[PATCH OLK-6.6 0/4] LoongArch: backport patches from upstream
Bibo Mao (1): LoongArch: Set initial pte entry with PAGE_GLOBAL for kernel space Huacai Chen (3): LoongArch: Use accessors to page table entries instead of direct dereference LoongArch: Remove superfluous flush_dcache_page() definition LoongArch: Improve hardware page table walker arch/loongarch/include/asm/atomic.h | 2 + arch/loongarch/include/asm/cacheflush.h | 3 - arch/loongarch/include/asm/hugetlb.h | 4 +- arch/loongarch/include/asm/kfence.h | 6 +- arch/loongarch/include/asm/mmu_context.h | 35 +++++++--- arch/loongarch/include/asm/pgalloc.h | 11 ++++ arch/loongarch/include/asm/pgtable.h | 83 ++++++++++-------------- arch/loongarch/kvm/mmu.c | 8 +-- arch/loongarch/mm/fault.c | 41 ++++++++++++ arch/loongarch/mm/hugetlbpage.c | 6 +- arch/loongarch/mm/init.c | 12 ++-- arch/loongarch/mm/kasan_init.c | 10 +-- arch/loongarch/mm/pgtable.c | 22 ++++++- include/linux/mm.h | 3 +- mm/kasan/init.c | 8 ++- mm/sparse-vmemmap.c | 5 ++ 16 files changed, 173 insertions(+), 86 deletions(-) -- 2.33.0
From: Huacai Chen <chenhuacai@loongson.cn> mainline inclusion from mainline-v6.11-rc3 commit 4574815abf43e2bf05643e1b3f7a2e5d6df894f0 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB7Y4K Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- As very well explained in commit 20a004e7b017cce282 ("arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose page table walker can modify the PTE in parallel must use READ_ONCE()/ WRITE_ONCE() macro to avoid any compiler transformation. So apply that to LoongArch which is such an architecture, in order to avoid potential problems. Similar to commit edf955647269422e ("riscv: Use accessors to page table entries instead of direct dereference"). Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> --- arch/loongarch/include/asm/hugetlb.h | 4 +-- arch/loongarch/include/asm/kfence.h | 6 ++-- arch/loongarch/include/asm/pgtable.h | 48 +++++++++++++++++----------- arch/loongarch/kvm/mmu.c | 8 ++--- arch/loongarch/mm/hugetlbpage.c | 6 ++-- arch/loongarch/mm/init.c | 10 +++--- arch/loongarch/mm/kasan_init.c | 10 +++--- arch/loongarch/mm/pgtable.c | 2 +- 8 files changed, 52 insertions(+), 42 deletions(-) diff --git a/arch/loongarch/include/asm/hugetlb.h b/arch/loongarch/include/asm/hugetlb.h index aa44b3fe43dd..5da32c00d483 100644 --- a/arch/loongarch/include/asm/hugetlb.h +++ b/arch/loongarch/include/asm/hugetlb.h @@ -34,7 +34,7 @@ static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_t clear; - pte_t pte = *ptep; + pte_t pte = ptep_get(ptep); pte_val(clear) = (unsigned long)invalid_pte_table; set_pte_at(mm, addr, ptep, clear); @@ -65,7 +65,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep, pte_t pte, int dirty) { - int changed = !pte_same(*ptep, pte); + int changed = !pte_same(ptep_get(ptep), pte); if (changed) { set_pte_at(vma->vm_mm, addr, ptep, pte); diff --git a/arch/loongarch/include/asm/kfence.h b/arch/loongarch/include/asm/kfence.h index 6c82aea1c993..2835b41d2a84 100644 --- a/arch/loongarch/include/asm/kfence.h +++ b/arch/loongarch/include/asm/kfence.h @@ -43,13 +43,13 @@ static inline bool kfence_protect_page(unsigned long addr, bool protect) { pte_t *pte = virt_to_kpte(addr); - if (WARN_ON(!pte) || pte_none(*pte)) + if (WARN_ON(!pte) || pte_none(ptep_get(pte))) return false; if (protect) - set_pte(pte, __pte(pte_val(*pte) & ~(_PAGE_VALID | _PAGE_PRESENT))); + set_pte(pte, __pte(pte_val(ptep_get(pte)) & ~(_PAGE_VALID | _PAGE_PRESENT))); else - set_pte(pte, __pte(pte_val(*pte) | (_PAGE_VALID | _PAGE_PRESENT))); + set_pte(pte, __pte(pte_val(ptep_get(pte)) | (_PAGE_VALID | _PAGE_PRESENT))); preempt_disable(); local_flush_tlb_one(addr); diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h index f5300b66a39d..6776f147ffde 100644 --- a/arch/loongarch/include/asm/pgtable.h +++ b/arch/loongarch/include/asm/pgtable.h @@ -106,6 +106,9 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; #define KFENCE_AREA_START (VMEMMAP_END + 1) #define KFENCE_AREA_END (KFENCE_AREA_START + KFENCE_AREA_SIZE - 1) +#define ptep_get(ptep) READ_ONCE(*(ptep)) +#define pmdp_get(pmdp) READ_ONCE(*(pmdp)) + #define pte_ERROR(e) \ pr_err("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e)) #ifndef __PAGETABLE_PMD_FOLDED @@ -147,11 +150,6 @@ static inline int p4d_present(p4d_t p4d) return p4d_val(p4d) != (unsigned long)invalid_pud_table; } -static inline void p4d_clear(p4d_t *p4dp) -{ - p4d_val(*p4dp) = (unsigned long)invalid_pud_table; -} - static inline pud_t *p4d_pgtable(p4d_t p4d) { return (pud_t *)p4d_val(p4d); @@ -159,7 +157,12 @@ static inline pud_t *p4d_pgtable(p4d_t p4d) static inline void set_p4d(p4d_t *p4d, p4d_t p4dval) { - *p4d = p4dval; + WRITE_ONCE(*p4d, p4dval); +} + +static inline void p4d_clear(p4d_t *p4dp) +{ + set_p4d(p4dp, __p4d((unsigned long)invalid_pud_table)); } #define p4d_phys(p4d) PHYSADDR(p4d_val(p4d)) @@ -193,17 +196,20 @@ static inline int pud_present(pud_t pud) return pud_val(pud) != (unsigned long)invalid_pmd_table; } -static inline void pud_clear(pud_t *pudp) +static inline pmd_t *pud_pgtable(pud_t pud) { - pud_val(*pudp) = ((unsigned long)invalid_pmd_table); + return (pmd_t *)pud_val(pud); } -static inline pmd_t *pud_pgtable(pud_t pud) +static inline void set_pud(pud_t *pud, pud_t pudval) { - return (pmd_t *)pud_val(pud); + WRITE_ONCE(*pud, pudval); } -#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while (0) +static inline void pud_clear(pud_t *pudp) +{ + set_pud(pudp, __pud((unsigned long)invalid_pmd_table)); +} #define pud_phys(pud) PHYSADDR(pud_val(pud)) #define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT)) @@ -231,12 +237,15 @@ static inline int pmd_present(pmd_t pmd) return pmd_val(pmd) != (unsigned long)invalid_pte_table; } -static inline void pmd_clear(pmd_t *pmdp) +static inline void set_pmd(pmd_t *pmd, pmd_t pmdval) { - pmd_val(*pmdp) = ((unsigned long)invalid_pte_table); + WRITE_ONCE(*pmd, pmdval); } -#define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while (0) +static inline void pmd_clear(pmd_t *pmdp) +{ + set_pmd(pmdp, __pmd((unsigned long)invalid_pte_table)); +} #define pmd_phys(pmd) PHYSADDR(pmd_val(pmd)) @@ -314,7 +323,8 @@ extern void paging_init(void); static inline void set_pte(pte_t *ptep, pte_t pteval) { - *ptep = pteval; + WRITE_ONCE(*ptep, pteval); + if (pte_val(pteval) & _PAGE_GLOBAL) { pte_t *buddy = ptep_buddy(ptep); /* @@ -341,8 +351,8 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp) : [global] "r" (page_global)); #else /* !CONFIG_SMP */ - if (pte_none(*buddy)) - pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL; + if (pte_none(ptep_get(buddy))) + WRITE_ONCE(*buddy, __pte(pte_val(ptep_get(buddy)) | _PAGE_GLOBAL)); #endif /* CONFIG_SMP */ } } @@ -350,7 +360,7 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { /* Preserve global status for the pair */ - if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL) + if (pte_val(ptep_get(ptep_buddy(ptep))) & _PAGE_GLOBAL) set_pte(ptep, __pte(_PAGE_GLOBAL)); else set_pte(ptep, __pte(0)); @@ -591,7 +601,7 @@ static inline pmd_t pmd_mkinvalid(pmd_t pmd) static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long address, pmd_t *pmdp) { - pmd_t old = *pmdp; + pmd_t old = pmdp_get(pmdp); pmd_clear(pmdp); diff --git a/arch/loongarch/kvm/mmu.c b/arch/loongarch/kvm/mmu.c index 915f17527893..3a0bd3486c86 100644 --- a/arch/loongarch/kvm/mmu.c +++ b/arch/loongarch/kvm/mmu.c @@ -727,19 +727,19 @@ static int host_pfn_mapping_level(struct kvm *kvm, gfn_t gfn, * value) and then p*d_offset() walks into the target huge page instead * of the old page table (sees the new value). */ - pgd = READ_ONCE(*pgd_offset(kvm->mm, hva)); + pgd = pgdp_get(pgd_offset(kvm->mm, hva)); if (pgd_none(pgd)) goto out; - p4d = READ_ONCE(*p4d_offset(&pgd, hva)); + p4d = p4dp_get(p4d_offset(&pgd, hva)); if (p4d_none(p4d) || !p4d_present(p4d)) goto out; - pud = READ_ONCE(*pud_offset(&p4d, hva)); + pud = pudp_get(pud_offset(&p4d, hva)); if (pud_none(pud) || !pud_present(pud)) goto out; - pmd = READ_ONCE(*pmd_offset(&pud, hva)); + pmd = pmdp_get(pmd_offset(&pud, hva)); if (pmd_none(pmd) || !pmd_present(pmd)) goto out; diff --git a/arch/loongarch/mm/hugetlbpage.c b/arch/loongarch/mm/hugetlbpage.c index 1e76fcb83093..62ddcea0aa14 100644 --- a/arch/loongarch/mm/hugetlbpage.c +++ b/arch/loongarch/mm/hugetlbpage.c @@ -39,11 +39,11 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, pmd_t *pmd = NULL; pgd = pgd_offset(mm, addr); - if (pgd_present(*pgd)) { + if (pgd_present(pgdp_get(pgd))) { p4d = p4d_offset(pgd, addr); - if (p4d_present(*p4d)) { + if (p4d_present(p4dp_get(p4d))) { pud = pud_offset(p4d, addr); - if (pud_present(*pud)) + if (pud_present(pudp_get(pud))) pmd = pmd_offset(pud, addr); } } diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c index 4dd53427f657..71fa4b773eb3 100644 --- a/arch/loongarch/mm/init.c +++ b/arch/loongarch/mm/init.c @@ -140,7 +140,7 @@ void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node, int __meminit vmemmap_check_pmd(pmd_t *pmd, int node, unsigned long addr, unsigned long next) { - int huge = pmd_val(*pmd) & _PAGE_HUGE; + int huge = pmd_val(pmdp_get(pmd)) & _PAGE_HUGE; if (huge) vmemmap_verify((pte_t *)pmd, node, addr, next); @@ -172,7 +172,7 @@ pte_t * __init populate_kernel_pte(unsigned long addr) pud_t *pud; pmd_t *pmd; - if (p4d_none(*p4d)) { + if (p4d_none(p4dp_get(p4d))) { pud = memblock_alloc(PAGE_SIZE, PAGE_SIZE); if (!pud) panic("%s: Failed to allocate memory\n", __func__); @@ -183,7 +183,7 @@ pte_t * __init populate_kernel_pte(unsigned long addr) } pud = pud_offset(p4d, addr); - if (pud_none(*pud)) { + if (pud_none(pudp_get(pud))) { pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE); if (!pmd) panic("%s: Failed to allocate memory\n", __func__); @@ -194,7 +194,7 @@ pte_t * __init populate_kernel_pte(unsigned long addr) } pmd = pmd_offset(pud, addr); - if (!pmd_present(*pmd)) { + if (!pmd_present(pmdp_get(pmd))) { pte_t *pte; pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); @@ -215,7 +215,7 @@ void __init __set_fixmap(enum fixed_addresses idx, BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); ptep = populate_kernel_pte(addr); - if (!pte_none(*ptep)) { + if (!pte_none(ptep_get(ptep))) { pte_ERROR(*ptep); return; } diff --git a/arch/loongarch/mm/kasan_init.c b/arch/loongarch/mm/kasan_init.c index c608adc99845..427d6b1aec09 100644 --- a/arch/loongarch/mm/kasan_init.c +++ b/arch/loongarch/mm/kasan_init.c @@ -105,7 +105,7 @@ static phys_addr_t __init kasan_alloc_zeroed_page(int node) static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node, bool early) { - if (__pmd_none(early, READ_ONCE(*pmdp))) { + if (__pmd_none(early, pmdp_get(pmdp))) { phys_addr_t pte_phys = early ? __pa_symbol(kasan_early_shadow_pte) : kasan_alloc_zeroed_page(node); if (!early) @@ -118,7 +118,7 @@ static pte_t *__init kasan_pte_offset(pmd_t *pmdp, unsigned long addr, int node, static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node, bool early) { - if (__pud_none(early, READ_ONCE(*pudp))) { + if (__pud_none(early, pudp_get(pudp))) { phys_addr_t pmd_phys = early ? __pa_symbol(kasan_early_shadow_pmd) : kasan_alloc_zeroed_page(node); if (!early) @@ -131,7 +131,7 @@ static pmd_t *__init kasan_pmd_offset(pud_t *pudp, unsigned long addr, int node, static pud_t *__init kasan_pud_offset(p4d_t *p4dp, unsigned long addr, int node, bool early) { - if (__p4d_none(early, READ_ONCE(*p4dp))) { + if (__p4d_none(early, p4dp_get(p4dp))) { phys_addr_t pud_phys = early ? __pa_symbol(kasan_early_shadow_pud) : kasan_alloc_zeroed_page(node); if (!early) @@ -154,7 +154,7 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr, : kasan_alloc_zeroed_page(node); next = addr + PAGE_SIZE; set_pte(ptep, pfn_pte(__phys_to_pfn(page_phys), PAGE_KERNEL)); - } while (ptep++, addr = next, addr != end && __pte_none(early, READ_ONCE(*ptep))); + } while (ptep++, addr = next, addr != end && __pte_none(early, ptep_get(ptep))); } static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr, @@ -166,7 +166,7 @@ static void __init kasan_pmd_populate(pud_t *pudp, unsigned long addr, do { next = pmd_addr_end(addr, end); kasan_pte_populate(pmdp, addr, next, node, early); - } while (pmdp++, addr = next, addr != end && __pmd_none(early, READ_ONCE(*pmdp))); + } while (pmdp++, addr = next, addr != end && __pmd_none(early, pmdp_get(pmdp))); } static void __init kasan_pud_populate(p4d_t *p4dp, unsigned long addr, diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c index 2aae72e63871..6a038a27373a 100644 --- a/arch/loongarch/mm/pgtable.c +++ b/arch/loongarch/mm/pgtable.c @@ -128,7 +128,7 @@ pmd_t mk_pmd(struct page *page, pgprot_t prot) void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd) { - *pmdp = pmd; + WRITE_ONCE(*pmdp, pmd); flush_tlb_all(); } -- 2.33.0
From: Huacai Chen <chenhuacai@loongson.cn> mainline inclusion from mainline-v6.9-rc1 commit 82bf60a6fed806d57e284a1fb40dbc1ad5097611 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB7Y4K Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- LoongArch doesn't have cache aliases, so flush_dcache_page() is a no-op. There is a generic implementation for this case in include/asm-generic/ cacheflush.h. So remove the superfluous flush_dcache_page() definition, which also silences such build warnings: In file included from crypto/scompress.c:12: include/crypto/scatterwalk.h: In function 'scatterwalk_pagedone': include/crypto/scatterwalk.h:76:30: warning: variable 'page' set but not used [-Wunused-but-set-variable] 76 | struct page *page; | ^~~~ crypto/scompress.c: In function 'scomp_acomp_comp_decomp':
crypto/scompress.c:174:38: warning: unused variable 'dst_page' [-Wunused-variable] 174 | struct page *dst_page = sg_page(req->dst); |
Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202403091614.NeUw5zcv-lkp@intel.com/ Suggested-by: Barry Song <baohua@kernel.org> Acked-by: Barry Song <baohua@kernel.org> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> --- arch/loongarch/include/asm/cacheflush.h | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/loongarch/include/asm/cacheflush.h b/arch/loongarch/include/asm/cacheflush.h index 80bd74106985..f8754d08a31a 100644 --- a/arch/loongarch/include/asm/cacheflush.h +++ b/arch/loongarch/include/asm/cacheflush.h @@ -37,8 +37,6 @@ void local_flush_icache_range(unsigned long start, unsigned long end); #define flush_icache_range local_flush_icache_range #define flush_icache_user_range local_flush_icache_range -#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0 - #define flush_cache_all() do { } while (0) #define flush_cache_mm(mm) do { } while (0) #define flush_cache_dup_mm(mm) do { } while (0) @@ -47,7 +45,6 @@ void local_flush_icache_range(unsigned long start, unsigned long end); #define flush_cache_vmap(start, end) do { } while (0) #define flush_cache_vunmap(start, end) do { } while (0) #define flush_icache_user_page(vma, page, addr, len) do { } while (0) -#define flush_dcache_page(page) do { } while (0) #define flush_dcache_mmap_lock(mapping) do { } while (0) #define flush_dcache_mmap_unlock(mapping) do { } while (0) -- 2.33.0
