1 // SPDX-License-Identifier: GPL-2.0-or-later
8  * Derived from the read-mod example from relay-examples by Tom Zanussi.
38 	unsigned long id;  member
41 /* Accessed per-cpu. */
42 static DEFINE_PER_CPU(struct trap_reason, pf_reason);
43 static DEFINE_PER_CPU(struct mmiotrace_rw, cpu_trace);
45 static DEFINE_MUTEX(mmiotrace_mutex);
46 static DEFINE_SPINLOCK(trace_lock);
47 static atomic_t mmiotrace_enabled;
48 static LIST_HEAD(trace_list);		/* struct remap_trace */
52  * - mmiotrace_mutex enforces enable/disable_mmiotrace() critical sections.
53  * - mmiotrace_enabled may be modified only when holding mmiotrace_mutex
55  * - Routines depending on is_enabled() must take trace_lock.
56  * - trace_list users must hold trace_lock.
57  * - is_enabled() guarantees that mmio_trace_{rw,mapping} are allowed.
58  * - pre/post callbacks assume the effect of is_enabled() being true.
62 static unsigned long	filter_offset;
63 static bool		nommiotrace;
64 static bool		trace_pc;
74 static bool is_enabled(void)  in is_enabled()
79 static void print_pte(unsigned long address)  in print_pte()
105 static void die_kmmio_nesting_error(struct pt_regs *regs, unsigned long addr)  in die_kmmio_nesting_error()
109 		 addr, my_reason->addr);  in die_kmmio_nesting_error()
111 	pr_emerg("faulting IP is at %pS\n", (void *)regs->ip);  in die_kmmio_nesting_error()
112 	pr_emerg("last faulting IP was at %pS\n", (void *)my_reason->ip);  in die_kmmio_nesting_error()
115 		 regs->ax, regs->bx, regs->cx, regs->dx);  in die_kmmio_nesting_error()
117 		 regs->si, regs->di, regs->bp, regs->sp);  in die_kmmio_nesting_error()
120 		 regs->ax, regs->cx, regs->dx);  in die_kmmio_nesting_error()
122 		 regs->si, regs->di, regs->bp, regs->sp);  in die_kmmio_nesting_error()
128 static void pre(struct kmmio_probe *p, struct pt_regs *regs,  in pre()
135 	struct remap_trace *trace = p->private;  in pre()  local
137 	/* it doesn't make sense to have more than one active trace per cpu */  in pre()
138 	if (my_reason->active_traces)  in pre()
141 		my_reason->active_traces++;  in pre()
143 	my_reason->type = type;  in pre()
144 	my_reason->addr = addr;  in pre()
145 	my_reason->ip = instptr;  in pre()
147 	my_trace->phys = addr - trace->probe.addr + trace->phys;  in pre()
148 	my_trace->map_id = trace->id;  in pre()
152 	 * It may taint clean-room reverse engineering.  in pre()
155 		my_trace->pc = instptr;  in pre()
157 		my_trace->pc = 0;  in pre()
167 		my_trace->opcode = MMIO_READ;  in pre()
168 		my_trace->width = get_ins_mem_width(instptr);  in pre()
171 		my_trace->opcode = MMIO_WRITE;  in pre()
172 		my_trace->width = get_ins_mem_width(instptr);  in pre()
173 		my_trace->value = get_ins_reg_val(instptr, regs);  in pre()
176 		my_trace->opcode = MMIO_WRITE;  in pre()
177 		my_trace->width = get_ins_mem_width(instptr);  in pre()
178 		my_trace->value = get_ins_imm_val(instptr);  in pre()
183 			my_trace->opcode = MMIO_UNKNOWN_OP;  in pre()
184 			my_trace->width = 0;  in pre()
185 			my_trace->value = (*ip) << 16 | *(ip + 1) << 8 |  in pre()
193 static void post(struct kmmio_probe *p, unsigned long condition,  in post()
200 	my_reason->active_traces--;  in post()
201 	if (my_reason->active_traces) {  in post()
206 	switch (my_reason->type) {  in post()
208 		my_trace->value = get_ins_reg_val(my_reason->ip, regs);  in post()
219 static void ioremap_trace_core(resource_size_t offset, unsigned long size,  in ioremap_trace_core()
222 	static atomic_t next_id;  in ioremap_trace_core()
223 	struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL);  in ioremap_trace_core()  local
224 	/* These are page-unaligned. */  in ioremap_trace_core()
232 	if (!trace) {  in ioremap_trace_core()
237 	*trace = (struct remap_trace) {  in ioremap_trace_core()
243 			.private = trace  in ioremap_trace_core()
246 		.id = atomic_inc_return(&next_id)  in ioremap_trace_core()
248 	map.map_id = trace->id;  in ioremap_trace_core()
252 		kfree(trace);  in ioremap_trace_core()
257 	list_add_tail(&trace->list, &trace_list);  in ioremap_trace_core()
259 		register_kmmio_probe(&trace->probe);  in ioremap_trace_core()
278 static void iounmap_trace_core(volatile void __iomem *addr)  in iounmap_trace_core()
286 	struct remap_trace *trace;  in iounmap_trace_core()  local
296 	list_for_each_entry_safe(trace, tmp, &trace_list, list) {  in iounmap_trace_core()
297 		if ((unsigned long)addr == trace->probe.addr) {  in iounmap_trace_core()
299 				unregister_kmmio_probe(&trace->probe);  in iounmap_trace_core()
300 			list_del(&trace->list);  in iounmap_trace_core()
301 			found_trace = trace;  in iounmap_trace_core()
305 	map.map_id = (found_trace) ? found_trace->id : -1;  in iounmap_trace_core()
340 static void clear_trace_list(void)  in clear_trace_list()
342 	struct remap_trace *trace;  in clear_trace_list()  local
351 	list_for_each_entry(trace, &trace_list, list) {  in clear_trace_list()
352 		pr_notice("purging non-iounmapped trace @0x%08lx, size 0x%lx.\n",  in clear_trace_list()
353 			  trace->probe.addr, trace->probe.len);  in clear_trace_list()
355 			unregister_kmmio_probe(&trace->probe);  in clear_trace_list()
359 	list_for_each_entry_safe(trace, tmp, &trace_list, list) {  in clear_trace_list()
360 		list_del(&trace->list);  in clear_trace_list()
361 		kfree(trace);  in clear_trace_list()
366 static cpumask_var_t downed_cpus;
368 static void enter_uniprocessor(void)  in enter_uniprocessor()
383 		pr_notice("Disabling non-boot CPUs...\n");  in enter_uniprocessor()
398 static void leave_uniprocessor(void)  in leave_uniprocessor()
405 	pr_notice("Re-enabling CPUs...\n");  in leave_uniprocessor()
411 			pr_err("cannot re-enable CPU%d: %d\n", cpu, err);  in leave_uniprocessor()
416 static void enter_uniprocessor(void)  in enter_uniprocessor()
423 static void leave_uniprocessor(void)  in leave_uniprocessor()