iommu: dma-mapping-fast: Avoid pci memory regions
Certain memory regions are reserved by pci devices. When an endpoint
makes an access to these regions, the access is routed to the appropriate
location with the pci complex, and does not pass through the iommu into
the greater system. Therefore these address cannot be used for dma.
Change-Id: I1e909e4c0fbcadd53576b27a57cc49ed131cf328
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
diff --git a/drivers/iommu/dma-mapping-fast.c b/drivers/iommu/dma-mapping-fast.c
index ac3059d..560bb43 100644
--- a/drivers/iommu/dma-mapping-fast.c
+++ b/drivers/iommu/dma-mapping-fast.c
@@ -765,6 +765,51 @@
return ERR_PTR(-ENOMEM);
}
+/*
+ * Based off of similar code from dma-iommu.c, but modified to use a different
+ * iova allocator
+ */
+static void fast_smmu_reserve_pci_windows(struct device *dev,
+ struct dma_fast_smmu_mapping *mapping)
+{
+ struct pci_host_bridge *bridge;
+ struct resource_entry *window;
+ phys_addr_t start, end;
+ struct pci_dev *pci_dev;
+ unsigned long flags;
+
+ if (!dev_is_pci(dev))
+ return;
+
+ pci_dev = to_pci_dev(dev);
+ bridge = pci_find_host_bridge(pci_dev->bus);
+
+ spin_lock_irqsave(&mapping->lock, flags);
+ resource_list_for_each_entry(window, &bridge->windows) {
+ if (resource_type(window->res) != IORESOURCE_MEM &&
+ resource_type(window->res) != IORESOURCE_IO)
+ continue;
+
+ start = round_down(window->res->start - window->offset,
+ FAST_PAGE_SIZE);
+ end = round_up(window->res->end - window->offset,
+ FAST_PAGE_SIZE);
+ start = max_t(unsigned long, mapping->base, start);
+ end = min_t(unsigned long, mapping->base + mapping->size, end);
+ if (start >= end)
+ continue;
+
+ dev_dbg(dev, "iova allocator reserved 0x%pa-0x%pa\n",
+ &start, &end);
+
+ start = (start - mapping->base) >> FAST_PAGE_SHIFT;
+ end = (end - mapping->base) >> FAST_PAGE_SHIFT;
+ bitmap_set(mapping->bitmap, start, end - start);
+ }
+ spin_unlock_irqrestore(&mapping->lock, flags);
+}
+
+
/**
* fast_smmu_attach_device
* @dev: valid struct device pointer
@@ -798,6 +843,8 @@
mapping->fast->domain = domain;
mapping->fast->dev = dev;
+ fast_smmu_reserve_pci_windows(dev, mapping->fast);
+
group = dev->iommu_group;
if (!group) {
dev_err(dev, "No iommu associated with device\n");