diff --git a/arch/loongarch/include/asm/atomic.h b/arch/loongarch/include/asm/atomic.h index 99af8b3160a8..c86f0ab922ec 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 85431f20a14d..9965f52ef65b 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; + /* + * 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"); - __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)); + 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;