1 // SPDX-License-Identifier: GPL-2.0+
16 #include <asm/asm-prototypes.h>
17 #include <asm/code-patching.h>
32 static enum branch_cache_flush_type count_cache_flush_type = BRANCH_CACHE_FLUSH_NONE;
33 static enum branch_cache_flush_type link_stack_flush_type = BRANCH_CACHE_FLUSH_NONE;
36 static bool no_nospec;
37 static bool btb_flush_enabled;
39 static bool no_spectrev2;
42 static void enable_barrier_nospec(bool enable)  in enable_barrier_nospec()  argument
44 	barrier_nospec_enabled = enable;  in enable_barrier_nospec()
45 	do_barrier_nospec_fixups(enable);  in enable_barrier_nospec()
50 	bool enable;  in setup_barrier_nospec()  local
59 	 * not been updated, we would like to enable the barrier. Dropping the  in setup_barrier_nospec()
61 	 * we potentially enable the barrier on systems where the host firmware  in setup_barrier_nospec()
62 	 * is not updated, but that's harmless as it's a no-op.  in setup_barrier_nospec()
64 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&  in setup_barrier_nospec()
68 		enable_barrier_nospec(enable);  in setup_barrier_nospec()
71 static int __init handle_nospectre_v1(char *p)  in handle_nospectre_v1()
80 static int barrier_nospec_set(void *data, u64 val)  in barrier_nospec_set()
87 		return -EINVAL;  in barrier_nospec_set()
98 static int barrier_nospec_get(void *data, u64 *val)  in barrier_nospec_get()
107 static __init int barrier_nospec_debugfs_init(void)  in barrier_nospec_debugfs_init()
116 static __init int security_feature_debugfs_init(void)  in security_feature_debugfs_init()
126 static int __init handle_nospectre_v2(char *p)  in handle_nospectre_v2()
154 		seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_meltdown()
185 	seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_spectre_v1()
208 	seq_buf_init(&s, buf, PAGE_SIZE - 1);  in cpu_show_spectre_v2()
251  * Store-forwarding barrier support.
254 static enum stf_barrier_type stf_enabled_flush_types;
255 static bool no_stf_barrier;
256 static bool stf_barrier;
258 static int __init handle_no_stf_barrier(char *p)  in handle_no_stf_barrier()
260 	pr_info("stf-barrier: disabled on command line.");  in handle_no_stf_barrier()
273 static int __init handle_ssbd(char *p)  in handle_ssbd()
289 static int __init handle_no_ssbd(char *p)  in handle_no_ssbd()
296 static void stf_barrier_enable(bool enable)  in stf_barrier_enable()  argument
298 	if (enable)  in stf_barrier_enable()
303 	stf_barrier = enable;  in stf_barrier_enable()
309 	bool enable;  in setup_stf_barrier()  local
311 	/* Default to fallback in case fw-features are not available */  in setup_stf_barrier()
321 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&  in setup_stf_barrier()
325 		pr_info("stf-barrier: fallback barrier available\n");  in setup_stf_barrier()
327 		pr_info("stf-barrier: hwsync barrier available\n");  in setup_stf_barrier()
329 		pr_info("stf-barrier: eieio barrier available\n");  in setup_stf_barrier()
335 		stf_barrier_enable(enable);  in setup_stf_barrier()
365 static int ssb_prctl_get(struct task_struct *task)  in ssb_prctl_get()
380 		 * barrier is not a global or per-process mitigation, so the  in ssb_prctl_get()
386 	return -EINVAL;  in ssb_prctl_get()
395 		return -ENODEV;  in arch_prctl_spec_ctrl_get()
400 static int stf_barrier_set(void *data, u64 val)  in stf_barrier_set()
402 	bool enable;  in stf_barrier_set()  local
405 		enable = true;  in stf_barrier_set()
407 		enable = false;  in stf_barrier_set()
409 		return -EINVAL;  in stf_barrier_set()
412 	if (enable != stf_barrier)  in stf_barrier_set()
413 		stf_barrier_enable(enable);  in stf_barrier_set()
418 static int stf_barrier_get(void *data, u64 *val)  in stf_barrier_get()
427 static __init int stf_barrier_debugfs_init(void)  in stf_barrier_debugfs_init()
436 static void update_branch_cache_flush(void)  in update_branch_cache_flush()
493 static void toggle_branch_cache_flush(bool enable)  in toggle_branch_cache_flush()  argument
495 	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_COUNT_CACHE)) {  in toggle_branch_cache_flush()
499 		pr_info("count-cache-flush: flush disabled.\n");  in toggle_branch_cache_flush()
503 			pr_info("count-cache-flush: hardware flush enabled.\n");  in toggle_branch_cache_flush()
506 			pr_info("count-cache-flush: software flush enabled.\n");  in toggle_branch_cache_flush()
510 	if (!enable || !security_ftr_enabled(SEC_FTR_FLUSH_LINK_STACK)) {  in toggle_branch_cache_flush()
514 		pr_info("link-stack-flush: flush disabled.\n");  in toggle_branch_cache_flush()
518 			pr_info("link-stack-flush: hardware flush enabled.\n");  in toggle_branch_cache_flush()
521 			pr_info("link-stack-flush: software flush enabled.\n");  in toggle_branch_cache_flush()
530 	bool enable = true;  in setup_count_cache_flush()  local
