xref: /openbmc/linux/arch/x86/include/asm/tlbflush.h (revision d236d361)
1 #ifndef _ASM_X86_TLBFLUSH_H
2 #define _ASM_X86_TLBFLUSH_H
3 
4 #include <linux/mm.h>
5 #include <linux/sched.h>
6 
7 #include <asm/processor.h>
8 #include <asm/cpufeature.h>
9 #include <asm/special_insns.h>
10 
11 static inline void __invpcid(unsigned long pcid, unsigned long addr,
12 			     unsigned long type)
13 {
14 	struct { u64 d[2]; } desc = { { pcid, addr } };
15 
16 	/*
17 	 * The memory clobber is because the whole point is to invalidate
18 	 * stale TLB entries and, especially if we're flushing global
19 	 * mappings, we don't want the compiler to reorder any subsequent
20 	 * memory accesses before the TLB flush.
21 	 *
22 	 * The hex opcode is invpcid (%ecx), %eax in 32-bit mode and
23 	 * invpcid (%rcx), %rax in long mode.
24 	 */
25 	asm volatile (".byte 0x66, 0x0f, 0x38, 0x82, 0x01"
26 		      : : "m" (desc), "a" (type), "c" (&desc) : "memory");
27 }
28 
29 #define INVPCID_TYPE_INDIV_ADDR		0
30 #define INVPCID_TYPE_SINGLE_CTXT	1
31 #define INVPCID_TYPE_ALL_INCL_GLOBAL	2
32 #define INVPCID_TYPE_ALL_NON_GLOBAL	3
33 
34 /* Flush all mappings for a given pcid and addr, not including globals. */
35 static inline void invpcid_flush_one(unsigned long pcid,
36 				     unsigned long addr)
37 {
38 	__invpcid(pcid, addr, INVPCID_TYPE_INDIV_ADDR);
39 }
40 
41 /* Flush all mappings for a given PCID, not including globals. */
42 static inline void invpcid_flush_single_context(unsigned long pcid)
43 {
44 	__invpcid(pcid, 0, INVPCID_TYPE_SINGLE_CTXT);
45 }
46 
47 /* Flush all mappings, including globals, for all PCIDs. */
48 static inline void invpcid_flush_all(void)
49 {
50 	__invpcid(0, 0, INVPCID_TYPE_ALL_INCL_GLOBAL);
51 }
52 
53 /* Flush all mappings for all PCIDs except globals. */
54 static inline void invpcid_flush_all_nonglobals(void)
55 {
56 	__invpcid(0, 0, INVPCID_TYPE_ALL_NON_GLOBAL);
57 }
58 
59 #ifdef CONFIG_PARAVIRT
60 #include <asm/paravirt.h>
61 #else
62 #define __flush_tlb() __native_flush_tlb()
63 #define __flush_tlb_global() __native_flush_tlb_global()
64 #define __flush_tlb_single(addr) __native_flush_tlb_single(addr)
65 #endif
66 
67 struct tlb_state {
68 #ifdef CONFIG_SMP
69 	struct mm_struct *active_mm;
70 	int state;
71 #endif
72 
73 	/*
74 	 * Access to this CR4 shadow and to H/W CR4 is protected by
75 	 * disabling interrupts when modifying either one.
76 	 */
77 	unsigned long cr4;
78 };
79 DECLARE_PER_CPU_SHARED_ALIGNED(struct tlb_state, cpu_tlbstate);
80 
81 /* Initialize cr4 shadow for this CPU. */
82 static inline void cr4_init_shadow(void)
83 {
84 	this_cpu_write(cpu_tlbstate.cr4, __read_cr4());
85 }
86 
87 /* Set in this cpu's CR4. */
88 static inline void cr4_set_bits(unsigned long mask)
89 {
90 	unsigned long cr4;
91 
92 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
93 	if ((cr4 | mask) != cr4) {
94 		cr4 |= mask;
95 		this_cpu_write(cpu_tlbstate.cr4, cr4);
96 		__write_cr4(cr4);
97 	}
98 }
99 
100 /* Clear in this cpu's CR4. */
101 static inline void cr4_clear_bits(unsigned long mask)
102 {
103 	unsigned long cr4;
104 
105 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
106 	if ((cr4 & ~mask) != cr4) {
107 		cr4 &= ~mask;
108 		this_cpu_write(cpu_tlbstate.cr4, cr4);
109 		__write_cr4(cr4);
110 	}
111 }
112 
113 static inline void cr4_toggle_bits(unsigned long mask)
114 {
115 	unsigned long cr4;
116 
117 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
118 	cr4 ^= mask;
119 	this_cpu_write(cpu_tlbstate.cr4, cr4);
120 	__write_cr4(cr4);
121 }
122 
123 /* Read the CR4 shadow. */
124 static inline unsigned long cr4_read_shadow(void)
125 {
126 	return this_cpu_read(cpu_tlbstate.cr4);
127 }
128 
129 /*
130  * Save some of cr4 feature set we're using (e.g.  Pentium 4MB
131  * enable and PPro Global page enable), so that any CPU's that boot
132  * up after us can get the correct flags.  This should only be used
133  * during boot on the boot cpu.
