[PATCH 3/4] s390: iommu: Adding get attributes for s390_iommu

[Pierre Morel <pmorel@xxxxxxxxxxxxx>]

We add "get attributes" to the S390 iommu operations to retrieve the S390
specific attributes through the call of zPCI dedicated CLP functions.

Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
---
 drivers/iommu/s390-iommu.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/iommu.h      |  4 +++
 2 files changed, 81 insertions(+)

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 22d4db3..98082f0 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -363,6 +363,82 @@ void zpci_destroy_iommu(struct zpci_dev *zdev)
 	iommu_device_sysfs_remove(&zdev->iommu_dev);
 }
 
+struct zpci_dev *get_zpci(struct s390_domain *s390_domain)
+{
+	struct s390_domain_device *domain_device;
+
+	domain_device = list_first_entry(&s390_domain->devices,
+					 struct s390_domain_device, list);
+	if (!domain_device)
+		return NULL;
+	return domain_device->zdev;
+}
+
+static int s390_domain_get_fn(struct iommu_domain *domain, void *data)
+{
+	struct zpci_dev *zdev;
+	struct clp_req_rsp_query_pci *rrb;
+	int rc;
+
+	zdev = get_zpci(to_s390_domain(domain));
+	if (!zdev)
+		return -ENODEV;
+	rrb = (struct clp_req_rsp_query_pci *)
+	      __get_free_pages(GFP_KERNEL, get_order(CLP_BLK_SIZE));
+	if (!rrb)
+		return -ENOMEM;
+	rc = zdev_query_pci_fn(zdev, rrb);
+
+	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK)
+		memcpy(data, &rrb->response, sizeof(struct clp_rsp_query_pci));
+	else
+		rc = -EIO;
+	free_pages((unsigned long) rrb, get_order(CLP_BLK_SIZE));
+	return rc;
+}
+
+static int s390_domain_get_grp(struct iommu_domain *domain, void *data)
+{
+	struct zpci_dev *zdev;
+	struct clp_req_rsp_query_pci_grp *rrb;
+	int rc;
+
+	zdev = get_zpci(to_s390_domain(domain));
+	if (!zdev)
+		return -ENODEV;
+	rrb = (struct clp_req_rsp_query_pci_grp *)
+	      __get_free_pages(GFP_KERNEL, get_order(CLP_BLK_SIZE));
+	if (!rrb)
+		return -ENOMEM;
+
+	rc = zdev_query_pci_fngrp(zdev, rrb);
+	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK)
+		memcpy(data, &rrb->response,
+		       sizeof(struct clp_rsp_query_pci_grp));
+	else
+		rc = -EIO;
+
+	free_pages((unsigned long) rrb, get_order(CLP_BLK_SIZE));
+	return rc;
+}
+
+static int s390_domain_get_attr(struct iommu_domain *domain,
+				enum iommu_attr attr, void *data)
+{
+	switch (attr) {
+	case DOMAIN_ATTR_ZPCI_FN_SIZE:
+		return sizeof(struct clp_rsp_query_pci);
+	case DOMAIN_ATTR_ZPCI_GRP_SIZE:
+		return sizeof(struct clp_rsp_query_pci_grp);
+	case DOMAIN_ATTR_ZPCI_FN:
+		return s390_domain_get_fn(domain, data);
+	case DOMAIN_ATTR_ZPCI_GRP:
+		return s390_domain_get_grp(domain, data);
+	default:
+		return -ENODEV;
+	}
+}
+
 static const struct iommu_ops s390_iommu_ops = {
 	.capable = s390_iommu_capable,
 	.domain_alloc = s390_domain_alloc,
@@ -376,6 +452,7 @@ static const struct iommu_ops s390_iommu_ops = {
 	.remove_device = s390_iommu_remove_device,
 	.device_group = generic_device_group,
 	.pgsize_bitmap = S390_IOMMU_PGSIZES,
+	.domain_get_attr = s390_domain_get_attr,
 };
 
 static int __init s390_iommu_init(void)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index ffbbc7e..ebdcac4 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -125,6 +125,10 @@ enum iommu_attr {
 	DOMAIN_ATTR_FSL_PAMUV1,
 	DOMAIN_ATTR_NESTING,	/* two stages of translation */
 	DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
+	DOMAIN_ATTR_ZPCI_FN_SIZE,
+	DOMAIN_ATTR_ZPCI_GRP_SIZE,
+	DOMAIN_ATTR_ZPCI_FN,
+	DOMAIN_ATTR_ZPCI_GRP,
 	DOMAIN_ATTR_MAX,
 };
 
-- 
2.7.4