Commit 483e0bd8 authored by Nicolin Chen's avatar Nicolin Chen Committed by Will Deacon
Browse files

iommu/tegra241-cmdqv: Do not allocate vcmdq until dma_set_mask_and_coherent 



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: 918eb5c8 ("iommu/arm-smmu-v3: Add in-kernel support for NVIDIA Tegra241 (Grace) CMDQV")
Reported-by: default avatarMatt Ochs <mochs@nvidia.com>
Signed-off-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/530993c3aafa1b0fc3d879b8119e13c629d12e2b.1725503154.git.nicolinc@nvidia.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 2408b81f

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

+8 −1
Original line number Diff line number Diff line
@@ -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,

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

};

drivers/iommu/arm/arm-smmu-v3/tegra241-cmdqv.c

+51 −32
Original line number Diff line number Diff line
@@ -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);