ARM: rockchip: fix broken build
[linux/fpc-iii.git] / arch / arm64 / kernel / armv8_deprecated.c
blob7922c2e710cadfc479a41a8008e02b25942f2751
1 /*
2 * Copyright (C) 2014 ARM Limited
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
9 #include <linux/cpu.h>
10 #include <linux/init.h>
11 #include <linux/list.h>
12 #include <linux/perf_event.h>
13 #include <linux/sched.h>
14 #include <linux/slab.h>
15 #include <linux/sysctl.h>
17 #include <asm/insn.h>
18 #include <asm/opcodes.h>
19 #include <asm/system_misc.h>
20 #include <asm/traps.h>
21 #include <asm/uaccess.h>
22 #include <asm/cpufeature.h>
24 #define CREATE_TRACE_POINTS
25 #include "trace-events-emulation.h"
28 * The runtime support for deprecated instruction support can be in one of
29 * following three states -
31 * 0 = undef
32 * 1 = emulate (software emulation)
33 * 2 = hw (supported in hardware)
35 enum insn_emulation_mode {
36 INSN_UNDEF,
37 INSN_EMULATE,
38 INSN_HW,
41 enum legacy_insn_status {
42 INSN_DEPRECATED,
43 INSN_OBSOLETE,
46 struct insn_emulation_ops {
47 const char *name;
48 enum legacy_insn_status status;
49 struct undef_hook *hooks;
50 int (*set_hw_mode)(bool enable);
53 struct insn_emulation {
54 struct list_head node;
55 struct insn_emulation_ops *ops;
56 int current_mode;
57 int min;
58 int max;
61 static LIST_HEAD(insn_emulation);
62 static int nr_insn_emulated;
63 static DEFINE_RAW_SPINLOCK(insn_emulation_lock);
65 static void register_emulation_hooks(struct insn_emulation_ops *ops)
67 struct undef_hook *hook;
69 BUG_ON(!ops->hooks);
71 for (hook = ops->hooks; hook->instr_mask; hook++)
72 register_undef_hook(hook);
74 pr_notice("Registered %s emulation handler\n", ops->name);
77 static void remove_emulation_hooks(struct insn_emulation_ops *ops)
79 struct undef_hook *hook;
81 BUG_ON(!ops->hooks);
83 for (hook = ops->hooks; hook->instr_mask; hook++)
84 unregister_undef_hook(hook);
86 pr_notice("Removed %s emulation handler\n", ops->name);
89 static void enable_insn_hw_mode(void *data)
91 struct insn_emulation *insn = (struct insn_emulation *)data;
92 if (insn->ops->set_hw_mode)
93 insn->ops->set_hw_mode(true);
96 static void disable_insn_hw_mode(void *data)
98 struct insn_emulation *insn = (struct insn_emulation *)data;
99 if (insn->ops->set_hw_mode)
100 insn->ops->set_hw_mode(false);
103 /* Run set_hw_mode(mode) on all active CPUs */
104 static int run_all_cpu_set_hw_mode(struct insn_emulation *insn, bool enable)
106 if (!insn->ops->set_hw_mode)
107 return -EINVAL;
108 if (enable)
109 on_each_cpu(enable_insn_hw_mode, (void *)insn, true);
110 else
111 on_each_cpu(disable_insn_hw_mode, (void *)insn, true);
112 return 0;
116 * Run set_hw_mode for all insns on a starting CPU.
117 * Returns:
118 * 0 - If all the hooks ran successfully.
119 * -EINVAL - At least one hook is not supported by the CPU.
