iommu/amd: Remove the special case from alloc_irq_table()

alloc_irq_table() has a special ioapic argument. If set then it will
pre-allocate / reserve the first 32 indexes. The argument is only once
true and it would make alloc_irq_table() a little simpler if we would
extract the special bits to the caller.
The caller of irq_remapping_alloc() is holding irq_domain_mutex so the
initialization of iommu->irte_ops->set_allocated() should not race
against other user.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index a87d2fe..a5982a6 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3617,7 +3617,7 @@ static struct irq_remap_table *get_irq_table(u16 devid)
        return table;
 }
 
-static struct irq_remap_table *alloc_irq_table(u16 devid, bool ioapic)
+static struct irq_remap_table *alloc_irq_table(u16 devid)
 {
        struct irq_remap_table *table = NULL;
        struct amd_iommu *iommu;
@@ -3651,10 +3651,6 @@ static struct irq_remap_table *alloc_irq_table(u16 devid, bool ioapic)
        /* Initialize table spin-lock */
        raw_spin_lock_init(&table->lock);
 
-       if (ioapic)
-               /* Keep the first 32 indexes free for IOAPIC interrupts */
-               table->min_index = 32;
-
        table->table = kmem_cache_alloc(amd_iommu_irq_cache, GFP_ATOMIC);
        if (!table->table) {
                kfree(table);
@@ -3669,12 +3665,6 @@ static struct irq_remap_table *alloc_irq_table(u16 devid, bool ioapic)
                memset(table->table, 0,
                       (MAX_IRQS_PER_TABLE * (sizeof(u64) * 2)));
 
-       if (ioapic) {
-               int i;
-
-               for (i = 0; i < 32; ++i)
-                       iommu->irte_ops->set_allocated(table, i);
-       }
 
        irq_lookup_table[devid] = table;
        set_dte_irq_entry(devid, table);
@@ -3704,7 +3694,7 @@ static int alloc_irq_index(u16 devid, int count, bool align)
        if (!iommu)
                return -ENODEV;
 
-       table = alloc_irq_table(devid, false);
+       table = alloc_irq_table(devid);
        if (!table)
                return -ENODEV;
 
@@ -4130,10 +4120,26 @@ static int irq_remapping_alloc(struct irq_domain *domain, unsigned int virq,
                return ret;
 
        if (info->type == X86_IRQ_ALLOC_TYPE_IOAPIC) {
-               if (alloc_irq_table(devid, true))
+               struct irq_remap_table *table;
+               struct amd_iommu *iommu;
+
+               table = alloc_irq_table(devid);
+               if (table) {
+                       if (!table->min_index) {
+                               /*
+                                * Keep the first 32 indexes free for IOAPIC
+                                * interrupts.
+                                */
+                               table->min_index = 32;
+                               iommu = amd_iommu_rlookup_table[devid];
+                               for (i = 0; i < 32; ++i)
+                                       iommu->irte_ops->set_allocated(table, i);
+                       }
+                       WARN_ON(table->min_index != 32);
                        index = info->ioapic_pin;
-               else
+               } else {
                        ret = -ENOMEM;
+               }
        } else {
                bool align = (info->type == X86_IRQ_ALLOC_TYPE_MSI);