From 0bb867e9f56500e30948ea7c440dd1166097df7f Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Tue, 24 Feb 2026 15:30:06 -0500
Subject: [PATCH] acpi: Split ACPI IVARs into global and private sets

ACPI_IVAR_HANDLE is the only true "global" IVAR that can be used
across multiple bus drivers.  The other IVARs are private to direct
children of acpi0.  However, they need to be numbered after ISA IVARs
as ACPI mimics an ISA bus device.  To ensure this remains true, add an
ISA_IVAR_LAST to use in assert that the private ACPI IVARs do not
overlap with ISA IVARs.

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D55354
---
 sys/dev/acpica/acpi.c    | 3 +++
 sys/dev/acpica/acpivar.h | 6 +++---
 sys/isa/isavar.h         | 3 ++-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index f903f265f9f..3a664523c27 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -1154,6 +1154,9 @@ acpi_child_deleted(device_t dev, device_t child)
     free(dinfo, M_ACPIDEV);
 }
 
+_Static_assert(ACPI_IVAR_PRIVATE >= ISA_IVAR_LAST,
+    "ACPI private IVARs overlap with ISA IVARs");
+
 /*
  * Handle per-device ivars
  */
diff --git a/sys/dev/acpica/acpivar.h b/sys/dev/acpica/acpivar.h
index d1d55d2b7e5..336f6ed1dc9 100644
--- a/sys/dev/acpica/acpivar.h
+++ b/sys/dev/acpica/acpivar.h
@@ -278,10 +278,10 @@ extern int	acpi_override_isa_irq_polarity;
  * attach to ACPI.
  */
 enum {
-	ACPI_IVAR_HANDLE = BUS_IVARS_ACPI,
-	ACPI_IVAR_PRIVATE,
+	ACPI_IVAR_PRIVATE = 20,
 	ACPI_IVAR_FLAGS,
-	ACPI_IVAR_DOMAIN
+	ACPI_IVAR_DOMAIN,
+	ACPI_IVAR_HANDLE = BUS_IVARS_ACPI
 };
 
 /*
diff --git a/sys/isa/isavar.h b/sys/isa/isavar.h
index f0b880de293..39eb7c2bc76 100644
--- a/sys/isa/isavar.h
+++ b/sys/isa/isavar.h
@@ -128,7 +128,8 @@ enum isa_device_ivars {
 	ISA_IVAR_CONFIGATTR,
 	ISA_IVAR_PNP_CSN,
 	ISA_IVAR_PNP_LDN,
-	ISA_IVAR_PNPBIOS_HANDLE
+	ISA_IVAR_PNPBIOS_HANDLE,
+	ISA_IVAR_LAST
 };
 
 /*