[PATCH v10 09/12] iommu/amd: Use is_attach_deferred call-back

[Baoquan He]

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 <b...@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 dab901b4f0f9..eebf4590cef9 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