134  */
135 extern unsigned long mmu_cr4_features;
136 extern u32 *trampoline_cr4_features;
137 
138 static inline void cr4_set_bits_and_update_boot(unsigned long mask)
139 {
140 	mmu_cr4_features |= mask;
141 	if (trampoline_cr4_features)
142 		*trampoline_cr4_features = mmu_cr4_features;
143 	cr4_set_bits(mask);
144 }
145 
146 static inline void __native_flush_tlb(void)
147 {
148 	/*
149 	 * If current->mm == NULL then we borrow a mm which may change during a
150 	 * task switch and therefore we must not be preempted while we write CR3
151 	 * back:
152 	 */
153 	preempt_disable();
154 	native_write_cr3(native_read_cr3());
155 	preempt_enable();
156 }
157 
158 static inline void __native_flush_tlb_global_irq_disabled(void)
159 {
160 	unsigned long cr4;
161 
162 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
163 	/* clear PGE */
164 	native_write_cr4(cr4 & ~X86_CR4_PGE);
165 	/* write old PGE again and flush TLBs */
166 	native_write_cr4(cr4);
167 }
168 
169 static inline void __native_flush_tlb_global(void)
170 {
171 	unsigned long flags;
172 
173 	if (static_cpu_has(X86_FEATURE_INVPCID)) {
174 		/*
175 		 * Using INVPCID is considerably faster than a pair of writes
176 		 * to CR4 sandwiched inside an IRQ flag save/restore.
177 		 */
178 		invpcid_flush_all();
179 		return;
180 	}
181 
182 	/*
183 	 * Read-modify-write to CR4 - protect it from preemption and
184 	 * from interrupts. (Use the raw variant because this code can
185 	 * be called from deep inside debugging code.)
186 	 */
187 	raw_local_irq_save(flags);
188 
189 	__native_flush_tlb_global_irq_disabled();
190 
191 	raw_local_irq_restore(flags);
192 }
193 
194 static inline void __native_flush_tlb_single(unsigned long addr)
195 {
196 	asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
197 }
198 
199 static inline void __flush_tlb_all(void)
200 {
201 	if (boot_cpu_has(X86_FEATURE_PGE))
202 		__flush_tlb_global();
203 	else
204 		__flush_tlb();
205 }
206 
207 static inline void __flush_tlb_one(unsigned long addr)
208 {
209 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
210 	__flush_tlb_single(addr);
211 }
212 
213 #define TLB_FLUSH_ALL	-1UL
214 
215 /*
216  * TLB flushing:
217  *
218  *  - flush_tlb_all() flushes all processes TLBs
219  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
220  *  - flush_tlb_page(vma, vmaddr) flushes one page
221  *  - flush_tlb_range(vma, start, end) flushes a range of pages
222  *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
223  *  - flush_tlb_others(cpumask, mm, start, end) flushes TLBs on other cpus
224  *
225  * ..but the i386 has somewhat limited tlb flushing capabilities,
226  * and page-granular flushes are available only on i486 and up.
227  */
228 
229 #ifndef CONFIG_SMP
230 
231 /* "_up" is for UniProcessor.
232  *
233  * This is a helper for other header functions.  *Not* intended to be called
234  * directly.  All global TLB flushes need to either call this, or to bump the
235  * vm statistics themselves.
236  */
237 static inline void __flush_tlb_up(void)
238 {
239 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
240 	__flush_tlb();
241 }
242 
243 static inline void flush_tlb_all(void)
244 {
245 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
246 	__flush_tlb_all();
247 }
248 
249 static inline void local_flush_tlb(void)
250 {
251 	__flush_tlb_up();
252 }
253 
254 static inline void flush_tlb_mm(struct mm_struct *mm)
255 {
256 	if (mm == current->active_mm)
257 		__flush_tlb_up();
258 }
259 
260 static inline void flush_tlb_page(struct vm_area_struct *vma,
261 				  unsigned long addr)
262 {
263 	if (vma->vm_mm == current->active_mm)
264 		__flush_tlb_one(addr);
265 }
266 
267 static inline void flush_tlb_range(struct vm_area_struct *vma,
268 				   unsigned long start, unsigned long end)
269 {
270 	if (vma->vm_mm == current->active_mm)
271 		__flush_tlb_up();
272 }
273 
274 static inline void flush_tlb_mm_range(struct mm_struct *mm,
275 	   unsigned long start, unsigned long end, unsigned long vmflag)
276 {
277 	if (mm == current->active_mm)
278 		__flush_tlb_up();
279 }
280 
281 static inline void native_flush_tlb_others(const struct cpumask *cpumask,
282 					   struct mm_struct *mm,
283 					   unsigned long start,
284 					   unsigned long end)
285 {
286 }
287 
288 static inline void reset_lazy_tlbstate(void)
289 {
290 }
291 
292 static inline void flush_tlb_kernel_range(unsigned long start,
293 					  unsigned long end)
294 {
295 	flush_tlb_all();
296 }
297 
298 #else  /* SMP */
299 
300 #include <asm/smp.h>
301 
302 #define local_flush_tlb() __flush_tlb()
303 
304 #define flush_tlb_mm(mm)	flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL)
305 
306 #define flush_tlb_range(vma, start, end)	\
307 		flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags)
308 
309 extern void flush_tlb_all(void);
310 extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
311 extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
312 				unsigned long end, unsigned long vmflag);
313 extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
314 
315 void native_flush_tlb_others(const struct cpumask *cpumask,
316 				struct mm_struct *mm,
317 				unsigned long start, unsigned long end);
318 
319 #define TLBSTATE_OK	1
320 #define TLBSTATE_LAZY	2
321 
322 static inline void reset_lazy_tlbstate(void)
323 {
324 	this_cpu_write(cpu_tlbstate.state, 0);
325 	this_cpu_write(cpu_tlbstate.active_mm, &init_mm);
326 }
327 
328 #endif	/* SMP */
329 
330 #ifndef CONFIG_PARAVIRT
331 #define flush_tlb_others(mask, mm, start, end)	\
332 	native_flush_tlb_others(mask, mm, start, end)
333 #endif
334 
335 #endif /* _ASM_X86_TLBFLUSH_H */
336