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 unsigned long secondary_ctx); 32 33 static inline void tsb_context_switch_ctx(struct mm_struct *mm, 34 unsigned long ctx) 35 { 36 __tsb_context_switch(__pa(mm->pgd), 37 &mm->context.tsb_block[MM_TSB_BASE], 38 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE) 39 (mm->context.tsb_block[MM_TSB_HUGE].tsb ? 40 &mm->context.tsb_block[MM_TSB_HUGE] : 41 NULL) 42 #else 43 NULL 44 #endif 45 , __pa(&mm->context.tsb_descr[MM_TSB_BASE]), 46 ctx); 47 } 48 49 #define tsb_context_switch(X) tsb_context_switch_ctx(X, 0) 50 51 void tsb_grow(struct mm_struct *mm, 52 unsigned long tsb_index, 53 unsigned long mm_rss); 54 #ifdef CONFIG_SMP 55 void smp_tsb_sync(struct mm_struct *mm); 56 #else 57 #define smp_tsb_sync(__mm) do { } while (0) 58 #endif 59 60 /* Set MMU context in the actual hardware. */ 61 #define load_secondary_context(__mm) \ 62 __asm__ __volatile__( \ 63 "\n661: stxa %0, [%1] %2\n" \ 64 " .section .sun4v_1insn_patch, \"ax\"\n" \ 65 " .word 661b\n" \ 66 " stxa %0, [%1] %3\n" \ 67 " .previous\n" \ 68 " flush %%g6\n" \ 69 : /* No outputs */ \ 70 : "r" (CTX_HWBITS((__mm)->context)), \ 71 "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU)) 72 73 void __flush_tlb_mm(unsigned long, unsigned long); 74 75 /* Switch the current MM context. */ 76 static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk) 77 { 78 unsigned long ctx_valid, flags; 79 int cpu = smp_processor_id(); 80 81 per_cpu(per_cpu_secondary_mm, cpu) = mm; 82 if (unlikely(mm == &init_mm)) 83 return; 84 85 spin_lock_irqsave(&mm->context.lock, flags); 86 ctx_valid = CTX_VALID(mm->context); 87 if (!ctx_valid) 88 get_new_mmu_context(mm); 89 90 /* We have to be extremely careful here or else we will miss 91 * a TSB grow if we switch back and forth between a kernel 92 * thread and an address space which has it's TSB size increased 93 * on another processor. 94 * 95 * It is possible to play some games in order to optimize the 96 * switch, but the safest thing to do is to unconditionally 97 * perform the secondary context load and the TSB context switch. 98 * 99 * For reference the bad case is, for address space "A": 100 * 101 * CPU 0 CPU 1 102 * run address space A 103 * set cpu0's bits in cpu_vm_mask 104 * switch to kernel thread, borrow 105 * address space A via entry_lazy_tlb 106 * run address space A 107 * set cpu1's bit in cpu_vm_mask 108 * flush_tlb_pending() 109 * reset cpu_vm_mask to just cpu1 110 * TSB grow 111 * run address space A 112 * context was valid, so skip 113 * TSB context switch 114 * 115 * At that point cpu0 continues to use a stale TSB, the one from 116 * before the TSB grow performed on cpu1. cpu1 did not cross-call 117 * cpu0 to update it's TSB because at that point the cpu_vm_mask 118 * only had cpu1 set in it. 119 */ 120 tsb_context_switch_ctx(mm, CTX_HWBITS(mm->context)); 121 122 /* Any time a processor runs a context on an address space 123 * for the first time, we must flush that context out of the 124 * local TLB. 125 */ 126 if (!ctx_valid || !cpumask_test_cpu(cpu, mm_cpumask(mm))) { 127 cpumask_set_cpu(cpu, mm_cpumask(mm)); 128 __flush_tlb_mm(CTX_HWBITS(mm->context), 129 SECONDARY_CONTEXT); 130 } 131 spin_unlock_irqrestore(&mm->context.lock, flags); 132 } 133 134 #define deactivate_mm(tsk,mm) do { } while (0) 135 #define activate_mm(active_mm, mm) switch_mm(active_mm, mm, NULL) 136 #endif /* !(__ASSEMBLY__) */ 137 138 #endif /* !(__SPARC64_MMU_CONTEXT_H) */ 139