537 		enable = false;  in setup_count_cache_flush()
549 	toggle_branch_cache_flush(enable);  in setup_count_cache_flush()
552 static enum l1d_flush_type enabled_flush_types;
553 static void *l1d_flush_fallback_area;
554 static bool no_rfi_flush;
555 static bool no_entry_flush;
556 static bool no_uaccess_flush;
558 static bool entry_flush;
559 static bool uaccess_flush;
563 static int __init handle_no_rfi_flush(char *p)  in handle_no_rfi_flush()
565 	pr_info("rfi-flush: disabled on command line.");  in handle_no_rfi_flush()
571 static int __init handle_no_entry_flush(char *p)  in handle_no_entry_flush()
573 	pr_info("entry-flush: disabled on command line.");  in handle_no_entry_flush()
579 static int __init handle_no_uaccess_flush(char *p)  in handle_no_uaccess_flush()
581 	pr_info("uaccess-flush: disabled on command line.");  in handle_no_uaccess_flush()
591 static int __init handle_no_pti(char *p)  in handle_no_pti()
593 	pr_info("rfi-flush: disabling due to 'nopti' on command line.\n");  in handle_no_pti()
599 static void do_nothing(void *unused)  in do_nothing()
607 void rfi_flush_enable(bool enable)  in rfi_flush_enable()  argument
609 	if (enable) {  in rfi_flush_enable()
615 	rfi_flush = enable;  in rfi_flush_enable()
618 static void entry_flush_enable(bool enable)  in entry_flush_enable()  argument
620 	if (enable) {  in entry_flush_enable()
627 	entry_flush = enable;  in entry_flush_enable()
630 static void uaccess_flush_enable(bool enable)  in uaccess_flush_enable()  argument
632 	if (enable) {  in uaccess_flush_enable()
641 	uaccess_flush = enable;  in uaccess_flush_enable()
644 static void __ref init_fallback_flush(void)  in init_fallback_flush()
656 	 * If there is no d-cache-size property in the device tree, l1d_size  in init_fallback_flush()
658 	 * 2^64-1, and then walking off the end of the fallback area and  in init_fallback_flush()
682 		paca->rfi_flush_fallback_area = l1d_flush_fallback_area;  in init_fallback_flush()
683 		paca->l1d_flush_size = l1d_size;  in init_fallback_flush()
687 void setup_rfi_flush(enum l1d_flush_type types, bool enable)  in setup_rfi_flush()  argument
690 		pr_info("rfi-flush: fallback displacement flush available\n");  in setup_rfi_flush()
695 		pr_info("rfi-flush: ori type flush available\n");  in setup_rfi_flush()
698 		pr_info("rfi-flush: mttrig type flush available\n");  in setup_rfi_flush()
703 		rfi_flush_enable(enable);  in setup_rfi_flush()
706 void setup_entry_flush(bool enable)  in setup_entry_flush()  argument
712 		entry_flush_enable(enable);  in setup_entry_flush()
715 void setup_uaccess_flush(bool enable)  in setup_uaccess_flush()  argument
721 		uaccess_flush_enable(enable);  in setup_uaccess_flush()
725 static int count_cache_flush_set(void *data, u64 val)  in count_cache_flush_set()
727 	bool enable;  in count_cache_flush_set()  local
730 		enable = true;  in count_cache_flush_set()
732 		enable = false;  in count_cache_flush_set()
734 		return -EINVAL;  in count_cache_flush_set()
736 	toggle_branch_cache_flush(enable);  in count_cache_flush_set()
741 static int count_cache_flush_get(void *data, u64 *val)  in count_cache_flush_get()
751 static int link_stack_flush_get(void *data, u64 *val)  in link_stack_flush_get()
766 static __init int count_cache_flush_debugfs_init(void)  in count_cache_flush_debugfs_init()
778 static int rfi_flush_set(void *data, u64 val)  in rfi_flush_set()
780 	bool enable;  in rfi_flush_set()  local
783 		enable = true;  in rfi_flush_set()
785 		enable = false;  in rfi_flush_set()
787 		return -EINVAL;  in rfi_flush_set()
790 	if (enable != rfi_flush)  in rfi_flush_set()
791 		rfi_flush_enable(enable);  in rfi_flush_set()
796 static int rfi_flush_get(void *data, u64 *val)  in rfi_flush_get()
804 static int entry_flush_set(void *data, u64 val)  in entry_flush_set()
806 	bool enable;  in entry_flush_set()  local
809 		enable = true;  in entry_flush_set()
811 		enable = false;  in entry_flush_set()
813 		return -EINVAL;  in entry_flush_set()
816 	if (enable != entry_flush)  in entry_flush_set()
817 		entry_flush_enable(enable);  in entry_flush_set()
822 static int entry_flush_get(void *data, u64 *val)  in entry_flush_get()
830 static int uaccess_flush_set(void *data, u64 val)  in uaccess_flush_set()
832 	bool enable;  in uaccess_flush_set()  local
835 		enable = true;  in uaccess_flush_set()
837 		enable = false;  in uaccess_flush_set()
839 		return -EINVAL;  in uaccess_flush_set()
842 	if (enable != uaccess_flush)  in uaccess_flush_set()
843 		uaccess_flush_enable(enable);  in uaccess_flush_set()
848 static int uaccess_flush_get(void *data, u64 *val)  in uaccess_flush_get()
856 static __init int rfi_flush_debugfs_init(void)  in rfi_flush_debugfs_init()