git: ddc20379099b - stable/14 - arm64: Add a sysctl to see if features are enabled

The branch stable/14 has been updated by andrew:

URL: https://cgit.FreeBSD.org/src/commit/?id=ddc20379099b8c3fea87bc0a8f2c8b6585b1d0bc

commit ddc20379099b8c3fea87bc0a8f2c8b6585b1d0bc
Author:     Andrew Turner <andrew@FreeBSD.org>
AuthorDate: 2025-09-04 14:44:31 +0000
Commit:     Andrew Turner <andrew@FreeBSD.org>
CommitDate: 2026-01-14 21:14:12 +0000

    arm64: Add a sysctl to see if features are enabled
    
    This will also be used as a tunable to control features in a later
    change.
    
    Reviewed by:    imp
    Sponsored by:   Arm Ltd
    Differential Revision:  https://reviews.freebsd.org/D52357
    
    (cherry picked from commit 9204a315a71c5aa9a9b8c11f2dcefb155dd5fc34)
---
 sys/arm64/arm64/cpu_feat.c   |  7 +++++--
 sys/arm64/include/cpu_feat.h | 13 ++++++++++---
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/sys/arm64/arm64/cpu_feat.c b/sys/arm64/arm64/cpu_feat.c
index cc262394913d..fd1b8429295f 100644
--- a/sys/arm64/arm64/cpu_feat.c
+++ b/sys/arm64/arm64/cpu_feat.c
@@ -32,6 +32,8 @@
 #include <machine/cpu.h>
 #include <machine/cpu_feat.h>
 
+SYSCTL_NODE(_hw, OID_AUTO, feat, CTLFLAG_RD, 0, "CPU features/errata");
+
 /* TODO: Make this a list if we ever grow a callback other than smccc_errata */
 static cpu_feat_errata_check_fn cpu_feat_check_cb = NULL;
 
@@ -97,8 +99,9 @@ enable_cpu_feat(uint32_t stage)
 		/* Shouldn't be possible */
 		MPASS(errata_status != ERRATA_UNKNOWN);
 
-		feat->feat_enable(feat, errata_status, errata_list,
-		    errata_count);
+		if (feat->feat_enable(feat, errata_status, errata_list,
+		    errata_count))
+			feat->feat_enabled = true;
 	}
 }
 
diff --git a/sys/arm64/include/cpu_feat.h b/sys/arm64/include/cpu_feat.h
index 6a0b2d78f526..f62f3e334dc1 100644
--- a/sys/arm64/include/cpu_feat.h
+++ b/sys/arm64/include/cpu_feat.h
@@ -29,6 +29,7 @@
 #define	_MACHINE_CPU_FEAT_H_
 
 #include <sys/linker_set.h>
+#include <sys/sysctl.h>
 
 typedef enum {
 	ERRATA_UNKNOWN,		/* Unknown erratum */
@@ -52,7 +53,7 @@ struct cpu_feat;
 typedef bool (cpu_feat_check)(const struct cpu_feat *, u_int);
 typedef bool (cpu_feat_has_errata)(const struct cpu_feat *, u_int,
     u_int **, u_int *);
-typedef void (cpu_feat_enable)(const struct cpu_feat *, cpu_feat_errata,
+typedef bool (cpu_feat_enable)(const struct cpu_feat *, cpu_feat_errata,
     u_int *, u_int);
 
 struct cpu_feat {
@@ -61,18 +62,24 @@ struct cpu_feat {
 	cpu_feat_has_errata	*feat_has_errata;
 	cpu_feat_enable		*feat_enable;
 	uint32_t		 feat_flags;
+	bool			 feat_enabled;
 };
 SET_DECLARE(cpu_feat_set, struct cpu_feat);
 
-#define	CPU_FEAT(name, check, has_errata, enable, flags)	\
+SYSCTL_DECL(_hw_feat);
+
+#define	CPU_FEAT(name, descr, check, has_errata, enable, flags)	\
 static struct cpu_feat name = {						\
 	.feat_name		= #name,				\
 	.feat_check		= check,				\
 	.feat_has_errata	= has_errata,				\
 	.feat_enable		= enable,				\
 	.feat_flags		= flags,				\
+	.feat_enabled		= false,				\
 };									\
-DATA_SET(cpu_feat_set, name)
+DATA_SET(cpu_feat_set, name);						\
+SYSCTL_BOOL(_hw_feat, OID_AUTO, name, CTLFLAG_RD, &name.feat_enabled,	\
+    0, descr)
 
 /*
  * Allow drivers to mark an erratum as worked around, e.g. the Errata