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-rw-r--r--arch/arm64/include/asm/mmu_context.h152
-rw-r--r--arch/arm64/include/asm/thread_info.h127
-rw-r--r--arch/arm64/kernel/process.c408
-rw-r--r--arch/arm64/mm/context.c159
4 files changed, 846 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
new file mode 100644
index 000000000000..f68465dee026
--- /dev/null
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -0,0 +1,152 @@
1/*
2 * Based on arch/arm/include/asm/mmu_context.h
3 *
4 * Copyright (C) 1996 Russell King.
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19#ifndef __ASM_MMU_CONTEXT_H
20#define __ASM_MMU_CONTEXT_H
21
22#include <linux/compiler.h>
23#include <linux/sched.h>
24
25#include <asm/cacheflush.h>
26#include <asm/proc-fns.h>
27#include <asm-generic/mm_hooks.h>
28#include <asm/cputype.h>
29#include <asm/pgtable.h>
30
31#define MAX_ASID_BITS 16
32
33extern unsigned int cpu_last_asid;
34
35void __init_new_context(struct task_struct *tsk, struct mm_struct *mm);
36void __new_context(struct mm_struct *mm);
37
38/*
39 * Set TTBR0 to empty_zero_page. No translations will be possible via TTBR0.
40 */
41static inline void cpu_set_reserved_ttbr0(void)
42{
43 unsigned long ttbr = page_to_phys(empty_zero_page);
44
45 asm(
46 " msr ttbr0_el1, %0 // set TTBR0\n"
47 " isb"
48 :
49 : "r" (ttbr));
50}
51
52static inline void switch_new_context(struct mm_struct *mm)
53{
54 unsigned long flags;
55
56 __new_context(mm);
57
58 local_irq_save(flags);
59 cpu_switch_mm(mm->pgd, mm);
60 local_irq_restore(flags);
61}
62
63static inline void check_and_switch_context(struct mm_struct *mm,
64 struct task_struct *tsk)
65{
66 /*
67 * Required during context switch to avoid speculative page table
68 * walking with the wrong TTBR.
69 */
70 cpu_set_reserved_ttbr0();
71
72 if (!((mm->context.id ^ cpu_last_asid) >> MAX_ASID_BITS))
73 /*
74 * The ASID is from the current generation, just switch to the
75 * new pgd. This condition is only true for calls from
76 * context_switch() and interrupts are already disabled.
77 */
78 cpu_switch_mm(mm->pgd, mm);
79 else if (irqs_disabled())
80 /*
81 * Defer the new ASID allocation until after the context
82 * switch critical region since __new_context() cannot be
83 * called with interrupts disabled.
84 */
85 set_ti_thread_flag(task_thread_info(tsk), TIF_SWITCH_MM);
86 else
87 /*
88 * That is a direct call to switch_mm() or activate_mm() with
89 * interrupts enabled and a new context.
90 */
91 switch_new_context(mm);
92}
93
94#define init_new_context(tsk,mm) (__init_new_context(tsk,mm),0)
95#define destroy_context(mm) do { } while(0)
96
97#define finish_arch_post_lock_switch \
98 finish_arch_post_lock_switch
99static inline void finish_arch_post_lock_switch(void)
100{
101 if (test_and_clear_thread_flag(TIF_SWITCH_MM)) {
102 struct mm_struct *mm = current->mm;
103 unsigned long flags;
104
105 __new_context(mm);
106
107 local_irq_save(flags);
108 cpu_switch_mm(mm->pgd, mm);
109 local_irq_restore(flags);
110 }
111}
112
113/*
114 * This is called when "tsk" is about to enter lazy TLB mode.
115 *
116 * mm: describes the currently active mm context
117 * tsk: task which is entering lazy tlb
118 * cpu: cpu number which is entering lazy tlb
119 *
120 * tsk->mm will be NULL
121 */
122static inline void
123enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
124{
125}
126
127/*
128 * This is the actual mm switch as far as the scheduler
129 * is concerned. No registers are touched. We avoid
130 * calling the CPU specific function when the mm hasn't
131 * actually changed.
