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path: root/arch/loongarch/mm/tlbex.S
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2023-06-29LoongArch: Introduce hardware page table walkerHuacai Chen
Loongson-3A6000 and newer processors have hardware page table walker (PTW) support. PTW can handle all fastpaths of TLBI/TLBL/TLBS/TLBM exceptions by hardware, software only need to handle slowpaths (page faults). BTW, PTW doesn't append _PAGE_MODIFIED for page table entries, so we change pmd_dirty() and pte_dirty() to also check _PAGE_DIRTY for the "dirty" attribute. Signed-off-by: Liang Gao <gaoliang@loongson.cn> Signed-off-by: Jun Yi <yijun@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-06-29LoongArch: Support dbar with different hintsHuacai Chen
Traditionally, LoongArch uses "dbar 0" (full completion barrier) for everything. But the full completion barrier is a performance killer, so Loongson-3A6000 and newer processors have made finer granularity hints available: Bit4: ordering or completion (0: completion, 1: ordering) Bit3: barrier for previous read (0: true, 1: false) Bit2: barrier for previous write (0: true, 1: false) Bit1: barrier for succeeding read (0: true, 1: false) Bit0: barrier for succeeding write (0: true, 1: false) Hint 0x700: barrier for "read after read" from the same address, which is needed by LL-SC loops on old models (dbar 0x700 behaves the same as nop if such reordering is disabled on new models). This patch makes use of the various new hints for different kinds of memory barriers. It brings performance improvements on Loongson-3A6000 series, while not affecting the existing models because all variants are treated as 'dbar 0' there. Why override queued_spin_unlock()? After commit 01e3b958efe85a26d9b ("drivers: Remove explicit invocations of mmiowb()") we need a completion barrier in queued_spin_unlock(), but the generic implementation use smp_store_release() which only provide an ordering barrier. Signed-off-by: Jun Yi <yijun@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25LoongArch: Add la_abs macro implementationYouling Tang
Use the "la_abs macro" instead of the "la.abs pseudo instruction" to prepare for the subsequent PIE kernel. When PIE is not enabled, la_abs is equivalent to la.abs. Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-02-25LoongArch: Use la.pcrel instead of la.abs when it's trivially possibleXi Ruoyao
Let's start to kill la.abs in preparation for the subsequent support of the PIE kernel. BTW, Re-tab the indention in arch/loongarch/kernel/entry.S for alignment. Signed-off-by: Xi Ruoyao <xry111@xry111.site> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-12-08LoongArch: mm: Fix huge page entry update for virtual machineHuacai Chen
In virtual machine (guest mode), the tlbwr instruction can not write the last entry of MTLB, so we need to make it non-present by invtlb and then write it by tlbfill. This also simplify the whole logic. Signed-off-by: Rui Wang <wangrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-10-12LoongArch: mm: Refactor TLB exception handlersRui Wang
This patch simplifies TLB load, store and modify exception handlers: 1. Reduce instructions, such as alu/csr and memory access; 2. Execute tlb search instruction only in the fast path; 3. Return directly from the fast path for both normal and huge pages; 4. Re-tab the assembly for better vertical alignment. And fixes the concurrent modification issue of fast path for huge pages. This issue will occur in the following steps: CPU-1 (In TLB exception) CPU-2 (In THP splitting) 1: Load PMD entry (HUGE=1) 2: Goto huge path 3: Store PMD entry (HUGE=0) 4: Reload PMD entry (HUGE=0) 5: Fill TLB entry (PA is incorrect) This patch also slightly improves the TLB processing performance: * Normal pages: 2.15%, Huge pages: 1.70%. #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> int main(int argc, char *argv[]) { size_t page_size; size_t mem_size; size_t off; void *base; int flags; int i; if (argc < 2) { fprintf(stderr, "%s MEM_SIZE [HUGE]\n", argv[0]); return -1; } page_size = sysconf(_SC_PAGESIZE); flags = MAP_PRIVATE | MAP_ANONYMOUS; mem_size = strtoul(argv[1], NULL, 10); if (argc > 2) flags |= MAP_HUGETLB; for (i = 0; i < 10; i++) { base = mmap(NULL, mem_size, PROT_READ, flags, -1, 0); if (base == MAP_FAILED) { fprintf(stderr, "Map memory failed!\n"); return -1; } for (off = 0; off < mem_size; off += page_size) *(volatile int *)(base + off); munmap(base, mem_size); } return 0; } Signed-off-by: Rui Wang <wangrui@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-08-05Merge tag 'mm-stable-2022-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...
2022-07-29LoongArch: Re-tab the assembly filesWANG Xuerui
Reflow the *.S files for better stylistic consistency, namely hard tabs after mnemonic position, and vertical alignment of the first operand with hard tabs. Tab width is obviously 8. Some pre-existing intra-block vertical alignments are preserved. Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29LoongArch: Simplify "BLT foo, zero" with BLTZWANG Xuerui
Support for the syntactic sugar is present in upstream binutils port from the beginning. Use it for shorter lines and better consistency. Generated code should be identical. Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29LoongArch: Simplify "BEQ/BNE foo, zero" with BEQZ/BNEZWANG Xuerui
While B{EQ,NE}Z and B{EQ,NE} are different instructions, and the vastly expanded range for branch destination does not really matter in the few cases touched, use the B{EQ,NE}Z where possible for shorter lines and better consistency (e.g. some places used "BEQ foo, zero", while some used "BEQ zero, foo"). Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29LoongArch: Use the "jr" pseudo-instruction where applicableWANG Xuerui
Some of the assembly code in the LoongArch port likely originated from a time when the assembler did not support pseudo-instructions like "move" or "jr", so the desugared form was used and readability suffers (to a minor degree) as a result. As the upstream toolchain supports these pseudo-instructions from the beginning, migrate the existing few usages to them for better readability. Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29LoongArch: Use ABI names of registers where appropriateWANG Xuerui
Some of the assembly in the LoongArch port seem to come from a prehistoric time, when the assembler didn't even have support for the ABI names we all come to know and love, thus used raw register numbers which hampered readability. The usages are found with a regex match inside arch/loongarch, then manually adjusted for those non-definitions. Signed-off-by: WANG Xuerui <git@xen0n.name> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-17loongarch: drop definition of PTE_ORDERMike Rapoport
This is the order of the page table allocation, not the order of a PTE. Since its always hardwired to 0, simply drop it. Link: https://lkml.kernel.org/r/20220703141203.147893-10-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Xuerui Wang <kernel@xen0n.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-03LoongArch: Add multi-processor (SMP) supportHuacai Chen
LoongArch-based procesors have 4, 8 or 16 cores per package. This patch adds multi-processor (SMP) support for LoongArch. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-06-03LoongArch: Add memory managementHuacai Chen
Add memory management support for LoongArch, including: cache and tlb management, page fault handling and ioremap/mmap support. Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>