121 static int run_all_insn_set_hw_mode(unsigned long cpu)
123 int rc = 0;
124 unsigned long flags;
125 struct insn_emulation *insn;
127 raw_spin_lock_irqsave(&insn_emulation_lock, flags);
128 list_for_each_entry(insn, &insn_emulation, node) {
129 bool enable = (insn->current_mode == INSN_HW);
130 if (insn->ops->set_hw_mode && insn->ops->set_hw_mode(enable)) {
131 pr_warn("CPU[%ld] cannot support the emulation of %s",
132 cpu, insn->ops->name);
133 rc = -EINVAL;
136 raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
137 return rc;
140 static int update_insn_emulation_mode(struct insn_emulation *insn,
141 enum insn_emulation_mode prev)
143 int ret = 0;
145 switch (prev) {
146 case INSN_UNDEF: /* Nothing to be done */
147 break;
148 case INSN_EMULATE:
149 remove_emulation_hooks(insn->ops);
150 break;
151 case INSN_HW:
152 if (!run_all_cpu_set_hw_mode(insn, false))
153 pr_notice("Disabled %s support\n", insn->ops->name);
154 break;
157 switch (insn->current_mode) {
158 case INSN_UNDEF:
159 break;
160 case INSN_EMULATE:
161 register_emulation_hooks(insn->ops);
162 break;
163 case INSN_HW:
164 ret = run_all_cpu_set_hw_mode(insn, true);
165 if (!ret)
166 pr_notice("Enabled %s support\n", insn->ops->name);
167 break;
170 return ret;
173 static void register_insn_emulation(struct insn_emulation_ops *ops)
175 unsigned long flags;
176 struct insn_emulation *insn;
178 insn = kzalloc(sizeof(*insn), GFP_KERNEL);
179 insn->ops = ops;
180 insn->min = INSN_UNDEF;
182 switch (ops->status) {
183 case INSN_DEPRECATED:
184 insn->current_mode = INSN_EMULATE;
185 /* Disable the HW mode if it was turned on at early boot time */
186 run_all_cpu_set_hw_mode(insn, false);
187 insn->max = INSN_HW;
188 break;
189 case INSN_OBSOLETE:
190 insn->current_mode = INSN_UNDEF;
191 insn->max = INSN_EMULATE;
192 break;
195 raw_spin_lock_irqsave(&insn_emulation_lock, flags);
196 list_add(&insn->node, &insn_emulation);
197 nr_insn_emulated++;
198 raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
200 /* Register any handlers if required */
201 update_insn_emulation_mode(insn, INSN_UNDEF);
204 static int emulation_proc_handler(struct ctl_table *table, int write,
205 void __user *buffer, size_t *lenp,
206 loff_t *ppos)
208 int ret = 0;
209 struct insn_emulation *insn = (struct insn_emulation *) table->data;
210 enum insn_emulation_mode prev_mode = insn->current_mode;
212 table->data = &insn->current_mode;
213 ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
215 if (ret || !write || prev_mode == insn->current_mode)
216 goto ret;
218 ret = update_insn_emulation_mode(insn, prev_mode);
219 if (ret) {
220 /* Mode change failed, revert to previous mode. */
221 insn->current_mode = prev_mode;
222 update_insn_emulation_mode(insn, INSN_UNDEF);
224 ret:
225 table->data = insn;
226 return ret;
229 static struct ctl_table ctl_abi[] = {
231 .procname = "abi",
232 .mode = 0555,
237 static void register_insn_emulation_sysctl(struct ctl_table *table)
239 unsigned long flags;
240 int i = 0;
241 struct insn_emulation *insn;
242 struct ctl_table *insns_sysctl, *sysctl;
244 insns_sysctl = kzalloc(sizeof(*sysctl) * (nr_insn_emulated + 1),
245 GFP_KERNEL);
247 raw_spin_lock_irqsave(&insn_emulation_lock, flags);
248 list_for_each_entry(insn, &insn_emulation, node) {
249 sysctl = &insns_sysctl[i];
251 sysctl->mode = 0644;
252 sysctl->maxlen = sizeof(int);
254 sysctl->procname = insn->ops->name;
255 sysctl->data = insn;
256 sysctl->extra1 = &insn->min;
257 sysctl->extra2 = &insn->max;
258 sysctl->proc_handler = emulation_proc_handler;
259 i++;
261 raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
263 table->child = insns_sysctl;
264 register_sysctl_table(table);
268 * Implement emulation of the SWP/SWPB instructions using load-exclusive and
269 * store-exclusive.
