xref: /openbmc/linux/arch/s390/include/asm/tlbflush.h (revision 6d99a79c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _S390_TLBFLUSH_H
3 #define _S390_TLBFLUSH_H
4 
5 #include <linux/mm.h>
6 #include <linux/sched.h>
7 #include <asm/processor.h>
8 #include <asm/pgalloc.h>
9 #include <asm/pgtable.h>
10 
11 /*
12  * Flush all TLB entries on the local CPU.
13  */
14 static inline void __tlb_flush_local(void)
15 {
16 	asm volatile("ptlb" : : : "memory");
17 }
18 
19 /*
20  * Flush TLB entries for a specific ASCE on all CPUs
21  */
22 static inline void __tlb_flush_idte(unsigned long asce)
23 {
24 	unsigned long opt;
25 
26 	opt = IDTE_PTOA;
27 	if (MACHINE_HAS_TLB_GUEST)
28 		opt |= IDTE_GUEST_ASCE;
29 	/* Global TLB flush for the mm */
30 	asm volatile(
31 		"	.insn	rrf,0xb98e0000,0,%0,%1,0"
32 		: : "a" (opt), "a" (asce) : "cc");
33 }
34 
35 #ifdef CONFIG_SMP
36 void smp_ptlb_all(void);
37 
38 /*
39  * Flush all TLB entries on all CPUs.
40  */
41 static inline void __tlb_flush_global(void)
42 {
43 	unsigned int dummy = 0;
44 
45 	csp(&dummy, 0, 0);
46 }
47 
48 /*
49  * Flush TLB entries for a specific mm on all CPUs (in case gmap is used
50  * this implicates multiple ASCEs!).
51  */
52 static inline void __tlb_flush_mm(struct mm_struct *mm)
53 {
54 	unsigned long gmap_asce;
55 
56 	/*
57 	 * If the machine has IDTE we prefer to do a per mm flush
58 	 * on all cpus instead of doing a local flush if the mm
59 	 * only ran on the local cpu.
60 	 */
61 	preempt_disable();
62 	atomic_inc(&mm->context.flush_count);
63 	/* Reset TLB flush mask */
64 	cpumask_copy(mm_cpumask(mm), &mm->context.cpu_attach_mask);
65 	barrier();
66 	gmap_asce = READ_ONCE(mm->context.gmap_asce);
67 	if (MACHINE_HAS_IDTE && gmap_asce != -1UL) {
68 		if (gmap_asce)
69 			__tlb_flush_idte(gmap_asce);
70 		__tlb_flush_idte(mm->context.asce);
71 	} else {
72 		/* Global TLB flush */
73 		__tlb_flush_global();
74 	}
75 	atomic_dec(&mm->context.flush_count);
76 	preempt_enable();
77 }
78 
79 static inline void __tlb_flush_kernel(void)
80 {
81 	if (MACHINE_HAS_IDTE)
82 		__tlb_flush_idte(init_mm.context.asce);
83 	else
84 		__tlb_flush_global();
85 }
86 #else
87 #define __tlb_flush_global()	__tlb_flush_local()
88 
89 /*
90  * Flush TLB entries for a specific ASCE on all CPUs.
91  */
92 static inline void __tlb_flush_mm(struct mm_struct *mm)
93 {
94 	__tlb_flush_local();
95 }
96 
97 static inline void __tlb_flush_kernel(void)
98 {
99 	__tlb_flush_local();
100 }
101 #endif
102 
103 static inline void __tlb_flush_mm_lazy(struct mm_struct * mm)
104 {
105 	spin_lock(&mm->context.lock);
106 	if (mm->context.flush_mm) {
107 		mm->context.flush_mm = 0;
108 		__tlb_flush_mm(mm);
109 	}
110 	spin_unlock(&mm->context.lock);
111 }
112 
113 /*
114  * TLB flushing:
115  *  flush_tlb() - flushes the current mm struct TLBs
116  *  flush_tlb_all() - flushes all processes TLBs
117  *  flush_tlb_mm(mm) - flushes the specified mm context TLB's
118  *  flush_tlb_page(vma, vmaddr) - flushes one page
119  *  flush_tlb_range(vma, start, end) - flushes a range of pages
120  *  flush_tlb_kernel_range(start, end) - flushes a range of kernel pages
121  */
122 
123 /*
124  * flush_tlb_mm goes together with ptep_set_wrprotect for the
125  * copy_page_range operation and flush_tlb_range is related to
126  * ptep_get_and_clear for change_protection. ptep_set_wrprotect and
127  * ptep_get_and_clear do not flush the TLBs directly if the mm has
128  * only one user. At the end of the update the flush_tlb_mm and
129  * flush_tlb_range functions need to do the flush.
130  */
131 #define flush_tlb()				do { } while (0)
132 #define flush_tlb_all()				do { } while (0)
133 #define flush_tlb_page(vma, addr)		do { } while (0)
134 
135 static inline void flush_tlb_mm(struct mm_struct *mm)
136 {
137 	__tlb_flush_mm_lazy(mm);
138 }
139 
140 static inline void flush_tlb_range(struct vm_area_struct *vma,
141 				   unsigned long start, unsigned long end)
142 {
143 	__tlb_flush_mm_lazy(vma->vm_mm);
144 }
145 
146 static inline void flush_tlb_kernel_range(unsigned long start,
147 					  unsigned long end)
148 {
149 	__tlb_flush_kernel();
150 }
151 
152 #endif /* _S390_TLBFLUSH_H */
153