drm/i915: Rephrase pwrite bounds checking to avoid any potential overflow
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / sh / mm / tlbflush_32.c
blob6f45c1f8a7fedd72a3d839190cfa33d5acc4d53e
1 /*
2 * TLB flushing operations for SH with an MMU.
4 * Copyright (C) 1999 Niibe Yutaka
5 * Copyright (C) 2003 Paul Mundt
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License. See the file "COPYING" in the main directory of this archive
9 * for more details.
11 #include <linux/mm.h>
12 #include <asm/mmu_context.h>
13 #include <asm/tlbflush.h>
15 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
17 unsigned int cpu = smp_processor_id();
19 if (vma->vm_mm && cpu_context(cpu, vma->vm_mm) != NO_CONTEXT) {
20 unsigned long flags;
21 unsigned long asid;
22 unsigned long saved_asid = MMU_NO_ASID;
24 asid = cpu_asid(cpu, vma->vm_mm);
25 page &= PAGE_MASK;
27 local_irq_save(flags);
28 if (vma->vm_mm != current->mm) {
29 saved_asid = get_asid();
30 set_asid(asid);
32 local_flush_tlb_one(asid, page);
33 if (saved_asid != MMU_NO_ASID)
34 set_asid(saved_asid);
35 local_irq_restore(flags);
39 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
40 unsigned long end)
42 struct mm_struct *mm = vma->vm_mm;
43 unsigned int cpu = smp_processor_id();
45 if (cpu_context(cpu, mm) != NO_CONTEXT) {
46 unsigned long flags;
47 int size;
49 local_irq_save(flags);
50 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
51 if (size > (MMU_NTLB_ENTRIES/4)) { /* Too many TLB to flush */
52 cpu_context(cpu, mm) = NO_CONTEXT;
53 if (mm == current->mm)
54 activate_context(mm, cpu);
55 } else {
56 unsigned long asid;
57 unsigned long saved_asid = MMU_NO_ASID;
59 asid = cpu_asid(cpu, mm);
60 start &= PAGE_MASK;
61 end += (PAGE_SIZE - 1);
62 end &= PAGE_MASK;
63 if (mm != current->mm) {
64 saved_asid = get_asid();
65 set_asid(asid);
67 while (start < end) {
68 local_flush_tlb_one(asid, start);
69 start += PAGE_SIZE;
71 if (saved_asid != MMU_NO_ASID)
72 set_asid(saved_asid);
74 local_irq_restore(flags);
78 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
80 unsigned int cpu = smp_processor_id();
81 unsigned long flags;
82 int size;
84 local_irq_save(flags);
85 size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
86 if (size > (MMU_NTLB_ENTRIES/4)) { /* Too many TLB to flush */
87 local_flush_tlb_all();
88 } else {
89 unsigned long asid;
90 unsigned long saved_asid = get_asid();
92 asid = cpu_asid(cpu, &init_mm);
93 start &= PAGE_MASK;
94 end += (PAGE_SIZE - 1);
95 end &= PAGE_MASK;
96 set_asid(asid);
97 while (start < end) {
98 local_flush_tlb_one(asid, start);
99 start += PAGE_SIZE;
101 set_asid(saved_asid);
103 local_irq_restore(flags);
106 void local_flush_tlb_mm(struct mm_struct *mm)
108 unsigned int cpu = smp_processor_id();
110 /* Invalidate all TLB of this process. */
111 /* Instead of invalidating each TLB, we get new MMU context. */
112 if (cpu_context(cpu, mm) != NO_CONTEXT) {
113 unsigned long flags;
115 local_irq_save(flags);
116 cpu_context(cpu, mm) = NO_CONTEXT;
117 if (mm == current->mm)
118 activate_context(mm, cpu);
119 local_irq_restore(flags);
123 void local_flush_tlb_all(void)
125 unsigned long flags, status;
128 * Flush all the TLB.
130 * Write to the MMU control register's bit:
131 * TF-bit for SH-3, TI-bit for SH-4.
132 * It's same position, bit #2.
134 local_irq_save(flags);
135 status = ctrl_inl(MMUCR);
136 status |= 0x04;
137 ctrl_outl(status, MMUCR);
138 ctrl_barrier();
139 local_irq_restore(flags);