Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
at v4.3 758 lines 18 kB view raw
1/* 2 * Copyright IBM Corp. 2007,2012 3 * 4 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>, 5 * Peter Oberparleiter <peter.oberparleiter@de.ibm.com> 6 */ 7 8#define KMSG_COMPONENT "sclp_cmd" 9#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 10 11#include <linux/completion.h> 12#include <linux/init.h> 13#include <linux/errno.h> 14#include <linux/err.h> 15#include <linux/export.h> 16#include <linux/slab.h> 17#include <linux/string.h> 18#include <linux/mm.h> 19#include <linux/mmzone.h> 20#include <linux/memory.h> 21#include <linux/module.h> 22#include <linux/platform_device.h> 23#include <asm/ctl_reg.h> 24#include <asm/chpid.h> 25#include <asm/setup.h> 26#include <asm/page.h> 27#include <asm/sclp.h> 28#include <asm/numa.h> 29 30#include "sclp.h" 31 32static void sclp_sync_callback(struct sclp_req *req, void *data) 33{ 34 struct completion *completion = data; 35 36 complete(completion); 37} 38 39int sclp_sync_request(sclp_cmdw_t cmd, void *sccb) 40{ 41 return sclp_sync_request_timeout(cmd, sccb, 0); 42} 43 44int sclp_sync_request_timeout(sclp_cmdw_t cmd, void *sccb, int timeout) 45{ 46 struct completion completion; 47 struct sclp_req *request; 48 int rc; 49 50 request = kzalloc(sizeof(*request), GFP_KERNEL); 51 if (!request) 52 return -ENOMEM; 53 if (timeout) 54 request->queue_timeout = timeout; 55 request->command = cmd; 56 request->sccb = sccb; 57 request->status = SCLP_REQ_FILLED; 58 request->callback = sclp_sync_callback; 59 request->callback_data = &completion; 60 init_completion(&completion); 61 62 /* Perform sclp request. */ 63 rc = sclp_add_request(request); 64 if (rc) 65 goto out; 66 wait_for_completion(&completion); 67 68 /* Check response. */ 69 if (request->status != SCLP_REQ_DONE) { 70 pr_warning("sync request failed (cmd=0x%08x, " 71 "status=0x%02x)\n", cmd, request->status); 72 rc = -EIO; 73 } 74out: 75 kfree(request); 76 return rc; 77} 78 79/* 80 * CPU configuration related functions. 81 */ 82 83#define SCLP_CMDW_READ_CPU_INFO 0x00010001 84#define SCLP_CMDW_CONFIGURE_CPU 0x00110001 85#define SCLP_CMDW_DECONFIGURE_CPU 0x00100001 86 87struct read_cpu_info_sccb { 88 struct sccb_header header; 89 u16 nr_configured; 90 u16 offset_configured; 91 u16 nr_standby; 92 u16 offset_standby; 93 u8 reserved[4096 - 16]; 94} __attribute__((packed, aligned(PAGE_SIZE))); 95 96static void sclp_fill_core_info(struct sclp_core_info *info, 97 struct read_cpu_info_sccb *sccb) 98{ 99 char *page = (char *) sccb; 100 101 memset(info, 0, sizeof(*info)); 102 info->configured = sccb->nr_configured; 103 info->standby = sccb->nr_standby; 104 info->combined = sccb->nr_configured + sccb->nr_standby; 105 memcpy(&info->core, page + sccb->offset_configured, 106 info->combined * sizeof(struct sclp_core_entry)); 107} 108 109int sclp_get_core_info(struct sclp_core_info *info) 110{ 111 int rc; 112 struct read_cpu_info_sccb *sccb; 113 114 if (!SCLP_HAS_CPU_INFO) 115 return -EOPNOTSUPP; 116 sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 117 if (!sccb) 118 return -ENOMEM; 119 sccb->header.length = sizeof(*sccb); 120 rc = sclp_sync_request_timeout(SCLP_CMDW_READ_CPU_INFO, sccb, 121 SCLP_QUEUE_INTERVAL); 