xref: /linux/arch/riscv/mm/tlbflush.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
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 <linux/hugetlb.h>
7 #include <linux/mmu_notifier.h>
8 #include <asm/sbi.h>
9 #include <asm/mmu_context.h>
10 #include <asm/cpufeature.h>
11 
12 #define has_svinval()	riscv_has_extension_unlikely(RISCV_ISA_EXT_SVINVAL)
13 
14 /*
15  * Flush entire TLB if number of entries to be flushed is greater
16  * than the threshold below.
17  */
18 unsigned long tlb_flush_all_threshold __read_mostly = 64;
19 
20 static void local_flush_tlb_range_threshold_asid(unsigned long start,
21 						 unsigned long size,
22 						 unsigned long stride,
23 						 unsigned long asid)
24 {
25 	unsigned long nr_ptes_in_range = DIV_ROUND_UP(size, stride);
26 	int i;
27 
28 	if (nr_ptes_in_range > tlb_flush_all_threshold) {
29 		local_flush_tlb_all_asid(asid);
30 		return;
31 	}
32 
33 	if (has_svinval()) {
34 		local_sfence_w_inval();
35 		for (i = 0; i < nr_ptes_in_range; ++i) {
36 			local_sinval_vma(start, asid);
37 			start += stride;
38 		}
39 		local_sfence_inval_ir();
40 		return;
41 	}
42 
43 	for (i = 0; i < nr_ptes_in_range; ++i) {
44 		local_flush_tlb_page_asid(start, asid);
45 		start += stride;
46 	}
47 }
48 
49 static inline void local_flush_tlb_range_asid(unsigned long start,
50 		unsigned long size, unsigned long stride, unsigned long asid)
51 {
52 	if (size <= stride)
53 		local_flush_tlb_page_asid(start, asid);
54 	else if (size == FLUSH_TLB_MAX_SIZE)
55 		local_flush_tlb_all_asid(asid);
56 	else
57 		local_flush_tlb_range_threshold_asid(start, size, stride, asid);
58 }
59 
60 /* Flush a range of kernel pages without broadcasting */
61 void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
62 {
63 	local_flush_tlb_range_asid(start, end - start, PAGE_SIZE, FLUSH_TLB_NO_ASID);
64 }
65 
66 static void __ipi_flush_tlb_all(void *info)
67 {
68 	local_flush_tlb_all();
69 }
70 
71 void flush_tlb_all(void)
72 {
73 	if (num_online_cpus() < 2)
74 		local_flush_tlb_all();
75 	else if (riscv_use_sbi_for_rfence())
76 		sbi_remote_sfence_vma_asid(NULL, 0, FLUSH_TLB_MAX_SIZE, FLUSH_TLB_NO_ASID);
77 	else
78 		on_each_cpu(__ipi_flush_tlb_all, NULL, 1);
79 }
80 
81 struct flush_tlb_range_data {
82 	unsigned long asid;
83 	unsigned long start;
84 	unsigned long size;
85 	unsigned long stride;
86 };
87 
88 static void __ipi_flush_tlb_range_asid(void *info)
89 {
90 	struct flush_tlb_range_data *d = info;
91 
92 	local_flush_tlb_range_asid(d->start, d->size, d->stride, d->asid);
93 }
94 
95 static void __flush_tlb_range(struct mm_struct *mm,
96 			      const struct cpumask *cmask,
97 			      unsigned long start, unsigned long size,
98 			      unsigned long stride)
99 {
100 	unsigned long asid = get_mm_asid(mm);
101 	unsigned int cpu;
102 
103 	if (cpumask_empty(cmask))
104 		return;
105 
106 	cpu = get_cpu();
107 
108 	/* Check if the TLB flush needs to be sent to other CPUs. */
109 	if (cpumask_any_but(cmask, cpu) >= nr_cpu_ids) {
110 		local_flush_tlb_range_asid(start, size, stride, asid);
111 	} else if (riscv_use_sbi_for_rfence()) {
112 		sbi_remote_sfence_vma_asid(cmask, start, size, asid);
113 	} else {
114 		struct flush_tlb_range_data ftd;
115 
116 		ftd.asid = asid;
117 		ftd.start = start;
118 		ftd.size = size;
119 		ftd.stride = stride;
120 		on_each_cpu_mask(cmask, __ipi_flush_tlb_range_asid, &ftd, 1);
121 	}
122 
123 	put_cpu();
124 
125 	if (mm)
126 		mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, start + size);
127 }
128 
129 void flush_tlb_mm(struct mm_struct *mm)
130 {
131 	__flush_tlb_range(mm, mm_cpumask(mm), 0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
132 }
133 
134 void flush_tlb_mm_range(struct mm_struct *mm,
135 			unsigned long start, unsigned long end,
136 			unsigned int page_size)
137 {
138 	__flush_tlb_range(mm, mm_cpumask(mm), start, end - start, page_size);
139 }
140 
141 void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
142 {
143 	__flush_tlb_range(vma->vm_mm, mm_cpumask(vma->vm_mm),
144 			  addr, PAGE_SIZE, PAGE_SIZE);
145 }
146 
147 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
148 		     unsigned long end)
149 {
150 	unsigned long stride_size;
151 
152 	if (!is_vm_hugetlb_page(vma)) {
153 		stride_size = PAGE_SIZE;
154 	} else {
155 		stride_size = huge_page_size(hstate_vma(vma));
156 
157 		/*
158 		 * As stated in the privileged specification, every PTE in a
159 		 * NAPOT region must be invalidated, so reset the stride in that
160 		 * case.
161 		 */
162 		if (has_svnapot()) {
163 			if (stride_size >= PGDIR_SIZE)
164 				stride_size = PGDIR_SIZE;
165 			else if (stride_size >= P4D_SIZE)
166 				stride_size = P4D_SIZE;
167 			else if (stride_size >= PUD_SIZE)
168 				stride_size = PUD_SIZE;
169 			else if (stride_size >= PMD_SIZE)
170 				stride_size = PMD_SIZE;
171 			else
172 				stride_size = PAGE_SIZE;
173 		}
174 	}
175 
176 	__flush_tlb_range(vma->vm_mm, mm_cpumask(vma->vm_mm),
177 			  start, end - start, stride_size);
178 }
179 
180 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
181 {
182 	__flush_tlb_range(NULL, cpu_online_mask,
183 			  start, end - start, PAGE_SIZE);
184 }
185 
186 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
187 void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
188 			unsigned long end)
189 {
190 	__flush_tlb_range(vma->vm_mm, mm_cpumask(vma->vm_mm),
191 			  start, end - start, PMD_SIZE);
192 }
193 
194 void flush_pud_tlb_range(struct vm_area_struct *vma, unsigned long start,
195 			 unsigned long end)
196 {
197 	__flush_tlb_range(vma->vm_mm, mm_cpumask(vma->vm_mm),
198 			  start, end - start, PUD_SIZE);
199 }
200 #endif
201 
202 bool arch_tlbbatch_should_defer(struct mm_struct *mm)
203 {
204 	return true;
205 }
206 
207 void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
208 		struct mm_struct *mm, unsigned long start, unsigned long end)
209 {
210 	cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
211 	mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
212 }
213 
214 void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch)
215 {
216 	__flush_tlb_range(NULL, &batch->cpumask,
217 			  0, FLUSH_TLB_MAX_SIZE, PAGE_SIZE);
218 	cpumask_clear(&batch->cpumask);
219 }
220