Re: [PATCH v3 1/4] kernel/resource: Provide mem region release for SOFT RESERVES
From: kernel test robot
Date: Fri Apr 04 2025 - 08:57:42 EST
Hi Terry,
kernel test robot noticed the following build warnings:
[auto build test WARNING on aae0594a7053c60b82621136257c8b648c67b512]
url: https://github.com/intel-lab-lkp/linux/commits/Terry-Bowman/kernel-resource-Provide-mem-region-release-for-SOFT-RESERVES/20250404-023601
base: aae0594a7053c60b82621136257c8b648c67b512
patch link: https://lore.kernel.org/r/20250403183315.286710-2-terry.bowman%40amd.com
patch subject: [PATCH v3 1/4] kernel/resource: Provide mem region release for SOFT RESERVES
config: i386-buildonly-randconfig-003-20250404 (https://download.01.org/0day-ci/archive/20250404/202504042030.Rs5G4dWd-lkp@xxxxxxxxx/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250404/202504042030.Rs5G4dWd-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202504042030.Rs5G4dWd-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
>> kernel/resource.c:1414: warning: Function parameter or struct member 'busy_check' not described in '__release_mem_region_adjustable'
>> kernel/resource.c:1414: warning: Function parameter or struct member 'res_desc' not described in '__release_mem_region_adjustable'
>> kernel/resource.c:1414: warning: expecting prototype for release_mem_region_adjustable(). Prototype was for __release_mem_region_adjustable() instead
vim +1414 kernel/resource.c
^1da177e4c3f41 Linus Torvalds 2005-04-16 1389
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1390 #if defined(CONFIG_MEMORY_HOTREMOVE) || defined(CONFIG_CXL_REGION)
825f787bb49676 Toshi Kani 2013-04-29 1391 /**
825f787bb49676 Toshi Kani 2013-04-29 1392 * release_mem_region_adjustable - release a previously reserved memory region
825f787bb49676 Toshi Kani 2013-04-29 1393 * @start: resource start address
825f787bb49676 Toshi Kani 2013-04-29 1394 * @size: resource region size
825f787bb49676 Toshi Kani 2013-04-29 1395 *
825f787bb49676 Toshi Kani 2013-04-29 1396 * This interface is intended for memory hot-delete. The requested region
825f787bb49676 Toshi Kani 2013-04-29 1397 * is released from a currently busy memory resource. The requested region
825f787bb49676 Toshi Kani 2013-04-29 1398 * must either match exactly or fit into a single busy resource entry. In
825f787bb49676 Toshi Kani 2013-04-29 1399 * the latter case, the remaining resource is adjusted accordingly.
825f787bb49676 Toshi Kani 2013-04-29 1400 * Existing children of the busy memory resource must be immutable in the
825f787bb49676 Toshi Kani 2013-04-29 1401 * request.
825f787bb49676 Toshi Kani 2013-04-29 1402 *
825f787bb49676 Toshi Kani 2013-04-29 1403 * Note:
825f787bb49676 Toshi Kani 2013-04-29 1404 * - Additional release conditions, such as overlapping region, can be
825f787bb49676 Toshi Kani 2013-04-29 1405 * supported after they are confirmed as valid cases.
825f787bb49676 Toshi Kani 2013-04-29 1406 * - When a busy memory resource gets split into two entries, the code
825f787bb49676 Toshi Kani 2013-04-29 1407 * assumes that all children remain in the lower address entry for
825f787bb49676 Toshi Kani 2013-04-29 1408 * simplicity. Enhance this logic when necessary.
825f787bb49676 Toshi Kani 2013-04-29 1409 */
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1410 static void __release_mem_region_adjustable(resource_size_t start,
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1411 resource_size_t size,
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1412 bool busy_check,
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1413 int res_desc)
825f787bb49676 Toshi Kani 2013-04-29 @1414 {
cb8e3c8b4f45e4 David Hildenbrand 2020-10-15 1415 struct resource *parent = &iomem_resource;
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1416 struct resource *new_res = NULL;
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1417 bool alloc_nofail = false;
825f787bb49676 Toshi Kani 2013-04-29 1418 struct resource **p;
825f787bb49676 Toshi Kani 2013-04-29 1419 struct resource *res;
825f787bb49676 Toshi Kani 2013-04-29 1420 resource_size_t end;
825f787bb49676 Toshi Kani 2013-04-29 1421
825f787bb49676 Toshi Kani 2013-04-29 1422 end = start + size - 1;
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1423 if (WARN_ON_ONCE((start < parent->start) || (end > parent->end)))
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1424 return;
825f787bb49676 Toshi Kani 2013-04-29 1425
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1426 /*
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1427 * We free up quite a lot of memory on memory hotunplug (esp., memap),
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1428 * just before releasing the region. This is highly unlikely to
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1429 * fail - let's play save and make it never fail as the caller cannot
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1430 * perform any error handling (e.g., trying to re-add memory will fail
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1431 * similarly).
