linux-dev/arch/sparc/mm, branch master

sparc: Unbreak the build

2022-09-30T02:21:10Z

Fix the following build errors: arch/sparc/mm/srmmu.c: In function ‘smp_flush_page_for_dma’: arch/sparc/mm/srmmu.c:1639:13: error: cast between incompatible function types from ‘void (*)(long unsigned int)’ to ‘void (*)(long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)’ [-Werror=cast-function-type] 1639 | xc1((smpfunc_t) local_ops->page_for_dma, page); | ^ arch/sparc/mm/srmmu.c: In function ‘smp_flush_cache_mm’: arch/sparc/mm/srmmu.c:1662:29: error: cast between incompatible function types from ‘void (*)(struct mm_struct *)’ to ‘void (*)(long unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)’ [-Werror=cast-function-type] 1662 | xc1((smpfunc_t) local_ops->cache_mm, (unsigned long) mm); | [ ... ] Compile-tested only. Fixes: 552a23a0e5d0 ("Makefile: Enable -Wcast-function-type") Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche Tested-by: Andreas Larsson Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220830205854.1918026-1-bvanassche@acm.org

sparc/mm: move protection_map[] inside the platform

2022-07-18T00:14:37Z

This moves protection_map[] inside the platform and while here, also enable ARCH_HAS_VM_GET_PAGE_PROT on 32 bit platforms via DECLARE_VM_GET_PAGE_PROT. Link: https://lkml.kernel.org/r/20220711070600.2378316-5-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Reviewed-by: Sam Ravnborg Cc: "David S. Miller" Cc: Arnd Bergmann Cc: Brian Cain Cc: Catalin Marinas Cc: Christophe Leroy Cc: Christoph Hellwig Cc: Christoph Hellwig Cc: Chris Zankel Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Heiko Carstens Cc: Huacai Chen Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Jeff Dike Cc: Jonas Bonn Cc: Michael Ellerman Cc: Michal Simek Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Richard Henderson Cc: Rich Felker Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vineet Gupta Cc: WANG Xuerui Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton

mm: avoid unnecessary page fault retires on shared memory types

2022-06-17T02:48:27Z

I observed that for each of the shared file-backed page faults, we're very likely to retry one more time for the 1st write fault upon no page. It's because we'll need to release the mmap lock for dirty rate limit purpose with balance_dirty_pages_ratelimited() (in fault_dirty_shared_page()). Then after that throttling we return VM_FAULT_RETRY. We did that probably because VM_FAULT_RETRY is the only way we can return to the fault handler at that time telling it we've released the mmap lock. However that's not ideal because it's very likely the fault does not need to be retried at all since the pgtable was well installed before the throttling, so the next continuous fault (including taking mmap read lock, walk the pgtable, etc.) could be in most cases unnecessary. It's not only slowing down page faults for shared file-backed, but also add more mmap lock contention which is in most cases not needed at all. To observe this, one could try to write to some shmem page and look at "pgfault" value in /proc/vmstat, then we should expect 2 counts for each shmem write simply because we retried, and vm event "pgfault" will capture that. To make it more efficient, add a new VM_FAULT_COMPLETED return code just to show that we've completed the whole fault and released the lock. It's also a hint that we should very possibly not need another fault immediately on this page because we've just completed it. This patch provides a ~12% perf boost on my aarch64 test VM with a simple program sequentially dirtying 400MB shmem file being mmap()ed and these are the time it needs: Before: 650.980 ms (+-1.94%) After: 569.396 ms (+-1.38%) I believe it could help more than that. We need some special care on GUP and the s390 pgfault handler (for gmap code before returning from pgfault), the rest changes in the page fault handlers should be relatively straightforward. Another thing to mention is that mm_account_fault() does take this new fault as a generic fault to be accounted, unlike VM_FAULT_RETRY. I explicitly didn't touch hmm_vma_fault() and break_ksm() because they do not handle VM_FAULT_RETRY even with existing code, so I'm literally keeping them as-is. Link: https://lkml.kernel.org/r/20220530183450.42886-1-peterx@redhat.com Signed-off-by: Peter Xu Acked-by: Geert Uytterhoeven Acked-by: Peter Zijlstra (Intel) Acked-by: Johannes Weiner Acked-by: Vineet Gupta Acked-by: Guo Ren Acked-by: Max Filippov Acked-by: Christian Borntraeger Acked-by: Michael Ellerman (powerpc) Acked-by: Catalin Marinas Reviewed-by: Alistair Popple Reviewed-by: Ingo Molnar Acked-by: Russell King (Oracle) [arm part] Acked-by: Heiko Carstens Cc: Vasily Gorbik Cc: Stafford Horne Cc: David S. Miller Cc: Johannes Berg Cc: Brian Cain Cc: Richard Henderson Cc: Richard Weinberger Cc: Benjamin Herrenschmidt Cc: Thomas Gleixner Cc: Janosch Frank Cc: Albert Ou Cc: Anton Ivanov Cc: Dave Hansen Cc: Borislav Petkov Cc: Sven Schnelle Cc: Andrea Arcangeli Cc: James Bottomley Cc: Al Viro Cc: Alexander Gordeev Cc: Jonas Bonn Cc: Will Deacon Cc: Vlastimil Babka Cc: Michal Simek Cc: Matt Turner Cc: Paul Mackerras Cc: David Hildenbrand Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Stefan Kristiansson Cc: Paul Walmsley Cc: Ivan Kokshaysky Cc: Chris Zankel Cc: Hugh Dickins Cc: Dinh Nguyen Cc: Rich Felker Cc: H. Peter Anvin Cc: Andy Lutomirski Cc: Thomas Bogendoerfer Cc: Helge Deller Cc: Yoshinori Sato Signed-off-by: Andrew Morton

sparc/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

2022-04-29T06:16:13Z

This defines and exports a platform specific custom vm_get_page_prot() via subscribing ARCH_HAS_VM_GET_PAGE_PROT. It localizes arch_vm_get_page_prot() as sparc_vm_get_page_prot() and moves near vm_get_page_prot(). Link: https://lkml.kernel.org/r/20220414062125.609297-5-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Acked-by: David S. Miller Reviewed-by: Khalid Aziz Reviewed-by: Christophe Leroy Cc: Khalid Aziz Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Ingo Molnar Cc: Michael Ellerman Cc: Paul Mackerras Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton

Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

2022-03-24T01:03:08Z

Pull asm-generic updates from Arnd Bergmann: "There are three sets of updates for 5.18 in the asm-generic tree: - The set_fs()/get_fs() infrastructure gets removed for good. This was already gone from all major architectures, but now we can finally remove it everywhere, which loses some particularly tricky and error-prone code. There is a small merge conflict against a parisc cleanup, the solution is to use their new version. - The nds32 architecture ends its tenure in the Linux kernel. The hardware is still used and the code is in reasonable shape, but the mainline port is not actively maintained any more, as all remaining users are thought to run vendor kernels that would never be updated to a future release. - A series from Masahiro Yamada cleans up some of the uapi header files to pass the compile-time checks" * tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits) nds32: Remove the architecture uaccess: remove CONFIG_SET_FS ia64: remove CONFIG_SET_FS support sh: remove CONFIG_SET_FS support sparc64: remove CONFIG_SET_FS support lib/test_lockup: fix kernel pointer check for separate address spaces uaccess: generalize access_ok() uaccess: fix type mismatch warnings from access_ok() arm64: simplify access_ok() m68k: fix access_ok for coldfire MIPS: use simpler access_ok() MIPS: Handle address errors for accesses above CPU max virtual user address uaccess: add generic __{get,put}_kernel_nofault nios2: drop access_ok() check from __put_user() x86: use more conventional access_ok() definition x86: remove __range_not_ok() sparc64: add __{get,put}_kernel_nofault() nds32: fix access_ok() checks in get/put_user uaccess: fix nios2 and microblaze get_user_8() sparc64: fix building assembly files ...

mm: merge pte_mkhuge() call into arch_make_huge_pte()

2022-03-22T22:57:04Z

Each call into pte_mkhuge() is invariably followed by arch_make_huge_pte(). Instead arch_make_huge_pte() can accommodate pte_mkhuge() at the beginning. This updates generic fallback stub for arch_make_huge_pte() and available platforms definitions. This makes huge pte creation much cleaner and easier to follow. Link: https://lkml.kernel.org/r/1643860669-26307-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Reviewed-by: Christophe Leroy Acked-by: Mike Kravetz Acked-by: Catalin Marinas Cc: Will Deacon Cc: Michael Ellerman Cc: Paul Mackerras Cc: "David S. Miller" Cc: Mike Kravetz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sparc64: remove CONFIG_SET_FS support

2022-02-25T08:36:06Z

sparc64 uses address space identifiers to differentiate between kernel and user space, using ASI_P for kernel threads but ASI_AIUS for normal user space, with the option of changing between them. As nothing really changes the ASI any more, just hardcode ASI_AIUS everywhere. Kernel threads are not allowed to access __user pointers anyway. Signed-off-by: Arnd Bergmann

mm: remove redundant check about FAULT_FLAG_ALLOW_RETRY bit

2022-01-15T14:30:27Z

Since commit 4064b9827063 ("mm: allow VM_FAULT_RETRY for multiple times") allowed VM_FAULT_RETRY for multiple times, the FAULT_FLAG_ALLOW_RETRY bit of fault_flag will not be changed in the page fault path, so the following check is no longer needed: flags & FAULT_FLAG_ALLOW_RETRY So just remove it. [akpm@linux-foundation.org: coding style fixes] Link: https://lkml.kernel.org/r/20211110123358.36511-1-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Cc: Peter Zijlstra Cc: Ingo Molnar Cc: David Hildenbrand Cc: Kirill Shutemov Cc: Peter Xu Cc: Muchun Song Cc: Chengming Zhou Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

signal/sparc: In setup_tsb_params convert open coded BUG into BUG

2021-10-25T20:56:29Z

The function setup_tsb_params has exactly one caller tsb_grow. The function tsb_grow passes in a tsb_bytes value that is between 8192 and 1048576 inclusive, and is guaranteed to be a power of 2. The function setup_tsb_params verifies this property with a switch statement and then prints an error and causes the task to exit if this is not true. In practice that print statement can never be reached because tsb_grow never passes in a bad tsb_size. So if tsb_size ever gets a bad value that is a kernel bug. So replace the do_exit which is effectively an open coded version of BUG() with an actuall call to BUG(). Making it clearer that this is a case that can never, and should never happen. Cc: David Miller Cc: sparclinux@vger.kernel.org Link: https://lkml.kernel.org/r/20211020174406.17889-8-ebiederm@xmission.com Signed-off-by: Eric W. Biederman

signal/sparc32: Remove unreachable do_exit in do_sparc_fault

2021-10-20T18:09:56Z

The call to do_exit in do_sparc_fault immediately follows a call to unhandled_fault. The function unhandled_fault never returns. This means the call to do_exit can never be reached. Cc: David Miller Cc: sparclinux@vger.kernel.org Fixes: 2.3.41 Link: https://lkml.kernel.org/r/20211020174406.17889-4-ebiederm@xmission.com Signed-off-by: Eric W. Biederman