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Commit f85843d3 authored by Isaac J. Manjarres's avatar Isaac J. Manjarres
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iommu/arm-smmu: Add support to disable page-table coherency 



There may be environments where page-table walker coherency
is enabled by default, so add support to allow clients to
disable it.

Change-Id: I1681c680e82cabb5b132867af03f2e599bfc72e3
Signed-off-by: default avatarIsaac J. Manjarres <isaacm@codeaurora.org>
parent 516747fd

drivers/iommu/arm-smmu.c

+30 −0
Original line number Diff line number Diff line
@@ -214,6 +214,9 @@ static bool is_iommu_pt_coherent(struct arm_smmu_domain *smmu_domain) 
	if (test_bit(DOMAIN_ATTR_PAGE_TABLE_FORCE_COHERENT,

		     smmu_domain->attributes))

		return true;

	else if (test_bit(DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT,

			  smmu_domain->attributes))

		return false;

	else if (smmu_domain->smmu && smmu_domain->smmu->dev)

		return dev_is_dma_coherent(smmu_domain->smmu->dev);

	else
@@ -2673,6 +2676,9 @@ static int arm_smmu_setup_default_domain(struct device *dev, 
	if (!strcmp(str, "coherent"))

		__arm_smmu_domain_set_attr(domain,

			DOMAIN_ATTR_PAGE_TABLE_FORCE_COHERENT, &attr);

	else if (!strcmp(str, "non-coherent"))

		__arm_smmu_domain_set_attr(domain,

			DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT, &attr);

	else if (!strcmp(str, "LLC"))

		__arm_smmu_domain_set_attr(domain,

			DOMAIN_ATTR_USE_UPSTREAM_HINT, &attr);
@@ -3449,6 +3455,12 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain, 
					  smmu_domain->attributes);

		ret = 0;

		break;

	case DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT:

		*((int *)data) =

			test_bit(DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT,

				 smmu_domain->attributes);

		ret = 0;

		break;

	case DOMAIN_ATTR_CB_STALL_DISABLE:

		*((int *)data) = test_bit(DOMAIN_ATTR_CB_STALL_DISABLE,

					  smmu_domain->attributes);
@@ -3689,6 +3701,24 @@ static int __arm_smmu_domain_set_attr2(struct iommu_domain *domain, 
		}

		break;

	}

	case DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT: {

		int force_non_coherent = *((int *)data);



		if (smmu_domain->smmu != NULL) {

			dev_err(smmu_domain->smmu->dev,

				"cannot change force non-coherent attribute while attached\n");

			ret = -EBUSY;

		} else if (force_non_coherent) {

			set_bit(DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT,

				smmu_domain->attributes);

			ret = 0;

		} else {

			clear_bit(DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT,

				  smmu_domain->attributes);

			ret = 0;

		}

		break;

	}

	default:

		ret = -ENODEV;

	}

include/linux/iommu.h

+5 −4
Original line number Diff line number Diff line
@@ -185,10 +185,11 @@ enum iommu_attr { 
#define DOMAIN_ATTR_EARLY_MAP			(EXTENDED_ATTR_BASE + 13)

#define DOMAIN_ATTR_PAGE_TABLE_IS_COHERENT	(EXTENDED_ATTR_BASE + 14)

#define DOMAIN_ATTR_PAGE_TABLE_FORCE_COHERENT	(EXTENDED_ATTR_BASE + 15)

#define DOMAIN_ATTR_CB_STALL_DISABLE		(EXTENDED_ATTR_BASE + 16)

#define DOMAIN_ATTR_USE_LLC_NWA			(EXTENDED_ATTR_BASE + 17)

#define DOMAIN_ATTR_NO_CFRE			(EXTENDED_ATTR_BASE + 18)

#define DOMAIN_ATTR_EXTENDED_MAX		(EXTENDED_ATTR_BASE + 19)

#define DOMAIN_ATTR_PAGE_TABLE_FORCE_NON_COHERENT (EXTENDED_ATTR_BASE + 16)

#define DOMAIN_ATTR_CB_STALL_DISABLE		(EXTENDED_ATTR_BASE + 17)

#define DOMAIN_ATTR_USE_LLC_NWA			(EXTENDED_ATTR_BASE + 18)

#define DOMAIN_ATTR_NO_CFRE			(EXTENDED_ATTR_BASE + 19)

#define DOMAIN_ATTR_EXTENDED_MAX		(EXTENDED_ATTR_BASE + 20)



/* These are the possible reserved region types */

enum iommu_resv_type {