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Revert "iommu/vt-d: Fix possible recursive locking in intel_iommu_init()"

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This reverts commit 9cd4f14344.

Some issues were reported on the original commit. Some thunderbolt devices
don't work anymore due to the following DMA fault.

DMAR: DRHD: handling fault status reg 2
DMAR: [INTR-REMAP] Request device [09:00.0] fault index 0x8080
      [fault reason 0x25]
      Blocked a compatibility format interrupt request

Bring it back for now to avoid functional regression.

Fixes: 9cd4f14344 ("iommu/vt-d: Fix possible recursive locking in intel_iommu_init()")
Link: https://lore.kernel.org/linux-iommu/485A6EA5-6D58-42EA-B298-8571E97422DE@getmailspring.com/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216497
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: <stable@vger.kernel.org> # 5.19.x
Reported-and-tested-by: George Hilliard <thirtythreeforty@gmail.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220920081701.3453504-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Lu Baolu 2022-09-21 10:40:53 +08:00 committed by Joerg Roedel
parent 521a547ced
commit 7ebb5f8e00
3 changed files with 26 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/iommu/intel/dmar.c
View File

@ -2349,13 +2349,6 @@ static int dmar_device_hotplug(acpi_handle handle, bool insert)
if (!dmar_in_use())
return 0;
/*
* It's unlikely that any I/O board is hot added before the IOMMU
* subsystem is initialized.
*/
if (IS_ENABLED(CONFIG_INTEL_IOMMU) && !intel_iommu_enabled)
return -EOPNOTSUPP;
if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
tmp = handle;
} else {

27
drivers/iommu/intel/iommu.c
View File

@ -3019,7 +3019,13 @@ static int __init init_dmars(void)
#ifdef CONFIG_INTEL_IOMMU_SVM
if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) {
/*
* Call dmar_alloc_hwirq() with dmar_global_lock held,
* could cause possible lock race condition.
*/
up_write(&dmar_global_lock);
ret = intel_svm_enable_prq(iommu);
down_write(&dmar_global_lock);
if (ret)
goto free_iommu;
}
@ -3932,6 +3938,7 @@ int __init intel_iommu_init(void)
force_on = (!intel_iommu_tboot_noforce && tboot_force_iommu()) ||
platform_optin_force_iommu();
down_write(&dmar_global_lock);
if (dmar_table_init()) {
if (force_on)
panic("tboot: Failed to initialize DMAR table\n");
@ -3944,6 +3951,16 @@ int __init intel_iommu_init(void)
goto out_free_dmar;
}
up_write(&dmar_global_lock);
/*
* The bus notifier takes the dmar_global_lock, so lockdep will
* complain later when we register it under the lock.
*/
dmar_register_bus_notifier();
down_write(&dmar_global_lock);
if (!no_iommu)
intel_iommu_debugfs_init();
@ -3988,9 +4005,11 @@ int __init intel_iommu_init(void)
pr_err("Initialization failed\n");
goto out_free_dmar;
}
up_write(&dmar_global_lock);
init_iommu_pm_ops();
down_read(&dmar_global_lock);
for_each_active_iommu(iommu, drhd) {
/*
* The flush queue implementation does not perform
@ -4008,11 +4027,13 @@ int __init intel_iommu_init(void)
"%s", iommu->name);
iommu_device_register(&iommu->iommu, &intel_iommu_ops, NULL);
}
up_read(&dmar_global_lock);
bus_set_iommu(&pci_bus_type, &intel_iommu_ops);
if (si_domain && !hw_pass_through)
register_memory_notifier(&intel_iommu_memory_nb);
down_read(&dmar_global_lock);
if (probe_acpi_namespace_devices())
pr_warn("ACPI name space devices didn't probe correctly\n");
@ -4023,15 +4044,17 @@ int __init intel_iommu_init(void)
iommu_disable_protect_mem_regions(iommu);
}
up_read(&dmar_global_lock);
pr_info("Intel(R) Virtualization Technology for Directed I/O\n");
intel_iommu_enabled = 1;
dmar_register_bus_notifier();
pr_info("Intel(R) Virtualization Technology for Directed I/O\n");
return 0;
out_free_dmar:
intel_iommu_free_dmars();
up_write(&dmar_global_lock);
return ret;
}

4
include/linux/dmar.h
View File

@ -65,7 +65,6 @@ struct dmar_pci_notify_info {
extern struct rw_semaphore dmar_global_lock;
extern struct list_head dmar_drhd_units;
extern int intel_iommu_enabled;
#define for_each_drhd_unit(drhd) \
list_for_each_entry_rcu(drhd, &dmar_drhd_units, list, \
@ -89,8 +88,7 @@ extern int intel_iommu_enabled;
static inline bool dmar_rcu_check(void)
{
return rwsem_is_locked(&dmar_global_lock) ||
system_state == SYSTEM_BOOTING ||
(IS_ENABLED(CONFIG_INTEL_IOMMU) && !intel_iommu_enabled);
system_state == SYSTEM_BOOTING;
}
#define dmar_rcu_dereference(p) rcu_dereference_check((p), dmar_rcu_check())