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Diffstat (limited to '')
| -rw-r--r-- | arch/s390/include/asm/mmu_context.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h new file mode 100644 index 000000000..c9f3d8a52 --- /dev/null +++ b/arch/s390/include/asm/mmu_context.h @@ -0,0 +1,139 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * S390 version + * + * Derived from "include/asm-i386/mmu_context.h" + */ + +#ifndef __S390_MMU_CONTEXT_H +#define __S390_MMU_CONTEXT_H + +#include <asm/pgalloc.h> +#include <linux/uaccess.h> +#include <linux/mm_types.h> +#include <asm/tlbflush.h> +#include <asm/ctl_reg.h> +#include <asm-generic/mm_hooks.h> + +static inline int init_new_context(struct task_struct *tsk, + struct mm_struct *mm) +{ + unsigned long asce_type, init_entry; + + spin_lock_init(&mm->context.lock); + INIT_LIST_HEAD(&mm->context.pgtable_list); + INIT_LIST_HEAD(&mm->context.gmap_list); + cpumask_clear(&mm->context.cpu_attach_mask); + atomic_set(&mm->context.flush_count, 0); + atomic_set(&mm->context.is_protected, 0); + mm->context.gmap_asce = 0; + mm->context.flush_mm = 0; +#ifdef CONFIG_PGSTE + mm->context.alloc_pgste = page_table_allocate_pgste || + test_thread_flag(TIF_PGSTE) || + (current->mm && current->mm->context.alloc_pgste); + mm->context.has_pgste = 0; + mm->context.uses_skeys = 0; + mm->context.uses_cmm = 0; + mm->context.allow_gmap_hpage_1m = 0; +#endif + switch (mm->context.asce_limit) { + default: + /* + * context created by exec, the value of asce_limit can + * only be zero in this case + */ + VM_BUG_ON(mm->context.asce_limit); + /* continue as 3-level task */ + mm->context.asce_limit = _REGION2_SIZE; + fallthrough; + case _REGION2_SIZE: + /* forked 3-level task */ + init_entry = _REGION3_ENTRY_EMPTY; + asce_type = _ASCE_TYPE_REGION3; + break; + case TASK_SIZE_MAX: + /* forked 5-level task */ + init_entry = _REGION1_ENTRY_EMPTY; + asce_type = _ASCE_TYPE_REGION1; + break; + case _REGION1_SIZE: + /* forked 4-level task */ + init_entry = _REGION2_ENTRY_EMPTY; + asce_type = _ASCE_TYPE_REGION2; + break; + } + mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH | + _ASCE_USER_BITS | asce_type; + crst_table_init((unsigned long *) mm->pgd, init_entry); + return 0; +} + +#define destroy_context(mm) do { } while (0) + +static inline void set_user_asce(struct mm_struct *mm) +{ + S390_lowcore.user_asce = mm->context.asce; + __ctl_load(S390_lowcore.user_asce, 1, 1); + clear_cpu_flag(CIF_ASCE_PRIMARY); +} + +static inline void clear_user_asce(void) +{ + S390_lowcore.user_asce = S390_lowcore.kernel_asce; + __ctl_load(S390_lowcore.kernel_asce, 1, 1); + set_cpu_flag(CIF_ASCE_PRIMARY); +} + +mm_segment_t enable_sacf_uaccess(void); +void disable_sacf_uaccess(mm_segment_t old_fs); + +static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + int cpu = smp_processor_id(); + + S390_lowcore.user_asce = next->context.asce; + cpumask_set_cpu(cpu, &next->context.cpu_attach_mask); + /* Clear previous user-ASCE from CR1 and CR7 */ + if (!test_cpu_flag(CIF_ASCE_PRIMARY)) { + __ctl_load(S390_lowcore.kernel_asce, 1, 1); + set_cpu_flag(CIF_ASCE_PRIMARY); + } + if (test_cpu_flag(CIF_ASCE_SECONDARY)) { + __ctl_load(S390_lowcore.vdso_asce, 7, 7); + clear_cpu_flag(CIF_ASCE_SECONDARY); + } + if (prev != next) + cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask); +} + +#define finish_arch_post_lock_switch finish_arch_post_lock_switch +static inline void finish_arch_post_lock_switch(void) +{ + struct task_struct *tsk = current; + struct mm_struct *mm = tsk->mm; + + if (mm) { + preempt_disable(); + while (atomic_read(&mm->context.flush_count)) + cpu_relax(); + cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm)); + __tlb_flush_mm_lazy(mm); + preempt_enable(); + } + set_fs(current->thread.mm_segment); +} + +#define enter_lazy_tlb(mm,tsk) do { } while (0) +#define deactivate_mm(tsk,mm) do { } while (0) + +static inline void activate_mm(struct mm_struct *prev, + struct mm_struct *next) +{ + switch_mm(prev, next, current); + cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); + set_user_asce(next); +} + +#endif /* __S390_MMU_CONTEXT_H */ |