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 <asm/system.h> 10 #include <asm/spitfire.h> 11 #include <asm-generic/mm_hooks.h> 12 13 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) 14 { 15 } 16 17 extern spinlock_t ctx_alloc_lock; 18 extern unsigned long tlb_context_cache; 19 extern unsigned long mmu_context_bmap[]; 20 21 extern void get_new_mmu_context(struct mm_struct *mm); 22 #ifdef CONFIG_SMP 23 extern void smp_new_mmu_context_version(void); 24 #else 25 #define smp_new_mmu_context_version() do { } while (0) 26 #endif 27 28 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm); 29 extern void destroy_context(struct mm_struct *mm); 30 31 extern void __tsb_context_switch(unsigned long pgd_pa, 32 struct tsb_config *tsb_base, 33 struct tsb_config *tsb_huge, 34 unsigned long tsb_descr_pa); 35 36 static inline void tsb_context_switch(struct mm_struct *mm) 37 { 38 __tsb_context_switch(__pa(mm->pgd), 39 &mm->context.tsb_block[0], 40 #ifdef CONFIG_HUGETLB_PAGE 41 (mm->context.tsb_block[1].tsb ? 42 &mm->context.tsb_block[1] : 43 NULL) 44 #else 45 NULL 46 #endif 47 , __pa(&mm->context.tsb_descr[0])); 48 } 49 50 extern void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long mm_rss); 51 #ifdef CONFIG_SMP 52 extern void smp_tsb_sync(struct mm_struct *mm); 53 #else 54 #define smp_tsb_sync(__mm) do { } while (0) 55 #endif 56 57 /* Set MMU context in the actual hardware. */ 58 #define load_secondary_context(__mm) \ 59 __asm__ __volatile__( \ 60 "\n661: stxa %0, [%1] %2\n" \ 61 " .section .sun4v_1insn_patch, \"ax\"\n" \ 62 " .word 661b\n" \ 63 " stxa %0, [%1] %3\n" \ 64 " .previous\n" \ 65 " flush %%g6\n" \ 66 : /* No outputs */ \ 67 : "r" (CTX_HWBITS((__mm)->context)), \ 68 "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU)) 69 70 extern void __flush_tlb_mm(unsigned long, unsigned long); 71 72 /* Switch the current MM context. Interrupts are disabled. */ 73 static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) 74 { 75 unsigned long ctx_valid, flags; 76 int cpu; 77 78 if (unlikely(mm == &init_mm)) 79 return; 80 81 spin_lock_irqsave(&mm->context.lock, flags); 82 ctx_valid = CTX_VALID(mm->context); 83 if (!ctx_valid) 84 get_new_mmu_context(mm); 85 86 /* We have to be extremely careful here or else we will miss 87 * a TSB grow if we switch back and forth between a kernel 88 * thread and an address space which has it's TSB size increased 89 * on another processor. 90 * 91 * It is possible to play some games in order to optimize the 92 * switch, but the safest thing to do is to unconditionally 93 * perform the secondary context load and the TSB context switch. 94 * 95 * For reference the bad case is, for address space "A": 96 * 97 * CPU 0 CPU 1 98 * run address space A 99 * set cpu0's bits in cpu_vm_mask 100 * switch to kernel thread, borrow 101 * address space A via entry_lazy_tlb 102 * run address space A 103 * set cpu1's bit in cpu_vm_mask 104 * flush_tlb_pending() 105 * reset cpu_vm_mask to just cpu1 106 * TSB grow 107 * run address space A 108 * context was valid, so skip 109 * TSB context switch 110 * 111 * At that point cpu0 continues to use a stale TSB, the one from 112 * before the TSB grow performed on cpu1. cpu1 did not cross-call 113 * cpu0 to update it's TSB because at that point the cpu_vm_mask 114 * only had cpu1 set in it. 115 */ 116 load_secondary_context(mm); 117 tsb_context_switch(mm); 118 119 /* Any time a processor runs a context on an address space 120 * for the first time, we must flush that context out of the 121 * local TLB. 122 */ 123 cpu = smp_processor_id(); 124 if (!ctx_valid || !cpu_isset(cpu, mm->cpu_vm_mask)) { 125 cpu_set(cpu, mm->cpu_vm_mask); 126 __flush_tlb_mm(CTX_HWBITS(mm->context), 127 SECONDARY_CONTEXT); 128 } 129 spin_unlock_irqrestore(&mm->context.lock, flags); 130 } 131 132 #define deactivate_mm(tsk,mm) do { } while (0) 133 134 /* Activate a new MM instance for the current task. */ 135 static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm) 136 { 137 unsigned long flags; 138 int cpu; 139 140 spin_lock_irqsave(&mm->context.lock, flags); 141 if (!CTX_VALID(mm->context)) 142 get_new_mmu_context(mm); 143 cpu = smp_processor_id(); 144 if (!cpu_isset(cpu, mm->cpu_vm_mask)) 145 cpu_set(cpu, mm->cpu_vm_mask); 146 147 load_secondary_context(mm); 148 __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT); 149 tsb_context_switch(mm); 150 spin_unlock_irqrestore(&mm->context.lock, flags); 151 } 152 153 #endif /* !(__ASSEMBLY__) */ 154 155 #endif /* !(__SPARC64_MMU_CONTEXT_H) */ 156