/* $Id: mmu_context.h,v 1.54 2002/02/09 19:49:31 davem Exp $ */ #ifndef __SPARC64_MMU_CONTEXT_H #define __SPARC64_MMU_CONTEXT_H /* Derived heavily from Linus's Alpha/AXP ASN code... */ #ifndef __ASSEMBLY__ #include <linux/spinlock.h> #include <asm/system.h> #include <asm/spitfire.h> static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) { } extern spinlock_t ctx_alloc_lock; extern unsigned long tlb_context_cache; extern unsigned long mmu_context_bmap[]; extern void get_new_mmu_context(struct mm_struct *mm); #ifdef CONFIG_SMP extern void smp_new_mmu_context_version(void); #else #define smp_new_mmu_context_version() do { } while (0) #endif extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm); extern void destroy_context(struct mm_struct *mm); extern void __tsb_context_switch(unsigned long pgd_pa, struct tsb_config *tsb_base, struct tsb_config *tsb_huge, unsigned long tsb_descr_pa); static inline void tsb_context_switch(struct mm_struct *mm) { __tsb_context_switch(__pa(mm->pgd), &mm->context.tsb_block[0], #ifdef CONFIG_HUGETLB_PAGE (mm->context.tsb_block[1].tsb ? &mm->context.tsb_block[1] : NULL) #else NULL #endif , __pa(&mm->context.tsb_descr[0])); } extern void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long mm_rss); #ifdef CONFIG_SMP extern void smp_tsb_sync(struct mm_struct *mm); #else #define smp_tsb_sync(__mm) do { } while (0) #endif /* Set MMU context in the actual hardware. */ #define load_secondary_context(__mm) \ __asm__ __volatile__( \ "\n661: stxa %0, [%1] %2\n" \ " .section .sun4v_1insn_patch, \"ax\"\n" \ " .word 661b\n" \ " stxa %0, [%1] %3\n" \ " .previous\n" \ " flush %%g6\n" \ : /* No outputs */ \ : "r" (CTX_HWBITS((__mm)->context)), \ "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU)) extern void __flush_tlb_mm(unsigned long, unsigned long); /* Switch the current MM context. Interrupts are disabled. */ static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) { unsigned long ctx_valid, flags; int cpu; spin_lock_irqsave(&mm->context.lock, flags); ctx_valid = CTX_VALID(mm->context); if (!ctx_valid) get_new_mmu_context(mm); /* We have to be extremely careful here or else we will miss * a TSB grow if we switch back and forth between a kernel * thread and an address space which has it's TSB size increased * on another processor. * * It is possible to play some games in order to optimize the * switch, but the safest thing to do is to unconditionally * perform the secondary context load and the TSB context switch. * * For reference the bad case is, for address space "A": * * CPU 0 CPU 1 * run address space A * set cpu0's bits in cpu_vm_mask * switch to kernel thread, borrow * address space A via entry_lazy_tlb * run address space A * set cpu1's bit in cpu_vm_mask * flush_tlb_pending() * reset cpu_vm_mask to just cpu1 * TSB grow * run address space A * context was valid, so skip * TSB context switch * * At that point cpu0 continues to use a stale TSB, the one from * before the TSB grow performed on cpu1. cpu1 did not cross-call * cpu0 to update it's TSB because at that point the cpu_vm_mask * only had cpu1 set in it. */ load_secondary_context(mm); tsb_context_switch(mm); /* Any time a processor runs a context on an address space * for the first time, we must flush that context out of the * local TLB. */ cpu = smp_processor_id(); if (!ctx_valid || !cpu_isset(cpu, mm->cpu_vm_mask)) { cpu_set(cpu, mm->cpu_vm_mask); __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT); } spin_unlock_irqrestore(&mm->context.lock, flags); } #define deactivate_mm(tsk,mm) do { } while (0) /* Activate a new MM instance for the current task. */ static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm) { unsigned long flags; int cpu; spin_lock_irqsave(&mm->context.lock, flags); if (!CTX_VALID(mm->context)) get_new_mmu_context(mm); cpu = smp_processor_id(); if (!cpu_isset(cpu, mm->cpu_vm_mask)) cpu_set(cpu, mm->cpu_vm_mask); load_secondary_context(mm); __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT); tsb_context_switch(mm); spin_unlock_irqrestore(&mm->context.lock, flags); } #endif /* !(__ASSEMBLY__) */ #endif /* !(__SPARC64_MMU_CONTEXT_H) */