Handle devices which defer their attach to the iommu in the dma-iommu api
Signed-off-by: Tom Murphy <[email protected]>
---
drivers/iommu/dma-iommu.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 7a96c2c8f56b..b383498e2dc3 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -22,6 +22,7 @@
#include <linux/pci.h>
#include <linux/scatterlist.h>
#include <linux/vmalloc.h>
+#include <linux/crash_dump.h>
struct iommu_dma_msi_page {
struct list_head list;
@@ -322,6 +323,22 @@ static int iommu_dma_init_domain(struct iommu_domain
*domain, dma_addr_t base,
return iova_reserve_iommu_regions(dev, domain);
}
+static int handle_deferred_device(struct device *dev)
+{
+ struct iommu_domain *domain;
+ const struct iommu_ops *ops;
+
+ if (!is_kdump_kernel())
+ return 0;
+
+ domain = iommu_get_domain_for_dev(dev);
+ ops = domain->ops;
+ if (ops->is_attach_deferred && ops->is_attach_deferred(domain, dev))
+ return iommu_attach_device(domain, dev);
+
+ return 0;
+}
+
/**
* dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
* page flags.
@@ -835,7 +852,10 @@ static dma_addr_t iommu_dma_map_page(struct device *dev,
struct page *page,
bool coherent = dev_is_dma_coherent(dev);
dma_addr_t dma_handle;
- dma_handle =__iommu_dma_map(dev, phys, size,
+ if (unlikely(handle_deferred_device(dev)))
+ return DMA_MAPPING_ERROR;
+
+ dma_handle = __iommu_dma_map(dev, phys, size,
dma_info_to_prot(dir, coherent, attrs),
iommu_get_dma_domain(dev));
if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
@@ -953,6 +973,9 @@ static int iommu_dma_map_sg(struct device *dev, struct
scatterlist *sg,
unsigned long mask = dma_get_seg_boundary(dev);
int i;
+ if (unlikely(handle_deferred_device(dev)))
+ return 0;
+
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
iommu_dma_sync_sg_for_device(dev, sg, nents, dir);
@@ -1056,6 +1079,9 @@ static void iommu_dma_unmap_resource(struct device *dev,
dma_addr_t handle,
static void *iommu_dma_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
+ if (unlikely(handle_deferred_device(dev)))
+ return NULL;
+
gfp |= __GFP_ZERO;
#ifdef CONFIG_DMA_DIRECT_REMAP
--
2.17.1
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