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 58 #include <cpu/lwbuf.h> 59 60 #include <vm/vm.h> 61 #include <vm/vm_param.h> 62 #include <sys/lock.h> 63 #include <vm/vm_kern.h> 64 #include <vm/pmap.h> 65 #include <vm/vm_map.h> 66 #include <vm/vm_object.h> 67 #include <vm/vm_page.h> 68 #include <vm/vm_pageout.h> 69 #include <vm/vm_pager.h> 70 #include <vm/vm_extern.h> 71 #include <vm/vm_page2.h> 72 73 /* 74 * Just do basic initialization of an empty XIO 75 */ 76 void 77 xio_init(xio_t xio) 78 { 79 xio->xio_flags = 0; 80 xio->xio_bytes = 0; 81 xio->xio_error = 0; 82 xio->xio_offset = 0; 83 xio->xio_npages = 0; 84 xio->xio_pages = xio->xio_internal_pages; 85 } 86 87 /* 88 * Initialize an XIO given a userspace buffer. 0 is returned on success, 89 * an error code on failure. The actual number of bytes that could be 90 * accomodated in the XIO will be stored in xio_bytes and the page offset 91 * will be stored in xio_offset. 92 */ 93 int 94 xio_init_ubuf(xio_t xio, void *ubase, size_t ubytes, int flags) 95 { 96 vm_offset_t addr; 97 vm_page_t m; 98 vm_page_t m0; 99 int error; 100 int i; 101 int n; 102 int vmprot; 103 104 addr = trunc_page((vm_offset_t)ubase); 105 xio->xio_flags = flags; 106 xio->xio_bytes = 0; 107 xio->xio_error = 0; 108 if (ubytes == 0) { 109 xio->xio_offset = 0; 110 xio->xio_npages = 0; 111 } else { 112 vmprot = (flags & XIOF_WRITE) ? VM_PROT_WRITE : VM_PROT_READ; 113 xio->xio_offset = (vm_offset_t)ubase & PAGE_MASK; 114 xio->xio_pages = xio->xio_internal_pages; 115 if ((n = PAGE_SIZE - xio->xio_offset) > ubytes) 116 n = ubytes; 117 m0 = NULL; 118 for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) { 119 m = vm_fault_page_quick(addr, vmprot, &error); 120 if (m == NULL) 121 break; 122 xio->xio_pages[i] = m; 123 ubytes -= n; 124 xio->xio_bytes += n; 125 if ((n = ubytes) > PAGE_SIZE) 126 n = PAGE_SIZE; 127 addr += PAGE_SIZE; 128 129 /* 130 * Check linearity, used by syslink to memory map DMA buffers. 131 */ 132 if (flags & XIOF_VMLINEAR) { 133 if (i == 0) { 134 m0 = m; 135 } else 136 if (m->object != m0->object || m->pindex != m0->pindex + i) { 137 error = EINVAL; 138 break; 139 } 140 } 141 } 142 xio->xio_npages = i; 143 144 /* 145 * If a failure occured clean out what we loaded and return EFAULT. 146 * Return 0 on success. Do not dirty the pages. 147 */ 148 if (i < XIO_INTERNAL_PAGES && n) { 149 xio->xio_flags &= ~XIOF_WRITE; 150 xio_release(xio); 151 xio->xio_error = EFAULT; 152 } 153 } 154 return(xio->xio_error); 155 } 156 157 /* 158 * Initialize an XIO given a kernelspace buffer. 0 is returned on success, 159 * an error code on failure. The actual number of bytes that could be 160 * accomodated in the XIO will be stored in xio_bytes and the page offset 161 * will be stored in xio_offset. 162 */ 163 int 164 xio_init_kbuf(xio_t xio, void *kbase, size_t kbytes) 165 { 166 vm_offset_t addr; 167 vm_paddr_t paddr; 168 vm_page_t m; 169 int i; 170 int n; 171 172 addr = trunc_page((vm_offset_t)kbase); 173 xio->xio_flags = 0; 174 xio->xio_offset = (vm_offset_t)kbase & PAGE_MASK; 175 xio->xio_bytes = 0; 176 xio->xio_pages = xio->xio_internal_pages; 177 xio->xio_error = 0; 178 if ((n = PAGE_SIZE - xio->xio_offset) > kbytes) 179 n = kbytes; 180 for (i = 0; n && i < XIO_INTERNAL_PAGES; ++i) { 181 if ((paddr = pmap_kextract(addr)) == 0) 182 break; 183 crit_enter(); 184 m = PHYS_TO_VM_PAGE(paddr); 185 vm_page_hold(m); 186 crit_exit(); 187 xio->xio_pages[i] = m; 188 kbytes -= n; 189 xio->xio_bytes += n; 190 if ((n = kbytes) > PAGE_SIZE) 191 n = PAGE_SIZE; 192 addr += PAGE_SIZE; 193 } 194 xio->xio_npages = i; 195 196 /* 197 * If a failure occured clean out what we loaded and return EFAULT. 