[PATCH 14/17] iommu: remove DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE

[Christoph Hellwig <hch@lst.de>]

Use explicit methods for setting and querying the information instead.

Also remove the now unused iommu_domain_get_attr functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/iommu/amd/iommu.c                   | 23 ++-------
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 47 ++++++-----------
 drivers/iommu/arm/arm-smmu/arm-smmu.c       | 56 +++++----------------
 drivers/iommu/dma-iommu.c                   |  8 ++-
 drivers/iommu/intel/iommu.c                 | 27 ++--------
 drivers/iommu/iommu.c                       | 19 +++----
 include/linux/iommu.h                       | 17 ++-----
 7 files changed, 51 insertions(+), 146 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index a69a8b573e40d0..37a8e51db17656 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -1771,24 +1771,11 @@ static struct iommu_group *amd_iommu_device_group(struct device *dev)
 	return acpihid_device_group(dev);
 }
 
-static int amd_iommu_domain_get_attr(struct iommu_domain *domain,
-		enum iommu_attr attr, void *data)
+static bool amd_iommu_dma_use_flush_queue(struct iommu_domain *domain)
 {
-	switch (domain->type) {
-	case IOMMU_DOMAIN_UNMANAGED:
-		return -ENODEV;
-	case IOMMU_DOMAIN_DMA:
-		switch (attr) {
-		case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
-			*(int *)data = !amd_iommu_unmap_flush;
-			return 0;
-		default:
-			return -ENODEV;
-		}
-		break;
-	default:
-		return -EINVAL;
-	}
+	if (domain->type != IOMMU_DOMAIN_DMA)
+		return false;
+	return !amd_iommu_unmap_flush;
 }
 
 /*****************************************************************************
@@ -2257,7 +2244,7 @@ const struct iommu_ops amd_iommu_ops = {
 	.release_device = amd_iommu_release_device,
 	.probe_finalize = amd_iommu_probe_finalize,
 	.device_group = amd_iommu_device_group,
-	.domain_get_attr = amd_iommu_domain_get_attr,
+	.dma_use_flush_queue = amd_iommu_dma_use_flush_queue,
 	.get_resv_regions = amd_iommu_get_resv_regions,
 	.put_resv_regions = generic_iommu_put_resv_regions,
 	.is_attach_deferred = amd_iommu_is_attach_deferred,
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 8594b4a8304375..bf96172e8c1f71 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2449,33 +2449,21 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
 	return group;
 }
 
-static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
-				    enum iommu_attr attr, void *data)
+static bool arm_smmu_dma_use_flush_queue(struct iommu_domain *domain)
 {
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
-	switch (domain->type) {
-	case IOMMU_DOMAIN_UNMANAGED:
-		switch (attr) {
-		case DOMAIN_ATTR_NESTING:
-			*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
-			return 0;
-		default:
-			return -ENODEV;
-		}
-		break;
-	case IOMMU_DOMAIN_DMA:
-		switch (attr) {
-		case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
-			*(int *)data = smmu_domain->non_strict;
-			return 0;
-		default:
-			return -ENODEV;
-		}
-		break;
-	default:
-		return -EINVAL;
-	}
+	if (domain->type != IOMMU_DOMAIN_DMA)
+		return false;
+	return smmu_domain->non_strict;
+}
+
+
+static void arm_smmu_dma_enable_flush_queue(struct iommu_domain *domain)
+{
+	if (domain->type != IOMMU_DOMAIN_DMA)
+		return;
+	to_smmu_domain(domain)->non_strict = true;
 }
 
 static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
@@ -2505,13 +2493,7 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
 		}
 		break;
 	case IOMMU_DOMAIN_DMA:
-		switch(attr) {
-		case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
-			smmu_domain->non_strict = *(int *)data;
-			break;
-		default:
-			ret = -ENODEV;
-		}
+		ret = -ENODEV;
 		break;
 	default:
 		ret = -EINVAL;
@@ -2619,7 +2601,8 @@ static struct iommu_ops arm_smmu_ops = {
 	.probe_device		= arm_smmu_probe_device,
 	.release_device		= arm_smmu_release_device,
 	.device_group		= arm_smmu_device_group,
-	.domain_get_attr	= arm_smmu_domain_get_attr,
+	.dma_use_flush_queue	= arm_smmu_dma_use_flush_queue,
+	.dma_enable_flush_queue	= arm_smmu_dma_enable_flush_queue,
 	.domain_set_attr	= arm_smmu_domain_set_attr,
 	.of_xlate		= arm_smmu_of_xlate,
 	.get_resv_regions	= arm_smmu_get_resv_regions,
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index d8c6bfde6a6158..e7893e96f5177a 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -1481,42 +1481,20 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
 	return group;
 }
 
