[PATCH v2 1/2] iommu/amd: Add helper functions to update domain->pt_root

Joerg Roedel
2020-06-26T08:08:42Z

Do not call atomic64_set() directly to update the domain page-table
root and use two new helper functions.

This makes it easier to implement additional work necessary when
the page-table is updated.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/amd/iommu.c | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 74cca1757172..5286ddcfc2f9 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -162,7 +162,18 @@ static void amd_iommu_domain_get_pgtable(struct protection_domain *domain,
pgtable->mode = pt_root & 7; /* lowest 3 bits encode pgtable mode */
}

-static u64 amd_iommu_domain_encode_pgtable(u64 *root, int mode)
+static void amd_iommu_domain_set_pt_root(struct protection_domain *domain, u64 root)
+{
+ atomic64_set(&domain->pt_root, root);
+}
+
+static void amd_iommu_domain_clr_pt_root(struct protection_domain *domain)
+{
+ amd_iommu_domain_set_pt_root(domain, 0);
+}
+
+static void amd_iommu_domain_set_pgtable(struct protection_domain *domain,
+ u64 *root, int mode)
{
u64 pt_root;

@@ -170,7 +181,7 @@ static u64 amd_iommu_domain_encode_pgtable(u64 *root, int mode)
pt_root = mode & 7;
pt_root |= (u64)root;

- return pt_root;
+ amd_iommu_domain_set_pt_root(domain, pt_root);
}

static struct iommu_dev_data *alloc_dev_data(u16 devid)
@@ -1410,7 +1421,7 @@ static bool increase_address_space(struct protection_domain *domain,
struct domain_pgtable pgtable;
unsigned long flags;
bool ret = true;
- u64 *pte, root;
+ u64 *pte;

spin_lock_irqsave(&domain->lock, flags);

@@ -1438,8 +1449,7 @@ static bool increase_address_space(struct protection_domain *domain,
* Device Table needs to be updated and flushed before the new root can
* be published.
*/
- root = amd_iommu_domain_encode_pgtable(pte, pgtable.mode);
- atomic64_set(&domain->pt_root, root);
+ amd_iommu_domain_set_pgtable(domain, pte, pgtable.mode);

ret = true;

@@ -2319,7 +2329,7 @@ static void protection_domain_free(struct protection_domain *domain)
domain_id_free(domain->id);

amd_iommu_domain_get_pgtable(domain, &pgtable);
- atomic64_set(&domain->pt_root, 0);
+ amd_iommu_domain_clr_pt_root(domain);
free_pagetable(&pgtable);

kfree(domain);
@@ -2327,7 +2337,7 @@ static void protection_domain_free(struct protection_domain *domain)

static int protection_domain_init(struct protection_domain *domain, int mode)
{
- u64 *pt_root = NULL, root;
+ u64 *pt_root = NULL;

BUG_ON(mode < PAGE_MODE_NONE || mode > PAGE_MODE_6_LEVEL);

@@ -2343,8 +2353,7 @@ static int protection_domain_init(struct protection_domain *domain, int mode)
return -ENOMEM;
}

- root = amd_iommu_domain_encode_pgtable(pt_root, mode);
- atomic64_set(&domain->pt_root, root);
+ amd_iommu_domain_set_pgtable(domain, pt_root, mode);

return 0;
}
@@ -2713,8 +2722,8 @@ void amd_iommu_domain_direct_map(struct iommu_domain *dom)
/* First save pgtable configuration*/
amd_iommu_domain_get_pgtable(domain, &pgtable);

- /* Update data structure */
- atomic64_set(&domain->pt_root, 0);
+ /* Remove page-table from domain */
+ amd_iommu_domain_clr_pt_root(domain);

/* Make changes visible to IOMMUs */
update_domain(domain);
--
2.27.0