155 156 /* 157 * Initialize an XIO given a kernelspace buffer. 0 is returned on success, 158 * an error code on failure. The actual number of bytes that could be 159 * accomodated in the XIO will be stored in xio_bytes and the page offset 160 * will be stored in xio_offset. 161 */ 162 int 163 xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes) 164 { 165 vm_offset_t addr; 166 vm_paddr_t paddr; 167 vm_page_t m; 168 int i; 169 int n; 170 171 addr = trunc_page((vm_offset_t)kbase); 172 xio->xio_flags = 0; 173 xio->xio_offset = (vm_offset_t)kbase & PAGE_MASK; 174 xio->xio_bytes = 0; 175 xio->xio_pages = xio->xio_internal_pages; 176 xio->xio_error = 0; 177 if ((n = PAGE_SIZE - xio->xio_offset) > kbytes) 178 n = kbytes; 179 for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) { 180 if ((paddr = pmap_kextract(addr)) == 0) 181 break; 182 crit_enter(); 183 m = PHYS_TO_VM_PAGE(paddr); 184 vm_page_hold(m); 185 crit_exit(); 186 xio->xio_pages[i] = m; 187 kbytes -= n; 188 xio->xio_bytes += n; 189 if ((n = kbytes) > PAGE_SIZE) 190 n = PAGE_SIZE; 191 addr += PAGE_SIZE; 192 } 193 xio->xio_npages = i; 194 195 /* 196 * If a failure occured clean out what we loaded and return EFAULT. 197 * Return 0 on success. 198 */ 199 if (i < XIO_INTERNAL_PAGES && n) { 200 xio_release(xio); 201 xio->xio_error = EFAULT; 202 } 203 return(xio->xio_error); 204 } 205 206 /* 207 * Initialize an XIO given an array of vm_page pointers. The caller is 208 * responsible for any modified state changes for the pages. 209 */ 210 int 211 xio_init_pages(xio_t xio, struct vm_page **mbase, int npages, int xflags) 212 { 213 int i; 214 215 KKASSERT(npages <= XIO_INTERNAL_PAGES); 216 217 xio->xio_flags = xflags; 218 xio->xio_offset = 0; 219 xio->xio_bytes = 0; 220 xio->xio_pages = xio->xio_internal_pages; 221 xio->xio_npages = npages; 222 xio->xio_error = 0; 223 crit_enter(); 224 for (i = 0; i < npages; ++i) { 225 vm_page_hold(mbase[i]); 226 xio->xio_pages[i] = mbase[i]; 227 } 228 crit_exit(); 229 return(0); 230 } 231 232 /* 233 * Cleanup an XIO so it can be destroyed. The pages associated with the 234 * XIO are released. 235 */ 236 void 237 xio_release(xio_t xio) 238 { 239 int i; 240 vm_page_t m; 241 242 crit_enter(); 243 for (i = 0; i < xio->xio_npages; ++i) { 244 m = xio->xio_pages[i]; 245 if (xio->xio_flags & XIOF_WRITE) 246 vm_page_dirty(m); 247 vm_page_unhold(m); 248 } 249 crit_exit(); 250 xio->xio_offset = 0; 251 xio->xio_npages = 0; 252 xio->xio_bytes = 0; 253 xio->xio_error = ENOBUFS; 254 } 255 256 /* 257 * Copy data between an XIO and a UIO. If the UIO represents userspace it 258 * must be relative to the current context. 259 * 260 * uoffset is the abstracted starting offset in the XIO, not the actual 261 * offset, and usually starts at 0. 262 * 263 * The XIO is not modified. The UIO is updated to reflect the copy. 264 * 265 * UIO_READ xio -> uio 266 * UIO_WRITE uio -> xio 267 */ 268 int 269 xio_uio_copy(xio_t xio, int uoffset, struct uio *uio, size_t *sizep) 270 { 271 size_t bytes; 272 int error; 273 274 bytes = xio->xio_bytes - uoffset; 275 if (bytes > uio->uio_resid) 276 bytes = uio->uio_resid; 277 KKASSERT(bytes >= 0); 278 error = uiomove_fromphys(xio->xio_pages, xio->xio_offset + uoffset, 279 bytes, uio); 280 if (error == 0) 281 *sizep = bytes; 282 else 283 *sizep = 0; 284 return(error); 285 } 286 287 /* 288 * Copy the specified number of bytes from the xio to a userland 289 * buffer. Return an error code or 0 on success. 290 * 291 * uoffset is the abstracted starting offset in the XIO, not the actual 292 * offset, and usually starts at 0. 293 * 294 * The XIO is not modified. 