[PATCH next 2/2] iommu/tegra241-cmdqv: Do not allocate vcmdq until dma_set_mask_and_coherent
Nicolin Chen
nicolinc at nvidia.com
Wed Sep 4 19:40:43 PDT 2024
It's observed that, when the first 4GB of system memory was reserved, all
VCMDQ allocations failed (even with the smallest qsz in the last attempt):
arm-smmu-v3: found companion CMDQV device: NVDA200C:00
arm-smmu-v3: option mask 0x10
arm-smmu-v3: failed to allocate queue (0x8000 bytes) for vcmdq0
acpi NVDA200C:00: tegra241_cmdqv: Falling back to standard SMMU CMDQ
arm-smmu-v3: ias 48-bit, oas 48-bit (features 0x001e1fbf)
arm-smmu-v3: allocated 524288 entries for cmdq
arm-smmu-v3: allocated 524288 entries for evtq
arm-smmu-v3: allocated 524288 entries for priq
This is because the 4GB reserved memory shifted the entire DMA zone from a
lower 32-bit range (on a system without the 4GB carveout) to higher range,
while the dev->coherent_dma_mask was set to DMA_BIT_MASK(32) by default.
The dma_set_mask_and_coherent() call is done in arm_smmu_device_hw_probe()
of the SMMU driver. So any DMA allocation from tegra241_cmdqv_probe() must
wait until the coherent_dma_mask is correctly set.
Move the vintf/vcmdq structure initialization routine into a different op,
"init_structures". Call it at the end of arm_smmu_init_structures(), where
standard SMMU queues get allocated.
Most of the impl_ops aren't ready until vintf/vcmdq structure are init-ed.
So replace the full impl_ops with an init_ops in __tegra241_cmdqv_probe().
And switch to tegra241_cmdqv_impl_ops later in arm_smmu_init_structures().
Note that tegra241_cmdqv_impl_ops does not link to the new init_structures
op after this switch, since there is no point in having it once it's done.
Fixes: 918eb5c856f6 ("iommu/arm-smmu-v3: Add in-kernel support for NVIDIA Tegra241 (Grace) CMDQV")
Reported-by: Matt Ochs <mochs at nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc at nvidia.com>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 +-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 +
.../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 83 ++++++++++++-------
3 files changed, 60 insertions(+), 33 deletions(-)
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index b2de56dfceb9..df852ab04fd7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3744,7 +3744,14 @@ static int arm_smmu_init_structures(struct arm_smmu_device *smmu)
if (ret)
return ret;
- return arm_smmu_init_strtab(smmu);
+ ret = arm_smmu_init_strtab(smmu);
+ if (ret)
+ return ret;
+
+ if (smmu->impl_ops && smmu->impl_ops->init_structures)
+ return smmu->impl_ops->init_structures(smmu);
+
+ return 0;
}
static int arm_smmu_write_reg_sync(struct arm_smmu_device *smmu, u32 val,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index e044ce5b5372..e8320e9341d7 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -643,6 +643,7 @@ struct arm_smmu_strtab_cfg {
struct arm_smmu_impl_ops {
int (*device_reset)(struct arm_smmu_device *smmu);
void (*device_remove)(struct arm_smmu_device *smmu);
+ int (*init_structures)(struct arm_smmu_device *smmu);
struct arm_smmu_cmdq *(*get_secondary_cmdq)(
struct arm_smmu_device *smmu, struct arm_smmu_cmdq_ent *ent);
};
diff --git a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
index 0766dc2789cb..fcd13d301fff 100644