From: Huacai Chen <chenhuacai@loongson.cn> linux-next inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB7Y4K Reference: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?... -------------------------------- LoongArch has similar problems explained in commit 7f0b1bf04511348995d6 ("arm64: Fix barriers used for page table modifications"), when hardware page table walker (PTW) enabled, speculative accesses may cause spurious page fault in kernel space. Theoretically, in order to completely avoid spurious page fault we need a "dbar + ibar" pair between the page table modifications and the subsequent memory accesses using the corresponding virtual address. But "ibar" is too heavy for performace, so we only use a "dbar 0b11000" in set_pte(). And let spurious_fault() filter the rest rare spurious page faults which should be avoided by "ibar". Besides, we replace the llsc loop with amo in set_pte() which has better performace, and refactor mmu_context.h to 1) avoid any load/store/branch instructions between the writing of CSR.ASID & CSR.PGDL, 2) ensure flush tlb operation is after updating ASID. Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> --- arch/loongarch/include/asm/atomic.h | 2 ++ arch/loongarch/include/asm/mmu_context.h | 35 +++++++++++++++----- arch/loongarch/include/asm/pgtable.h | 32 ++++++++---------- arch/loongarch/mm/fault.c | 41 ++++++++++++++++++++++++ 4 files changed, 83 insertions(+), 27 deletions(-) diff --git a/arch/loongarch/include/asm/atomic.h b/arch/loongarch/include/asm/atomic.h index e27f0c72d324..2143202cb380 100644 --- a/arch/loongarch/include/asm/atomic.h +++ b/arch/loongarch/include/asm/atomic.h @@ -15,6 +15,7 @@ #define __LL "ll.w " #define __SC "sc.w " #define __AMADD "amadd.w " +#define __AMOR "amor.w " #define __AMAND_DB "amand_db.w " #define __AMOR_DB "amor_db.w " #define __AMXOR_DB "amxor_db.w " @@ -22,6 +23,7 @@ #define __LL "ll.d " #define __SC "sc.d " #define __AMADD "amadd.d " +#define __AMOR "amor.d " #define __AMAND_DB "amand_db.d " #define __AMOR_DB "amor_db.d " #define __AMXOR_DB "amxor_db.d " diff --git a/arch/loongarch/include/asm/mmu_context.h b/arch/loongarch/include/asm/mmu_context.h index 9f97c3453b9c..304363bd3935 100644 --- a/arch/loongarch/include/asm/mmu_context.h +++ b/arch/loongarch/include/asm/mmu_context.h @@ -49,12 +49,12 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) /* Normal, classic get_new_mmu_context */ static inline void -get_new_mmu_context(struct mm_struct *mm, unsigned long cpu) +get_new_mmu_context(struct mm_struct *mm, unsigned long cpu, bool *need_flush) { u64 asid = asid_cache(cpu); if (!((++asid) & cpu_asid_mask(&cpu_data[cpu]))) - local_flush_tlb_user(); /* start new asid cycle */ + *need_flush = true; /* start new asid cycle */ cpu_context(cpu, mm) = asid_cache(cpu) = asid; } @@ -74,21 +74,34 @@ init_new_context(struct task_struct *tsk, struct mm_struct *mm) return 0; } +static inline void atomic_update_pgd_asid(unsigned long asid, unsigned long pgdl) +{ + __asm__ __volatile__( + "csrwr %[pgdl_val], %[pgdl_reg] \n\t" + "csrwr %[asid_val], %[asid_reg] \n\t" + : [asid_val] "+r" (asid), [pgdl_val] "+r" (pgdl) + : [asid_reg] "i" (LOONGARCH_CSR_ASID), [pgdl_reg] "i" (LOONGARCH_CSR_PGDL) + : "memory" + ); +} + static inline