271 * Syntax of SWP{B} instruction: SWP{B}<c> <Rt>, <Rt2>, [<Rn>]
272 * Where: Rt = destination
273 * Rt2 = source
274 * Rn = address
278 * Error-checking SWP macros implemented using ldxr{b}/stxr{b}
280 #define __user_swpX_asm(data, addr, res, temp, B) \
281 __asm__ __volatile__( \
282 " mov %w2, %w1\n" \
283 "0: ldxr"B" %w1, [%3]\n" \
284 "1: stxr"B" %w0, %w2, [%3]\n" \
285 " cbz %w0, 2f\n" \
286 " mov %w0, %w4\n" \
287 "2:\n" \
288 " .pushsection .fixup,\"ax\"\n" \
289 " .align 2\n" \
290 "3: mov %w0, %w5\n" \
291 " b 2b\n" \
292 " .popsection" \
293 " .pushsection __ex_table,\"a\"\n" \
294 " .align 3\n" \
295 " .quad 0b, 3b\n" \
296 " .quad 1b, 3b\n" \
297 " .popsection" \
298 : "=&r" (res), "+r" (data), "=&r" (temp) \
299 : "r" (addr), "i" (-EAGAIN), "i" (-EFAULT) \
300 : "memory")
302 #define __user_swp_asm(data, addr, res, temp) \
303 __user_swpX_asm(data, addr, res, temp, "")
304 #define __user_swpb_asm(data, addr, res, temp) \
305 __user_swpX_asm(data, addr, res, temp, "b")
308 * Bit 22 of the instruction encoding distinguishes between
309 * the SWP and SWPB variants (bit set means SWPB).
311 #define TYPE_SWPB (1 << 22)
314 * Set up process info to signal segmentation fault - called on access error.
316 static void set_segfault(struct pt_regs *regs, unsigned long addr)
318 siginfo_t info;
320 down_read(&current->mm->mmap_sem);
321 if (find_vma(current->mm, addr) == NULL)
322 info.si_code = SEGV_MAPERR;
323 else
324 info.si_code = SEGV_ACCERR;
325 up_read(&current->mm->mmap_sem);
327 info.si_signo = SIGSEGV;
328 info.si_errno = 0;
329 info.si_addr = (void *) instruction_pointer(regs);
331 pr_debug("SWP{B} emulation: access caused memory abort!\n");
332 arm64_notify_die("Illegal memory access", regs, &info, 0);
335 static int emulate_swpX(unsigned int address, unsigned int *data,
336 unsigned int type)
338 unsigned int res = 0;
340 if ((type != TYPE_SWPB) && (address & 0x3)) {
341 /* SWP to unaligned address not permitted */
342 pr_debug("SWP instruction on unaligned pointer!\n");
343 return -EFAULT;
346 while (1) {
347 unsigned long temp;
349 if (type == TYPE_SWPB)
350 __user_swpb_asm(*data, address, res, temp);
351 else
352 __user_swp_asm(*data, address, res, temp);
354 if (likely(res != -EAGAIN) || signal_pending(current))
355 break;
357 cond_resched();
360 return res;
364 * swp_handler logs the id of calling process, dissects the instruction, sanity
365 * checks the memory location, calls emulate_swpX for the actual operation and
366 * deals with fixup/error handling before returning
368 static int swp_handler(struct pt_regs *regs, u32 instr)
370 u32 destreg, data, type, address = 0;
371 int rn, rt2, res = 0;
373 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
375 type = instr & TYPE_SWPB;
377 switch (arm_check_condition(instr, regs->pstate)) {
378 case ARM_OPCODE_CONDTEST_PASS:
379 break;
380 case ARM_OPCODE_CONDTEST_FAIL:
381 /* Condition failed - return to next instruction */
382 goto ret;
383 case ARM_OPCODE_CONDTEST_UNCOND:
384 /* If unconditional encoding - not a SWP, undef */
385 return -EFAULT;
386 default:
387 return -EINVAL;
390 rn = aarch32_insn_extract_reg_num(instr, A32_RN_OFFSET);
391 rt2 = aarch32_insn_extract_reg_num(instr, A32_RT2_OFFSET);
393 address = (u32)regs->user_regs.regs[rn];
394 data = (u32)regs->user_regs.regs[rt2];
395 destreg = aarch32_insn_extract_reg_num(instr, A32_RT_OFFSET);
397 pr_debug("addr in r%d->0x%08x, dest is r%d, source in r%d->0x%08x)\n",
398 rn, address, destreg,
399 aarch32_insn_extract_reg_num(instr, A32_RT2_OFFSET), data);
401 /* Check access in reasonable access range for both SWP and SWPB */
402 if (!access_ok(VERIFY_WRITE, (address & ~3), 4)) {
403 pr_debug("SWP{B} emulation: access to 0x%08x not allowed!\n",
404 address);
405 goto fault;
408 res = emulate_swpX(address, &data, type);
409 if (res == -EFAULT)
410 goto fault;
411 else if (res == 0)
412 regs->user_regs.regs[destreg] = data;
414 ret:
415 if (type == TYPE_SWPB)
416 trace_instruction_emulation("swpb", regs->pc);
417 else
418 trace_instruction_emulation("swp", regs->pc);
420 pr_warn_ratelimited("\"%s\" (%ld) uses obsolete SWP{B} instruction at 0x%llx\n",
421 current->comm, (unsigned long)current->pid, regs->pc);
423 regs->pc += 4;
424 return 0;
426 fault:
427 set_segfault(regs, address);
429 return 0;
433 * Only emulate SWP/SWPB executed in ARM state/User mode.
