From 37946d95fc1a41ed79efb613b0818c2cdecbb2fa Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Fri, 6 Oct 2017 12:16:39 +0200 Subject: [PATCH] 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 Fixes: 2b324506341cb ('iommu/amd: Add routines to manage irq remapping tables') Reviewed-by: Thomas Gleixner Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 51f8215..2d4ee25 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -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"); -- 2.7.4