1 // SPDX-License-Identifier: GPL-2.0+
14 #include <asm/asm-prototypes.h>
15 #include <asm/code-patching.h>
29 static enum branch_cache_flush_type count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
30 static enum branch_cache_flush_type link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE;
33 static bool no_nospec;
34 static bool btb_flush_enabled;
36 static bool no_spectrev2;
39 static void enable_barrier_nospec(bool enable)  in enable_barrier_nospec()  argument
41 	barrier_nospec_enabled = enable;  in enable_barrier_nospec()
42 	do_barrier_nospec_fixups(enable);  in enable_barrier_nospec()
47 	bool enable;  in setup_barrier_nospec()  local
56 	 * not been updated, we would like to enable the barrier. Dropping the  in setup_barrier_nospec()
58 	 * we potentially enable the barrier on systems where the host firmware  in setup_barrier_nospec()
59 	 * is not updated, but that's harmless as it's a no-op.  in setup_barrier_nospec()
61 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&  in setup_barrier_nospec()
65 		enable_barrier_nospec(enable);  in setup_barrier_nospec()
68 static int __init handle_nospectre_v1(char *p)  in handle_nospectre_v1()
77 static int barrier_nospec_set(void *data, u64 val)  in barrier_nospec_set()
84 		return -EINVAL;  in barrier_nospec_set()
95 static int barrier_nospec_get(void *data, u64 *val)  in barrier_nospec_get()
104 static __init int barrier_nospec_debugfs_init(void)  in barrier_nospec_debugfs_init()
113 static __init int security_feature_debugfs_init(void)  in security_feature_debugfs_init()
123 static int __init handle_nospectre_v2(char *p)  in handle_nospectre_v2()
151 		seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_meltdown()
182 	seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_spectre_v1()
205 	seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_spectre_v2()
248  * Store-forwarding barrier support.
251 static enum stf_barrier_type stf_enabled_flush_types;
252 static bool no_stf_barrier;
255 static int __init handle_no_stf_barrier(char *p)  in handle_no_stf_barrier()
257 	pr_info("stf-barrier: disabled on command line.");  in handle_no_stf_barrier()
265 static int __init handle_ssbd(char *p)  in handle_ssbd()
281 static int __init handle_no_ssbd(char *p)  in handle_no_ssbd()
288 static void stf_barrier_enable(bool enable)  in stf_barrier_enable()  argument
290 	if (enable)  in stf_barrier_enable()
295 	stf_barrier = enable;  in stf_barrier_enable()
301 	bool enable, hv;  in setup_stf_barrier()  local
305 	/* Default to fallback in case fw-features are not available */  in setup_stf_barrier()
315 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&  in setup_stf_barrier()
320 		pr_info("stf-barrier: fallback barrier available\n");  in setup_stf_barrier()
322 		pr_info("stf-barrier: hwsync barrier available\n");  in setup_stf_barrier()
324 		pr_info("stf-barrier: eieio barrier available\n");  in setup_stf_barrier()
330 		stf_barrier_enable(enable);  in setup_stf_barrier()
360 static int ssb_prctl_get(struct task_struct *task)  in ssb_prctl_get()
375 		 * barrier is not a global or per-process mitigation, so the  in ssb_prctl_get()
381 	return -EINVAL;  in ssb_prctl_get()
390 		return -ENODEV;  in arch_prctl_spec_ctrl_get()
395 static int stf_barrier_set(void *data, u64 val)  in stf_barrier_set()
397 	bool enable;  in stf_barrier_set()  local
400 		enable = true;  in stf_barrier_set()
402 		enable = false;  in stf_barrier_set()
404 		return -EINVAL;  in stf_barrier_set()
407 	if (enable != stf_barrier)  in stf_barrier_set()
408 		stf_barrier_enable(enable);  in stf_barrier_set()
413 static int stf_barrier_get(void *data, u64 *val)  in stf_barrier_get()
422 static __init int stf_barrier_debugfs_init(void)  in stf_barrier_debugfs_init()
431 static void update_branch_cache_flush(void)  in update_branch_cache_flush()
485 static void toggle_branch_cache_flush(bool enable)  in toggle_branch_cache_flush()  argument
487 	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {  in toggle_branch_cache_flush()
491 		pr_info("count-cache-flush: flush disabled.\n");  in toggle_branch_cache_flush()
495 			pr_info("count-cache-flush: hardware flush enabled.\n");  in toggle_branch_cache_flush()
498 			pr_info("count-cache-flush: software flush enabled.\n");  in toggle_branch_cache_flush()
502 	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK)) {  in toggle_branch_cache_flush()
506 		pr_info("link-stack-flush: flush disabled.\n");  in toggle_branch_cache_flush()
510 			pr_info("link-stack-flush: hardware flush enabled.\n");  in toggle_branch_cache_flush()
513 			pr_info("link-stack-flush: software flush enabled.\n");  in toggle_branch_cache_flush()
522 	bool enable = true;  in setup_count_cache_flush()  local
529 		enable = false;  in setup_count_cache_flush()
541 	toggle_branch_cache_flush(enable);  in setup_count_cache_flush()
545 static int count_cache_flush_set(void *data, u64 val)  in count_cache_flush_set()
547 	bool enable;  in count_cache_flush_set()  local
550 		enable = true;  in count_cache_flush_set()
552 		enable = false;  in count_cache_flush_set()
554 		return -EINVAL;  in count_cache_flush_set()
556 	toggle_branch_cache_flush(enable);  in count_cache_flush_set()
561 static int count_cache_flush_get(void *data, u64 *val)  in count_cache_flush_get()
574 static __init int count_cache_flush_debugfs_init(void)  in count_cache_flush_debugfs_init()