198 * Return 0 on success. 199 */ 200 if (i < XIO_INTERNAL_PAGES && n) { 201 xio_release(xio); 202 xio->xio_error = EFAULT; 203 } 204 return(xio->xio_error); 205 } 206 207 /* 208 * Initialize an XIO given an array of vm_page pointers. The caller is 209 * responsible for any modified state changes for the pages. 210 */ 211 int 212 xio_init_pages(xio_t xio, struct vm_page **mbase, int npages, int xflags) 213 { 214 int i; 215 216 KKASSERT(npages <= XIO_INTERNAL_PAGES); 217 218 xio->xio_flags = xflags; 219 xio->xio_offset = 0; 220 xio->xio_bytes = npages * PAGE_SIZE; 221 xio->xio_pages = xio->xio_internal_pages; 222 xio->xio_npages = npages; 223 xio->xio_error = 0; 224 crit_enter(); 225 for (i = 0; i < npages; ++i) { 226 vm_page_hold(mbase[i]); 227 xio->xio_pages[i] = mbase[i]; 228 } 229 crit_exit(); 230 return(0); 231 } 232 233 /* 234 * Cleanup an XIO so it can be destroyed. The pages associated with the 235 * XIO are released. 236 */ 237 void 238 xio_release(xio_t xio) 239 { 240 int i; 241 vm_page_t m; 242 243 crit_enter(); 244 for (i = 0; i < xio->xio_npages; ++i) { 245 m = xio->xio_pages[i]; 246 if (xio->xio_flags & XIOF_WRITE) 247 vm_page_dirty(m); 248 vm_page_unhold(m); 249 } 250 crit_exit(); 251 xio->xio_offset = 0; 252 xio->xio_npages = 0; 253 xio->xio_bytes = 0; 254 xio->xio_error = ENOBUFS; 255 } 256 257 /* 258 * Copy data between an XIO and a UIO. If the UIO represents userspace it 259 * must be relative to the current context. 260 * 261 * uoffset is the abstracted starting offset in the XIO, not the actual 262 * offset, and usually starts at 0. 263 * 264 * The XIO is not modified. The UIO is updated to reflect the copy. 265 * 266 * UIO_READ xio -> uio 267 * UIO_WRITE uio -> xio 268 */ 269 int 270 xio_uio_copy(xio_t xio, int uoffset, struct uio *uio, size_t *sizep) 271 { 272 size_t bytes; 273 int error; 274 275 bytes = xio->xio_bytes - uoffset; 276 if (bytes > uio->uio_resid) 277 bytes = uio->uio_resid; 278 KKASSERT(bytes >= 0); 279 error = uiomove_fromphys(xio->xio_pages, xio->xio_offset + uoffset, 280 bytes, uio); 281 if (error == 0) 282 *sizep = bytes; 283 else 284 *sizep = 0; 285 return(error); 286 } 287 288 /* 289 * Copy the specified number of bytes from the xio to a userland 290 * buffer. Return an error code or 0 on success. 291 * 292 * uoffset is the abstracted starting offset in the XIO, not the actual 293 * offset, and usually starts at 0. 294 * 295 * The XIO is not modified. 296 */ 297 int 298 xio_copy_xtou(xio_t xio, int uoffset, void *uptr, int bytes) 299 { 300 int i; 301 int n; 302 int error; 303 int offset; 304 vm_page_t m; 305 struct lwbuf *lwb; 306 307 if (uoffset + bytes > xio->xio_bytes) 308 return(EFAULT); 309 310 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 311 if ((n = PAGE_SIZE - offset) > bytes) 312 n = bytes; 313 314 error = 0; 315 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 316 i < xio->xio_npages; 317 ++i 318 ) { 319 m = xio->xio_pages[i]; 320 lwb = lwbuf_alloc(m); 321 error = copyout((char *)lwbuf_kva(lwb) + offset, uptr, n); 322 lwbuf_free(lwb); 323 if (error) 324 break; 325 bytes -= n; 326 uptr = (char *)uptr + n; 327 if (bytes == 0) 328 break; 329 if ((n = bytes) > PAGE_SIZE) 330 n = PAGE_SIZE; 331 offset = 0; 332 } 333 return(error); 334 } 335 336 /* 337 * Copy the specified number of bytes from the xio to a kernel 338 * buffer. Return an error code or 0 on success. 