lwn.git/arch/s390/include/asm/hugetlb.h, branch docs-mw

KVM: S390: Remove PGSTE code from linux/s390 mm

2026-02-04T16:00:10+00:00

Remove the PGSTE config option. Remove all code from linux/s390 mm that involves PGSTEs. Acked-by: Heiko Carstens Signed-off-by: Claudio Imbrenda

mm: introduce memdesc_flags_t

2025-09-13T23:55:07+00:00

Patch series "Add and use memdesc_flags_t". At some point struct page will be separated from struct slab and struct folio. This is a step towards that by introducing a type for the 'flags' word of all three structures. This gives us a certain amount of type safety by establishing that some of these unsigned longs are different from other unsigned longs in that they contain things like node ID, section number and zone number in the upper bits. That lets us have functions that can be easily called by anyone who has a slab, folio or page (but not easily by anyone else) to get the node or zone. There's going to be some unusual merge problems with this as some odd bits of the kernel decide they want to print out the flags value or something similar by writing page->flags and now they'll need to write page->flags.f instead. That's most of the churn here. Maybe we should be removing these things from the debug output? This patch (of 11): Wrap the unsigned long flags in a typedef. In upcoming patches, this will provide a strong hint that you can't just pass a random unsigned long to functions which take this as an argument. [willy@infradead.org: s/flags/flags.f/ in several architectures] Link: https://lkml.kernel.org/r/aKMgPRLD-WnkPxYm@casper.infradead.org [nicola.vetrini@gmail.com: mips: fix compilation error] Link: https://lore.kernel.org/lkml/CA+G9fYvkpmqGr6wjBNHY=dRp71PLCoi2341JxOudi60yqaeUdg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20250825214245.1838158-1-nicola.vetrini@gmail.com Link: https://lkml.kernel.org/r/20250805172307.1302730-1-willy@infradead.org Link: https://lkml.kernel.org/r/20250805172307.1302730-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Zi Yan Cc: Shakeel Butt Signed-off-by: Andrew Morton

Merge tag 's390-6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2025-03-29T18:59:43+00:00

Pull s390 updates from Vasily Gorbik: - Add sorting of mcount locations at build time - Rework uaccess functions with C exception handling to shorten inline assembly size and enable full inlining. This yields near-optimal code for small constant copies with a ~40kb kernel size increase - Add support for a configurable STRICT_MM_TYPECHECKS which allows to generate better code, but also allows to have type checking for debug builds - Optimize get_lowcore() for common callers with alternatives that nearly revert to the pre-relocated lowcore code, while also slightly reducing syscall entry and exit time - Convert MACHINE_HAS_* checks for single facility tests into cpu_has_* style macros that call test_facility(), and for features with additional conditions, add a new ALT_TYPE_FEATURE alternative to provide a static branch via alternative patching. Also, move machine feature detection to the decompressor for early patching and add debugging functionality to easily show which alternatives are patched - Add exception table support to early boot / startup code to get rid of the open coded exception handling - Use asm_inline for all inline assemblies with EX_TABLE or ALTERNATIVE to ensure correct inlining and unrolling decisions - Remove 2k page table leftovers now that s390 has been switched to always allocate 4k page tables - Split kfence pool into 4k mappings in arch_kfence_init_pool() and remove the architecture-specific kfence_split_mapping() - Use READ_ONCE_NOCHECK() in regs_get_kernel_stack_nth() to silence spurious KASAN warnings from opportunistic ftrace argument tracing - Force __atomic_add_const() variants on s390 to always return void, ensuring compile errors for improper usage - Remove s390's ioremap_wt() and pgprot_writethrough() due to mismatched semantics and lack of known users, relying on asm-generic fallbacks - Signal eventfd in vfio-ap to notify userspace when the guest AP configuration changes, including during mdev removal - Convert mdev_types from an array to a pointer in vfio-ccw and vfio-ap drivers to avoid fake flex array confusion - Cleanup trap code - Remove references to the outdated linux390@de.ibm.com address - Other various small fixes and improvements all over the code * tag 's390-6.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (78 commits) s390: Use inline qualifier for all EX_TABLE and ALTERNATIVE inline assemblies s390/kfence: Split kfence pool into 4k mappings in arch_kfence_init_pool() s390/ptrace: Avoid KASAN false positives in regs_get_kernel_stack_nth() s390/boot: Ignore vmlinux.map s390/sysctl: Remove "vm/allocate_pgste" sysctl s390: Remove 2k vs 4k page table leftovers s390/tlb: Use mm_has_pgste() instead of mm_alloc_pgste() s390/lowcore: Use lghi instead llilh to clear register s390/syscall: Merge __do_syscall() and do_syscall() s390/spinlock: Implement SPINLOCK_LOCKVAL with inline assembly s390/smp: Implement raw_smp_processor_id() with inline assembly s390/current: Implement current with inline assembly s390/lowcore: Use inline qualifier for get_lowcore() inline assembly s390: Move s390 sysctls into their own file under arch/s390 s390/syscall: Simplify syscall_get_arguments() s390/vfio-ap: Notify userspace that guest's AP config changed when mdev removed s390: Remove ioremap_wt() and pgprot_writethrough() s390/mm: Add configurable STRICT_MM_TYPECHECKS s390/mm: Convert pgste_val() into function s390/mm: Convert pgprot_val() into function ...

