1 #ifndef __SPARC64_MMU_CONTEXT_H 2 #define __SPARC64_MMU_CONTEXT_H 3 4 /* Derived heavily from Linus's Alpha/AXP ASN code... */ 5 6 #ifndef __ASSEMBLY__ 7 8 #include <linux/spinlock.h> 9 #include <linux/mm_types.h> 10 11 #include <asm/spitfire.h> 12 #include <asm-generic/mm_hooks.h> 13 14 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) 15 { 16 } 17 18 extern spinlock_t ctx_alloc_lock; 19 extern unsigned long tlb_context_cache; 20 extern unsigned long mmu_context_bmap[]; 21 22 DECLARE_PER_CPU(struct mm_struct *, per_cpu_secondary_mm); 23 void get_new_mmu_context(struct mm_struct *mm); 24 int init_new_context(struct task_struct *tsk, struct mm_struct *mm); 25 void destroy_context(struct mm_struct *mm); 26 27 void __tsb_context_switch(unsigned long pgd_pa, 28 struct tsb_config *tsb_base, 29 struct tsb_config *tsb_huge, 30 unsigned long tsb_descr_pa); 31 32 static inline void tsb_context_switch(struct mm_struct *mm) 33 { 34 __tsb_context_switch(__pa(mm->pgd), 35 &mm->context.tsb_block[MM_TSB_BASE], 36 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) 37 (mm->context.tsb_block[MM_TSB_HUGE].tsb ? 38 &mm->context.tsb_block[MM_TSB_HUGE] : 39 NULL) 40 #else 41 NULL 42 #endif 43 , __pa(&mm->context.tsb_descr[MM_TSB_BASE])); 44 } 45 46 void tsb_grow(struct mm_struct *mm, 47 unsigned long tsb_index, 48 unsigned long mm_rss); 49 #ifdef CONFIG_SMP 50 void smp_tsb_sync(struct mm_struct *mm); 51 #else 52 #define smp_tsb_sync(__mm) do { } while (0) 53 #endif 54 55 /* Set MMU context in the actual hardware. */ 56 #define load_secondary_context(__mm) \ 57 __asm__ __volatile__( \ 58 "\n661: stxa %0, [%1] %2\n" \ 59 " .section .sun4v_1insn_patch, \"ax\"\n" \ 60 " .word 661b\n" \ 61 " stxa %0, [%1] %3\n" \ 62 " .previous\n" \ 63 " flush %%g6\n" \ 64 : /* No outputs */ \ 65 : "r" (CTX_HWBITS((__mm)->context)), \ 66 "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU)) 67 68 void __flush_tlb_mm(unsigned long, unsigned long); 69 70 /* Switch the current MM context. */ 71 static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) 72 { 73 unsigned long ctx_valid, flags; 74 int cpu = smp_processor_id(); 75 76 per_cpu(per_cpu_secondary_mm, cpu) = mm; 77 if (unlikely(mm == &init_mm)) 78 return; 79 80 spin_lock_irqsave(&mm->context.lock, flags); 81 ctx_valid = CTX_VALID(mm->context); 82 if (!ctx_valid) 83 get_new_mmu_context(mm); 84 85 /* We have to be extremely careful here or else we will miss 86 * a TSB grow if we switch back and forth between a kernel 87 * thread and an address space which has it's TSB size increased 88 * on another processor. 89 * 90 * It is possible to play some games in order to optimize the 91 * switch, but the safest thing to do is to unconditionally 92 * perform the secondary context load and the TSB context switch. 93 * 94 * For reference the bad case is, for address space "A": 95 * 96 * CPU 0 CPU 1 97 * run address space A 98 * set cpu0's bits in cpu_vm_mask 99 * switch to kernel thread, borrow 100 * address space A via entry_lazy_tlb 101 * run address space A 102 * set cpu1's bit in cpu_vm_mask 103 * flush_tlb_pending() 104 * reset cpu_vm_mask to just cpu1 105 * TSB grow 106 * run address space A 107 * context was valid, so skip 108 * TSB context switch 109 * 110 * At that point cpu0 continues to use a stale TSB, the one from 111 * before the TSB grow performed on cpu1. cpu1 did not cross-call 112 * cpu0 to update it's TSB because at that point the cpu_vm_mask 113 * only had cpu1 set in it. 114 */ 115 load_secondary_context(mm); 116 tsb_context_switch(mm); 117 118 /* Any time a processor runs a context on an address space 119 * for the first time, we must flush that context out of the 120 * local TLB. 121 */ 122 if (!ctx_valid || !cpumask_test_cpu(cpu, mm_cpumask(mm))) { 123 cpumask_set_cpu(cpu, mm_cpumask(mm)); 124 __flush_tlb_mm(CTX_HWBITS(mm->context), 125 SECONDARY_CONTEXT); 126 } 127 spin_unlock_irqrestore(&mm->context.lock, flags); 128 } 129 130 #define deactivate_mm(tsk,mm) do { } while (0) 131 #define activate_mm(active_mm, mm) switch_mm(active_mm, mm, NULL) 132 #endif /* !(__ASSEMBLY__) */ 133 134 #endif /* !(__SPARC64_MMU_CONTEXT_H) */ 135