This is a note to let you know that I've just added the patch titled

iommu/arm-smmu-v3: Clear prior settings when updating STEs

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: iommu-arm-smmu-v3-clear-prior-settings-when-updating-stes.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Thu Nov 9 18:22:51 CET 2017

From: Nate Watterson nwatters@codeaurora.org Date: Tue, 20 Dec 2016 23:11:48 -0500 Subject: iommu/arm-smmu-v3: Clear prior settings when updating STEs

From: Nate Watterson nwatters@codeaurora.org

[ Upstream commit 810871c57011eb3e89e6768932757f169d666cd2 ]

To prevent corruption of the stage-1 context pointer field when updating STEs, rebuild the entire containing dword instead of clearing individual fields.

Signed-off-by: Nate Watterson nwatters@codeaurora.org Signed-off-by: Will Deacon will.deacon@arm.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iommu/arm-smmu-v3.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-)

--- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -1033,13 +1033,8 @@ static void arm_smmu_write_strtab_ent(st } }

- /* Nuke the existing Config, as we're going to rewrite it */ - val &= ~(STRTAB_STE_0_CFG_MASK << STRTAB_STE_0_CFG_SHIFT); - - if (ste->valid) - val |= STRTAB_STE_0_V; - else - val &= ~STRTAB_STE_0_V; + /* Nuke the existing STE_0 value, as we're going to rewrite it */ + val = ste->valid ? STRTAB_STE_0_V : 0;

if (ste->bypass) { val |= disable_bypass ? STRTAB_STE_0_CFG_ABORT @@ -1068,7 +1063,6 @@ static void arm_smmu_write_strtab_ent(st val |= (ste->s1_cfg->cdptr_dma & STRTAB_STE_0_S1CTXPTR_MASK << STRTAB_STE_0_S1CTXPTR_SHIFT) | STRTAB_STE_0_CFG_S1_TRANS; - }

if (ste->s2_cfg) {

Patches currently in stable-queue which might be from nwatters@codeaurora.org are

queue-4.4/iommu-arm-smmu-v3-clear-prior-settings-when-updating-stes.patch