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-rw-r--r--drivers/iommu/dmar.c19
-rw-r--r--drivers/iommu/intel-iommu.c22
-rw-r--r--drivers/iommu/intel_irq_remapping.c108
-rw-r--r--include/linux/dmar.h2
4 files changed, 103 insertions, 48 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 4ae6df27ad5d..c9aca8841fa0 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -43,10 +43,19 @@
#include "irq_remapping.h"
-/* No locks are needed as DMA remapping hardware unit
- * list is constructed at boot time and hotplug of
- * these units are not supported by the architecture.
+/*
+ * Assumptions:
+ * 1) The hotplug framework guarentees that DMAR unit will be hot-added
+ * before IO devices managed by that unit.
+ * 2) The hotplug framework guarantees that DMAR unit will be hot-removed
+ * after IO devices managed by that unit.
+ * 3) Hotplug events are rare.
+ *
+ * Locking rules for DMA and interrupt remapping related global data structures:
+ * 1) Use dmar_global_lock in process context
+ * 2) Use RCU in interrupt context
*/
+DECLARE_RWSEM(dmar_global_lock);
LIST_HEAD(dmar_drhd_units);
struct acpi_table_header * __initdata dmar_tbl;
@@ -565,6 +574,7 @@ int __init detect_intel_iommu(void)
{
int ret;
+ down_write(&dmar_global_lock);
ret = dmar_table_detect();
if (ret)
ret = check_zero_address();
@@ -582,6 +592,7 @@ int __init detect_intel_iommu(void)
}
early_acpi_os_unmap_memory((void __iomem *)dmar_tbl, dmar_tbl_size);
dmar_tbl = NULL;
+ up_write(&dmar_global_lock);
return ret ? 1 : -ENODEV;
}
@@ -1394,10 +1405,12 @@ static int __init dmar_free_unused_resources(void)
if (irq_remapping_enabled || intel_iommu_enabled)
return 0;
+ down_write(&dmar_global_lock);
list_for_each_entry_safe(dmaru, dmaru_n, &dmar_drhd_units, list) {
list_del(&dmaru->list);
dmar_free_drhd(dmaru);
}
+ up_write(&dmar_global_lock);
return 0;
}
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index bb98e37f2cf7..50d639a2df88 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3637,11 +3637,13 @@ static int device_notifier(struct notifier_block *nb,
if (!domain)
return 0;
+ down_read(&dmar_global_lock);
domain_remove_one_dev_info(domain, pdev);
if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&
!(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) &&
list_empty(&domain->devices))
domain_exit(domain);
+ up_read(&dmar_global_lock);
return 0;
}
@@ -3659,6 +3661,13 @@ int __init intel_iommu_init(void)
/* VT-d is required for a TXT/tboot launch, so enforce that */
force_on = tboot_force_iommu();
+ if (iommu_init_mempool()) {
+ if (force_on)
+ panic("tboot: Failed to initialize iommu memory\n");
+ return -ENOMEM;
+ }
+
+ down_write(&dmar_global_lock);
if (dmar_table_init()) {
if (force_on)
panic("tboot: Failed to initialize DMAR table\n");
@@ -3681,12 +3690,6 @@ int __init intel_iommu_init(void)
if (no_iommu || dmar_disabled)
goto out_free_dmar;
- if (iommu_init_mempool()) {
- if (force_on)
- panic("tboot: Failed to initialize iommu memory\n");
- goto out_free_dmar;
- }
-
if (list_empty(&dmar_rmrr_units))
printk(KERN_INFO "DMAR: No RMRR found\n");
@@ -3696,7 +3699,7 @@ int __init intel_iommu_init(void)
