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iommu/amd: Use raw locks on atomic context paths

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Several functions in this driver are called from atomic context,
and thus raw locks must be used in order to be safe on PREEMPT_RT.

This includes paths that must wait for command completion, which is
a potential PREEMPT_RT latency concern but not easily avoidable.

Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Scott Wood 2018-01-21 03:28:54 -06:00 committed by Joerg Roedel
parent 7928b2cbe5
commit 27790398c2
3 changed files with 18 additions and 18 deletions
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30
drivers/iommu/amd_iommu.c
View file

@ -1056,9 +1056,9 @@ static int iommu_queue_command_sync(struct amd_iommu *iommu,
unsigned long flags;
int ret;
spin_lock_irqsave(&iommu->lock, flags);
raw_spin_lock_irqsave(&iommu->lock, flags);
ret = __iommu_queue_command_sync(iommu, cmd, sync);
spin_unlock_irqrestore(&iommu->lock, flags);
raw_spin_unlock_irqrestore(&iommu->lock, flags);
return ret;
}
@ -1084,7 +1084,7 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
build_completion_wait(&cmd, (u64)&iommu->cmd_sem);
spin_lock_irqsave(&iommu->lock, flags);
raw_spin_lock_irqsave(&iommu->lock, flags);
iommu->cmd_sem = 0;
@ -1095,7 +1095,7 @@ static int iommu_completion_wait(struct amd_iommu *iommu)
ret = wait_on_sem(&iommu->cmd_sem);
out_unlock:
spin_unlock_irqrestore(&iommu->lock, flags);
raw_spin_unlock_irqrestore(&iommu->lock, flags);
return ret;
}
@ -3627,7 +3627,7 @@ static struct irq_remap_table *get_irq_table(u16 devid, bool ioapic)
goto out_unlock;
/* Initialize table spin-lock */
spin_lock_init(&table->lock);
raw_spin_lock_init(&table->lock);
if (ioapic)
/* Keep the first 32 indexes free for IOAPIC interrupts */
@ -3689,7 +3689,7 @@ static int alloc_irq_index(u16 devid, int count, bool align)
if (align)
alignment = roundup_pow_of_two(count);
spin_lock_irqsave(&table->lock, flags);
raw_spin_lock_irqsave(&table->lock, flags);
/* Scan table for free entries */
for (index = ALIGN(table->min_index, alignment), c = 0;
@ -3716,7 +3716,7 @@ static int alloc_irq_index(u16 devid, int count, bool align)
index = -ENOSPC;
out:
spin_unlock_irqrestore(&table->lock, flags);
raw_spin_unlock_irqrestore(&table->lock, flags);
return index;
}
@ -3737,7 +3737,7 @@ static int modify_irte_ga(u16 devid, int index, struct irte_ga *irte,
if (!table)
return -ENOMEM;
spin_lock_irqsave(&table->lock, flags);
raw_spin_lock_irqsave(&table->lock, flags);
entry = (struct irte_ga *)table->table;
entry = &entry[index];
@ -3748,7 +3748,7 @@ static int modify_irte_ga(u16 devid, int index, struct irte_ga *irte,
if (data)
data->ref = entry;
spin_unlock_irqrestore(&table->lock, flags);
raw_spin_unlock_irqrestore(&table->lock, flags);
iommu_flush_irt(iommu, devid);
iommu_completion_wait(iommu);
@ -3770,9 +3770,9 @@ static int modify_irte(u16 devid, int index, union irte *irte)
if (!table)
return -ENOMEM;
spin_lock_irqsave(&table->lock, flags);
raw_spin_lock_irqsave(&table->lock, flags);
table->table[index] = irte->val;
spin_unlock_irqrestore(&table->lock, flags);
raw_spin_unlock_irqrestore(&table->lock, flags);
iommu_flush_irt(iommu, devid);
iommu_completion_wait(iommu);
@ -3794,9 +3794,9 @@ static void free_irte(u16 devid, int index)
if (!table)
return;
spin_lock_irqsave(&table->lock, flags);
raw_spin_lock_irqsave(&table->lock, flags);
iommu->irte_ops->clear_allocated(table, index);
spin_unlock_irqrestore(&table->lock, flags);
raw_spin_unlock_irqrestore(&table->lock, flags);
iommu_flush_irt(iommu, devid);
iommu_completion_wait(iommu);
@ -4397,7 +4397,7 @@ int amd_iommu_update_ga(int cpu, bool is_run, void *data)
if (!irt)
return -ENODEV;
spin_lock_irqsave(&irt->lock, flags);
raw_spin_lock_irqsave(&irt->lock, flags);
if (ref->lo.fields_vapic.guest_mode) {
if (cpu >= 0)
@ -4406,7 +4406,7 @@ int amd_iommu_update_ga(int cpu, bool is_run, void *data)
barrier();
}
spin_unlock_irqrestore(&irt->lock, flags);
raw_spin_unlock_irqrestore(&irt->lock, flags);
iommu_flush_irt(iommu, devid);
iommu_completion_wait(iommu);

2
drivers/iommu/amd_iommu_init.c
View file

@ -1474,7 +1474,7 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
{
int ret;
spin_lock_init(&iommu->lock);
raw_spin_lock_init(&iommu->lock);
/* Add IOMMU to internal data structures */
list_add_tail(&iommu->list, &amd_iommu_list);

4
drivers/iommu/amd_iommu_types.h
View file

@ -408,7 +408,7 @@ extern bool amd_iommu_iotlb_sup;
#define IRQ_TABLE_ALIGNMENT 128
struct irq_remap_table {
spinlock_t lock;
raw_spinlock_t lock;
unsigned min_index;
u32 *table;
};
@ -490,7 +490,7 @@ struct amd_iommu {
int index;
/* locks the accesses to the hardware */
spinlock_t lock;
raw_spinlock_t lock;
/* Pointer to PCI device of this IOMMU */
struct pci_dev *dev;