295 */ 296 int 297 xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes) 298 { 299 int i; 300 int n; 301 int error; 302 int offset; 303 vm_page_t m; 304 struct sf_buf *sf; 305 306 if (uoffset + bytes > xio->xio_bytes) 307 return(EFAULT); 308 309 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 310 if ((n = PAGE_SIZE - offset) > bytes) 311 n = bytes; 312 313 error = 0; 314 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 315 i < xio->xio_npages; 316 ++i 317 ) { 318 m = xio->xio_pages[i]; 319 sf = sf_buf_alloc(m, SFB_CPUPRIVATE); 320 error = copyout((char *)sf_buf_kva(sf) + offset, uptr, n); 321 sf_buf_free(sf); 322 if (error) 323 break; 324 bytes -= n; 325 uptr = (char *)uptr + n; 326 if (bytes == 0) 327 break; 328 if ((n = bytes) > PAGE_SIZE) 329 n = PAGE_SIZE; 330 offset = 0; 331 } 332 return(error); 333 } 334 335 /* 336 * Copy the specified number of bytes from the xio to a kernel 337 * buffer. Return an error code or 0 on success. 338 * 339 * uoffset is the abstracted starting offset in the XIO, not the actual 340 * offset, and usually starts at 0. 341 * 342 * The XIO is not modified. 343 */ 344 int 345 xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes) 346 { 347 int i; 348 int n; 349 int error; 350 int offset; 351 vm_page_t m; 352 struct sf_buf *sf; 353 354 if (bytes + uoffset > xio->xio_bytes) 355 return(EFAULT); 356 357 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 358 if ((n = PAGE_SIZE - offset) > bytes) 359 n = bytes; 360 361 error = 0; 362 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 363 i < xio->xio_npages; 364 ++i 365 ) { 366 m = xio->xio_pages[i]; 367 sf = sf_buf_alloc(m, SFB_CPUPRIVATE); 368 bcopy((char *)sf_buf_kva(sf) + offset, kptr, n); 369 sf_buf_free(sf); 370 bytes -= n; 371 kptr = (char *)kptr + n; 372 if (bytes == 0) 373 break; 374 if ((n = bytes) > PAGE_SIZE) 375 n = PAGE_SIZE; 376 offset = 0; 377 } 378 return(error); 379 } 380 381 /* 382 * Copy the specified number of bytes from userland to the xio. 383 * Return an error code or 0 on success. 384 * 385 * uoffset is the abstracted starting offset in the XIO, not the actual 386 * offset, and usually starts at 0. 387 * 388 * Data in pages backing the XIO will be modified. 389 */ 390 int 391 xio_copy_utox(xio_t xio, int uoffset, const void *uptr, int bytes) 392 { 393 int i; 394 int n; 395 int error; 396 int offset; 397 vm_page_t m; 398 struct sf_buf *sf; 399 400 if (uoffset + bytes > xio->xio_bytes) 401 return(EFAULT); 402 403 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 404 if ((n = PAGE_SIZE - offset) > bytes) 405 n = bytes; 406 407 error = 0; 408 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 409 i < xio->xio_npages; 410 ++i 411 ) { 412 m = xio->xio_pages[i]; 413 sf = sf_buf_alloc(m, SFB_CPUPRIVATE); 414 error = copyin(uptr, (char *)sf_buf_kva(sf) + offset, n); 415 sf_buf_free(sf); 416 if (error) 417 break; 418 bytes -= n; 419 uptr = (const char *)uptr + n; 420 if (bytes == 0) 421 break; 422 if ((n = bytes) > PAGE_SIZE) 423 n = PAGE_SIZE; 424 offset = 0; 425 } 426 return(error); 427 } 428 429 /* 430 * Copy the specified number of bytes from the kernel to the xio. 431 * Return an error code or 0 on success. 432 * 433 * uoffset is the abstracted starting offset in the XIO, not the actual 434 * offset, and usually starts at 0. 435 * 436 * Data in pages backing the XIO will be modified. 437 */ 438 int 439 xio_copy_ktox(xio_t xio, int uoffset, const void *kptr, int bytes) 440 { 441 int i; 442 int n; 443 int error; 444 int offset; 445 vm_page_t m; 446 struct sf_buf *sf; 447 448 if (uoffset + bytes > xio->xio_bytes) 449 return(EFAULT); 450 451 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 452 if ((n = PAGE_SIZE - offset) > bytes) 453 n = bytes; 454 455 error = 0; 456 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 457 i < xio->xio_npages; 458 ++i 459 ) { 460 m = xio->xio_pages[i]; 461 sf = sf_buf_alloc(m, SFB_CPUPRIVATE); 462 bcopy(kptr, (char *)sf_buf_kva(sf) + offset, n); 463 sf_buf_free(sf); 464 bytes -= n; 465 kptr = (const char *)kptr + n; 466 if (bytes == 0) 467 break; 468 if ((n = bytes) > PAGE_SIZE) 469 n = PAGE_SIZE; 470 offset = 0; 471 } 472 return(error); 473 } 474