--- a/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
+++ b/drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c
@@ -755,18 +755,65 @@ tegra241_cmdqv_find_acpi_resource(struct device *dev, int *irq)
return res;
}
+static int tegra241_cmdqv_init_structures(struct arm_smmu_device *smmu)
+{
+ struct tegra241_cmdqv *cmdqv =
+ container_of(smmu, struct tegra241_cmdqv, smmu);
+ struct tegra241_vintf *vintf;
+ int lidx;
+ int ret;
+
+ vintf = kzalloc(sizeof(*vintf), GFP_KERNEL);
+ if (!vintf)
+ goto out_fallback;
+
+ /* Init VINTF0 for in-kernel use */
+ ret = tegra241_cmdqv_init_vintf(cmdqv, 0, vintf);
+ if (ret) {
+ dev_err(cmdqv->dev, "failed to init vintf0: %d\n", ret);
+ goto free_vintf;
+ }
+
+ /* Preallocate logical VCMDQs to VINTF0 */
+ for (lidx = 0; lidx < cmdqv->num_lvcmdqs_per_vintf; lidx++) {
+ struct tegra241_vcmdq *vcmdq;
+
+ vcmdq = tegra241_vintf_alloc_lvcmdq(vintf, lidx);
+ if (IS_ERR(vcmdq))
+ goto free_lvcmdq;
+ }
+
+ /* Now, we are ready to run all the impl ops */
+ smmu->impl_ops = &tegra241_cmdqv_impl_ops;
+ return 0;
+
+free_lvcmdq:
+ for (lidx--; lidx >= 0; lidx--)
+ tegra241_vintf_free_lvcmdq(vintf, lidx);
+ tegra241_cmdqv_deinit_vintf(cmdqv, vintf->idx);
+free_vintf:
+ kfree(vintf);
+out_fallback:
+ dev_info(smmu->impl_dev, "Falling back to standard SMMU CMDQ\n");
+ smmu->options &= ~ARM_SMMU_OPT_TEGRA241_CMDQV;
+ tegra241_cmdqv_remove(smmu);
+ return 0;
+}
+
struct dentry *cmdqv_debugfs_dir;
static struct arm_smmu_device *
__tegra241_cmdqv_probe(struct arm_smmu_device *smmu, struct resource *res,
int irq)
{
+ static const struct arm_smmu_impl_ops init_ops = {
+ .init_structures = tegra241_cmdqv_init_structures,
+ .device_remove = tegra241_cmdqv_remove,
+ };
struct tegra241_cmdqv *cmdqv = NULL;
struct arm_smmu_device *new_smmu;
- struct tegra241_vintf *vintf;
void __iomem *base;
u32 regval;
- int lidx;
int ret;
static_assert(offsetof(struct tegra241_cmdqv, smmu) == 0);
@@ -815,26 +862,6 @@ __tegra241_cmdqv_probe(struct arm_smmu_device *smmu, struct resource *res,
ida_init(&cmdqv->vintf_ids);
- vintf = kzalloc(sizeof(*vintf), GFP_KERNEL);
- if (!vintf)
- goto destroy_ids;
-
- /* Init VINTF0 for in-kernel use */
- ret = tegra241_cmdqv_init_vintf(cmdqv, 0, vintf);
- if (ret) {
- dev_err(cmdqv->dev, "failed to init vintf0: %d\n", ret);
- goto free_vintf;
- }
-
- /* Preallocate logical VCMDQs to VINTF0 */
- for (lidx = 0; lidx < cmdqv->num_lvcmdqs_per_vintf; lidx++) {
- struct tegra241_vcmdq *vcmdq;
-
- vcmdq = tegra241_vintf_alloc_lvcmdq(vintf, lidx);
- if (IS_ERR(vcmdq))
- goto free_lvcmdq;
- }
-
#ifdef CONFIG_IOMMU_DEBUGFS
if (!cmdqv_debugfs_dir) {
cmdqv_debugfs_dir =
@@ -844,19 +871,11 @@ __tegra241_cmdqv_probe(struct arm_smmu_device *smmu, struct resource *res,
}
#endif
- new_smmu->impl_ops = &tegra241_cmdqv_impl_ops;
+ /* Provide init-level ops only, until tegra241_cmdqv_init_structures */
+ new_smmu->impl_ops = &init_ops;
return new_smmu;
-free_lvcmdq:
- for (lidx--; lidx >= 0; lidx--)
- tegra241_vintf_free_lvcmdq(vintf, lidx);
- tegra241_cmdqv_deinit_vintf(cmdqv, vintf->idx);
-free_vintf:
- kfree(vintf);
-destroy_ids:
- ida_destroy(&cmdqv->vintf_ids);
- kfree(cmdqv->vintfs);
free_irq:
if (cmdqv->irq > 0)
free_irq(cmdqv->irq, cmdqv);
--
2.43.0
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