132 */
133static inline void
134switch_mm(struct mm_struct *prev, struct mm_struct *next,
135 struct task_struct *tsk)
136{
137 unsigned int cpu = smp_processor_id();
138
139#ifdef CONFIG_SMP
140 /* check for possible thread migration */
141 if (!cpumask_empty(mm_cpumask(next)) &&
142 !cpumask_test_cpu(cpu, mm_cpumask(next)))
143 __flush_icache_all();
144#endif
145 if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next)
146 check_and_switch_context(next, tsk);
147}
148
149#define deactivate_mm(tsk,mm) do { } while (0)
150#define activate_mm(prev,next) switch_mm(prev, next, NULL)
151
152#endif
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
new file mode 100644
index 000000000000..3659e460071d
--- /dev/null
+++ b/arch/arm64/include/asm/thread_info.h
@@ -0,0 +1,127 @@
1/*
2 * Based on arch/arm/include/asm/thread_info.h
3 *
4 * Copyright (C) 2002 Russell King.
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19#ifndef __ASM_THREAD_INFO_H
20#define __ASM_THREAD_INFO_H
21
22#ifdef __KERNEL__
23
24#include <linux/compiler.h>
25
26#ifndef CONFIG_ARM64_64K_PAGES
27#define THREAD_SIZE_ORDER 1
28#endif
29
30#define THREAD_SIZE 8192
31#define THREAD_START_SP (THREAD_SIZE - 16)
32
33#ifndef __ASSEMBLY__
34
35struct task_struct;
36struct exec_domain;
37
38#include <asm/types.h>
39
40typedef unsigned long mm_segment_t;
41
42/*
43 * low level task data that entry.S needs immediate access to.
44 * __switch_to() assumes cpu_context follows immediately after cpu_domain.
45 */
46struct thread_info {
47 unsigned long flags; /* low level flags */
48 mm_segment_t addr_limit; /* address limit */
49 struct task_struct *task; /* main task structure */
50 struct exec_domain *exec_domain; /* execution domain */
51 struct restart_block restart_block;
52 int preempt_count; /* 0 => preemptable, <0 => bug */
53 int cpu; /* cpu */
54};
55
56#define INIT_THREAD_INFO(tsk) \
57{ \
58 .task = &tsk, \
59 .exec_domain = &default_exec_domain, \
60 .flags = 0, \
61 .preempt_count = INIT_PREEMPT_COUNT, \
62 .addr_limit = KERNEL_DS, \
63 .restart_block = { \
64 .fn = do_no_restart_syscall, \
65 }, \
66}
67
68#define init_thread_info (init_thread_union.thread_info)
69#define init_stack (init_thread_union.stack)
70
71/*
72 * how to get the thread information struct from C
73 */
74static inline struct thread_info *current_thread_info(void) __attribute_const__;
75
76static inline struct thread_info *current_thread_info(void)
77{
78 register unsigned long sp asm ("sp");
79 return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
80}
81
82#define thread_saved_pc(tsk) \
83 ((unsigned long)(tsk->thread.cpu_context.pc))
84#define thread_saved_sp(tsk) \
85 ((unsigned long)(tsk->thread.cpu_context.sp))
86#define thread_saved_fp(tsk) \
87 ((unsigned long)(tsk->thread.cpu_context.fp))
88
89#endif
90
91/*
92 * We use bit 30 of the preempt_count to indicate that kernel
93 * preemption is occurring. See <asm/hardirq.h>.