339 * 340 * uoffset is the abstracted starting offset in the XIO, not the actual 341 * offset, and usually starts at 0. 342 * 343 * The XIO is not modified. 344 */ 345 int 346 xio_copy_xtok(xio_t xio, int uoffset, void *kptr, int bytes) 347 { 348 int i; 349 int n; 350 int error; 351 int offset; 352 vm_page_t m; 353 struct lwbuf *lwb; 354 355 if (bytes + uoffset > xio->xio_bytes) 356 return(EFAULT); 357 358 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 359 if ((n = PAGE_SIZE - offset) > bytes) 360 n = bytes; 361 362 error = 0; 363 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 364 i < xio->xio_npages; 365 ++i 366 ) { 367 m = xio->xio_pages[i]; 368 lwb = lwbuf_alloc(m); 369 bcopy((char *)lwbuf_kva(lwb) + offset, kptr, n); 370 lwbuf_free(lwb); 371 bytes -= n; 372 kptr = (char *)kptr + n; 373 if (bytes == 0) 374 break; 375 if ((n = bytes) > PAGE_SIZE) 376 n = PAGE_SIZE; 377 offset = 0; 378 } 379 return(error); 380 } 381 382 /* 383 * Copy the specified number of bytes from userland to the xio. 384 * Return an error code or 0 on success. 385 * 386 * uoffset is the abstracted starting offset in the XIO, not the actual 387 * offset, and usually starts at 0. 388 * 389 * Data in pages backing the XIO will be modified. 390 */ 391 int 392 xio_copy_utox(xio_t xio, int uoffset, const void *uptr, int bytes) 393 { 394 int i; 395 int n; 396 int error; 397 int offset; 398 vm_page_t m; 399 struct lwbuf *lwb; 400 401 if (uoffset + bytes > xio->xio_bytes) 402 return(EFAULT); 403 404 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 405 if ((n = PAGE_SIZE - offset) > bytes) 406 n = bytes; 407 408 error = 0; 409 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 410 i < xio->xio_npages; 411 ++i 412 ) { 413 m = xio->xio_pages[i]; 414 lwb = lwbuf_alloc(m); 415 error = copyin(uptr, (char *)lwbuf_kva(lwb) + offset, n); 416 lwbuf_free(lwb); 417 if (error) 418 break; 419 bytes -= n; 420 uptr = (const char *)uptr + n; 421 if (bytes == 0) 422 break; 423 if ((n = bytes) > PAGE_SIZE) 424 n = PAGE_SIZE; 425 offset = 0; 426 } 427 return(error); 428 } 429 430 /* 431 * Copy the specified number of bytes from the kernel to the xio. 432 * Return an error code or 0 on success. 433 * 434 * uoffset is the abstracted starting offset in the XIO, not the actual 435 * offset, and usually starts at 0. 436 * 437 * Data in pages backing the XIO will be modified. 438 */ 439 int 440 xio_copy_ktox(xio_t xio, int uoffset, const void *kptr, int bytes) 441 { 442 int i; 443 int n; 444 int error; 445 int offset; 446 vm_page_t m; 447 struct lwbuf *lwb; 448 449 if (uoffset + bytes > xio->xio_bytes) 450 return(EFAULT); 451 452 offset = (xio->xio_offset + uoffset) & PAGE_MASK; 453 if ((n = PAGE_SIZE - offset) > bytes) 454 n = bytes; 455 456 error = 0; 457 for (i = (xio->xio_offset + uoffset) >> PAGE_SHIFT; 458 i < xio->xio_npages; 459 ++i 460 ) { 461 m = xio->xio_pages[i]; 462 lwb = lwbuf_alloc(m); 463 bcopy(kptr, (char *)lwbuf_kva(lwb) + offset, n); 464 lwbuf_free(lwb); 465 bytes -= n; 466 kptr = (const char *)kptr + n; 467 if (bytes == 0) 468 break; 469 if ((n = bytes) > PAGE_SIZE) 470 n = PAGE_SIZE; 471 offset = 0; 472 } 473 return(error); 474 } 475