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1432 */
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1433 retry:
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1434 new_res = alloc_resource(GFP_KERNEL | (alloc_nofail ? __GFP_NOFAIL : 0));
825f787bb49676 Toshi Kani 2013-04-29 1435
825f787bb49676 Toshi Kani 2013-04-29 1436 p = &parent->child;
825f787bb49676 Toshi Kani 2013-04-29 1437 write_lock(&resource_lock);
825f787bb49676 Toshi Kani 2013-04-29 1438
825f787bb49676 Toshi Kani 2013-04-29 1439 while ((res = *p)) {
825f787bb49676 Toshi Kani 2013-04-29 1440 if (res->start >= end)
825f787bb49676 Toshi Kani 2013-04-29 1441 break;
825f787bb49676 Toshi Kani 2013-04-29 1442
825f787bb49676 Toshi Kani 2013-04-29 1443 /* look for the next resource if it does not fit into */
825f787bb49676 Toshi Kani 2013-04-29 1444 if (res->start > start || res->end < end) {
825f787bb49676 Toshi Kani 2013-04-29 1445 p = &res->sibling;
825f787bb49676 Toshi Kani 2013-04-29 1446 continue;
825f787bb49676 Toshi Kani 2013-04-29 1447 }
825f787bb49676 Toshi Kani 2013-04-29 1448
825f787bb49676 Toshi Kani 2013-04-29 1449 if (!(res->flags & IORESOURCE_MEM))
825f787bb49676 Toshi Kani 2013-04-29 1450 break;
825f787bb49676 Toshi Kani 2013-04-29 1451
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1452 if (busy_check && !(res->flags & IORESOURCE_BUSY)) {
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1453 p = &res->child;
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1454 continue;
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1455 }
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1456
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1457 if (res_desc != IORES_DESC_NONE && res->desc != res_desc) {
825f787bb49676 Toshi Kani 2013-04-29 1458 p = &res->child;
825f787bb49676 Toshi Kani 2013-04-29 1459 continue;
825f787bb49676 Toshi Kani 2013-04-29 1460 }
825f787bb49676 Toshi Kani 2013-04-29 1461
825f787bb49676 Toshi Kani 2013-04-29 1462 /* found the target resource; let's adjust accordingly */
825f787bb49676 Toshi Kani 2013-04-29 1463 if (res->start == start && res->end == end) {
825f787bb49676 Toshi Kani 2013-04-29 1464 /* free the whole entry */
825f787bb49676 Toshi Kani 2013-04-29 1465 *p = res->sibling;
ebff7d8f270d04 Yasuaki Ishimatsu 2013-04-29 1466 free_resource(res);
825f787bb49676 Toshi Kani 2013-04-29 1467 } else if (res->start == start && res->end != end) {
825f787bb49676 Toshi Kani 2013-04-29 1468 /* adjust the start */
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1469 WARN_ON_ONCE(__adjust_resource(res, end + 1,
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1470 res->end - end));
825f787bb49676 Toshi Kani 2013-04-29 1471 } else if (res->start != start && res->end == end) {
825f787bb49676 Toshi Kani 2013-04-29 1472 /* adjust the end */
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1473 WARN_ON_ONCE(__adjust_resource(res, res->start,
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1474 start - res->start));
825f787bb49676 Toshi Kani 2013-04-29 1475 } else {
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1476 /* split into two entries - we need a new resource */
825f787bb49676 Toshi Kani 2013-04-29 1477 if (!new_res) {
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1478 new_res = alloc_resource(GFP_ATOMIC);
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1479 if (!new_res) {
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1480 alloc_nofail = true;
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1481 write_unlock(&resource_lock);
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1482 goto retry;
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1483 }
825f787bb49676 Toshi Kani 2013-04-29 1484 }
825f787bb49676 Toshi Kani 2013-04-29 1485 new_res->name = res->name;
825f787bb49676 Toshi Kani 2013-04-29 1486 new_res->start = end + 1;
825f787bb49676 Toshi Kani 2013-04-29 1487 new_res->end = res->end;
825f787bb49676 Toshi Kani 2013-04-29 1488 new_res->flags = res->flags;
43ee493bde78da Toshi Kani 2016-01-26 1489 new_res->desc = res->desc;
825f787bb49676 Toshi Kani 2013-04-29 1490 new_res->parent = res->parent;
825f787bb49676 Toshi Kani 2013-04-29 1491 new_res->sibling = res->sibling;
825f787bb49676 Toshi Kani 2013-04-29 1492 new_res->child = NULL;
825f787bb49676 Toshi Kani 2013-04-29 1493
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1494 if (WARN_ON_ONCE(__adjust_resource(res, res->start,
ec62d04e3fdc4b David Hildenbrand 2020-10-15 1495 start - res->start)))
825f787bb49676 Toshi Kani 2013-04-29 1496 break;
825f787bb49676 Toshi Kani 2013-04-29 1497 res->sibling = new_res;
825f787bb49676 Toshi Kani 2013-04-29 1498 new_res = NULL;
825f787bb49676 Toshi Kani 2013-04-29 1499 }
825f787bb49676 Toshi Kani 2013-04-29 1500
825f787bb49676 Toshi Kani 2013-04-29 1501 break;
825f787bb49676 Toshi Kani 2013-04-29 1502 }
825f787bb49676 Toshi Kani 2013-04-29 1503
825f787bb49676 Toshi Kani 2013-04-29 1504 write_unlock(&resource_lock);
ebff7d8f270d04 Yasuaki Ishimatsu 2013-04-29 1505 free_resource(new_res);
825f787bb49676 Toshi Kani 2013-04-29 1506 }
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1507 #endif
e4ebc182a59bbb Nathan Fontenot 2025-04-03 1508
--
0-DAY CI Kernel Test Service
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