xref: /openbmc/linux/arch/riscv/mm/tlbflush.c (revision 94b00cd6)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/mm.h>
4 #include <linux/smp.h>
5 #include <linux/sched.h>
6 #include <asm/sbi.h>
7 #include <asm/mmu_context.h>
8 
9 static inline void local_flush_tlb_all_asid(unsigned long asid)
10 {
11 	if (asid != FLUSH_TLB_NO_ASID)
12 		__asm__ __volatile__ ("sfence.vma x0, %0"
13 				:
14 				: "r" (asid)
15 				: "memory");
16 	else
17 		local_flush_tlb_all();
18 }
19 
20 static inline void local_flush_tlb_page_asid(unsigned long addr,
21 		unsigned long asid)
22 {
23 	if (asid != FLUSH_TLB_NO_ASID)
24 		__asm__ __volatile__ ("sfence.vma %0, %1"
25 				:
26 				: "r" (addr), "r" (asid)
27 				: "memory");
28 	else
29 		local_flush_tlb_page(addr);
30 }
31 
32 /*
33  * Flush entire TLB if number of entries to be flushed is greater
34  * than the threshold below.
35  */
36 static unsigned long tlb_flush_all_threshold __read_mostly = 64;
37 
38 static void local_flush_tlb_range_threshold_asid(unsigned long start,
39 						 unsigned long size,
40 						 unsigned long stride,
41 						 unsigned long asid)
42 {
43 	unsigned long nr_ptes_in_range = DIV_ROUND_UP(size, stride);
44 	int i;
45 
46 	if (nr_ptes_in_range > tlb_flush_all_threshold) {
47 		local_flush_tlb_all_asid(asid);
48 		return;
49 	}
50 
51 	for (i = 0; i < nr_ptes_in_range; ++i) {
52 		local_flush_tlb_page_asid(start, asid);
53 		start += stride;
54 	}
55 }
56 
57 static inline void local_flush_tlb_range_asid(unsigned long start,
58 		unsigned long size, unsigned long stride, unsigned long asid)
59 {
60 	if (size <= stride)
61 		local_flush_tlb_page_asid(start, asid);
62 	else if (size == FLUSH_TLB_MAX_SIZE)
63 		local_flush_tlb_all_asid(asid);
64 	else
65 		local_flush_tlb_range_threshold_asid(start, size, stride, asid);
66 }
67 
68 /* Flush a range of kernel pages without broadcasting */
69 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
70 {
71 	local_flush_tlb_range_asid(start, end - start, PAGE_SIZE, FLUSH_TLB_NO_ASID);
72 }
73 
74 static void __ipi_flush_tlb_all(void *info)
75 {
76 	local_flush_tlb_all();
77 }
78 
79 void flush_tlb_all(void)
80 {
81 	if (riscv_use_ipi_for_rfence())
82 		on_each_cpu(__ipi_flush_tlb_all, NULL, 1);
83 	else
84 		sbi_remote_sfence_vma_asid(NULL, 0, FLUSH_TLB_MAX_SIZE, FLUSH_TLB_NO_ASID);
85 }
86 
87 struct flush_tlb_range_data {
88 	unsigned long asid;
89 	unsigned long start;
90 	unsigned long size;
91 	unsigned long stride;
92 };
93 
94 static void __ipi_flush_tlb_range_asid(void *info)
95 {
96 	struct flush_tlb_range_data *d = info;
97 
98 	local_flush_tlb_range_asid(d->start, d->size, d->stride, d->asid);
99 }
100 
101 static void __flush_tlb_range(struct mm_struct *mm, unsigned long start,
102 			      unsigned long size, unsigned long stride)
103 {
104 	struct flush_tlb_range_data ftd;
105 	const struct cpumask *cmask;
106 	unsigned long asid = FLUSH_TLB_NO_ASID;
107 	bool broadcast;
108 
109 	if (mm) {
110 		unsigned int cpuid;
111 
112 		cmask = mm_cpumask(mm);
113 		if (cpumask_empty(cmask))
114 			return;
115 
116 		cpuid = get_cpu();
117 		/* check if the tlbflush needs to be sent to other CPUs */
118 		broadcast = cpumask_any_but(cmask, cpuid) < nr_cpu_ids;
119 
120 		if (static_branch_unlikely(&use_asid_allocator))
121 			asid = atomic_long_read(&mm->context.id) & asid_mask;
122 	} else {
123 		cmask = cpu_online_mask;
124 		broadcast = true;
125 	}
126 
127 	if (broadcast) {
128 		if (riscv_use_ipi_for_rfence()) {
129 			ftd.asid = asid;
130 			ftd.start = start;
131 			ftd.size = size;
132 			ftd.stride = stride;
133 			on_each_cpu_mask(cmask,
134 					 __ipi_flush_tlb_range_asid,
135 					 &ftd, 1);
136 		} else
137 			sbi_remote_sfence_vma_asid(cmask,
138 						   start, size, asid);
139 	} else {
140 		local_flush_tlb_range_asid(start, size, stride, asid);
141 	}
142 
143 	if (mm)
144 		put_cpu();
145 }
146 
147 void flush_tlb_mm(struct mm_struct *mm)
148 {
149 	__flush_tlb_range(mm, 0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
150 }
151 
152 void flush_tlb_mm_range(struct mm_struct *mm,
153 			unsigned long start, unsigned long end,
154 			unsigned int page_size)
155 {
156 	__flush_tlb_range(mm, start, end - start, page_size);
157 }
158 
159 void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
160 {
161 	__flush_tlb_range(vma->vm_mm, addr, PAGE_SIZE, PAGE_SIZE);
162 }
163 
164 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
165 		     unsigned long end)
166 {
167 	__flush_tlb_range(vma->vm_mm, start, end - start, PAGE_SIZE);
168 }
169 
170 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
171 {
172 	__flush_tlb_range(NULL, start, end - start, PAGE_SIZE);
173 }
174 
175 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
176 void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
177 			unsigned long end)
178 {
179 	__flush_tlb_range(vma->vm_mm, start, end - start, PMD_SIZE);
180 }
181 #endif
182