94 */
95#define PREEMPT_ACTIVE 0x40000000
96
97/*
98 * thread information flags:
99 * TIF_SYSCALL_TRACE - syscall trace active
100 * TIF_SIGPENDING - signal pending
101 * TIF_NEED_RESCHED - rescheduling necessary
102 * TIF_NOTIFY_RESUME - callback before returning to user
103 * TIF_USEDFPU - FPU was used by this task this quantum (SMP)
104 * TIF_POLLING_NRFLAG - true if poll_idle() is polling TIF_NEED_RESCHED
105 */
106#define TIF_SIGPENDING 0
107#define TIF_NEED_RESCHED 1
108#define TIF_NOTIFY_RESUME 2 /* callback before returning to user */
109#define TIF_SYSCALL_TRACE 8
110#define TIF_POLLING_NRFLAG 16
111#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
112#define TIF_FREEZE 19
113#define TIF_RESTORE_SIGMASK 20
114#define TIF_SINGLESTEP 21
115#define TIF_32BIT 22 /* 32bit process */
116#define TIF_SWITCH_MM 23 /* deferred switch_mm */
117
118#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
119#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
120#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
121#define _TIF_32BIT (1 << TIF_32BIT)
122
123#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
124 _TIF_NOTIFY_RESUME)
125
126#endif /* __KERNEL__ */
127#endif /* __ASM_THREAD_INFO_H */
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
new file mode 100644
index 000000000000..f22965ea1cfc
--- /dev/null
+++ b/arch/arm64/kernel/process.c
@@ -0,0 +1,408 @@
1/*
2 * Based on arch/arm/kernel/process.c
3 *
4 * Original Copyright (C) 1995 Linus Torvalds
5 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
6 * Copyright (C) 2012 ARM Ltd.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21#include <stdarg.h>
22
23#include <linux/export.h>
24#include <linux/sched.h>
25#include <linux/kernel.h>
26#include <linux/mm.h>
27#include <linux/stddef.h>
28#include <linux/unistd.h>
29#include <linux/user.h>
30#include <linux/delay.h>
31#include <linux/reboot.h>
32#include <linux/interrupt.h>
33#include <linux/kallsyms.h>
34#include <linux/init.h>
35#include <linux/cpu.h>
36#include <linux/elfcore.h>
37#include <linux/pm.h>
38#include <linux/tick.h>
39#include <linux/utsname.h>
40#include <linux/uaccess.h>
41#include <linux/random.h>
42#include <linux/hw_breakpoint.h>
43#include <linux/personality.h>
44#include <linux/notifier.h>
45
46#include <asm/compat.h>
47#include <asm/cacheflush.h>
48#include <asm/processor.h>
49#include <asm/stacktrace.h>
50#include <asm/fpsimd.h>
51
52static void setup_restart(void)
53{
54 /*
55 * Tell the mm system that we are going to reboot -
56 * we may need it to insert some 1:1 mappings so that
57 * soft boot works.
58 */
59 setup_mm_for_reboot();
60
61 /* Clean and invalidate caches */
62 flush_cache_all();
63
64 /* Turn D-cache off */
65 cpu_cache_off();
66
67 /* Push out any further dirty data, and ensure cache is empty */
68 flush_cache_all();
69}
70
71void soft_restart(unsigned long addr)
72{
73 setup_restart();
74 cpu_reset(addr);
75}
76
77/*
78 * Function pointers to optional machine specific functions
79 */
80void (*pm_power_off)(void);
81EXPORT_SYMBOL_GPL(pm_power_off);
82
83void (*pm_restart)(const char *cmd);
84EXPORT_SYMBOL_GPL(pm_restart);
85
86
87/*
88 * This is our default idle handler.
89 */
90static void default_idle(void)
91{
92 /*
93 * This should do all the clock switching and wait for interrupt
94 * tricks
95 */
96 cpu_do_idle();
97 local_irq_enable();
98}
99
100void (*pm_idle)(void) = default_idle;
101EXPORT_SYMBOL_GPL(pm_idle);
102
103/*
104 * The idle thread, has rather strange semantics for calling pm_idle,
105 * but this is what x86 does and we need to do the same, so that
106 * things like cpuidle get called in the same way. The only difference
107 * is that we always respect 'hlt_counter' to prevent low power idle.
108 */
109void cpu_idle(void)
110{
111 local_fiq_enable();
112
113 /* endless idle loop with no priority at all */
114 while (1) {
115 tick_nohz_idle_enter();
116 rcu_idle_enter();
117 while (!need_resched()) {
118 /*
119 * We need to disable interrupts here to ensure
120 * we don't miss a wakeup call.
121 */
122 local_irq_disable();
123 if (!need_resched()) {
124 stop_critical_timings();
125 pm_idle();
126 start_critical_timings();
127 /*
128 * pm_idle functions should always return
129 * with IRQs enabled.
