[PATCH v9 09/13] iommu/amd: Use is_attach_deferred call-back

Baoquan He
2017-08-01T11:38:04Z

Implement call-back is_attach_deferred and use it to defer the
domain attach from iommu driver init to device driver init when
iommu is pre-enabled in kdump kernel.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
drivers/iommu/amd_iommu.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 5508f57a3e4f..4ff413b34b51 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -121,6 +121,7 @@ struct iommu_dev_data {
PPR completions */
u32 errata; /* Bitmap for errata to apply */
bool use_vapic; /* Enable device to use vapic mode */
+ bool defer_attach;

struct ratelimit_state rs; /* Ratelimit IOPF messages */
};
@@ -371,12 +372,17 @@ static u16 get_alias(struct device *dev)
static struct iommu_dev_data *find_dev_data(u16 devid)
{
struct iommu_dev_data *dev_data;
+ struct amd_iommu *iommu = amd_iommu_rlookup_table[devid];

dev_data = search_dev_data(devid);

- if (dev_data == NULL)
+ if (dev_data == NULL) {
dev_data = alloc_dev_data(devid);

+ if (translation_pre_enabled(iommu))
+ dev_data->defer_attach = true;
+ }
+
return dev_data;
}

@@ -2477,11 +2483,18 @@ static struct iommu_group *amd_iommu_device_group(struct device *dev)
static struct protection_domain *get_domain(struct device *dev)
{
struct protection_domain *domain;
+ struct iommu_domain *io_domain;

if (!check_device(dev))
return ERR_PTR(-EINVAL);

domain = get_dev_data(dev)->domain;
+ if (domain == NULL && get_dev_data(dev)->defer_attach) {
+ get_dev_data(dev)->defer_attach = false;
+ io_domain = iommu_get_domain_for_dev(dev);
+ domain = to_pdomain(io_domain);
+ attach_device(dev, domain);
+ }
if (!dma_ops_domain(domain))
return ERR_PTR(-EBUSY);

@@ -3372,6 +3385,13 @@ static void amd_iommu_apply_resv_region(struct device *dev,
WARN_ON_ONCE(reserve_iova(&dma_dom->iovad, start, end) == NULL);
}

+static bool amd_iommu_is_attach_deferred(struct iommu_domain *domain,
+ struct device *dev)
+{
+ struct iommu_dev_data *dev_data = dev->archdata.iommu;
+ return dev_data->defer_attach;
+}
+
const struct iommu_ops amd_iommu_ops = {
.capable = amd_iommu_capable,
.domain_alloc = amd_iommu_domain_alloc,
@@ -3388,6 +3408,7 @@ const struct iommu_ops amd_iommu_ops = {
.get_resv_regions = amd_iommu_get_resv_regions,
.put_resv_regions = amd_iommu_put_resv_regions,
.apply_resv_region = amd_iommu_apply_resv_region,
+ .is_attach_deferred = amd_iommu_is_attach_deferred,
.pgsize_bitmap = AMD_IOMMU_PGSIZES,
};

--
2.5.5