if (dmar_init_reserved_ranges()) {
if (force_on)
panic("tboot: Failed to reserve iommu ranges\n");
- goto out_free_mempool;
+ goto out_free_reserved_range;
}
init_no_remapping_devices();
@@ -3708,6 +3711,7 @@ int __init intel_iommu_init(void)
printk(KERN_ERR "IOMMU: dmar init failed\n");
goto out_free_reserved_range;
}
+ up_write(&dmar_global_lock);
printk(KERN_INFO
"PCI-DMA: Intel(R) Virtualization Technology for Directed I/O\n");
@@ -3729,10 +3733,10 @@ int __init intel_iommu_init(void)
out_free_reserved_range:
put_iova_domain(&reserved_iova_list);
-out_free_mempool:
- iommu_exit_mempool();
out_free_dmar:
intel_iommu_free_dmars();
+ up_write(&dmar_global_lock);
+ iommu_exit_mempool();
return ret;
}
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index ef5f65dbafe9..9b174893f0f5 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -38,6 +38,17 @@ static struct ioapic_scope ir_ioapic[MAX_IO_APICS];
static struct hpet_scope ir_hpet[MAX_HPET_TBS];
static int ir_ioapic_num, ir_hpet_num;
+/*
+ * Lock ordering:
+ * ->dmar_global_lock
+ * ->irq_2_ir_lock
+ * ->qi->q_lock
+ * ->iommu->register_lock
+ * Note:
+ * intel_irq_remap_ops.{supported,prepare,enable,disable,reenable} are called
+ * in single-threaded environment with interrupt disabled, so no need to tabke
+ * the dmar_global_lock.
+ */
static DEFINE_RAW_SPINLOCK(irq_2_ir_lock);
static int __init parse_ioapics_under_ir(void);
@@ -307,12 +318,14 @@ static int set_ioapic_sid(struct irte *irte, int apic)
if (!irte)
return -1;
+ down_read(&dmar_global_lock);
for (i = 0; i < MAX_IO_APICS; i++) {
if (ir_ioapic[i].id == apic) {
sid = (ir_ioapic[i].bus << 8) | ir_ioapic[i].devfn;
break;
}
}
+ up_read(&dmar_global_lock);
if (sid == 0) {
pr_warning("Failed to set source-id of IOAPIC (%d)\n", apic);
@@ -332,12 +345,14 @@ static int set_hpet_sid(struct irte *irte, u8 id)
if (!irte)
return -1;
+ down_read(&dmar_global_lock);
for (i = 0; i < MAX_HPET_TBS; i++) {
if (ir_hpet[i].id == id) {
sid = (ir_hpet[i].bus << 8) | ir_hpet[i].devfn;
break;
}
}
+ up_read(&dmar_global_lock);
if (sid == 0) {
pr_warning("Failed to set source-id of HPET block (%d)\n", id);
@@ -794,10 +809,16 @@ static int __init parse_ioapics_under_ir(void)
static int __init ir_dev_scope_init(void)
{
+ int ret;
+
if (!irq_remapping_enabled)
return 0;
- return dmar_dev_scope_init();
+ down_write(&dmar_global_lock);
+ ret = dmar_dev_scope_init();
+ up_write(&dmar_global_lock);
+
+ return ret;
}
rootfs_initcall(ir_dev_scope_init);
@@ -878,23 +899,27 @@ static int intel_setup_ioapic_entry(int irq,
struct io_apic_irq_attr *attr)
{
int ioapic_id = mpc_ioapic_id(attr->ioapic);
- struct intel_iommu *iommu = map_ioapic_to_ir(ioapic_id);
+ struct intel_iommu *iommu;
struct IR_IO_APIC_route_entry *entry;
struct irte irte;
int index;
+ down_read(&dmar_global_lock);
+ iommu = map_ioapic_to_ir(ioapic_id);
if (!iommu) {
pr_warn("No mapping iommu for ioapic %d\n", ioapic_id);
- return -ENODEV;
- }
-
- entry = (struct IR_IO_APIC_route_entry *)route_entry;
-
- index = alloc_irte(iommu, irq, 1);
- if (index < 0) {
- pr_warn("Failed to allocate IRTE for ioapic %d\n", ioapic_id);
