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Diffstat (limited to 'include/asm-sparc64/mmu_context.h')
| -rw-r--r-- | include/asm-sparc64/mmu_context.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/include/asm-sparc64/mmu_context.h b/include/asm-sparc64/mmu_context.h new file mode 100644 index 000000000000..87c43c67866e --- /dev/null +++ b/include/asm-sparc64/mmu_context.h @@ -0,0 +1,145 @@ +/* $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); + +/* Initialize a new mmu context. This is invoked when a new + * address space instance (unique or shared) is instantiated. + * This just needs to set mm->context to an invalid context. + */ +#define init_new_context(__tsk, __mm) \ + (((__mm)->context.sparc64_ctx_val = 0UL), 0) + +/* Destroy a dead context. This occurs when mmput drops the + * mm_users count to zero, the mmaps have been released, and + * all the page tables have been flushed. Our job is to destroy + * any remaining processor-specific state, and in the sparc64 + * case this just means freeing up the mmu context ID held by + * this task if valid. + */ +#define destroy_context(__mm) \ +do { spin_lock(&ctx_alloc_lock); \ + if (CTX_VALID((__mm)->context)) { \ + unsigned long nr = CTX_NRBITS((__mm)->context); \ + mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63)); \ + } \ + spin_unlock(&ctx_alloc_lock); \ +} while(0) + +/* Reload the two core values used by TLB miss handler + * processing on sparc64. They are: + * 1) The physical address of mm->pgd, when full page + * table walks are necessary, this is where the + * search begins. + * 2) A "PGD cache". For 32-bit tasks only pgd[0] is + * ever used since that maps the entire low 4GB + * completely. To speed up TLB miss processing we + * make this value available to the handlers. This + * decreases the amount of memory traffic incurred. + */ +#define reload_tlbmiss_state(__tsk, __mm) \ +do { \ + register unsigned long paddr asm("o5"); \ + register unsigned long pgd_cache asm("o4"); \ + paddr = __pa((__mm)->pgd); \ + pgd_cache = 0UL; \ + if ((__tsk)->thread_info->flags & _TIF_32BIT) \ + pgd_cache = get_pgd_cache((__mm)->pgd); \ + __asm__ __volatile__("wrpr %%g0, 0x494, %%pstate\n\t" \ + "mov %3, %%g4\n\t" \ + "mov %0, %%g7\n\t" \ + "stxa %1, [%%g4] %2\n\t" \ + "membar #Sync\n\t" \ + "wrpr %%g0, 0x096, %%pstate" \ + : /* no outputs */ \ + : "r" (paddr), "r" (pgd_cache),\ + "i" (ASI_DMMU), "i" (TSB_REG)); \ +} while(0) + +/* Set MMU context in the actual hardware. */ +#define load_secondary_context(__mm) \ + __asm__ __volatile__("stxa %0, [%1] %2\n\t" \ + "flush %%g6" \ + : /* No outputs */ \ + : "r" (CTX_HWBITS((__mm)->context)), \ + "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU)) + +extern void __flush_tlb_mm(unsigned long, unsigned long); + +/* Switch the current MM context. */ +static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) +{ + unsigned long ctx_valid; + + spin_lock(&mm->page_table_lock); + if (CTX_VALID(mm->context)) + ctx_valid = 1; + else + ctx_valid = 0; + + if (!ctx_valid || (old_mm != mm)) { + if (!ctx_valid) + get_new_mmu_context(mm); + + load_secondary_context(mm); + reload_tlbmiss_state(tsk, mm); + } + + { + int cpu = smp_processor_id(); + + /* Even if (mm == old_mm) we _must_ check + * the cpu_vm_mask. If we do not we could + * corrupt the TLB state because of how + * smp_flush_tlb_{page,range,mm} on sparc64 + * and lazy tlb switches work. -DaveM + */ + 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(&mm->page_table_lock); +} + +#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) +{ + int cpu; + + spin_lock(&mm->page_table_lock); + 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); + spin_unlock(&mm->page_table_lock); + + load_secondary_context(mm); + __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT); + reload_tlbmiss_state(current, mm); +} + +#endif /* !(__ASSEMBLY__) */ + +#endif /* !(__SPARC64_MMU_CONTEXT_H) */ |