void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { + bool need_flush = false; unsigned int cpu = smp_processor_id(); /* Check if our ASID is of an older version and thus invalid */ if (!asid_valid(next, cpu)) - get_new_mmu_context(next, cpu); - - write_csr_asid(cpu_asid(cpu, next)); + get_new_mmu_context(next, cpu, &need_flush); if (next != &init_mm) - csr_write64((unsigned long)next->pgd, LOONGARCH_CSR_PGDL); + atomic_update_pgd_asid(cpu_asid(cpu, next), (unsigned long)next->pgd); else - csr_write64((unsigned long)invalid_pg_dir, LOONGARCH_CSR_PGDL); + atomic_update_pgd_asid(cpu_asid(cpu, next), (unsigned long)invalid_pg_dir); + + if (need_flush) + local_flush_tlb_user(); /* Flush tlb after update ASID */ /* * Mark current->active_mm as not "active" anymore. @@ -135,9 +148,15 @@ drop_mmu_context(struct mm_struct *mm, unsigned int cpu) asid = read_csr_asid() & cpu_asid_mask(¤t_cpu_data); if (asid == cpu_asid(cpu, mm)) { + bool need_flush = false; + if (!current->mm || (current->mm == mm)) { - get_new_mmu_context(mm, cpu); + get_new_mmu_context(mm, cpu, &need_flush); + write_csr_asid(cpu_asid(cpu, mm)); + if (need_flush) + local_flush_tlb_user(); /* Flush tlb after update ASID */ + goto out; } } diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h index 6776f147ffde..5db17c367b1e 100644 --- a/arch/loongarch/include/asm/pgtable.h +++ b/arch/loongarch/include/asm/pgtable.h @@ -331,29 +331,23 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) * Make sure the buddy is global too (if it's !none, * it better already be global) */ + if (pte_none(ptep_get(buddy))) { #ifdef CONFIG_SMP - /* - * For SMP, multiple CPUs can race, so we need to do - * this atomically. - */ - unsigned long page_global = _PAGE_GLOBAL; - unsigned long tmp; - - __asm__ __volatile__ ( - "1:" __LL "%[tmp], %[buddy] \n" - " bnez %[tmp], 2f \n" - " or %[tmp], %[tmp], %[global] \n" - __SC "%[tmp], %[buddy] \n" - " beqz %[tmp], 1b \n" - " nop \n" - "2: \n" - __WEAK_LLSC_MB - : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp) - : [global] "r" (page_global)); + /* + * For SMP, multiple CPUs can race, so we need + * to do this atomically. + */ + __asm__ __volatile__( + __AMOR "$zero, %[global], %[buddy] \n" + : [buddy] "+ZB" (buddy->pte) + : [global] "r" (_PAGE_GLOBAL) + : "memory"); + + DBAR(0b11000); /* o_wrw = 0b11000 */ #else /* !CONFIG_SMP */ - if (pte_none(ptep_get(buddy))) WRITE_ONCE(*buddy, __pte(pte_val(ptep_get(buddy)) | _PAGE_GLOBAL)); #endif /* CONFIG_SMP */ + } } } diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c index 97b40defde06..deefd9617d00 100644 --- a/arch/loongarch/mm/fault.c +++ b/arch/loongarch/mm/fault.c @@ -31,11 +31,52 @@ int show_unhandled_signals = 1; +static int __kprobes spurious_fault(unsigned long write, unsigned long address) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + if (!(address & __UA_LIMIT)) + return 0; + + pgd = pgd_offset_k(address); + if (!pgd_present(pgdp_get(pgd))) + return 0; + + p4d = p4d_offset(pgd, address); + if (!p4d_present(p4dp_get(p4d))) + return 0; + + pud = pud_offset(p4d, address); + if (!pud_present(pudp_get(pud))) + return 0; + + pmd = pmd_offset(pud, address); + if (!pmd_present(pmdp_get(pmd))) + return 0; + + if (pmd_leaf(*pmd)) { + return write ? pmd_write(pmdp_get(pmd)) : 1; + } else { + pte = pte_offset_kernel(pmd, address); + if (!pte_present(ptep_get(pte))) + return 0; + + return write ? pte_write(ptep_get(pte)) : 1; + } +} + static void __kprobes no_context(struct pt_regs *regs, unsigned long write, unsigned long address) { const int field = sizeof(unsigned long) * 2; + if (spurious_fault(write, address)) + return; + /* Are we prepared to handle this kernel fault? */ if (fixup_exception(regs)) return; -- 2.33.0