- return -ENOMEM;
+ index = -ENODEV;
+ } else {
+ index = alloc_irte(iommu, irq, 1);
+ if (index < 0) {
+ pr_warn("Failed to allocate IRTE for ioapic %d\n",
+ ioapic_id);
+ index = -ENOMEM;
+ }
}
+ up_read(&dmar_global_lock);
+ if (index < 0)
+ return index;
prepare_irte(&irte, vector, destination);
@@ -913,6 +938,7 @@ static int intel_setup_ioapic_entry(int irq,
irte.avail, irte.vector, irte.dest_id,
irte.sid, irte.sq, irte.svt);
+ entry = (struct IR_IO_APIC_route_entry *)route_entry;
memset(entry, 0, sizeof(*entry));
entry->index2 = (index >> 15) & 0x1;
@@ -1043,20 +1069,23 @@ static int intel_msi_alloc_irq(struct pci_dev *dev, int irq, int nvec)
struct intel_iommu *iommu;
int index;
+ down_read(&dmar_global_lock);
iommu = map_dev_to_ir(dev);
if (!iommu) {
printk(KERN_ERR
"Unable to map PCI %s to iommu\n", pci_name(dev));
- return -ENOENT;
+ index = -ENOENT;
+ } else {
+ index = alloc_irte(iommu, irq, nvec);
+ if (index < 0) {
+ printk(KERN_ERR
+ "Unable to allocate %d IRTE for PCI %s\n",
+ nvec, pci_name(dev));
+ index = -ENOSPC;
+ }
}
+ up_read(&dmar_global_lock);
- index = alloc_irte(iommu, irq, nvec);
- if (index < 0) {
- printk(KERN_ERR
- "Unable to allocate %d IRTE for PCI %s\n", nvec,
- pci_name(dev));
- return -ENOSPC;
- }
return index;
}
@@ -1064,33 +1093,40 @@ static int intel_msi_setup_irq(struct pci_dev *pdev, unsigned int irq,
int index, int sub_handle)
{
struct intel_iommu *iommu;
+ int ret = -ENOENT;
+ down_read(&dmar_global_lock);
iommu = map_dev_to_ir(pdev);
- if (!iommu)
- return -ENOENT;
- /*
- * setup the mapping between the irq and the IRTE
- * base index, the sub_handle pointing to the
- * appropriate interrupt remap table entry.
- */
- set_irte_irq(irq, iommu, index, sub_handle);
+ if (iommu) {
+ /*
+ * setup the mapping between the irq and the IRTE
+ * base index, the sub_handle pointing to the
+ * appropriate interrupt remap table entry.
+ */
+ set_irte_irq(irq, iommu, index, sub_handle);
+ ret = 0;
+ }
+ up_read(&dmar_global_lock);
- return 0;
+ return ret;
}
static int intel_setup_hpet_msi(unsigned int irq, unsigned int id)
{
- struct intel_iommu *iommu = map_hpet_to_ir(id);
+ int ret = -1;
+ struct intel_iommu *iommu;
int index;
- if (!iommu)
- return -1;
-
- index = alloc_irte(iommu, irq, 1);
- if (index < 0)
- return -1;
+ down_read(&dmar_global_lock);
+ iommu = map_hpet_to_ir(id);
+ if (iommu) {
+ index = alloc_irte(iommu, irq, 1);
+ if (index >= 0)
+ ret = 0;
+ }
+ up_read(&dmar_global_lock);
- return 0;
+ return ret;
}
struct irq_remap_ops intel_irq_remap_ops = {
diff --git a/include/linux/dmar.h b/include/linux/dmar.h
index 4b77fd8fde76..8f06a0135a84 100644
--- a/include/linux/dmar.h
+++ b/include/linux/dmar.h
@@ -25,6 +25,7 @@
#include <linux/types.h>
#include <linux/msi.h>
#include <linux/irqreturn.h>
+#include <linux/rwsem.h>
struct acpi_dmar_header;
@@ -48,6 +49,7 @@ struct dmar_drhd_unit {
struct intel_iommu *iommu;
};
+extern struct rw_semaphore dmar_global_lock;
extern struct list_head dmar_drhd_units;
#define for_each_drhd_unit(drhd) \
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-14 11:52:31 +0000