xref: /openbmc/linux/arch/xtensa/mm/tlb.c (revision 8fdff1dc)
1 /*
2  * arch/xtensa/mm/tlb.c
3  *
4  * Logic that manipulates the Xtensa MMU.  Derived from MIPS.
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  *
10  * Copyright (C) 2001 - 2003 Tensilica Inc.
11  *
12  * Joe Taylor
13  * Chris Zankel	<chris@zankel.net>
14  * Marc Gauthier
15  */
16 
17 #include <linux/mm.h>
18 #include <asm/processor.h>
19 #include <asm/mmu_context.h>
20 #include <asm/tlbflush.h>
21 #include <asm/cacheflush.h>
22 
23 
24 static inline void __flush_itlb_all (void)
25 {
26 	int w, i;
27 
28 	for (w = 0; w < ITLB_ARF_WAYS; w++) {
29 		for (i = 0; i < (1 << XCHAL_ITLB_ARF_ENTRIES_LOG2); i++) {
30 			int e = w + (i << PAGE_SHIFT);
31 			invalidate_itlb_entry_no_isync(e);
32 		}
33 	}
34 	asm volatile ("isync\n");
35 }
36 
37 static inline void __flush_dtlb_all (void)
38 {
39 	int w, i;
40 
41 	for (w = 0; w < DTLB_ARF_WAYS; w++) {
42 		for (i = 0; i < (1 << XCHAL_DTLB_ARF_ENTRIES_LOG2); i++) {
43 			int e = w + (i << PAGE_SHIFT);
44 			invalidate_dtlb_entry_no_isync(e);
45 		}
46 	}
47 	asm volatile ("isync\n");
48 }
49 
50 
51 void flush_tlb_all (void)
52 {
53 	__flush_itlb_all();
54 	__flush_dtlb_all();
55 }
56 
57 /* If mm is current, we simply assign the current task a new ASID, thus,
58  * invalidating all previous tlb entries. If mm is someone else's user mapping,
59  * wie invalidate the context, thus, when that user mapping is swapped in,
60  * a new context will be assigned to it.
61  */
62 
63 void flush_tlb_mm(struct mm_struct *mm)
64 {
65 	if (mm == current->active_mm) {
66 		unsigned long flags;
67 		local_save_flags(flags);
68 		__get_new_mmu_context(mm);
69 		__load_mmu_context(mm);
70 		local_irq_restore(flags);
71 	}
72 	else
73 		mm->context = 0;
74 }
75 
76 #define _ITLB_ENTRIES (ITLB_ARF_WAYS << XCHAL_ITLB_ARF_ENTRIES_LOG2)
77 #define _DTLB_ENTRIES (DTLB_ARF_WAYS << XCHAL_DTLB_ARF_ENTRIES_LOG2)
78 #if _ITLB_ENTRIES > _DTLB_ENTRIES
79 # define _TLB_ENTRIES _ITLB_ENTRIES
80 #else
81 # define _TLB_ENTRIES _DTLB_ENTRIES
82 #endif
83 
84 void flush_tlb_range (struct vm_area_struct *vma,
85 		      unsigned long start, unsigned long end)
86 {
87 	struct mm_struct *mm = vma->vm_mm;
88 	unsigned long flags;
89 
90 	if (mm->context == NO_CONTEXT)
91 		return;
92 
93 #if 0
94 	printk("[tlbrange<%02lx,%08lx,%08lx>]\n",
95 			(unsigned long)mm->context, start, end);
96 #endif
97 	local_save_flags(flags);
98 
99 	if (end-start + (PAGE_SIZE-1) <= _TLB_ENTRIES << PAGE_SHIFT) {
100 		int oldpid = get_rasid_register();
101 		set_rasid_register (ASID_INSERT(mm->context));
102 		start &= PAGE_MASK;
103 		if (vma->vm_flags & VM_EXEC)
104 			while(start < end) {
105 				invalidate_itlb_mapping(start);
106 				invalidate_dtlb_mapping(start);
107 				start += PAGE_SIZE;
108 			}
109 		else
110 			while(start < end) {
111 				invalidate_dtlb_mapping(start);
112 				start += PAGE_SIZE;
113 			}
114 
115 		set_rasid_register(oldpid);
116 	} else {
117 		flush_tlb_mm(mm);
118 	}
119 	local_irq_restore(flags);
120 }
121 
122 void flush_tlb_page (struct vm_area_struct *vma, unsigned long page)
123 {
124 	struct mm_struct* mm = vma->vm_mm;
125 	unsigned long flags;
126 	int oldpid;
127 
128 	if(mm->context == NO_CONTEXT)
129 		return;
130 
131 	local_save_flags(flags);
132 
133 	oldpid = get_rasid_register();
134 
135 	if (vma->vm_flags & VM_EXEC)
136 		invalidate_itlb_mapping(page);
137 	invalidate_dtlb_mapping(page);
138 
139 	set_rasid_register(oldpid);
140 
141 	local_irq_restore(flags);
142 }
143