xref: /linux/arch/hexagon/mm/vm_tlb.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Hexagon Virtual Machine TLB functions
4  *
5  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
6  */
7 
8 /*
9  * The Hexagon Virtual Machine conceals the real workings of
10  * the TLB, but there are one or two functions that need to
11  * be instantiated for it, differently from a native build.
12  */
13 #include <linux/mm.h>
14 #include <linux/sched.h>
15 #include <asm/page.h>
16 #include <asm/hexagon_vm.h>
17 #include <asm/tlbflush.h>
18 
19 /*
20  * Initial VM implementation has only one map active at a time, with
21  * TLB purgings on changes.  So either we're nuking the current map,
22  * or it's a no-op.  This operation is messy on true SMPs where other
23  * processors must be induced to flush the copies in their local TLBs,
24  * but Hexagon thread-based virtual processors share the same MMU.
25  */
26 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
27 			unsigned long end)
28 {
29 	struct mm_struct *mm = vma->vm_mm;
30 
31 	if (mm->context.ptbase == current->active_mm->context.ptbase)
32 		__vmclrmap((void *)start, end - start);
33 }
34 
35 /*
36  * Flush a page from the kernel virtual map - used by highmem
37  */
38 void flush_tlb_one(unsigned long vaddr)
39 {
40 	__vmclrmap((void *)vaddr, PAGE_SIZE);
41 }
42 
43 /*
44  * Flush all TLBs across all CPUs, virtual or real.
45  * A single Hexagon core has 6 thread contexts but
46  * only one TLB.
47  */
48 void tlb_flush_all(void)
49 {
50 	/*  should probably use that fixaddr end or whateve label  */
51 	__vmclrmap(0, 0xffff0000);
52 }
53 
54 /*
55  * Flush TLB entries associated with a given mm_struct mapping.
56  */
57 void flush_tlb_mm(struct mm_struct *mm)
58 {
59 	/* Current Virtual Machine has only one map active at a time */
60 	if (current->active_mm->context.ptbase == mm->context.ptbase)
61 		tlb_flush_all();
62 }
63 
64 /*
65  * Flush TLB state associated with a page of a vma.
66  */
67 void flush_tlb_page(struct vm_area_struct *vma, unsigned long vaddr)
68 {
69 	struct mm_struct *mm = vma->vm_mm;
70 
71 	if (mm->context.ptbase  == current->active_mm->context.ptbase)
72 		__vmclrmap((void *)vaddr, PAGE_SIZE);
73 }
74 
75 /*
76  * Flush TLB entries associated with a kernel address range.
77  * Like flush range, but without the check on the vma->vm_mm.
78  */
79 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
80 {
81 		__vmclrmap((void *)start, end - start);
82 }
83