From: Tom Murphy <murphyt7@tcd.ie>
Date: Sun, 8 Sep 2019 09:56:39 -0700
Subject: iommu/dma-iommu: Handle deferred devices
Git-commit: 795bbbb9b6f80306be3d45c79527324036a68509
Patch-mainline: v5.5-rc1
References: bsc#1175713
Handle devices which defer their attach to the iommu in the dma-iommu api
Signed-off-by: Tom Murphy <murphyt7@tcd.ie>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/dma-iommu.c | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
--- 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;
@@ -353,6 +354,21 @@ static int iommu_dma_init_domain(struct
return iova_reserve_iommu_regions(dev, domain);
}
+static int iommu_dma_deferred_attach(struct device *dev,
+ struct iommu_domain *domain)
+{
+ const struct iommu_ops *ops = domain->ops;
+
+ if (!is_kdump_kernel())
+ return 0;
+
+ if (unlikely(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.
@@ -469,6 +485,9 @@ static dma_addr_t __iommu_dma_map(struct
size_t iova_off = iova_offset(iovad, phys);
dma_addr_t iova;
+ if (unlikely(iommu_dma_deferred_attach(dev, domain)))
+ return DMA_MAPPING_ERROR;
+
size = iova_align(iovad, size + iova_off);
iova = iommu_dma_alloc_iova(domain, size, dma_get_mask(dev), dev);
@@ -578,6 +597,9 @@ static void *iommu_dma_alloc_remap(struc
*dma_handle = DMA_MAPPING_ERROR;
+ if (unlikely(iommu_dma_deferred_attach(dev, domain)))
+ return NULL;
+
min_size = alloc_sizes & -alloc_sizes;
if (min_size < PAGE_SIZE) {
min_size = PAGE_SIZE;
@@ -710,7 +732,7 @@ static dma_addr_t iommu_dma_map_page(str
int prot = dma_info_to_prot(dir, coherent, attrs);
dma_addr_t dma_handle;
- dma_handle =__iommu_dma_map(dev, phys, size, prot);
+ dma_handle = __iommu_dma_map(dev, phys, size, prot);
if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
dma_handle != DMA_MAPPING_ERROR)
arch_sync_dma_for_device(phys, size, dir);
@@ -820,6 +842,9 @@ static int iommu_dma_map_sg(struct devic
unsigned long mask = dma_get_seg_boundary(dev);
int i;
+ if (unlikely(iommu_dma_deferred_attach(dev, domain)))
+ return 0;
+
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
iommu_dma_sync_sg_for_device(dev, sg, nents, dir);