From 07d1c91b6c649705fdd9acf58001071845ecf068 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 3 Nov 2017 10:50:31 -0600 Subject: iommu/amd: Fix alloc_irq_index() increment On an is_allocated() interrupt index, we ALIGN() the current index and then increment it via the for loop, guaranteeing that it is no longer aligned for alignments >1. We instead need to align the next index, to guarantee forward progress, moving the increment-only to the case where the index was found to be unallocated. Fixes: 37946d95fc1a ('iommu/amd: Add align parameter to alloc_irq_index()') Signed-off-by: Alex Williamson --- drivers/iommu/amd_iommu.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/iommu') diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 9dc7facfd2e5..3c1a29104f0e 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -3682,13 +3682,12 @@ static int alloc_irq_index(u16 devid, int count, bool align) /* Scan table for free entries */ for (index = ALIGN(table->min_index, alignment), c = 0; - index < MAX_IRQS_PER_TABLE; - index++) { + index < MAX_IRQS_PER_TABLE;) { if (!iommu->irte_ops->is_allocated(table, index)) { c += 1; } else { c = 0; - index = ALIGN(index, alignment); + index = ALIGN(index + 1, alignment); continue; } @@ -3699,6 +3698,8 @@ static int alloc_irq_index(u16 devid, int count, bool align) index -= count - 1; goto out; } + + index++; } index = -ENOSPC; -- cgit