iommu/amd: Initialize new aperture range before making it visible

Make sure the aperture range is fully initialized before it
is visible to the address allocator.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index ecdd3f7..11ee885 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1425,8 +1425,10 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom,
                           bool populate, gfp_t gfp)
 {
        int index = dma_dom->aperture_size >> APERTURE_RANGE_SHIFT;
-       struct amd_iommu *iommu;
        unsigned long i, old_size, pte_pgsize;
+       struct aperture_range *range;
+       struct amd_iommu *iommu;
+       unsigned long flags;
 
 #ifdef CONFIG_IOMMU_STRESS
        populate = false;
@@ -1435,17 +1437,17 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom,
        if (index >= APERTURE_MAX_RANGES)
                return -ENOMEM;
 
-       dma_dom->aperture[index] = kzalloc(sizeof(struct aperture_range), gfp);
-       if (!dma_dom->aperture[index])
+       range = kzalloc(sizeof(struct aperture_range), gfp);
+       if (!range)
                return -ENOMEM;
 
-       dma_dom->aperture[index]->bitmap = (void *)get_zeroed_page(gfp);
-       if (!dma_dom->aperture[index]->bitmap)
+       range->bitmap = (void *)get_zeroed_page(gfp);
+       if (!range->bitmap)
                goto out_free;
 
-       dma_dom->aperture[index]->offset = dma_dom->aperture_size;
+       range->offset = dma_dom->aperture_size;
 
-       spin_lock_init(&dma_dom->aperture[index]->bitmap_lock);
+       spin_lock_init(&range->bitmap_lock);
 
        if (populate) {
                unsigned long address = dma_dom->aperture_size;
@@ -1458,14 +1460,18 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom,
                        if (!pte)
                                goto out_free;
 
-                       dma_dom->aperture[index]->pte_pages[i] = pte_page;
+                       range->pte_pages[i] = pte_page;
 
                        address += APERTURE_RANGE_SIZE / 64;
                }
        }
 
-       old_size                = dma_dom->aperture_size;
-       dma_dom->aperture_size += APERTURE_RANGE_SIZE;
+       /* First take the bitmap_lock and then publish the range */
+       spin_lock_irqsave(&range->bitmap_lock, flags);
+
+       old_size                 = dma_dom->aperture_size;
+       dma_dom->aperture[index] = range;
+       dma_dom->aperture_size  += APERTURE_RANGE_SIZE;
 
        /* Reserve address range used for MSI messages */
        if (old_size < MSI_ADDR_BASE_LO &&
@@ -1512,15 +1518,16 @@ static int alloc_new_range(struct dma_ops_domain *dma_dom,
 
        update_domain(&dma_dom->domain);
 
+       spin_unlock_irqrestore(&range->bitmap_lock, flags);
+
        return 0;
 
 out_free:
        update_domain(&dma_dom->domain);
 
-       free_page((unsigned long)dma_dom->aperture[index]->bitmap);
+       free_page((unsigned long)range->bitmap);
 
-       kfree(dma_dom->aperture[index]);
-       dma_dom->aperture[index] = NULL;
+       kfree(range);
 
        return -ENOMEM;
 }