[PATCH rc 1/2] iommu/tegra241-cmdqv: Fix warnings due to dmam_free_coherent()

[Nicolin Chen <nicolinc@nvidia.com>]

Two WARNINGs are observed when SMMU driver rolls back upon failure:
 arm-smmu-v3.9.auto: Failed to register iommu
 arm-smmu-v3.9.auto: probe with driver arm-smmu-v3 failed with error -22
 ------------[ cut here ]------------
 WARNING: CPU: 5 PID: 1 at kernel/dma/mapping.c:74 dmam_free_coherent+0xc0/0xd8
 Call trace:
  dmam_free_coherent+0xc0/0xd8 (P)
  tegra241_vintf_free_lvcmdq+0x74/0x188
  tegra241_cmdqv_remove_vintf+0x60/0x148
  tegra241_cmdqv_remove+0x48/0xc8
  arm_smmu_impl_remove+0x28/0x60
  devm_action_release+0x1c/0x40
 ------------[ cut here ]------------
 128 pages are still in use!
 WARNING: CPU: 16 PID: 1 at mm/page_alloc.c:6902 free_contig_range+0x18c/0x1c8
 Call trace:
  free_contig_range+0x18c/0x1c8 (P)
  cma_release+0x154/0x2f0
  dma_free_contiguous+0x38/0xa0
  dma_direct_free+0x10c/0x248
  dma_free_attrs+0x100/0x290
  dmam_free_coherent+0x78/0xd8
  tegra241_vintf_free_lvcmdq+0x74/0x160
  tegra241_cmdqv_remove+0x98/0x198
  arm_smmu_impl_remove+0x28/0x60
  devm_action_release+0x1c/0x40

For the first warning: when the main SMMU driver cleans up its resources,
any routine in arm_smmu_impl_remove() should not use any devres function.

For the second warning: since those pages were allocated using smmu->dev
via devres, they should be just freed by devres.

tegra241_vcmdq_free_smmu_cmdq() is called by tegra241_cmdqv_init_vintf()
as well, cleaning up all CMDQV resources but it doesn't removing SMMU as
arm_smmu_impl_remove() does.

Add a removing_smmu boolean to skip tegra241_vcmdq_free_smmu_cmdq() when
SMMU driver itself is being removed.

Fixes: 483e0bd8883a ("iommu/tegra241-cmdqv: Do not allocate vcmdq until dma_set_mask_and_coherent")
Cc: stable@vger.kernel.org
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
index d525ab43a4ae..ce7be8eeb43c 100644
--- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
+++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
@@ -555,12 +555,15 @@ static int tegra241_vintf_init_lvcmdq(struct tegra241_vintf *vintf, u16 lidx,
 	return 0;
 }
 
-static void tegra241_vintf_free_lvcmdq(struct tegra241_vintf *vintf, u16 lidx)
+static void tegra241_vintf_free_lvcmdq(struct tegra241_vintf *vintf, u16 lidx,
+				       bool removing_smmu)
 {
 	struct tegra241_vcmdq *vcmdq = vintf->lvcmdqs[lidx];
 	char header[64];
 
-	tegra241_vcmdq_free_smmu_cmdq(vcmdq);
+	/* When removing SMMU, the queue memory space will be freed by devres */
+	if (!removing_smmu)
+		tegra241_vcmdq_free_smmu_cmdq(vcmdq);
 	tegra241_vintf_deinit_lvcmdq(vintf, lidx);
 
 	dev_dbg(vintf->cmdqv->dev,
@@ -641,7 +644,7 @@ static int tegra241_cmdqv_init_vintf(struct tegra241_cmdqv *cmdqv, u16 max_idx,
 static void tegra241_vintf_remove_lvcmdq(struct tegra241_vintf *vintf, u16 lidx)
 {
 	tegra241_vcmdq_hw_deinit(vintf->lvcmdqs[lidx]);
-	tegra241_vintf_free_lvcmdq(vintf, lidx);
+	tegra241_vintf_free_lvcmdq(vintf, lidx, true);
 }
 
 static void tegra241_cmdqv_remove_vintf(struct tegra241_cmdqv *cmdqv, u16 idx)
@@ -792,7 +795,7 @@ static int tegra241_cmdqv_init_structures(struct arm_smmu_device *smmu)
 
 free_lvcmdq:
 	for (lidx--; lidx >= 0; lidx--)
-		tegra241_vintf_free_lvcmdq(vintf, lidx);
+		tegra241_vintf_free_lvcmdq(vintf, lidx, false);
 	tegra241_cmdqv_deinit_vintf(cmdqv, vintf->idx);
 free_vintf:
 	kfree(vintf);
-- 
2.43.0