1 // SPDX-License-Identifier: GPL-2.0+
16 #include <asm/asm-prototypes.h>
17 #include <asm/code-patching.h>
31 static enum branch_cache_flush_type count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
32 static enum branch_cache_flush_type link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE;
35 static bool no_nospec;
36 static bool btb_flush_enabled;
38 static bool no_spectrev2;
41 static void enable_barrier_nospec(bool enable)  in enable_barrier_nospec()  argument
43 	barrier_nospec_enabled = enable;  in enable_barrier_nospec()
44 	do_barrier_nospec_fixups(enable);  in enable_barrier_nospec()
49 	bool enable;  in setup_barrier_nospec()  local
58 	 * not been updated, we would like to enable the barrier. Dropping the  in setup_barrier_nospec()
60 	 * we potentially enable the barrier on systems where the host firmware  in setup_barrier_nospec()
61 	 * is not updated, but that's harmless as it's a no-op.  in setup_barrier_nospec()
63 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&  in setup_barrier_nospec()
67 		enable_barrier_nospec(enable);  in setup_barrier_nospec()
70 static int __init handle_nospectre_v1(char *p)  in handle_nospectre_v1()
79 static int barrier_nospec_set(void *data, u64 val)  in barrier_nospec_set()
86 		return -EINVAL;  in barrier_nospec_set()
97 static int barrier_nospec_get(void *data, u64 *val)  in barrier_nospec_get()
106 static __init int barrier_nospec_debugfs_init(void)  in barrier_nospec_debugfs_init()
115 static __init int security_feature_debugfs_init(void)  in security_feature_debugfs_init()
125 static int __init handle_nospectre_v2(char *p)  in handle_nospectre_v2()
153 		seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_meltdown()
184 	seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_spectre_v1()
207 	seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_spectre_v2()
250  * Store-forwarding barrier support.
253 static enum stf_barrier_type stf_enabled_flush_types;
254 static bool no_stf_barrier;
255 static bool stf_barrier;
257 static int __init handle_no_stf_barrier(char *p)  in handle_no_stf_barrier()
259 	pr_info("stf-barrier: disabled on command line.");  in handle_no_stf_barrier()
272 static int __init handle_ssbd(char *p)  in handle_ssbd()
288 static int __init handle_no_ssbd(char *p)  in handle_no_ssbd()
295 static void stf_barrier_enable(bool enable)  in stf_barrier_enable()  argument
297 	if (enable)  in stf_barrier_enable()
302 	stf_barrier = enable;  in stf_barrier_enable()
308 	bool enable;  in setup_stf_barrier()  local
310 	/* Default to fallback in case fw-features are not available */  in setup_stf_barrier()
320 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&  in setup_stf_barrier()
324 		pr_info("stf-barrier: fallback barrier available\n");  in setup_stf_barrier()
326 		pr_info("stf-barrier: hwsync barrier available\n");  in setup_stf_barrier()
328 		pr_info("stf-barrier: eieio barrier available\n");  in setup_stf_barrier()
334 		stf_barrier_enable(enable);  in setup_stf_barrier()
364 static int ssb_prctl_get(struct task_struct *task)  in ssb_prctl_get()
379 		 * barrier is not a global or per-process mitigation, so the  in ssb_prctl_get()
385 	return -EINVAL;  in ssb_prctl_get()
394 		return -ENODEV;  in arch_prctl_spec_ctrl_get()
399 static int stf_barrier_set(void *data, u64 val)  in stf_barrier_set()
401 	bool enable;  in stf_barrier_set()  local
404 		enable = true;  in stf_barrier_set()
406 		enable = false;  in stf_barrier_set()
408 		return -EINVAL;  in stf_barrier_set()
411 	if (enable != stf_barrier)  in stf_barrier_set()
412 		stf_barrier_enable(enable);  in stf_barrier_set()
417 static int stf_barrier_get(void *data, u64 *val)  in stf_barrier_get()
426 static __init int stf_barrier_debugfs_init(void)  in stf_barrier_debugfs_init()
435 static void update_branch_cache_flush(void)  in update_branch_cache_flush()
492 static void toggle_branch_cache_flush(bool enable)  in toggle_branch_cache_flush()  argument
494 	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {  in toggle_branch_cache_flush()
498 		pr_info("count-cache-flush: flush disabled.\n");  in toggle_branch_cache_flush()
502 			pr_info("count-cache-flush: hardware flush enabled.\n");  in toggle_branch_cache_flush()
505 			pr_info("count-cache-flush: software flush enabled.\n");  in toggle_branch_cache_flush()
509 	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK)) {  in toggle_branch_cache_flush()
513 		pr_info("link-stack-flush: flush disabled.\n");  in toggle_branch_cache_flush()
517 			pr_info("link-stack-flush: hardware flush enabled.\n");  in toggle_branch_cache_flush()
520 			pr_info("link-stack-flush: software flush enabled.\n");  in toggle_branch_cache_flush()