130 */
131 WARN_ON(irqs_disabled());
132 } else {
133 local_irq_enable();
134 }
135 }
136 rcu_idle_exit();
137 tick_nohz_idle_exit();
138 schedule_preempt_disabled();
139 }
140}
141
142void machine_shutdown(void)
143{
144#ifdef CONFIG_SMP
145 smp_send_stop();
146#endif
147}
148
149void machine_halt(void)
150{
151 machine_shutdown();
152 while (1);
153}
154
155void machine_power_off(void)
156{
157 machine_shutdown();
158 if (pm_power_off)
159 pm_power_off();
160}
161
162void machine_restart(char *cmd)
163{
164 machine_shutdown();
165
166 /* Disable interrupts first */
167 local_irq_disable();
168 local_fiq_disable();
169
170 /* Now call the architecture specific reboot code. */
171 if (pm_restart)
172 pm_restart(cmd);
173
174 /*
175 * Whoops - the architecture was unable to reboot.
176 */
177 printk("Reboot failed -- System halted\n");
178 while (1);
179}
180
181void __show_regs(struct pt_regs *regs)
182{
183 int i;
184
185 printk("CPU: %d %s (%s %.*s)\n",
186 raw_smp_processor_id(), print_tainted(),
187 init_utsname()->release,
188 (int)strcspn(init_utsname()->version, " "),
189 init_utsname()->version);
190 print_symbol("PC is at %s\n", instruction_pointer(regs));
191 print_symbol("LR is at %s\n", regs->regs[30]);
192 printk("pc : [<%016llx>] lr : [<%016llx>] pstate: %08llx\n",
193 regs->pc, regs->regs[30], regs->pstate);
194 printk("sp : %016llx\n", regs->sp);
195 for (i = 29; i >= 0; i--) {
196 printk("x%-2d: %016llx ", i, regs->regs[i]);
197 if (i % 2 == 0)
198 printk("\n");
199 }
200 printk("\n");
201}
202
203void show_regs(struct pt_regs * regs)
204{
205 printk("\n");
206 printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
207 __show_regs(regs);
208}
209
210/*
211 * Free current thread data structures etc..
212 */
213void exit_thread(void)
214{
215}
216
217void flush_thread(void)
218{
219 fpsimd_flush_thread();
220 flush_ptrace_hw_breakpoint(current);
221}
222
223void release_thread(struct task_struct *dead_task)
224{
225}
226
227int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
228{
229 fpsimd_save_state(&current->thread.fpsimd_state);
230 *dst = *src;
231 return 0;
232}
233
234asmlinkage void ret_from_fork(void) asm("ret_from_fork");
235
236int copy_thread(unsigned long clone_flags, unsigned long stack_start,
237 unsigned long stk_sz, struct task_struct *p,
238 struct pt_regs *regs)
239{
240 struct pt_regs *childregs = task_pt_regs(p);
241 unsigned long tls = p->thread.tp_value;
242
243 *childregs = *regs;
244 childregs->regs[0] = 0;
245
246 if (is_compat_thread(task_thread_info(p)))
247 childregs->compat_sp = stack_start;
248 else {
249 /*
250 * Read the current TLS pointer from tpidr_el0 as it may be
251 * out-of-sync with the saved value.
252 */
253 asm("mrs %0, tpidr_el0" : "=r" (tls));
254 childregs->sp = stack_start;
255 }
256
257 memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
258 p->thread.cpu_context.sp = (unsigned long)childregs;
259 p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
260
261 /* If a TLS pointer was passed to clone, use that for the new thread. */
262 if (clone_flags & CLONE_SETTLS)
263 tls = regs->regs[3];
264 p->thread.tp_value = tls;
265
266 ptrace_hw_copy_thread(p);
267
268 return 0;
269}
270
271static void tls_thread_switch(struct task_struct *next)
272{
273 unsigned long tpidr, tpidrro;
274
275 if (!is_compat_task()) {
276 asm("mrs %0, tpidr_el0" : "=r" (tpidr));
277 current->thread.tp_value = tpidr;
278 }
279
280 if (is_compat_thread(task_thread_info(next))) {
281 tpidr = 0;
282 tpidrro = next->thread.tp_value;
283 } else {
284 tpidr = next->thread.tp_value;
285 tpidrro = 0;
286 }
287
288 asm(
289 " msr tpidr_el0, %0\n"
290 " msr tpidrro_el0, %1"
291 : : "r" (tpidr), "r" (tpidrro));
292}
293
294/*
295 * Thread switching.
