[PATCH 13/18] iommu/tegra: Add IOMMU_DOMAIN_DMA support

Robin Murphy
2020-08-20T15:11:38Z

Now that arch/arm is wired up for default domains and iommu-dma,
implement the corresponding driver-side support for DMA domains.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
drivers/iommu/tegra-smmu.c | 37 +++++++++++++++++++++----------------
1 file changed, 21 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 124c8848ab7e..8e276eac84d9 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -5,6 +5,7 @@

#include <linux/bitops.h>
#include <linux/debugfs.h>
+#include <linux/dma-iommu.h>
#include <linux/err.h>
#include <linux/iommu.h>
#include <linux/kernel.h>
@@ -278,7 +279,7 @@ static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
{
struct tegra_smmu_as *as;

- if (type != IOMMU_DOMAIN_UNMANAGED)
+ if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
return NULL;

as = kzalloc(sizeof(*as), GFP_KERNEL);
@@ -288,25 +289,19 @@ static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
as->attr = SMMU_PD_READABLE | SMMU_PD_WRITABLE | SMMU_PD_NONSECURE;

as->pd = alloc_page(GFP_KERNEL | __GFP_DMA | __GFP_ZERO);
- if (!as->pd) {
- kfree(as);
- return NULL;
- }
+ if (!as->pd)
+ goto out_free_as;

as->count = kcalloc(SMMU_NUM_PDE, sizeof(u32), GFP_KERNEL);
- if (!as->count) {
- __free_page(as->pd);
- kfree(as);
- return NULL;
- }
+ if (!as->count)
+ goto out_free_all;

as->pts = kcalloc(SMMU_NUM_PDE, sizeof(*as->pts), GFP_KERNEL);
- if (!as->pts) {
- kfree(as->count);
- __free_page(as->pd);
- kfree(as);
- return NULL;
- }
+ if (!as->pts)
+ goto out_free_all;
+
+ if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(&as->domain))
+ goto out_free_all;

/* setup aperture */
as->domain.geometry.aperture_start = 0;
@@ -314,12 +309,22 @@ static struct iommu_domain *tegra_smmu_domain_alloc(unsigned type)
as->domain.geometry.force_aperture = true;

return &as->domain;
+
+out_free_all:
+ kfree(as->pts);
+ kfree(as->count);
+ __free_page(as->pd);
+out_free_as:
+ kfree(as);
+ return NULL;
}

static void tegra_smmu_domain_free(struct iommu_domain *domain)
{
struct tegra_smmu_as *as = to_smmu_as(domain);

+ iommu_put_dma_cookie(domain);
+
/* TODO: free page directory and page tables */

WARN_ON_ONCE(as->use_count);
--
2.28.0.dirty