[PATCH 12/20] iommu/vt-d: Remove dmar_disabled

Lu Baolu <[email protected]> Tue, 4 Aug 2026 10:37:06 +0800
Newsgroups dev.linux.lists.iommu,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
From: Kevin Tian <[email protected]>

It's replaced by dmar_policy_off() now, covering both "iommu=off"
and "intel_iommu=off". Also remove unnecessary checks on no_iommu,
leaving only one exception in intel_iommu_init() which skips debugfs
init for "iommu=off" but not "intel_iommu=off". Keep it to avoid
surprise for now.

Signed-off-by: Kevin Tian <[email protected]>
Signed-off-by: Lu Baolu <[email protected]>
---
 drivers/iommu/intel/iommu.h | 1 -
 drivers/iommu/intel/iommu.c | 9 ++-------
 drivers/iommu/intel/svm.c   | 2 +-
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 40da2ed7e254..9805edb8c7df 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -1401,7 +1401,6 @@ static inline bool dmar_policy_force_on(void)
 
 bool dmar_can_force_on(enum dmar_force_on force_on);
 
-extern int dmar_disabled;
 extern int intel_iommu_enabled;
 extern int intel_iommu_tboot_noforce;
 
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 118c62e859fd..a996b72aca57 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -202,7 +202,6 @@ int dmar_policy = DMAR_ON;
 #else
 int dmar_policy = DMAR_DEFAULT_OFF;
 #endif
-int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON);
 int intel_iommu_sm = IS_ENABLED(CONFIG_INTEL_IOMMU_SCALABLE_MODE_DEFAULT_ON);
 
 int intel_iommu_enabled = 0;
@@ -244,11 +243,9 @@ static int __init intel_iommu_setup(char *str)
 	while (*str) {
 		if (!strncmp(str, "on", 2)) {
 			dmar_policy = DMAR_ON;
-			dmar_disabled = 0;
 			pr_info("IOMMU enabled\n");
 		} else if (!strncmp(str, "off", 3)) {
 			dmar_policy = DMAR_USER_OFF;
-			dmar_disabled = 1;
 			pr_info("IOMMU disabled\n");
 		} else if (!strncmp(str, "igfx_off", 8)) {
 			disable_igfx_iommu = 1;
@@ -2371,7 +2368,7 @@ void intel_iommu_shutdown(void)
 	struct dmar_drhd_unit *drhd;
 	struct intel_iommu *iommu = NULL;
 
-	if (no_iommu || dmar_disabled)
+	if (dmar_policy_off())
 		return;
 
 	/*
@@ -2505,7 +2502,6 @@ static void __init platform_optin_force_iommu(void)
 
 	/* No concurrent access to dmar_policy at this point. */
 	dmar_policy = DMAR_FORCE_ON;
-	dmar_disabled = 0;
 }
 
 static int __init probe_acpi_namespace_devices(void)
@@ -2558,7 +2554,6 @@ static __init void tboot_force_iommu(void)
 
 	/* No concurrent access to dmar_policy at this point. */
 	dmar_policy = DMAR_FORCE_ON;
-	dmar_disabled = 0;
 	no_iommu = 0;
 }
 
@@ -2602,7 +2597,7 @@ int __init intel_iommu_init(void)
 	if (!no_iommu)
 		intel_iommu_debugfs_init();
 
-	if (no_iommu || dmar_disabled) {
+	if (dmar_policy_off()) {
 		/*
 		 * We exit the function here to ensure IOMMU's remapping and
 		 * mempool aren't setup, which means that the IOMMU's PMRs
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 726f7b6d0bff..432e35723ce9 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -115,7 +115,7 @@ static int intel_iommu_sva_supported(struct device *dev)
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
 	struct intel_iommu *iommu;
 
-	if (!info || dmar_disabled)
+	if (!info || dmar_policy_off())
 		return -EINVAL;
 
 	iommu = info->iommu;
-- 
2.43.0