iommu/amd: Add align parameter to alloc_irq_index()

For multi-MSI IRQ ranges the IRQ index needs to be aligned
to the power-of-two of the requested IRQ count. Extend the
alloc_irq_index() function to allow such an allocation.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Fixes: 2b32450634 ('iommu/amd: Add routines to manage irq remapping tables')
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Joerg Roedel 2017-10-06 12:16:39 +02:00
parent 9e66317d3c
commit 37946d95fc

View File

@ -3660,11 +3660,11 @@ out_unlock:
return table;
}
static int alloc_irq_index(u16 devid, int count)
static int alloc_irq_index(u16 devid, int count, bool align)
{
struct irq_remap_table *table;
int index, c, alignment = 1;
unsigned long flags;
int index, c;
struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];
if (!iommu)
@ -3674,16 +3674,22 @@ static int alloc_irq_index(u16 devid, int count)
if (!table)
return -ENODEV;
if (align)
alignment = roundup_pow_of_two(count);
spin_lock_irqsave(&table->lock, flags);
/* Scan table for free entries */
for (c = 0, index = table->min_index;
for (index = ALIGN(table->min_index, alignment), c = 0;
index < MAX_IRQS_PER_TABLE;
++index) {
if (!iommu->irte_ops->is_allocated(table, index))
index++) {
if (!iommu->irte_ops->is_allocated(table, index)) {
c += 1;
else
c = 0;
} else {
c = 0;
index = ALIGN(index, alignment);
continue;
}
if (c == count) {
for (; c != 0; --c)
@ -4096,7 +4102,7 @@ static int irq_remapping_alloc(struct irq_domain *domain, unsigned int virq,
else
ret = -ENOMEM;
} else {
index = alloc_irq_index(devid, nr_irqs);
index = alloc_irq_index(devid, nr_irqs, false);
}
if (index < 0) {
pr_warn("Failed to allocate IRTE\n");