xref: /openbmc/linux/arch/x86/include/asm/tlbflush.h (revision 4e1a33b1)
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 /* Read the CR4 shadow. */
114 static inline unsigned long cr4_read_shadow(void)
115 {
116 	return this_cpu_read(cpu_tlbstate.cr4);
117 }
118 
119 /*
120  * Save some of cr4 feature set we're using (e.g.  Pentium 4MB
121  * enable and PPro Global page enable), so that any CPU's that boot
122  * up after us can get the correct flags.  This should only be used
123  * during boot on the boot cpu.
124  */
125 extern unsigned long mmu_cr4_features;
126 extern u32 *trampoline_cr4_features;
127 
128 static inline void cr4_set_bits_and_update_boot(unsigned long mask)
129 {
130 	mmu_cr4_features |= mask;
131 	if (trampoline_cr4_features)
132 		*trampoline_cr4_features = mmu_cr4_features;
133 	cr4_set_bits(mask);
134 }
135 
136 static inline void __native_flush_tlb(void)
137 {
138 	/*
139 	 * If current->mm == NULL then we borrow a mm which may change during a
140 	 * task switch and therefore we must not be preempted while we write CR3
141 	 * back:
142 	 */
143 	preempt_disable();
144 	native_write_cr3(native_read_cr3());
145 	preempt_enable();
146 }
147 
148 static inline void __native_flush_tlb_global_irq_disabled(void)
149 {
150 	unsigned long cr4;
151 
152 	cr4 = this_cpu_read(cpu_tlbstate.cr4);
153 	/* clear PGE */
154 	native_write_cr4(cr4 & ~X86_CR4_PGE);
155 	/* write old PGE again and flush TLBs */
156 	native_write_cr4(cr4);
157 }
158 
159 static inline void __native_flush_tlb_global(void)
160 {
161 	unsigned long flags;
162 
163 	if (static_cpu_has(X86_FEATURE_INVPCID)) {
164 		/*
165 		 * Using INVPCID is considerably faster than a pair of writes
166 		 * to CR4 sandwiched inside an IRQ flag save/restore.
167 		 */
168 		invpcid_flush_all();
169 		return;
170 	}
171 
172 	/*
173 	 * Read-modify-write to CR4 - protect it from preemption and
174 	 * from interrupts. (Use the raw variant because this code can
175 	 * be called from deep inside debugging code.)
176 	 */
177 	raw_local_irq_save(flags);
178 
179 	__native_flush_tlb_global_irq_disabled();
180 
181 	raw_local_irq_restore(flags);
182 }
183 
184 static inline void __native_flush_tlb_single(unsigned long addr)
185 {
186 	asm volatile("invlpg (%0)" ::"r" (addr) : "memory");
187 }
188 
189 static inline void __flush_tlb_all(void)
190 {
191 	if (static_cpu_has(X86_FEATURE_PGE))
192 		__flush_tlb_global();
193 	else
194 		__flush_tlb();
195 }
196 
197 static inline void __flush_tlb_one(unsigned long addr)
198 {
199 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ONE);
200 	__flush_tlb_single(addr);
201 }
202 
203 #define TLB_FLUSH_ALL	-1UL
204 
205 /*
206  * TLB flushing:
207  *
208  *  - flush_tlb() flushes the current mm struct TLBs
209  *  - flush_tlb_all() flushes all processes TLBs
210  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
211  *  - flush_tlb_page(vma, vmaddr) flushes one page
212  *  - flush_tlb_range(vma, start, end) flushes a range of pages
213  *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
214  *  - flush_tlb_others(cpumask, mm, start, end) flushes TLBs on other cpus
215  *
216  * ..but the i386 has somewhat limited tlb flushing capabilities,
217  * and page-granular flushes are available only on i486 and up.
218  */
219 
220 #ifndef CONFIG_SMP
221 
222 /* "_up" is for UniProcessor.
223  *
224  * This is a helper for other header functions.  *Not* intended to be called
225  * directly.  All global TLB flushes need to either call this, or to bump the
226  * vm statistics themselves.
227  */
228 static inline void __flush_tlb_up(void)
229 {
230 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
231 	__flush_tlb();
232 }
233 
234 static inline void flush_tlb_all(void)
235 {
236 	count_vm_tlb_event(NR_TLB_LOCAL_FLUSH_ALL);
237 	__flush_tlb_all();
238 }
239 
240 static inline void flush_tlb(void)
241 {
242 	__flush_tlb_up();
243 }
244 
245 static inline void local_flush_tlb(void)
246 {
247 	__flush_tlb_up();
248 }
249 
250 static inline void flush_tlb_mm(struct mm_struct *mm)
251 {
252 	if (mm == current->active_mm)
253 		__flush_tlb_up();
254 }
255 
256 static inline void flush_tlb_page(struct vm_area_struct *vma,
257 				  unsigned long addr)
258 {
259 	if (vma->vm_mm == current->active_mm)
260 		__flush_tlb_one(addr);
261 }
262 
263 static inline void flush_tlb_range(struct vm_area_struct *vma,
264 				   unsigned long start, unsigned long end)
265 {
266 	if (vma->vm_mm == current->active_mm)
267 		__flush_tlb_up();
268 }
269 
270 static inline void flush_tlb_mm_range(struct mm_struct *mm,
271 	   unsigned long start, unsigned long end, unsigned long vmflag)
272 {
273 	if (mm == current->active_mm)
274 		__flush_tlb_up();
275 }
276 
277 static inline void native_flush_tlb_others(const struct cpumask *cpumask,
278 					   struct mm_struct *mm,
279 					   unsigned long start,
280 					   unsigned long end)
281 {
282 }
283 
284 static inline void reset_lazy_tlbstate(void)
285 {
286 }
287 
288 static inline void flush_tlb_kernel_range(unsigned long start,
289 					  unsigned long end)
290 {
291 	flush_tlb_all();
292 }
293 
294 #else  /* SMP */
295 
296 #include <asm/smp.h>
297 
298 #define local_flush_tlb() __flush_tlb()
299 
300 #define flush_tlb_mm(mm)	flush_tlb_mm_range(mm, 0UL, TLB_FLUSH_ALL, 0UL)
301 
302 #define flush_tlb_range(vma, start, end)	\
303 		flush_tlb_mm_range(vma->vm_mm, start, end, vma->vm_flags)
304 
305 extern void flush_tlb_all(void);
306 extern void flush_tlb_current_task(void);
307 extern void flush_tlb_page(struct vm_area_struct *, unsigned long);
308 extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
309 				unsigned long end, unsigned long vmflag);
310 extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
311 
312 #define flush_tlb()	flush_tlb_current_task()
313 
314 void native_flush_tlb_others(const struct cpumask *cpumask,
315 				struct mm_struct *mm,
316 				unsigned long start, unsigned long end);
317 
318 #define TLBSTATE_OK	1
319 #define TLBSTATE_LAZY	2
320 
321 static inline void reset_lazy_tlbstate(void)
322 {
323 	this_cpu_write(cpu_tlbstate.state, 0);
324 	this_cpu_write(cpu_tlbstate.active_mm, &init_mm);
325 }
326 
327 #endif	/* SMP */
328 
329 #ifndef CONFIG_PARAVIRT
330 #define flush_tlb_others(mask, mm, start, end)	\
331 	native_flush_tlb_others(mask, mm, start, end)
332 #endif
333 
334 #endif /* _ASM_X86_TLBFLUSH_H */
335