122 if (rc) 123 goto out; 124 if (sccb->header.response_code != 0x0010) { 125 pr_warning("readcpuinfo failed (response=0x%04x)\n", 126 sccb->header.response_code); 127 rc = -EIO; 128 goto out; 129 } 130 sclp_fill_core_info(info, sccb); 131out: 132 free_page((unsigned long) sccb); 133 return rc; 134} 135 136struct cpu_configure_sccb { 137 struct sccb_header header; 138} __attribute__((packed, aligned(8))); 139 140static int do_core_configure(sclp_cmdw_t cmd) 141{ 142 struct cpu_configure_sccb *sccb; 143 int rc; 144 145 if (!SCLP_HAS_CPU_RECONFIG) 146 return -EOPNOTSUPP; 147 /* 148 * This is not going to cross a page boundary since we force 149 * kmalloc to have a minimum alignment of 8 bytes on s390. 150 */ 151 sccb = kzalloc(sizeof(*sccb), GFP_KERNEL | GFP_DMA); 152 if (!sccb) 153 return -ENOMEM; 154 sccb->header.length = sizeof(*sccb); 155 rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL); 156 if (rc) 157 goto out; 158 switch (sccb->header.response_code) { 159 case 0x0020: 160 case 0x0120: 161 break; 162 default: 163 pr_warning("configure cpu failed (cmd=0x%08x, " 164 "response=0x%04x)\n", cmd, 165 sccb->header.response_code); 166 rc = -EIO; 167 break; 168 } 169out: 170 kfree(sccb); 171 return rc; 172} 173 174int sclp_core_configure(u8 core) 175{ 176 return do_core_configure(SCLP_CMDW_CONFIGURE_CPU | core << 8); 177} 178 179int sclp_core_deconfigure(u8 core) 180{ 181 return do_core_configure(SCLP_CMDW_DECONFIGURE_CPU | core << 8); 182} 183 184#ifdef CONFIG_MEMORY_HOTPLUG 185 186static DEFINE_MUTEX(sclp_mem_mutex); 187static LIST_HEAD(sclp_mem_list); 188static u8 sclp_max_storage_id; 189static DECLARE_BITMAP(sclp_storage_ids, 256); 190static int sclp_mem_state_changed; 191 192struct memory_increment { 193 struct list_head list; 194 u16 rn; 195 int standby; 196}; 197 198struct assign_storage_sccb { 199 struct sccb_header header; 200 u16 rn; 201} __packed; 202 203int arch_get_memory_phys_device(unsigned long start_pfn) 204{ 205 if (!sclp.rzm) 206 return 0; 207 return PFN_PHYS(start_pfn) >> ilog2(sclp.rzm); 208} 209 210static unsigned long long rn2addr(u16 rn) 211{ 212 return (unsigned long long) (rn - 1) * sclp.rzm; 213} 214 215static int do_assign_storage(sclp_cmdw_t cmd, u16 rn) 216{ 217 struct assign_storage_sccb *sccb; 218 int rc; 219 220 sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 221 if (!sccb) 222 return -ENOMEM; 223 sccb->header.length = PAGE_SIZE; 224 sccb->rn = rn; 225 rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL); 226 if (rc) 227 goto out; 228 switch (sccb->header.response_code) { 229 case 0x0020: 230 case 0x0120: 231 break; 232 default: 233 pr_warning("assign storage failed (cmd=0x%08x, " 234 "response=0x%04x, rn=0x%04x)\n", cmd, 235 sccb->header.response_code, rn); 236 rc = -EIO; 237 break; 238 } 239out: 240 free_page((unsigned long) sccb); 241 return rc; 242} 243 244static int sclp_assign_storage(u16 rn) 245{ 246 unsigned long long start; 247 int rc; 248 249 rc = do_assign_storage(0x000d0001, rn); 250 if (rc) 251 return rc; 252 start = rn2addr(rn); 253 storage_key_init_range(start, start + sclp.rzm); 254 return 0; 255} 256 257static int sclp_unassign_storage(u16 rn) 258{ 259 return do_assign_storage(0x000c0001, rn); 260} 261 262struct