-static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
-				    enum iommu_attr attr, void *data)
+static bool arm_smmu_dma_use_flush_queue(struct iommu_domain *domain)
 {
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 
-	switch(domain->type) {
-	case IOMMU_DOMAIN_UNMANAGED:
-		switch (attr) {
-		case DOMAIN_ATTR_NESTING:
-			*(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
-			return 0;
-		case DOMAIN_ATTR_IO_PGTABLE_CFG: {
-			struct io_pgtable_domain_attr *pgtbl_cfg = data;
-			*pgtbl_cfg = smmu_domain->pgtbl_cfg;
+	if (domain->type != IOMMU_DOMAIN_DMA)
+		return false;
+	return smmu_domain->pgtbl_cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT;
+}
 
-			return 0;
-		}
-		default:
-			return -ENODEV;
-		}
-		break;
-	case IOMMU_DOMAIN_DMA:
-		switch (attr) {
-		case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE: {
-			bool non_strict = smmu_domain->pgtbl_cfg.quirks &
-					  IO_PGTABLE_QUIRK_NON_STRICT;
-			*(int *)data = non_strict;
-			return 0;
-		}
-		default:
-			return -ENODEV;
-		}
-		break;
-	default:
-		return -EINVAL;
-	}
+static void arm_smmu_dma_enable_flush_queue(struct iommu_domain *domain)
+{
+	if (domain->type != IOMMU_DOMAIN_DMA)
+		return;
+	to_smmu_domain(domain)->pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
 }
 
 static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
@@ -1557,16 +1535,7 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
 		}
 		break;
 	case IOMMU_DOMAIN_DMA:
-		switch (attr) {
-		case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
-			if (*(int *)data)
-				smmu_domain->pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
-			else
-				smmu_domain->pgtbl_cfg.quirks &= ~IO_PGTABLE_QUIRK_NON_STRICT;
-			break;
-		default:
-			ret = -ENODEV;
-		}
+		ret = -ENODEV;
 		break;
 	default:
 		ret = -EINVAL;
@@ -1631,7 +1600,8 @@ static struct iommu_ops arm_smmu_ops = {
 	.probe_device		= arm_smmu_probe_device,
 	.release_device		= arm_smmu_release_device,
 	.device_group		= arm_smmu_device_group,
-	.domain_get_attr	= arm_smmu_domain_get_attr,
+	.dma_use_flush_queue	= arm_smmu_dma_use_flush_queue,
+	.dma_enable_flush_queue	= arm_smmu_dma_enable_flush_queue,
 	.domain_set_attr	= arm_smmu_domain_set_attr,
 	.of_xlate		= arm_smmu_of_xlate,
 	.get_resv_regions	= arm_smmu_get_resv_regions,
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 9ab6ee22c11088..d3fe5aad9d6ecf 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -305,8 +305,8 @@ static void iommu_dma_flush_iotlb_all(struct iova_domain *iovad)
 	cookie = container_of(iovad, struct iommu_dma_cookie, iovad);
 	domain = cookie->fq_domain;
 	/*
-	 * The IOMMU driver supporting DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE
-	 * implies that ops->flush_iotlb_all must be non-NULL.
+	 * The IOMMU driver supporting a DMA flush queue implies that
+	 * ops->flush_iotlb_all must be non-NULL.
 	 */
 	domain->ops->flush_iotlb_all(domain);
 }
@@ -329,7 +329,6 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 	struct iommu_dma_cookie *cookie = domain->iova_cookie;
 	unsigned long order, base_pfn;
 	struct iova_domain *iovad;
-	int attr;
 
 	if (!cookie || cookie->type != IOMMU_DMA_IOVA_COOKIE)
 		return -EINVAL;
@@ -365,8 +364,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 
 	init_iova_domain(iovad, 1UL << order, base_pfn);
 
-	if (!cookie->fq_domain && !iommu_domain_get_attr(domain,
-			DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, &attr) && attr) {
+	if (!cookie->fq_domain && iommu_dma_use_flush_queue(domain)) {
 		if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
 					  iommu_dma_entry_dtor))
 			pr_warn("iova flush queue initialization failed\n");
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index ee0932307d646b..eaa80c33f4bc91 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5453,13 +5453,13 @@ intel_iommu_domain_set_attr(struct iommu_domain *domain,
 	return ret;
 }
 
-static bool domain_use_flush_queue(void)
+static bool intel_iommu_dma_use_flush_queue(struct iommu_domain *domain)
 {
 	struct dmar_drhd_unit *drhd;
 	struct intel_iommu *iommu;
 	bool r = true;
 
-	if (intel_iommu_strict)
+	if (domain->type != IOMMU_DOMAIN_DMA || intel_iommu_strict)
 		return false;
 
 	/*
@@ -5483,27 +5483,6 @@ static bool domain_use_flush_queue(void)
 	return r;
 }
 