296 */
297struct task_struct *__switch_to(struct task_struct *prev,
298 struct task_struct *next)
299{
300 struct task_struct *last;
301
302 fpsimd_thread_switch(next);
303 tls_thread_switch(next);
304 hw_breakpoint_thread_switch(next);
305
306 /* the actual thread switch */
307 last = cpu_switch_to(prev, next);
308
309 return last;
310}
311
312/*
313 * Fill in the task's elfregs structure for a core dump.
314 */
315int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
316{
317 elf_core_copy_regs(elfregs, task_pt_regs(t));
318 return 1;
319}
320
321/*
322 * fill in the fpe structure for a core dump...
323 */
324int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
325{
326 return 0;
327}
328EXPORT_SYMBOL(dump_fpu);
329
330/*
331 * Shuffle the argument into the correct register before calling the
332 * thread function. x1 is the thread argument, x2 is the pointer to
333 * the thread function, and x3 points to the exit function.
334 */
335extern void kernel_thread_helper(void);
336asm( ".section .text\n"
337" .align\n"
338" .type kernel_thread_helper, #function\n"
339"kernel_thread_helper:\n"
340" mov x0, x1\n"
341" mov x30, x3\n"
342" br x2\n"
343" .size kernel_thread_helper, . - kernel_thread_helper\n"
344" .previous");
345
346#define kernel_thread_exit do_exit
347
348/*
349 * Create a kernel thread.
350 */
351pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
352{
353 struct pt_regs regs;
354
355 memset(&regs, 0, sizeof(regs));
356
357 regs.regs[1] = (unsigned long)arg;
358 regs.regs[2] = (unsigned long)fn;
359 regs.regs[3] = (unsigned long)kernel_thread_exit;
360 regs.pc = (unsigned long)kernel_thread_helper;
361 regs.pstate = PSR_MODE_EL1h;
362
363 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
364}
365EXPORT_SYMBOL(kernel_thread);
366
367unsigned long get_wchan(struct task_struct *p)
368{
369 struct stackframe frame;
370 int count = 0;
371 if (!p || p == current || p->state == TASK_RUNNING)
372 return 0;
373
374 frame.fp = thread_saved_fp(p);
375 frame.sp = thread_saved_sp(p);
376 frame.pc = thread_saved_pc(p);
377 do {
378 int ret = unwind_frame(&frame);
379 if (ret < 0)
380 return 0;
381 if (!in_sched_functions(frame.pc))
382 return frame.pc;
383 } while (count ++ < 16);
384 return 0;
385}
386
387unsigned long arch_align_stack(unsigned long sp)
388{
389 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
390 sp -= get_random_int() & ~PAGE_MASK;
391 return sp & ~0xf;
392}
393
394static unsigned long randomize_base(unsigned long base)
395{
396 unsigned long range_end = base + (STACK_RND_MASK << PAGE_SHIFT) + 1;
397 return randomize_range(base, range_end, 0) ? : base;
398}
399
400unsigned long arch_randomize_brk(struct mm_struct *mm)
401{
402 return randomize_base(mm->brk);
403}
404
405unsigned long randomize_et_dyn(unsigned long base)
406{
407 return randomize_base(base);
408}
diff --git a/arch/arm64/mm/context.c b/arch/arm64/mm/context.c
new file mode 100644
index 000000000000..baa758d37021
--- /dev/null
+++ b/arch/arm64/mm/context.c
@@ -0,0 +1,159 @@
1/*
2 * Based on arch/arm/mm/context.c
3 *
4 * Copyright (C) 2002-2003 Deep Blue Solutions Ltd, all rights reserved.
5 * Copyright (C) 2012 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/init.h>
21#include <linux/sched.h>
22#include <linux/mm.h>
23#include <linux/smp.h>
24#include <linux/percpu.h>
25
26#include <asm/mmu_context.h>
27#include <asm/tlbflush.h>
28#include <asm/cachetype.h>
29
30#define asid_bits(reg) \
31 (((read_cpuid(ID_AA64MMFR0_EL1) & 0xf0) >> 2) + 8)
32
33#define ASID_FIRST_VERSION (1 << MAX_ASID_BITS)
34
35static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
36unsigned int cpu_last_asid = ASID_FIRST_VERSION;
37
38/*
39 * We fork()ed a process, and we need a new context for the child to run in.