attach_storage_sccb { 263 struct sccb_header header; 264 u16 :16; 265 u16 assigned; 266 u32 :32; 267 u32 entries[0]; 268} __packed; 269 270static int sclp_attach_storage(u8 id) 271{ 272 struct attach_storage_sccb *sccb; 273 int rc; 274 int i; 275 276 sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 277 if (!sccb) 278 return -ENOMEM; 279 sccb->header.length = PAGE_SIZE; 280 rc = sclp_sync_request_timeout(0x00080001 | id << 8, sccb, 281 SCLP_QUEUE_INTERVAL); 282 if (rc) 283 goto out; 284 switch (sccb->header.response_code) { 285 case 0x0020: 286 set_bit(id, sclp_storage_ids); 287 for (i = 0; i < sccb->assigned; i++) { 288 if (sccb->entries[i]) 289 sclp_unassign_storage(sccb->entries[i] >> 16); 290 } 291 break; 292 default: 293 rc = -EIO; 294 break; 295 } 296out: 297 free_page((unsigned long) sccb); 298 return rc; 299} 300 301static int sclp_mem_change_state(unsigned long start, unsigned long size, 302 int online) 303{ 304 struct memory_increment *incr; 305 unsigned long long istart; 306 int rc = 0; 307 308 list_for_each_entry(incr, &sclp_mem_list, list) { 309 istart = rn2addr(incr->rn); 310 if (start + size - 1 < istart) 311 break; 312 if (start > istart + sclp.rzm - 1) 313 continue; 314 if (online) 315 rc |= sclp_assign_storage(incr->rn); 316 else 317 sclp_unassign_storage(incr->rn); 318 if (rc == 0) 319 incr->standby = online ? 0 : 1; 320 } 321 return rc ? -EIO : 0; 322} 323 324static bool contains_standby_increment(unsigned long start, unsigned long end) 325{ 326 struct memory_increment *incr; 327 unsigned long istart; 328 329 list_for_each_entry(incr, &sclp_mem_list, list) { 330 istart = rn2addr(incr->rn); 331 if (end - 1 < istart) 332 continue; 333 if (start > istart + sclp.rzm - 1) 334 continue; 335 if (incr->standby) 336 return true; 337 } 338 return false; 339} 340 341static int sclp_mem_notifier(struct notifier_block *nb, 342 unsigned long action, void *data) 343{ 344 unsigned long start, size; 345 struct memory_notify *arg; 346 unsigned char id; 347 int rc = 0; 348 349 arg = data; 350 start = arg->start_pfn << PAGE_SHIFT; 351 size = arg->nr_pages << PAGE_SHIFT; 352 mutex_lock(&sclp_mem_mutex); 353 for_each_clear_bit(id, sclp_storage_ids, sclp_max_storage_id + 1) 354 sclp_attach_storage(id); 355 switch (action) { 356 case MEM_GOING_OFFLINE: 357 /* 358 * We do not allow to set memory blocks offline that contain 359 * standby memory. This is done to simplify the "memory online" 360 * case. 361 */ 362 if (contains_standby_increment(start, start + size)) 363 rc = -EPERM; 364 break; 365 case MEM_ONLINE: 366 case MEM_CANCEL_OFFLINE: 367 break; 368 case MEM_GOING_ONLINE: 369 rc = sclp_mem_change_state(start, size, 1); 370 break; 371 case MEM_CANCEL_ONLINE: 372 sclp_mem_change_state(start, size, 0); 373 break; 374 case MEM_OFFLINE: 375 sclp_mem_change_state(start, size, 0); 376 break; 377 default: 378 rc = -EINVAL; 379 break; 380 } 381 if (!rc) 382 sclp_mem_state_changed = 1; 383 mutex_unlock(&sclp_mem_mutex); 384 return rc ? NOTIFY_BAD : NOTIFY_OK; 385} 386 387static struct notifier_block sclp_mem_nb = { 388 .notifier_call = sclp_mem_notifier, 389}; 390 391static void __init align_to_block_size(unsigned long long *start, 392 unsigned long long *size, 393 unsigned long long