s390/cpufeature: Convert MACHINE_HAS_EDAT1 to cpu_has_edat1()

2025-03-04T16:18:05+00:00

Convert MACHINE_HAS_... to cpu_has_...() which uses test_facility() instead of testing the machine_flags lowcore member if the feature is present. test_facility() generates better code since it results in a static branch without accessing memory. The branch is patched via alternatives by the decompressor depending on the availability of the required facility. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()

2025-02-27T17:40:57+00:00

In order to fix a bug, arm64 needs to be told the size of the huge page for which the huge_pte is being cleared in huge_ptep_get_and_clear(). Provide for this by adding an `unsigned long sz` parameter to the function. This follows the same pattern as huge_pte_clear() and set_huge_pte_at(). This commit makes the required interface modifications to the core mm as well as all arches that implement this function (arm64, loongarch, mips, parisc, powerpc, riscv, s390, sparc). The actual arm64 bug will be fixed in a separate commit. Cc: stable@vger.kernel.org Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit") Acked-by: David Hildenbrand Reviewed-by: Alexandre Ghiti # riscv Reviewed-by: Christophe Leroy Reviewed-by: Catalin Marinas Reviewed-by: Anshuman Khandual Signed-off-by: Ryan Roberts Acked-by: Alexander Gordeev # s390 Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com Signed-off-by: Will Deacon

s390/mm/hugetlbfs: Remove huge_pte_none() / huge_pte_none_mostly()

2024-12-15T22:33:04+00:00

Slightly cleanup arch/s390/include/asm/hugetlb.h: - Remove huge_pte_none() / huge_pte_none_mostly() which are identical to the generic variants - Coding style adjustments Acked-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

Merge tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2024-11-29T18:40:52+00:00

