1 // SPDX-License-Identifier: GPL-2.0-only
22 #include "trace-events-emulation.h"
26  * following three states -
53 	int max;  member
80  *  Implement emulation of the SWP/SWPB instructions using load-exclusive and
81  *  store-exclusive.
83  *  Syntax of SWP{B} instruction: SWP{B}<c> <Rt>, <Rt2>, [<Rn>]
84  *  Where: Rt  = destination
90  * Error-checking SWP macros implemented using ldxr{b}/stxr{b}
93 /* Arbitrary constant to ensure forward-progress of the LL/SC loop */
114 	: "r" ((unsigned long)addr), "i" (-EAGAIN),		\
139 		return -EFAULT;  in emulate_swpX()
150 		if (likely(res != -EAGAIN) || signal_pending(current))  in emulate_swpX()
170 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);  in swp_handler()
174 	switch (aarch32_check_condition(instr, regs->pstate)) {  in swp_handler()
178 		/* Condition failed - return to next instruction */  in swp_handler()
181 		/* If unconditional encoding - not a SWP, undef */  in swp_handler()
182 		return -EFAULT;  in swp_handler()
184 		return -EINVAL;  in swp_handler()
190 	address = (u32)regs->user_regs.regs[rn];  in swp_handler()
191 	data	= (u32)regs->user_regs.regs[rt2];  in swp_handler()
194 	pr_debug("addr in r%d->0x%08x, dest is r%d, source in r%d->0x%08x)\n",  in swp_handler()
207 	if (res == -EFAULT)  in swp_handler()
210 		regs->user_regs.regs[destreg] = data;  in swp_handler()
214 		trace_instruction_emulation("swpb", regs->pc);  in swp_handler()
216 		trace_instruction_emulation("swp", regs->pc);  in swp_handler()
219 			current->comm, (unsigned long)current->pid, regs->pc);  in swp_handler()
254 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);  in cp15barrier_handler()
256 	switch (aarch32_check_condition(instr, regs->pstate)) {  in cp15barrier_handler()
260 		/* Condition failed - return to next instruction */  in cp15barrier_handler()
263 		/* If unconditional encoding - not a barrier instruction */  in cp15barrier_handler()
264 		return -EFAULT;  in cp15barrier_handler()
266 		return -EINVAL;  in cp15barrier_handler()
272 		 * dmb - mcr p15, 0, Rt, c7, c10, 5  in cp15barrier_handler()
273 		 * dsb - mcr p15, 0, Rt, c7, c10, 4  in cp15barrier_handler()
278 				"mcr p15, 0, Rt, c7, c10, 5 ; dmb", regs->pc);  in cp15barrier_handler()
282 				"mcr p15, 0, Rt, c7, c10, 4 ; dsb", regs->pc);  in cp15barrier_handler()
287 		 * isb - mcr p15, 0, Rt, c7, c5, 4  in cp15barrier_handler()
293 			"mcr p15, 0, Rt, c7, c5, 4 ; isb", regs->pc);  in cp15barrier_handler()
299 			current->comm, (unsigned long)current->pid, regs->pc);  in cp15barrier_handler()
340 		return -EINVAL;  in setend_set_hw_mode()
353 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);  in compat_setend_handler()
357 		regs->pstate |= PSR_AA32_E_BIT;  in compat_setend_handler()
360 		regs->pstate &= ~PSR_AA32_E_BIT;  in compat_setend_handler()
363 	trace_instruction_emulation(insn, regs->pc);  in compat_setend_handler()
365 			current->comm, (unsigned long)current->pid, regs->pc);  in compat_setend_handler()
422 	if (insn->set_hw_mode)  in enable_insn_hw_mode()
423 		insn->set_hw_mode(true);  in enable_insn_hw_mode()
429 	if (insn->set_hw_mode)  in disable_insn_hw_mode()
430 		insn->set_hw_mode(false);  in disable_insn_hw_mode()
436 	if (!insn->set_hw_mode)  in run_all_cpu_set_hw_mode()
437 		return -EINVAL;  in run_all_cpu_set_hw_mode()
448  *  0 		- If all the hooks ran successfully.
449  * -EINVAL	- At least one hook is not supported by the CPU.
464 		bool enable = READ_ONCE(insn->current_mode) == INSN_HW;  in run_all_insn_set_hw_mode()
465 		if (insn->status == INSN_UNAVAILABLE)  in run_all_insn_set_hw_mode()
468 		if (insn->set_hw_mode && insn->set_hw_mode(enable)) {  in run_all_insn_set_hw_mode()
470 				cpu, insn->name);  in run_all_insn_set_hw_mode()
471 			rc = -EINVAL;  in run_all_insn_set_hw_mode()
491 			pr_notice("Disabled %s support\n", insn->name);  in update_insn_emulation_mode()
495 	switch (insn->current_mode) {  in update_insn_emulation_mode()
503 			pr_notice("Enabled %s support\n", insn->name);  in update_insn_emulation_mode()
515 	struct insn_emulation *insn = container_of(table->data, struct insn_emulation, current_mode);  in emulation_proc_handler()
516 	enum insn_emulation_mode prev_mode = insn->current_mode;  in emulation_proc_handler()
521 	if (ret || !write || prev_mode == insn->current_mode)  in emulation_proc_handler()
527 		WRITE_ONCE(insn->current_mode, prev_mode);  in emulation_proc_handler()
539 	insn->min = INSN_UNDEF;  in register_insn_emulation()
541 	switch (insn->status) {  in register_insn_emulation()
543 		insn->current_mode = INSN_EMULATE;  in register_insn_emulation()
546 		insn->max = INSN_HW;  in register_insn_emulation()
549 		insn->current_mode = INSN_UNDEF;  in register_insn_emulation()
550 		insn->max = INSN_EMULATE;  in register_insn_emulation()
553 		insn->current_mode = INSN_UNDEF;  in register_insn_emulation()
554 		insn->max = INSN_UNDEF;  in register_insn_emulation()
561 	if (insn->status != INSN_UNAVAILABLE) {  in register_insn_emulation()
562 		sysctl = &insn->sysctl;  in register_insn_emulation()
564 		sysctl->mode = 0644;  in register_insn_emulation()
565 		sysctl->maxlen = sizeof(int);  in register_insn_emulation()
567 		sysctl->procname = insn->name;  in register_insn_emulation()
568 		sysctl->data = &insn->current_mode;  in register_insn_emulation()
569 		sysctl->extra1 = &insn->min;  in register_insn_emulation()
570 		sysctl->extra2 = &insn->max;  in register_insn_emulation()
571 		sysctl->proc_handler = emulation_proc_handler;  in register_insn_emulation()
582 		if (ie->status == INSN_UNAVAILABLE)  in try_emulate_armv8_deprecated()
587 		 * INSN_EMULATE<->INSN_HW. Try to emulate the instruction to  in try_emulate_armv8_deprecated()
590 		if (READ_ONCE(ie->current_mode) == INSN_UNDEF)  in try_emulate_armv8_deprecated()
593 		if (ie->try_emulate(regs, insn))  in try_emulate_armv8_deprecated()
616 		if (ie->status == INSN_UNAVAILABLE)  in armv8_deprecated_init()