alignment) 394{ 395 unsigned long long start_align, size_align; 396 397 start_align = roundup(*start, alignment); 398 size_align = rounddown(*start + *size, alignment) - start_align; 399 400 pr_info("Standby memory at 0x%llx (%lluM of %lluM usable)\n", 401 *start, size_align >> 20, *size >> 20); 402 *start = start_align; 403 *size = size_align; 404} 405 406static void __init add_memory_merged(u16 rn) 407{ 408 unsigned long long start, size, addr, block_size; 409 static u16 first_rn, num; 410 411 if (rn && first_rn && (first_rn + num == rn)) { 412 num++; 413 return; 414 } 415 if (!first_rn) 416 goto skip_add; 417 start = rn2addr(first_rn); 418 size = (unsigned long long) num * sclp.rzm; 419 if (start >= VMEM_MAX_PHYS) 420 goto skip_add; 421 if (start + size > VMEM_MAX_PHYS) 422 size = VMEM_MAX_PHYS - start; 423 if (memory_end_set && (start >= memory_end)) 424 goto skip_add; 425 if (memory_end_set && (start + size > memory_end)) 426 size = memory_end - start; 427 block_size = memory_block_size_bytes(); 428 align_to_block_size(&start, &size, block_size); 429 if (!size) 430 goto skip_add; 431 for (addr = start; addr < start + size; addr += block_size) 432 add_memory(numa_pfn_to_nid(PFN_DOWN(addr)), addr, block_size); 433skip_add: 434 first_rn = rn; 435 num = 1; 436} 437 438static void __init sclp_add_standby_memory(void) 439{ 440 struct memory_increment *incr; 441 442 list_for_each_entry(incr, &sclp_mem_list, list) 443 if (incr->standby) 444 add_memory_merged(incr->rn); 445 add_memory_merged(0); 446} 447 448static void __init insert_increment(u16 rn, int standby, int assigned) 449{ 450 struct memory_increment *incr, *new_incr; 451 struct list_head *prev; 452 u16 last_rn; 453 454 new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL); 455 if (!new_incr) 456 return; 457 new_incr->rn = rn; 458 new_incr->standby = standby; 459 last_rn = 0; 460 prev = &sclp_mem_list; 461 list_for_each_entry(incr, &sclp_mem_list, list) { 462 if (assigned && incr->rn > rn) 463 break; 464 if (!assigned && incr->rn - last_rn > 1) 465 break; 466 last_rn = incr->rn; 467 prev = &incr->list; 468 } 469 if (!assigned) 470 new_incr->rn = last_rn + 1; 471 if (new_incr->rn > sclp.rnmax) { 472 kfree(new_incr); 473 return; 474 } 475 list_add(&new_incr->list, prev); 476} 477 478static int sclp_mem_freeze(struct device *dev) 479{ 480 if (!sclp_mem_state_changed) 481 return 0; 482 pr_err("Memory hotplug state changed, suspend refused.\n"); 483 return -EPERM; 484} 485 486struct read_storage_sccb { 487 struct sccb_header header; 488 u16 max_id; 489 u16 assigned; 490 u16 standby; 491 u16 :16; 492 u32 entries[0]; 493} __packed; 494 495static const struct dev_pm_ops sclp_mem_pm_ops = { 496 .freeze = sclp_mem_freeze, 497}; 498 499static struct platform_driver sclp_mem_pdrv = { 500 .driver = { 501 .name = "sclp_mem", 502 .pm = &sclp_mem_pm_ops, 503 }, 504}; 505 506static int __init sclp_detect_standby_memory(void) 507{ 508 struct platform_device *sclp_pdev; 509 struct read_storage_sccb *sccb; 510 int i, id, assigned, rc; 511 512 if (OLDMEM_BASE) /* No standby memory in kdump mode */ 513 return 0; 514 if ((sclp.facilities & 0xe00000000000ULL) != 0xe00000000000ULL) 515 return 0; 516 rc = -ENOMEM; 517 sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA); 518 if (!sccb) 519 goto out; 520 assigned = 0; 521 for (id = 0; id <= sclp_max_storage_id; id++) { 522 memset(sccb, 0, PAGE_SIZE); 523 sccb->header.length = PAGE_SIZE; 524 rc = sclp_sync_request(0x00040001 | id << 8, sccb); 525 if (rc) 526 goto out; 527 switch (sccb->header.response_code) { 528 case 0x0010: 529 set_bit(id, sclp_storage_ids); 530 for (i = 0; i < sccb->assigned; i++) { 531 if (!sccb->entries[i]) 532 continue; 533 assigned++; 534 insert_increment(sccb->entries[i] >> 16, 0, 1); 535 } 536 break; 537 case 0x0310: 538 break; 539 case 0x0410: 540 for (i = 0; i < sccb->assigned; i++) { 541 if (!sccb->entries[i]) 542 continue; 543 assigned++; 544 insert_increment(sccb->entries[i] >> 16, 1, 1); 545 } 546 break; 547 default: 548 rc = -EIO; 549 break; 550 } 551 if (!rc) 552 sclp_max_storage_id = sccb->max_id; 553 } 554 if (rc || list_empty(&sclp_mem_list)) 555 goto out; 556 for (i = 1; i <= sclp.rnmax - assigned; i++) 557 insert_increment(0, 1, 0); 558 rc = register_memory_notifier(&sclp_mem_nb); 559 if (rc) 560 goto out; 561 rc = platform_driver_register(&sclp_mem_pdrv); 562 if (rc) 563 goto out; 564 sclp_pdev = platform_device_register_simple("sclp_mem", -1, NULL, 0); 565 rc = PTR_ERR_OR_ZERO(sclp_pdev); 566 if (rc) 567 goto out_driver; 568 sclp_add_standby_memory(); 569 goto out; 570out_driver: 571 platform_driver_unregister(&sclp_mem_pdrv); 572out: 573 free_page((unsigned long) sccb); 574 return rc; 575} 576__initcall(sclp_detect_standby_memory); 577 578#endif /* CONFIG_MEMORY_HOTPLUG */ 579 580/* 581 * PCI I/O adapter configuration related functions. 582 */ 583#define SCLP_CMDW_CONFIGURE_PCI 0x001a0001 584#define SCLP_CMDW_DECONFIGURE_PCI 0x001b0001 585 586#define SCLP_RECONFIG_PCI_ATPYE 2 587 588struct pci_cfg_sccb { 589 struct sccb_header header; 590 u8 atype; /* adapter type */ 591 u8 reserved1; 592 u16 reserved2; 593 u32 aid; /* adapter identifier */ 594} __packed; 595 596static int do_pci_configure(sclp_cmdw_t cmd, u32 fid) 597{ 598 struct pci_cfg_sccb *sccb; 599 int rc; 600 601 if (!SCLP_HAS_PCI_RECONFIG) 602 return -EOPNOTSUPP; 603 604 sccb = (struct pci_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 605 if (!sccb) 606 return -ENOMEM; 607 608 sccb->header.length = PAGE_SIZE; 609 sccb->atype = SCLP_RECONFIG_PCI_ATPYE; 610 sccb->aid = fid; 611 rc = sclp_sync_request(cmd, sccb); 612 if (rc) 613 goto out; 614 switch (sccb->header.response_code) { 615 case 0x0020: 616 case 0x0120: 617 break; 618 default: 619 pr_warn("configure PCI I/O adapter failed: cmd=0x%08x response=0x%04x\n", 620 cmd, sccb->header.response_code); 621 rc = -EIO; 622 break; 623 } 624out: 625 free_page((unsigned long) sccb); 626 return rc; 627} 628 629int sclp_pci_configure(u32 fid) 630{ 631 return do_pci_configure(SCLP_CMDW_CONFIGURE_PCI, fid); 632} 633EXPORT_SYMBOL(sclp_pci_configure); 634 635int sclp_pci_deconfigure(u32 fid) 636{ 637 return do_pci_configure(SCLP_CMDW_DECONFIGURE_PCI, fid); 638} 639EXPORT_SYMBOL(sclp_pci_deconfigure); 640 641/* 642 * Channel path configuration related functions. 