434 * The kernel must be SWP free and SWP{B} does not exist in Thumb.
436 static struct undef_hook swp_hooks[] = {
438 .instr_mask = 0x0fb00ff0,
439 .instr_val = 0x01000090,
440 .pstate_mask = COMPAT_PSR_MODE_MASK,
441 .pstate_val = COMPAT_PSR_MODE_USR,
442 .fn = swp_handler
447 static struct insn_emulation_ops swp_ops = {
448 .name = "swp",
449 .status = INSN_OBSOLETE,
450 .hooks = swp_hooks,
451 .set_hw_mode = NULL,
454 static int cp15barrier_handler(struct pt_regs *regs, u32 instr)
456 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
458 switch (arm_check_condition(instr, regs->pstate)) {
459 case ARM_OPCODE_CONDTEST_PASS:
460 break;
461 case ARM_OPCODE_CONDTEST_FAIL:
462 /* Condition failed - return to next instruction */
463 goto ret;
464 case ARM_OPCODE_CONDTEST_UNCOND:
465 /* If unconditional encoding - not a barrier instruction */
466 return -EFAULT;
467 default:
468 return -EINVAL;
471 switch (aarch32_insn_mcr_extract_crm(instr)) {
472 case 10:
474 * dmb - mcr p15, 0, Rt, c7, c10, 5
475 * dsb - mcr p15, 0, Rt, c7, c10, 4
477 if (aarch32_insn_mcr_extract_opc2(instr) == 5) {
478 dmb(sy);
479 trace_instruction_emulation(
480 "mcr p15, 0, Rt, c7, c10, 5 ; dmb", regs->pc);
481 } else {
482 dsb(sy);
483 trace_instruction_emulation(
484 "mcr p15, 0, Rt, c7, c10, 4 ; dsb", regs->pc);
486 break;
487 case 5:
489 * isb - mcr p15, 0, Rt, c7, c5, 4
491 * Taking an exception or returning from one acts as an
492 * instruction barrier. So no explicit barrier needed here.
