This is a note to let you know that I've just added the patch titled
iommu/tegra-smmu: Fix page tables in > 4 GiB memory
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommu-tegra-smmu-fix-page-tables-in-4-gib-memory.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 6954e33b27c4c19c6f18659a813b2d255c1fbbfa
Author: Thierry Reding <treding@xxxxxxxxxx>
Date: Wed Oct 16 13:50:26 2019 +0200
iommu/tegra-smmu: Fix page tables in > 4 GiB memory
[ Upstream commit 96d3ab802e4930a29a33934373157d6dff1b2c7e ]
Page tables that reside in physical memory beyond the 4 GiB boundary are
currently not working properly. The reason is that when the physical
address for page directory entries is read, it gets truncated at 32 bits
and can cause crashes when passing that address to the DMA API.
Fix this by first casting the PDE value to a dma_addr_t and then using
the page frame number mask for the SMMU instance to mask out the invalid
bits, which are typically used for mapping attributes, etc.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 40eb8138546a..848dac3e4580 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -156,9 +156,9 @@ static bool smmu_dma_addr_valid(struct tegra_smmu *smmu, dma_addr_t addr)
return (addr & smmu->pfn_mask) == addr;
}
-static dma_addr_t smmu_pde_to_dma(u32 pde)
+static dma_addr_t smmu_pde_to_dma(struct tegra_smmu *smmu, u32 pde)
{
- return pde << 12;
+ return (dma_addr_t)(pde & smmu->pfn_mask) << 12;
}
static void smmu_flush_ptc_all(struct tegra_smmu *smmu)
@@ -543,6 +543,7 @@ static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
dma_addr_t *dmap)
{
unsigned int pd_index = iova_pd_index(iova);
+ struct tegra_smmu *smmu = as->smmu;
struct page *pt_page;
u32 *pd;
@@ -551,7 +552,7 @@ static u32 *tegra_smmu_pte_lookup(struct tegra_smmu_as *as, unsigned long iova,
return NULL;
pd = page_address(as->pd);
- *dmap = smmu_pde_to_dma(pd[pd_index]);
+ *dmap = smmu_pde_to_dma(smmu, pd[pd_index]);
return tegra_smmu_pte_offset(pt_page, iova);
}
@@ -593,7 +594,7 @@ static u32 *as_get_pte(struct tegra_smmu_as *as, dma_addr_t iova,
} else {
u32 *pd = page_address(as->pd);
- *dmap = smmu_pde_to_dma(pd[pde]);
+ *dmap = smmu_pde_to_dma(smmu, pd[pde]);
}
return tegra_smmu_pte_offset(as->pts[pde], iova);
@@ -618,7 +619,7 @@ static void tegra_smmu_pte_put_use(struct tegra_smmu_as *as, unsigned long iova)
if (--as->count[pde] == 0) {
struct tegra_smmu *smmu = as->smmu;
u32 *pd = page_address(as->pd);
- dma_addr_t pte_dma = smmu_pde_to_dma(pd[pde]);
+ dma_addr_t pte_dma = smmu_pde_to_dma(smmu, pd[pde]);
tegra_smmu_set_pde(as, iova, 0);