-static int
-intel_iommu_domain_get_attr(struct iommu_domain *domain,
-			    enum iommu_attr attr, void *data)
-{
-	switch (domain->type) {
-	case IOMMU_DOMAIN_UNMANAGED:
-		return -ENODEV;
-	case IOMMU_DOMAIN_DMA:
-		switch (attr) {
-		case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
-			*(int *)data = domain_use_flush_queue();
-			return 0;
-		default:
-			return -ENODEV;
-		}
-		break;
-	default:
-		return -EINVAL;
-	}
-}
-
 /*
  * Check that the device does not live on an external facing PCI port that is
  * marked as untrusted. Such devices should not be able to apply quirks and
@@ -5576,7 +5555,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.capable		= intel_iommu_capable,
 	.domain_alloc		= intel_iommu_domain_alloc,
 	.domain_free		= intel_iommu_domain_free,
-	.domain_get_attr        = intel_iommu_domain_get_attr,
+	.dma_use_flush_queue	= intel_iommu_dma_use_flush_queue,
 	.domain_set_attr	= intel_iommu_domain_set_attr,
 	.attach_dev		= intel_iommu_attach_device,
 	.detach_dev		= intel_iommu_detach_device,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 23daaea7883b75..0f12c4d58cdc42 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1512,12 +1512,8 @@ static int iommu_group_alloc_default_domain(struct bus_type *bus,
 	if (!group->domain)
 		group->domain = dom;
 
-	if (!iommu_dma_strict) {
-		int attr = 1;
-		iommu_domain_set_attr(dom,
-				      DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
-				      &attr);
-	}
+	if (!iommu_dma_strict && dom->ops->dma_enable_flush_queue)
+		dom->ops->dma_enable_flush_queue(dom);
 
 	return 0;
 }
@@ -2664,14 +2660,13 @@ static int __init iommu_init(void)
 }
 core_initcall(iommu_init);
 
-int iommu_domain_get_attr(struct iommu_domain *domain,
-			  enum iommu_attr attr, void *data)
+bool iommu_dma_use_flush_queue(struct iommu_domain *domain)
 {
-	if (!domain->ops->domain_get_attr)
-		return -EINVAL;
-	return domain->ops->domain_get_attr(domain, attr, data);
+	if (!domain->ops->dma_use_flush_queue)
+		return false;
+	return domain->ops->dma_use_flush_queue(domain);
 }
-EXPORT_SYMBOL_GPL(iommu_domain_get_attr);
+EXPORT_SYMBOL_GPL(iommu_dma_use_flush_queue);
 
 int iommu_domain_set_attr(struct iommu_domain *domain,
 			  enum iommu_attr attr, void *data)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index c15a8658daad64..f30de33c6ff56e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -108,7 +108,6 @@ enum iommu_cap {
 
 enum iommu_attr {
 	DOMAIN_ATTR_NESTING,	/* two stages of translation */
-	DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
 	DOMAIN_ATTR_IO_PGTABLE_CFG,
 	DOMAIN_ATTR_MAX,
 };
@@ -194,7 +193,8 @@ struct iommu_iotlb_gather {
  * @probe_finalize: Do final setup work after the device is added to an IOMMU
  *                  group and attached to the groups domain
  * @device_group: find iommu group for a particular device
- * @domain_get_attr: Query domain attributes
+ * @dma_use_flush_queue: Returns %true if a DMA flush queue is used
+ * @dma_enable_flush_queue: Try to enable the DMA flush queue
  * @domain_set_attr: Change domain attributes
  * @get_resv_regions: Request list of reserved regions for a device
  * @put_resv_regions: Free list of reserved regions for a device
@@ -244,8 +244,8 @@ struct iommu_ops {
 	void (*release_device)(struct device *dev);
 	void (*probe_finalize)(struct device *dev);
 	struct iommu_group *(*device_group)(struct device *dev);
-	int (*domain_get_attr)(struct iommu_domain *domain,
-			       enum iommu_attr attr, void *data);
+	bool (*dma_use_flush_queue)(struct iommu_domain *domain);
+	void (*dma_enable_flush_queue)(struct iommu_domain *domain);
 	int (*domain_set_attr)(struct iommu_domain *domain,
 			       enum iommu_attr attr, void *data);
 
@@ -491,8 +491,7 @@ extern int iommu_page_response(struct device *dev,
 extern int iommu_group_id(struct iommu_group *group);
 extern struct iommu_domain *iommu_group_default_domain(struct iommu_group *);
 
-extern int iommu_domain_get_attr(struct iommu_domain *domain, enum iommu_attr,
-				 void *data);
+bool iommu_dma_use_flush_queue(struct iommu_domain *domain);
 extern int iommu_domain_set_attr(struct iommu_domain *domain, enum iommu_attr,
 				 void *data);
 
@@ -861,12 +860,6 @@ static inline int iommu_group_id(struct iommu_group *group)
 	return -ENODEV;
 }
 
-static inline int iommu_domain_get_attr(struct iommu_domain *domain,
-					enum iommu_attr attr, void *data)
-{
-	return -EINVAL;
-}
-
 static inline int iommu_domain_set_attr(struct iommu_domain *domain,
 					enum iommu_attr attr, void *data)
 {
-- 
2.29.2