/* * Copyright (C) 1999 Niibe Yutaka * Copyright (C) 2003 - 2007 Paul Mundt * * ASID handling idea taken from MIPS implementation. */ #ifndef __ASM_SH_MMU_CONTEXT_H #define __ASM_SH_MMU_CONTEXT_H #ifdef __KERNEL__ #include <cpu/mmu_context.h> #include <asm/tlbflush.h> #include <asm/uaccess.h> #include <asm/io.h> #include <asm-generic/mm_hooks.h> /* * The MMU "context" consists of two things: * (a) TLB cache version (or round, cycle whatever expression you like) * (b) ASID (Address Space IDentifier) */ #ifdef CONFIG_CPU_HAS_PTEAEX #define MMU_CONTEXT_ASID_MASK 0x0000ffff #else #define MMU_CONTEXT_ASID_MASK 0x000000ff #endif #define MMU_CONTEXT_VERSION_MASK (~0UL & ~MMU_CONTEXT_ASID_MASK) #define MMU_CONTEXT_FIRST_VERSION (MMU_CONTEXT_ASID_MASK + 1) /* Impossible ASID value, to differentiate from NO_CONTEXT. */ #define MMU_NO_ASID MMU_CONTEXT_FIRST_VERSION #define NO_CONTEXT 0UL #define asid_cache(cpu) (cpu_data[cpu].asid_cache) #ifdef CONFIG_MMU #define cpu_context(cpu, mm) ((mm)->context.id[cpu]) #define cpu_asid(cpu, mm) \ (cpu_context((cpu), (mm)) & MMU_CONTEXT_ASID_MASK) /* * Virtual Page Number mask */ #define MMU_VPN_MASK 0xfffff000 #if defined(CONFIG_SUPERH32) #include <asm/mmu_context_32.h> #else #include <asm/mmu_context_64.h> #endif /* * Get MMU context if needed. */ static inline void get_mmu_context(struct mm_struct *mm, unsigned int cpu) { unsigned long asid = asid_cache(cpu); /* Check if we have old version of context. */ if (((cpu_context(cpu, mm) ^ asid) & MMU_CONTEXT_VERSION_MASK) == 0) /* It's up to date, do nothing */ return; /* It's old, we need to get new context with new version. */ if (!(++asid & MMU_CONTEXT_ASID_MASK)) { /* * We exhaust ASID of this version. * Flush all TLB and start new cycle. */ local_flush_tlb_all(); #ifdef CONFIG_SUPERH64 /* * The SH-5 cache uses the ASIDs, requiring both the I and D * cache to be flushed when the ASID is exhausted. Weak. */ flush_cache_all(); #endif /* * Fix version; Note that we avoid version #0 * to distinguish NO_CONTEXT. */ if (!asid) asid = MMU_CONTEXT_FIRST_VERSION; } cpu_context(cpu, mm) = asid_cache(cpu) = asid; } /* * Initialize the context related info for a new mm_struct * instance. */ static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { int i; for (i = 0; i < num_online_cpus(); i++) cpu_context(i, mm) = NO_CONTEXT; return 0; } /* * After we have set current->mm to a new value, this activates * the context for the new mm so we see the new mappings. */ static inline void activate_context(struct mm_struct *mm, unsigned int cpu) { get_mmu_context(mm, cpu); set_asid(cpu_asid(cpu, mm)); } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { unsigned int cpu = smp_processor_id(); if (likely(prev != next)) { cpumask_set_cpu(cpu, mm_cpumask(next)); set_TTB(next->pgd); activate_context(next, cpu); } else if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next))) activate_context(next, cpu); } #define activate_mm(prev, next) switch_mm((prev),(next),NULL) #define deactivate_mm(tsk,mm) do { } while (0) #define enter_lazy_tlb(mm,tsk) do { } while (0) #else #define set_asid(asid) do { } while (0) #define get_asid() (0) #define cpu_asid(cpu, mm) ({ (void)cpu; NO_CONTEXT; }) #define switch_and_save_asid(asid) (0) #define set_TTB(pgd) do { } while (0) #define get_TTB() (0) #include <asm-generic/mmu_context.h> #endif /* CONFIG_MMU */ #if defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4) /* * If this processor has an MMU, we need methods to turn it off/on .. * paging_init() will also have to be updated for the processor in * question. */ static inline void enable_mmu(void) { unsigned int cpu = smp_processor_id(); /* Enable MMU */ __raw_writel(MMU_CONTROL_INIT, MMUCR); ctrl_barrier(); if (asid_cache(cpu) == NO_CONTEXT) asid_cache(cpu) = MMU_CONTEXT_FIRST_VERSION; set_asid(asid_cache(cpu) & MMU_CONTEXT_ASID_MASK); } static inline void disable_mmu(void) { unsigned long cr; cr = __raw_readl(MMUCR); cr &= ~MMU_CONTROL_INIT; __raw_writel(cr, MMUCR); ctrl_barrier(); } #else /* * MMU control handlers for processors lacking memory * management hardware. */ #define enable_mmu() do { } while (0) #define disable_mmu() do { } while (0) #endif #endif /* __KERNEL__ */ #endif /* __ASM_SH_MMU_CONTEXT_H */