40 */
41void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
42{
43 mm->context.id = 0;
44 raw_spin_lock_init(&mm->context.id_lock);
45}
46
47static void flush_context(void)
48{
49 /* set the reserved TTBR0 before flushing the TLB */
50 cpu_set_reserved_ttbr0();
51 flush_tlb_all();
52 if (icache_is_aivivt())
53 __flush_icache_all();
54}
55
56#ifdef CONFIG_SMP
57
58static void set_mm_context(struct mm_struct *mm, unsigned int asid)
59{
60 unsigned long flags;
61
62 /*
63 * Locking needed for multi-threaded applications where the same
64 * mm->context.id could be set from different CPUs during the
65 * broadcast. This function is also called via IPI so the
66 * mm->context.id_lock has to be IRQ-safe.
67 */
68 raw_spin_lock_irqsave(&mm->context.id_lock, flags);
69 if (likely((mm->context.id ^ cpu_last_asid) >> MAX_ASID_BITS)) {
70 /*
71 * Old version of ASID found. Set the new one and reset
72 * mm_cpumask(mm).
73 */
74 mm->context.id = asid;
75 cpumask_clear(mm_cpumask(mm));
76 }
77 raw_spin_unlock_irqrestore(&mm->context.id_lock, flags);
78
79 /*
80 * Set the mm_cpumask(mm) bit for the current CPU.
81 */
82 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
83}
84
85/*
86 * Reset the ASID on the current CPU. This function call is broadcast from the
87 * CPU handling the ASID rollover and holding cpu_asid_lock.
88 */
89static void reset_context(void *info)
90{
91 unsigned int asid;
92 unsigned int cpu = smp_processor_id();
93 struct mm_struct *mm = current->active_mm;
94
95 smp_rmb();
96 asid = cpu_last_asid + cpu;
97
98 flush_context();
99 set_mm_context(mm, asid);
100
101 /* set the new ASID */
102 cpu_switch_mm(mm->pgd, mm);
103}
104
105#else
106
107static inline void set_mm_context(struct mm_struct *mm, unsigned int asid)
108{
109 mm->context.id = asid;
110 cpumask_copy(mm_cpumask(mm), cpumask_of(smp_processor_id()));
111}
112
113#endif
114
115void __new_context(struct mm_struct *mm)
116{
117 unsigned int asid;
118 unsigned int bits = asid_bits();
119
120 raw_spin_lock(&cpu_asid_lock);
121#ifdef CONFIG_SMP
122 /*
123 * Check the ASID again, in case the change was broadcast from another
124 * CPU before we acquired the lock.
125 */
126 if (!unlikely((mm->context.id ^ cpu_last_asid) >> MAX_ASID_BITS)) {
127 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
128 raw_spin_unlock(&cpu_asid_lock);
129 return;
130 }
131#endif
132 /*
133 * At this point, it is guaranteed that the current mm (with an old
134 * ASID) isn't active on any other CPU since the ASIDs are changed
135 * simultaneously via IPI.
136 */
137 asid = ++cpu_last_asid;
138
139 /*
140 * If we've used up all our ASIDs, we need to start a new version and
141 * flush the TLB.
142 */
143 if (unlikely((asid & ((1 << bits) - 1)) == 0)) {
144 /* increment the ASID version */
145 cpu_last_asid += (1 << MAX_ASID_BITS) - (1 << bits);
146 if (cpu_last_asid == 0)
147 cpu_last_asid = ASID_FIRST_VERSION;
148 asid = cpu_last_asid + smp_processor_id();
149 flush_context();
150#ifdef CONFIG_SMP
151 smp_wmb();
152 smp_call_function(reset_context, NULL, 1);
153#endif
154 cpu_last_asid += NR_CPUS - 1;
155 }
156
157 set_mm_context(mm, asid);
158 raw_spin_unlock(&cpu_asid_lock);
159}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-18 02:08:16 -0500