tree: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git master head: 1a880941a087613ed42f77001229edfcf75ea8a5 commit: a097e96997f0e6b9c840e1de19af68c01be7b12e [2232/2382] headers/deps: mm: Optimize <linux/dmapool.h> dependencies, remove <linux/scatterlist.h> and <asm/io.h> inclusion config: i386-randconfig-a003 (https://download.01.org/0day-ci/archive/20220114/202201141011.xY2EpZxX-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git/commit/?id=... git remote add mingo-tip git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git git fetch --no-tags mingo-tip master git checkout a097e96997f0e6b9c840e1de19af68c01be7b12e # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/entry/vdso/ arch/x86/kernel/cpu/mtrr/ net/ipv6/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): 570 | int arch_phys_wc_add(unsigned long base, unsigned long size) | ^~~~~~~~~~~~~~~~ 596 | void arch_phys_wc_del(int handle) | ^~~~~~~~~~~~~~~~ 616 | int arch_phys_wc_index(int handle) | ^~~~~~~~~~~~~~~~~~ vim +/arch_phys_wc_add +570 arch/x86/kernel/cpu/mtrr/mtrr.c ^1da177e4c3f41 arch/i386/kernel/cpu/mtrr/main.c Linus Torvalds 2005-04-16 554 d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 555 /** d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 556 * arch_phys_wc_add - add a WC MTRR and handle errors if PAT is unavailable d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 557 * @base: Physical base address d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 558 * @size: Size of region d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 559 * d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 560 * If PAT is available, this does nothing. If PAT is unavailable, it d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 561 * attempts to add a WC MTRR covering size bytes starting at base and d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 562 * logs an error if this fails. d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 563 * 2f9e897353fcb9 arch/x86/kernel/cpu/mtrr/main.c Luis R. Rodriguez 2015-05-26 564 * The called should provide a power of two size on an equivalent 2f9e897353fcb9 arch/x86/kernel/cpu/mtrr/main.c Luis R. Rodriguez 2015-05-26 565 * power of two boundary. 2f9e897353fcb9 arch/x86/kernel/cpu/mtrr/main.c Luis R. Rodriguez 2015-05-26 566 * d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 567 * Drivers must store the return value to pass to mtrr_del_wc_if_needed, d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 568 * but drivers should not try to interpret that return value. d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 569 */ d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 @570 int arch_phys_wc_add(unsigned long base, unsigned long size) d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 571 { d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 572 int ret; d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 573 cb32edf65bf219 arch/x86/kernel/cpu/mtrr/main.c Luis R. Rodriguez 2015-05-26 574 if (pat_enabled() || !mtrr_enabled()) d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 575 return 0; /* Success! (We don't need to do anything.) */ d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 576 d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 577 ret = mtrr_add(base, size, MTRR_TYPE_WRCOMB, true); d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 578 if (ret < 0) { d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 579 pr_warn("Failed to add WC MTRR for [%p-%p]; performance may suffer.", d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 580 (void *)base, (void *)(base + size - 1)); d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 581 return ret; d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 582 } d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 583 return ret + MTRR_TO_PHYS_WC_OFFSET; d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 584 } d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 585 EXPORT_SYMBOL(arch_phys_wc_add); d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 586 d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 587 /* d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 588 * arch_phys_wc_del - undoes arch_phys_wc_add d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 589 * @handle: Return value from arch_phys_wc_add d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 590 * d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 591 * This cleans up after mtrr_add_wc_if_needed. d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 592 * d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 593 * The API guarantees that mtrr_del_wc_if_needed(error code) and d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 594 * mtrr_del_wc_if_needed(0) do nothing. d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 595 */ d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 @596 void arch_phys_wc_del(int handle) d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 597 { d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 598 if (handle >= 1) { d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 599 WARN_ON(handle < MTRR_TO_PHYS_WC_OFFSET); d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 600 mtrr_del(handle - MTRR_TO_PHYS_WC_OFFSET, 0, 0); d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 601 } d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 602 } d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 603 EXPORT_SYMBOL(arch_phys_wc_del); d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 604 d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 605 /* 7d010fdf299929 arch/x86/kernel/cpu/mtrr/main.c Luis R. Rodriguez 2015-05-26 606 * arch_phys_wc_index - translates arch_phys_wc_add's return value d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 607 * @handle: Return value from arch_phys_wc_add d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 608 * d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 609 * This will turn the return value from arch_phys_wc_add into an mtrr d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 610 * index suitable for debugging. d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 611 * d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 612 * Note: There is no legitimate use for this function, except possibly d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 613 * in printk line. Alas there is an illegitimate use in some ancient d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 614 * drm ioctls. d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 615 */ 7d010fdf299929 arch/x86/kernel/cpu/mtrr/main.c Luis R. Rodriguez 2015-05-26 @616 int arch_phys_wc_index(int handle) d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 617 { d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 618 if (handle < MTRR_TO_PHYS_WC_OFFSET) d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 619 return -1; d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 620 else d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 621 return handle - MTRR_TO_PHYS_WC_OFFSET; d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 622 } 7d010fdf299929 arch/x86/kernel/cpu/mtrr/main.c Luis R. Rodriguez 2015-05-26 623 EXPORT_SYMBOL_GPL(arch_phys_wc_index); d0d98eedee2178 arch/x86/kernel/cpu/mtrr/main.c Andy Lutomirski 2013-05-13 624 :::::: The code at line 570 was first introduced by commit :::::: d0d98eedee2178c803dd824bb09f52b0e2ac1811 Add arch_phys_wc_{add, del} to manipulate WC MTRRs if needed :::::: TO: Andy Lutomirski <luto(a)amacapital.net&gt; :::::: CC: Dave Airlie <airlied(a)redhat.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org