From: Bibo Mao <maobibo@loongson.cn> linux-next inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IB7Y4K Reference: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?... -------------------------------- There are two pages in one TLB entry on LoongArch system. For kernel space, it requires both two pte entries (buddies) with PAGE_GLOBAL bit set, otherwise HW treats it as non-global tlb, there will be potential problems if tlb entry for kernel space is not global. Such as fail to flush kernel tlb with the function local_flush_tlb_kernel_range() which supposed only flush tlb with global bit. Kernel address space areas include percpu, vmalloc, vmemmap, fixmap and kasan areas. For these areas both two consecutive page table entries should be enabled with PAGE_GLOBAL bit. So with function set_pte() and pte_clear(), pte buddy entry is checked and set besides its own pte entry. However it is not atomic operation to set both two pte entries, there is problem with test_vmalloc test case. So function kernel_pte_init() is added to init a pte table when it is created for kernel address space, and the default initial pte value is PAGE_GLOBAL rather than zero at beginning. Then only its own pte entry need update with function set_pte() and pte_clear(), nothing to do with the pte buddy entry. Signed-off-by: Bibo Mao <maobibo@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> --- arch/loongarch/include/asm/pgalloc.h | 11 +++++++++ arch/loongarch/include/asm/pgtable.h | 35 ++++++---------------------- arch/loongarch/mm/init.c | 2 ++ arch/loongarch/mm/pgtable.c | 20 ++++++++++++++++ include/linux/mm.h | 3 ++- mm/kasan/init.c | 8 ++++++- mm/sparse-vmemmap.c | 5 ++++ 7 files changed, 54 insertions(+), 30 deletions(-) diff --git a/arch/loongarch/include/asm/pgalloc.h b/arch/loongarch/include/asm/pgalloc.h index 79470f0b4f1d..c9f9895f237d 100644 --- a/arch/loongarch/include/asm/pgalloc.h +++ b/arch/loongarch/include/asm/pgalloc.h @@ -10,6 +10,7 @@ #define __HAVE_ARCH_PMD_ALLOC_ONE #define __HAVE_ARCH_PUD_ALLOC_ONE +#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL #include <asm-generic/pgalloc.h> static inline void pmd_populate_kernel(struct mm_struct *mm, @@ -44,6 +45,16 @@ extern void pagetable_init(void); extern pgd_t *pgd_alloc(struct mm_struct *mm); +static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) +{ + pte_t *pte = __pte_alloc_one_kernel(mm); + + if (pte) + kernel_pte_init(pte); + + return pte; +} + #define __pte_free_tlb(tlb, pte, address) \ do { \ pagetable_pte_dtor(page_ptdesc(pte)); \ diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h index 5db17c367b1e..4f4498ce2255 100644 --- a/arch/loongarch/include/asm/pgtable.h +++ b/arch/loongarch/include/asm/pgtable.h @@ -269,6 +269,7 @@ extern void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pm extern void pgd_init(void *addr); extern void pud_init(void *addr); extern void pmd_init(void *addr); +extern void kernel_pte_init(void *addr); /* * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that @@ -325,39 +326,17 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) { WRITE_ONCE(*ptep, pteval); - if (pte_val(pteval) & _PAGE_GLOBAL) { - pte_t *buddy = ptep_buddy(ptep); - /* - * Make sure the buddy is global too (if it's !none, - * it better already be global) - */ - if (pte_none(ptep_get(buddy))) { #ifdef CONFIG_SMP - /* - * For SMP, multiple CPUs can race, so we need - * to do this atomically. - */ - __asm__ __volatile__( - __AMOR "$zero, %[global], %[buddy] \n" - : [buddy] "+ZB" (buddy->pte) - : [global] "r" (_PAGE_GLOBAL) - : "memory"); - - DBAR(0b11000); /* o_wrw = 0b11000 */ -#else /* !CONFIG_SMP */ - WRITE_ONCE(*buddy, __pte(pte_val(ptep_get(buddy)) | _PAGE_GLOBAL)); -#endif /* CONFIG_SMP */ - } - } + if (pte_val(pteval) & _PAGE_GLOBAL) + DBAR(0b11000); /* o_wrw = 0b11000 */ +#endif } static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { - /* Preserve global status for the pair */ - if (pte_val(ptep_get(ptep_buddy(ptep))) & _PAGE_GLOBAL) - set_pte(ptep, __pte(_PAGE_GLOBAL)); - else - set_pte(ptep, __pte(0)); + pte_t pte = ptep_get(ptep); + pte_val(pte) &= _PAGE_GLOBAL; + set_pte(ptep, pte); } #define PGD_T_LOG2 (__builtin_ffs(sizeof(pgd_t)) - 1) diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c index 71fa4b773eb3..14f74a55baae 100644 --- a/arch/loongarch/mm/init.c +++ b/arch/loongarch/mm/init.c @@ -200,7 +200,9 @@ pte_t * __init populate_kernel_pte(unsigned long addr) pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); if (!pte) panic("%s: Failed to allocate memory\n", __func__); + pmd_populate_kernel(&init_mm, pmd, pte); + kernel_pte_init(pte); } return pte_offset_kernel(pmd, addr); diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c index 6a038a27373a..3b2fbe74d7d9 100644 --- a/arch/loongarch/mm/pgtable.c +++ b/arch/loongarch/mm/pgtable.c @@ -116,6 +116,26 @@ void pud_init(void *addr) EXPORT_SYMBOL_GPL(pud_init); #endif +void kernel_pte_init(void *addr) +{ + unsigned long *p, *end; + + p = (unsigned long *)addr; + end = p + PTRS_PER_PTE; + + do { + p[0] = _PAGE_GLOBAL; + p[1] = _PAGE_GLOBAL; + p[2] = _PAGE_GLOBAL; + p[3] = _PAGE_GLOBAL; + p[4] = _PAGE_GLOBAL; + p += 8; + p[-3] = _PAGE_GLOBAL; + p[-2] = _PAGE_GLOBAL; + p[-1] = _PAGE_GLOBAL; + } while (p != end); +} + pmd_t mk_pmd(struct page *page, pgprot_t prot) { pmd_t pmd; diff --git a/include/linux/mm.h b/include/linux/mm.h index ffdd46c1108a..f47c3e714c3a 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3890,8 +3890,9 @@ void *sparse_buffer_alloc(unsigned long size); struct page * __populate_section_memmap(unsigned long pfn, unsigned long nr_pages, int nid, struct vmem_altmap *altmap, struct dev_pagemap *pgmap); -void pmd_init(void *addr); void pud_init(void *addr); +void pmd_init(void *addr); +void kernel_pte_init(void *addr); pgd_t *vmemmap_pgd_populate(unsigned long addr, int node); p4d_t *vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node); pud_t *vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node); diff --git a/mm/kasan/init.c b/mm/kasan/init.c index 89895f38f722..ac607c306292 100644 --- a/mm/kasan/init.c +++ b/mm/kasan/init.c @@ -106,6 +106,10 @@ static void __ref zero_pte_populate(pmd_t *pmd, unsigned long addr, } } +void __weak __meminit kernel_pte_init(void *addr) +{ +} + static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr, unsigned long end) { @@ -126,8 +130,10 @@ static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr, if (slab_is_available()) p = pte_alloc_one_kernel(&init_mm); - else + else { p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); + kernel_pte_init(p); + } if (!p) return -ENOMEM; diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index a2cbe44c48e1..2628fc02be08 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -184,6 +184,10 @@ static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node) return p; } +void __weak __meminit kernel_pte_init(void *addr) +{ +} + pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node) { pmd_t *pmd = pmd_offset(pud, addr); @@ -191,6 +195,7 @@ pmd_t * __meminit vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node) void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); if (!p) return NULL; + kernel_pte_init(p); pmd_populate_kernel(&init_mm, pmd, p); } return pmd; -- 2.33.0
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