643 */ 644 645#define SCLP_CMDW_CONFIGURE_CHPATH 0x000f0001 646#define SCLP_CMDW_DECONFIGURE_CHPATH 0x000e0001 647#define SCLP_CMDW_READ_CHPATH_INFORMATION 0x00030001 648 649struct chp_cfg_sccb { 650 struct sccb_header header; 651 u8 ccm; 652 u8 reserved[6]; 653 u8 cssid; 654} __attribute__((packed)); 655 656static int do_chp_configure(sclp_cmdw_t cmd) 657{ 658 struct chp_cfg_sccb *sccb; 659 int rc; 660 661 if (!SCLP_HAS_CHP_RECONFIG) 662 return -EOPNOTSUPP; 663 /* Prepare sccb. */ 664 sccb = (struct chp_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 665 if (!sccb) 666 return -ENOMEM; 667 sccb->header.length = sizeof(*sccb); 668 rc = sclp_sync_request(cmd, sccb); 669 if (rc) 670 goto out; 671 switch (sccb->header.response_code) { 672 case 0x0020: 673 case 0x0120: 674 case 0x0440: 675 case 0x0450: 676 break; 677 default: 678 pr_warning("configure channel-path failed " 679 "(cmd=0x%08x, response=0x%04x)\n", cmd, 680 sccb->header.response_code); 681 rc = -EIO; 682 break; 683 } 684out: 685 free_page((unsigned long) sccb); 686 return rc; 687} 688 689/** 690 * sclp_chp_configure - perform configure channel-path sclp command 691 * @chpid: channel-path ID 692 * 693 * Perform configure channel-path command sclp command for specified chpid. 694 * Return 0 after command successfully finished, non-zero otherwise. 695 */ 696int sclp_chp_configure(struct chp_id chpid) 697{ 698 return do_chp_configure(SCLP_CMDW_CONFIGURE_CHPATH | chpid.id << 8); 699} 700 701/** 702 * sclp_chp_deconfigure - perform deconfigure channel-path sclp command 703 * @chpid: channel-path ID 704 * 705 * Perform deconfigure channel-path command sclp command for specified chpid 706 * and wait for completion. On success return 0. Return non-zero otherwise. 707 */ 708int sclp_chp_deconfigure(struct chp_id chpid) 709{ 710 return do_chp_configure(SCLP_CMDW_DECONFIGURE_CHPATH | chpid.id << 8); 711} 712 713struct chp_info_sccb { 714 struct sccb_header header; 715 u8 recognized[SCLP_CHP_INFO_MASK_SIZE]; 716 u8 standby[SCLP_CHP_INFO_MASK_SIZE]; 717 u8 configured[SCLP_CHP_INFO_MASK_SIZE]; 718 u8 ccm; 719 u8 reserved[6]; 720 u8 cssid; 721} __attribute__((packed)); 722 723/** 724 * sclp_chp_read_info - perform read channel-path information sclp command 725 * @info: resulting channel-path information data 726 * 727 * Perform read channel-path information sclp command and wait for completion. 728 * On success, store channel-path information in @info and return 0. Return 729 * non-zero otherwise. 730 */ 731int sclp_chp_read_info(struct sclp_chp_info *info) 732{ 733 struct chp_info_sccb *sccb; 734 int rc; 735 736 if (!SCLP_HAS_CHP_INFO) 737 return -EOPNOTSUPP; 738 /* Prepare sccb. */ 739 sccb = (struct chp_info_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 740 if (!sccb) 741 return -ENOMEM; 742 sccb->header.length = sizeof(*sccb); 743 rc = sclp_sync_request(SCLP_CMDW_READ_CHPATH_INFORMATION, sccb); 744 if (rc) 745 goto out; 746 if (sccb->header.response_code != 0x0010) { 747 pr_warning("read channel-path info failed " 748 "(response=0x%04x)\n", sccb->header.response_code); 749 rc = -EIO; 750 goto out; 751 } 752 memcpy(info->recognized, sccb->recognized, SCLP_CHP_INFO_MASK_SIZE); 753 memcpy(info->standby, sccb->standby, SCLP_CHP_INFO_MASK_SIZE); 754 memcpy(info->configured, sccb->configured, SCLP_CHP_INFO_MASK_SIZE); 755out: 756 free_page((unsigned long) sccb); 757 return rc; 758}