529 	bool enable = true;  in setup_count_cache_flush()  local
536 		enable = false;  in setup_count_cache_flush()
548 	toggle_branch_cache_flush(enable);  in setup_count_cache_flush()
551 static enum l1d_flush_type enabled_flush_types;
552 static void *l1d_flush_fallback_area;
553 static bool no_rfi_flush;
554 static bool no_entry_flush;
555 static bool no_uaccess_flush;
557 static bool entry_flush;
558 static bool uaccess_flush;
562 static int __init handle_no_rfi_flush(char *p)  in handle_no_rfi_flush()
564 	pr_info("rfi-flush: disabled on command line.");  in handle_no_rfi_flush()
570 static int __init handle_no_entry_flush(char *p)  in handle_no_entry_flush()
572 	pr_info("entry-flush: disabled on command line.");  in handle_no_entry_flush()
578 static int __init handle_no_uaccess_flush(char *p)  in handle_no_uaccess_flush()
580 	pr_info("uaccess-flush: disabled on command line.");  in handle_no_uaccess_flush()
590 static int __init handle_no_pti(char *p)  in handle_no_pti()
592 	pr_info("rfi-flush: disabling due to 'nopti' on command line.\n");  in handle_no_pti()
598 static void do_nothing(void *unused)  in do_nothing()
606 void rfi_flush_enable(bool enable)  in rfi_flush_enable()  argument
608 	if (enable) {  in rfi_flush_enable()
614 	rfi_flush = enable;  in rfi_flush_enable()
617 static void entry_flush_enable(bool enable)  in entry_flush_enable()  argument
619 	if (enable) {  in entry_flush_enable()
626 	entry_flush = enable;  in entry_flush_enable()
629 static void uaccess_flush_enable(bool enable)  in uaccess_flush_enable()  argument
631 	if (enable) {  in uaccess_flush_enable()
640 	uaccess_flush = enable;  in uaccess_flush_enable()
643 static void __ref init_fallback_flush(void)  in init_fallback_flush()
655 	 * If there is no d-cache-size property in the device tree, l1d_size  in init_fallback_flush()
657 	 * 2^64-1, and then walking off the end of the fallback area and  in init_fallback_flush()
681 		paca->rfi_flush_fallback_area = l1d_flush_fallback_area;  in init_fallback_flush()
682 		paca->l1d_flush_size = l1d_size;  in init_fallback_flush()
686 void setup_rfi_flush(enum l1d_flush_type types, bool enable)  in setup_rfi_flush()  argument
689 		pr_info("rfi-flush: fallback displacement flush available\n");  in setup_rfi_flush()
694 		pr_info("rfi-flush: ori type flush available\n");  in setup_rfi_flush()
697 		pr_info("rfi-flush: mttrig type flush available\n");  in setup_rfi_flush()
702 		rfi_flush_enable(enable);  in setup_rfi_flush()
705 void setup_entry_flush(bool enable)  in setup_entry_flush()  argument
711 		entry_flush_enable(enable);  in setup_entry_flush()
714 void setup_uaccess_flush(bool enable)  in setup_uaccess_flush()  argument
720 		uaccess_flush_enable(enable);  in setup_uaccess_flush()
724 static int count_cache_flush_set(void *data, u64 val)  in count_cache_flush_set()
726 	bool enable;  in count_cache_flush_set()  local
729 		enable = true;  in count_cache_flush_set()
731 		enable = false;  in count_cache_flush_set()
733 		return -EINVAL;  in count_cache_flush_set()
735 	toggle_branch_cache_flush(enable);  in count_cache_flush_set()
740 static int count_cache_flush_get(void *data, u64 *val)  in count_cache_flush_get()
753 static __init int count_cache_flush_debugfs_init(void)  in count_cache_flush_debugfs_init()
762 static int rfi_flush_set(void *data, u64 val)  in rfi_flush_set()
764 	bool enable;  in rfi_flush_set()  local
767 		enable = true;  in rfi_flush_set()
769 		enable = false;  in rfi_flush_set()
771 		return -EINVAL;  in rfi_flush_set()
774 	if (enable != rfi_flush)  in rfi_flush_set()
775 		rfi_flush_enable(enable);  in rfi_flush_set()
780 static int rfi_flush_get(void *data, u64 *val)  in rfi_flush_get()
788 static int entry_flush_set(void *data, u64 val)  in entry_flush_set()
790 	bool enable;  in entry_flush_set()  local
793 		enable = true;  in entry_flush_set()
795 		enable = false;  in entry_flush_set()
797 		return -EINVAL;  in entry_flush_set()
800 	if (enable != entry_flush)  in entry_flush_set()
801 		entry_flush_enable(enable);  in entry_flush_set()
806 static int entry_flush_get(void *data, u64 *val)  in entry_flush_get()
814 static int uaccess_flush_set(void *data, u64 val)  in uaccess_flush_set()
816 	bool enable;  in uaccess_flush_set()  local
819 		enable = true;  in uaccess_flush_set()
821 		enable = false;  in uaccess_flush_set()
823 		return -EINVAL;  in uaccess_flush_set()
826 	if (enable != uaccess_flush)  in uaccess_flush_set()
827 		uaccess_flush_enable(enable);  in uaccess_flush_set()
832 static int uaccess_flush_get(void *data, u64 *val)  in uaccess_flush_get()
840 static __init int rfi_flush_debugfs_init(void)  in rfi_flush_debugfs_init()