Pull more s390 updates from Heiko Carstens: - Add swap entry for hugetlbfs support - Add PTE_MARKER support for hugetlbs mappings; this fixes a regression (possible page fault loop) which was introduced when support for UFFDIO_POISON for hugetlbfs was added - Add ARCH_HAS_PREEMPT_LAZY and PREEMPT_DYNAMIC support - Mark IRQ entries in entry code, so that stack tracers can filter out the non-IRQ parts of stack traces. This fixes stack depot capacity limit warnings, since without filtering the number of unique stack traces is huge - In PCI code fix leak of struct zpci_dev object, and fix potential double remove of hotplug slot - Fix pagefault_disable() / pagefault_enable() unbalance in arch_stack_user_walk_common() - A couple of inline assembly optimizations, more cmpxchg() to try_cmpxchg() conversions, and removal of usages of xchg() and cmpxchg() on one and two byte memory areas - Various other small improvements and cleanups * tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (27 commits) Revert "s390/mm: Allow large pages for KASAN shadow mapping" s390/spinlock: Use flag output constraint for arch_cmpxchg_niai8() s390/spinlock: Use R constraint for arch_load_niai4() s390/spinlock: Generate shorter code for arch_spin_unlock() s390/spinlock: Remove condition code clobber from arch_spin_unlock() s390/spinlock: Use symbolic names in inline assemblies s390: Support PREEMPT_DYNAMIC s390/pci: Fix potential double remove of hotplug slot s390/pci: Fix leak of struct zpci_dev when zpci_add_device() fails s390/mm/hugetlbfs: Add missing includes s390/mm: Add PTE_MARKER support for hugetlbfs mappings s390/mm: Introduce region-third and segment table swap entries s390/mm: Introduce region-third and segment table entry present bits s390/mm: Rearrange region-third and segment table entry SW bits KVM: s390: Increase size of union sca_utility to four bytes KVM: s390: Remove one byte cmpxchg() usage KVM: s390: Use try_cmpxchg() instead of cmpxchg() loops s390/ap: Replace xchg() with WRITE_ONCE() s390/mm: Allow large pages for KASAN shadow mapping s390: Add ARCH_HAS_PREEMPT_LAZY support ...

s390/mm/hugetlbfs: Add missing includes

2024-11-28T13:11:44+00:00

Add missing includes to fix this randconfig compile error: All errors (new ones prefixed by >>): In file included from mm/pagewalk.c:5: In file included from include/linux/hugetlb.h:798: >> arch/s390/include/asm/hugetlb.h:94:31: error: call to undeclared function 'is_pte_marker'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 94 | return huge_pte_none(pte) || is_pte_marker(pte); | ^ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202411281002.IPkRpIcR-lkp@intel.com/ Fixes: 487ef5d4d912 ("s390/mm: Add PTE_MARKER support for hugetlbfs mappings") Signed-off-by: Heiko Carstens

s390/mm: Add PTE_MARKER support for hugetlbfs mappings

2024-11-27T11:57:01+00:00

Commit 8a13897fb0daa ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs") added support for PTE_MARKER_POISONED for hugetlbfs, but PTE_MARKER also needs support for swap entries. For s390, swap entries were only supported on PTE level, not on the PMD/PUD levels that are used for large hugetlbfs mappings. Therefore, when writing a PTE_MARKER_POISONED entry, the resulting entry on PMD/PUD level would be an invalid / empty entry. Further access would then generate a pagefault loop, instead of the expected SIGBUS. It is a loop inside the kernel, but interruptible and uffd fault handling also calls schedule() in between, so at least it won't completely block the system. Previous commits prepared support for swap entries on PMD/PUD levels. PTE_MARKER support for hugetlbfs can now be enabled by simply adding an extra is_pte_marker() check to huge_pte_none_mostly(). Fault handling code also needs to be adjusted to expect the VM_FAULT_HWPOISON_LARGE fault flag, which was not possible on s390 before. Reviewed-by: Alexander Gordeev Signed-off-by: Gerald Schaefer Signed-off-by: Heiko Carstens

mm: consolidate common checks in hugetlb_get_unmapped_area

2024-11-07T04:11:10+00:00

prepare_hugepage_range() performs almost the same checks for all architectures that define it, with the exception of mips and loongarch that also check for overflows. The rest checks for the addr and len to be properly aligned, so we can move that to hugetlb_get_unmapped_area() and get rid of a fair amount of duplicated code. [akpm@linux-foundation.org: remove now-unused local] Link: https://lore.kernel.org/oe-kbuild-all/202410081210.uNLbf3Jk-lkp@intel.com/ Link: https://lkml.kernel.org/r/20241007075037.267650-10-osalvador@suse.de Signed-off-by: Oscar Salvador Cc: David Hildenbrand Cc: Donet Tom Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Muchun Song Cc: Peter Xu Cc: Vlastimil Babka Signed-off-by: Andrew Morton