From: Chunyan Zhang <[email protected]>
V3:
* Split into two patches;
* Added support reattching an existing domain;
* Release DMA buffer only when domain freed.
V2: https://lkml.org/lkml/2023/3/7/1717
* Added some comment in sprd_iommu_attach_device() for the reason
of calling sprd_iommu_cleanup().
V1: https://lkml.org/lkml/2023/2/10/198
Chunyan Zhang (2):
iommu: sprd: release dma buffer to avoid memory leak
iommu: sprd: Add support for reattaching an existing domain
drivers/iommu/sprd-iommu.c | 54 +++++++++++++++++++++++++++++---------
1 file changed, 41 insertions(+), 13 deletions(-)
--
2.25.1
From: Chunyan Zhang <[email protected]>
When attaching to a domain, the driver would alloc a DMA buffer which
is used to store address mapping table, and it need to be released
when the IOMMU domain is freed.
Signed-off-by: Chunyan Zhang <[email protected]>
---
drivers/iommu/sprd-iommu.c | 29 ++++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c
index ae94d74b73f4..7df1f730c778 100644
--- a/drivers/iommu/sprd-iommu.c
+++ b/drivers/iommu/sprd-iommu.c
@@ -151,13 +151,6 @@ static struct iommu_domain *sprd_iommu_domain_alloc(unsigned int domain_type)
return &dom->domain;
}
-static void sprd_iommu_domain_free(struct iommu_domain *domain)
-{
- struct sprd_iommu_domain *dom = to_sprd_domain(domain);
-
- kfree(dom);
-}
-
static void sprd_iommu_first_vpn(struct sprd_iommu_domain *dom)
{
struct sprd_iommu_device *sdev = dom->sdev;
@@ -230,6 +223,28 @@ static void sprd_iommu_hw_en(struct sprd_iommu_device *sdev, bool en)
sprd_iommu_update_bits(sdev, reg_cfg, mask, 0, val);
}
+static void sprd_iommu_cleanup(struct sprd_iommu_domain *dom)
+{
+ size_t pgt_size;
+
+ /* Nothing need to do if the domain hasn't been attached */
+ if (!dom->sdev)
+ return;
+
+ pgt_size = sprd_iommu_pgt_size(&dom->domain);
+ dma_free_coherent(dom->sdev->dev, pgt_size, dom->pgt_va, dom->pgt_pa);
+ dom->sdev = NULL;
+ sprd_iommu_hw_en(dom->sdev, false);
+}
+
+static void sprd_iommu_domain_free(struct iommu_domain *domain)
+{
+ struct sprd_iommu_domain *dom = to_sprd_domain(domain);
+
+ sprd_iommu_cleanup(dom);
+ kfree(dom);
+}
+
static int sprd_iommu_attach_device(struct iommu_domain *domain,
struct device *dev)
{
--
2.25.1
From: Chunyan Zhang <[email protected]>
This IOMMU driver should allow a domain to be attached more than once.
If IOMMU is reattaching to the same domain which is attached, there's
nothing to be done.
If reattching to a previously-used domain, do not alloc DMA buffer
again which stores address mapping table to avoid memory leak.
Signed-off-by: Chunyan Zhang <[email protected]>
---
drivers/iommu/sprd-iommu.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/sprd-iommu.c b/drivers/iommu/sprd-iommu.c
index 7df1f730c778..3513b2b108bf 100644
--- a/drivers/iommu/sprd-iommu.c
+++ b/drivers/iommu/sprd-iommu.c
@@ -62,6 +62,7 @@ enum sprd_iommu_version {
* @eb: gate clock which controls IOMMU access
*/
struct sprd_iommu_device {
+ struct sprd_iommu_domain *dom;
enum sprd_iommu_version ver;
u32 *prot_page_va;
dma_addr_t prot_page_pa;
@@ -252,15 +253,27 @@ static int sprd_iommu_attach_device(struct iommu_domain *domain,
struct sprd_iommu_domain *dom = to_sprd_domain(domain);
size_t pgt_size = sprd_iommu_pgt_size(domain);
- if (dom->sdev)
- return -EINVAL;
+ /* The device is attached to this domain */
+ if (sdev->dom == dom)
+ return 0;
- dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL);
- if (!dom->pgt_va)
- return -ENOMEM;
+ /* The first time that domain is attaching to a device */
+ if (!dom->pgt_va) {
+ dom->pgt_va = dma_alloc_coherent(sdev->dev, pgt_size, &dom->pgt_pa, GFP_KERNEL);
+ if (!dom->pgt_va)
+ return -ENOMEM;
+
+ dom->sdev = sdev;
+ }
- dom->sdev = sdev;
+ sdev->dom = dom;
+ /*
+ * One sprd IOMMU serves one client device only, disabled it before
+ * configure mapping table to avoid access conflict in case other
+ * mapping table is stored in.
+ */
+ sprd_iommu_hw_en(sdev, false);
sprd_iommu_first_ppn(dom);
sprd_iommu_first_vpn(dom);
sprd_iommu_vpn_range(dom);
--
2.25.1
On Fri, Mar 31, 2023 at 11:31:22AM +0800, Chunyan Zhang wrote:
> Chunyan Zhang (2):
> iommu: sprd: release dma buffer to avoid memory leak
> iommu: sprd: Add support for reattaching an existing domain
Applied, thanks.