xref: /openbmc/linux/arch/s390/include/asm/tlbflush.h (revision b830f94f)
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 void smp_ptlb_all(void);
36 
37 /*
38  * Flush all TLB entries on all CPUs.
39  */
40 static inline void __tlb_flush_global(void)
41 {
42 	unsigned int dummy = 0;
43 
44 	csp(&dummy, 0, 0);
45 }
46 
47 /*
48  * Flush TLB entries for a specific mm on all CPUs (in case gmap is used
49  * this implicates multiple ASCEs!).
50  */
51 static inline void __tlb_flush_mm(struct mm_struct *mm)
52 {
53 	unsigned long gmap_asce;
54 
55 	/*
56 	 * If the machine has IDTE we prefer to do a per mm flush
57 	 * on all cpus instead of doing a local flush if the mm
58 	 * only ran on the local cpu.
59 	 */
60 	preempt_disable();
61 	atomic_inc(&mm->context.flush_count);
62 	/* Reset TLB flush mask */
63 	cpumask_copy(mm_cpumask(mm), &mm->context.cpu_attach_mask);
64 	barrier();
65 	gmap_asce = READ_ONCE(mm->context.gmap_asce);
66 	if (MACHINE_HAS_IDTE && gmap_asce != -1UL) {
67 		if (gmap_asce)
68 			__tlb_flush_idte(gmap_asce);
69 		__tlb_flush_idte(mm->context.asce);
70 	} else {
71 		/* Global TLB flush */
72 		__tlb_flush_global();
73 	}
74 	atomic_dec(&mm->context.flush_count);
75 	preempt_enable();
76 }
77 
78 static inline void __tlb_flush_kernel(void)
79 {
80 	if (MACHINE_HAS_IDTE)
81 		__tlb_flush_idte(init_mm.context.asce);
82 	else
83 		__tlb_flush_global();
84 }
85 
86 static inline void __tlb_flush_mm_lazy(struct mm_struct * mm)
87 {
88 	spin_lock(&mm->context.lock);
89 	if (mm->context.flush_mm) {
90 		mm->context.flush_mm = 0;
91 		__tlb_flush_mm(mm);
92 	}
93 	spin_unlock(&mm->context.lock);
94 }
95 
96 /*
97  * TLB flushing:
98  *  flush_tlb() - flushes the current mm struct TLBs
99  *  flush_tlb_all() - flushes all processes TLBs
100  *  flush_tlb_mm(mm) - flushes the specified mm context TLB's
101  *  flush_tlb_page(vma, vmaddr) - flushes one page
102  *  flush_tlb_range(vma, start, end) - flushes a range of pages
103  *  flush_tlb_kernel_range(start, end) - flushes a range of kernel pages
104  */
105 
106 /*
107  * flush_tlb_mm goes together with ptep_set_wrprotect for the
108  * copy_page_range operation and flush_tlb_range is related to
109  * ptep_get_and_clear for change_protection. ptep_set_wrprotect and
110  * ptep_get_and_clear do not flush the TLBs directly if the mm has
111  * only one user. At the end of the update the flush_tlb_mm and
112  * flush_tlb_range functions need to do the flush.
113  */
114 #define flush_tlb()				do { } while (0)
115 #define flush_tlb_all()				do { } while (0)
116 #define flush_tlb_page(vma, addr)		do { } while (0)
117 
118 static inline void flush_tlb_mm(struct mm_struct *mm)
119 {
120 	__tlb_flush_mm_lazy(mm);
121 }
122 
123 static inline void flush_tlb_range(struct vm_area_struct *vma,
124 				   unsigned long start, unsigned long end)
125 {
126 	__tlb_flush_mm_lazy(vma->vm_mm);
127 }
128 
129 static inline void flush_tlb_kernel_range(unsigned long start,
130 					  unsigned long end)
131 {
132 	__tlb_flush_kernel();
133 }
134 
135 #endif /* _S390_TLBFLUSH_H */
136