494 trace_instruction_emulation(
495 "mcr p15, 0, Rt, c7, c5, 4 ; isb", regs->pc);
496 break;
499 ret:
500 pr_warn_ratelimited("\"%s\" (%ld) uses deprecated CP15 Barrier instruction at 0x%llx\n",
501 current->comm, (unsigned long)current->pid, regs->pc);
503 regs->pc += 4;
504 return 0;
507 static inline void config_sctlr_el1(u32 clear, u32 set)
509 u32 val;
511 asm volatile("mrs %0, sctlr_el1" : "=r" (val));
512 val &= ~clear;
513 val |= set;
514 asm volatile("msr sctlr_el1, %0" : : "r" (val));
517 static int cp15_barrier_set_hw_mode(bool enable)
519 if (enable)
520 config_sctlr_el1(0, SCTLR_EL1_CP15BEN);
521 else
522 config_sctlr_el1(SCTLR_EL1_CP15BEN, 0);
523 return 0;
526 static struct undef_hook cp15_barrier_hooks[] = {
528 .instr_mask = 0x0fff0fdf,
529 .instr_val = 0x0e070f9a,
530 .pstate_mask = COMPAT_PSR_MODE_MASK,
531 .pstate_val = COMPAT_PSR_MODE_USR,
532 .fn = cp15barrier_handler,
535 .instr_mask = 0x0fff0fff,
536 .instr_val = 0x0e070f95,
537 .pstate_mask = COMPAT_PSR_MODE_MASK,
538 .pstate_val = COMPAT_PSR_MODE_USR,
539 .fn = cp15barrier_handler,
544 static struct insn_emulation_ops cp15_barrier_ops = {
545 .name = "cp15_barrier",
546 .status = INSN_DEPRECATED,
547 .hooks = cp15_barrier_hooks,
548 .set_hw_mode = cp15_barrier_set_hw_mode,
551 static int setend_set_hw_mode(bool enable)
553 if (!cpu_supports_mixed_endian_el0())
554 return -EINVAL;
556 if (enable)
557 config_sctlr_el1(SCTLR_EL1_SED, 0);
558 else
559 config_sctlr_el1(0, SCTLR_EL1_SED);
560 return 0;
563 static int compat_setend_handler(struct pt_regs *regs, u32 big_endian)
565 char *insn;
567 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
569 if (big_endian) {
570 insn = "setend be";
571 regs->pstate |= COMPAT_PSR_E_BIT;
572 } else {
573 insn = "setend le";
574 regs->pstate &= ~COMPAT_PSR_E_BIT;
577 trace_instruction_emulation(insn, regs->pc);
578 pr_warn_ratelimited("\"%s\" (%ld) uses deprecated setend instruction at 0x%llx\n",
579 current->comm, (unsigned long)current->pid, regs->pc);
581 return 0;
584 static int a32_setend_handler(struct pt_regs *regs, u32 instr)
586 int rc = compat_setend_handler(regs, (instr >> 9) & 1);
587 regs->pc += 4;
588 return rc;
591 static int t16_setend_handler(struct pt_regs *regs, u32 instr)
593 int rc = compat_setend_handler(regs, (instr >> 3) & 1);
594 regs->pc += 2;
595 return rc;
598 static struct undef_hook setend_hooks[] = {
600 .instr_mask = 0xfffffdff,
601 .instr_val = 0xf1010000,
602 .pstate_mask = COMPAT_PSR_MODE_MASK,
603 .pstate_val = COMPAT_PSR_MODE_USR,
604 .fn = a32_setend_handler,
607 /* Thumb mode */
608 .instr_mask = 0x0000fff7,
609 .instr_val = 0x0000b650,
610 .pstate_mask = (COMPAT_PSR_T_BIT | COMPAT_PSR_MODE_MASK),
611 .pstate_val = (COMPAT_PSR_T_BIT | COMPAT_PSR_MODE_USR),
612 .fn = t16_setend_handler,
617 static struct insn_emulation_ops setend_ops = {
618 .name = "setend",
619 .status = INSN_DEPRECATED,
620 .hooks = setend_hooks,
621 .set_hw_mode = setend_set_hw_mode,
624 static int insn_cpu_hotplug_notify(struct notifier_block *b,
625 unsigned long action, void *hcpu)
627 int rc = 0;
628 if ((action & ~CPU_TASKS_FROZEN) == CPU_STARTING)
629 rc = run_all_insn_set_hw_mode((unsigned long)hcpu);
631 return notifier_from_errno(rc);
634 static struct notifier_block insn_cpu_hotplug_notifier = {
635 .notifier_call = insn_cpu_hotplug_notify,
639 * Invoked as late_initcall, since not needed before init spawned.
641 static int __init armv8_deprecated_init(void)
643 if (IS_ENABLED(CONFIG_SWP_EMULATION))
644 register_insn_emulation(&swp_ops);
646 if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION))
647 register_insn_emulation(&cp15_barrier_ops);
649 if (IS_ENABLED(CONFIG_SETEND_EMULATION)) {
650 if(system_supports_mixed_endian_el0())
651 register_insn_emulation(&setend_ops);
652 else
653 pr_info("setend instruction emulation is not supported on the system");
656 register_cpu_notifier(&insn_cpu_hotplug_notifier);
657 register_insn_emulation_sysctl(ctl_abi);
659 return 0;
662 late_initcall(armv8_deprecated_init);