From: Joerg Roedel <jroedel@suse.de>
Date: Fri, 6 Oct 2017 12:16:39 +0200
Subject: iommu/amd: Add align parameter to alloc_irq_index()
Git-commit: 37946d95fc1a41ed79efb613b0818c2cdecbb2fa
Patch-mainline: v4.15-rc1
References: bsc#975772
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: 2b324506341cb ('iommu/amd: Add routines to manage irq remapping tables')
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/amd_iommu.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3863,11 +3863,11 @@ 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)
@@ -3877,16 +3877,22 @@ static int alloc_irq_index(u16 devid, in
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)
@@ -4299,7 +4305,7 @@ static int irq_remapping_alloc(struct ir
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");