[PATCH v3] iommu/s390: Add support for iommu_device handling

From: Joerg Roedel
Date: Wed Aug 09 2017 - 06:26:05 EST


From: Joerg Roedel <jroedel@xxxxxxx>

Add support for the iommu_device_register interface to make
the s390 hardware iommus visible to the iommu core and in
sysfs.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/s390/include/asm/pci.h | 7 +++++++
arch/s390/pci/pci.c | 9 ++++++++-
drivers/iommu/s390-iommu.c | 35 +++++++++++++++++++++++++++++++++++
3 files changed, 50 insertions(+), 1 deletion(-)

v2->v3:
- Rebased to v4.13-rc4
- Fixed error path in zpci_create_device() to
destroy the iommu instance too (noted by
Gerald Schaefer)

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index f36b4b726057..386df9adef0a 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -8,6 +8,7 @@

#include <linux/pci.h>
#include <linux/mutex.h>
+#include <linux/iommu.h>
#include <asm-generic/pci.h>
#include <asm/pci_clp.h>
#include <asm/pci_debug.h>
@@ -122,6 +123,8 @@ struct zpci_dev {
unsigned long iommu_pages;
unsigned int next_bit;

+ struct iommu_device iommu_dev; /* IOMMU core handle */
+
char res_name[16];
struct zpci_bar_struct bars[PCI_BAR_COUNT];

@@ -174,6 +177,10 @@ int clp_enable_fh(struct zpci_dev *, u8);
int clp_disable_fh(struct zpci_dev *);
int clp_get_state(u32 fid, enum zpci_state *state);

+/* IOMMU Interface */
+int zpci_init_iommu(struct zpci_dev *zdev);
+void zpci_destroy_iommu(struct zpci_dev *zdev);
+
#ifdef CONFIG_PCI
/* Error handling and recovery */
void zpci_event_error(void *);
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 7b30af5da222..001ca80fa2fe 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -776,6 +776,7 @@ void pcibios_remove_bus(struct pci_bus *bus)

zpci_exit_slot(zdev);
zpci_cleanup_bus_resources(zdev);
+ zpci_destroy_iommu(zdev);
zpci_free_domain(zdev);

spin_lock(&zpci_list_lock);
@@ -848,11 +849,15 @@ int zpci_create_device(struct zpci_dev *zdev)
if (rc)
goto out;

+ rc = zpci_init_iommu(zdev);
+ if (rc)
+ goto out_free;
+
mutex_init(&zdev->lock);
if (zdev->state == ZPCI_FN_STATE_CONFIGURED) {
rc = zpci_enable_device(zdev);
if (rc)
- goto out_free;
+ goto out_destroy_iommu;
}
rc = zpci_scan_bus(zdev);
if (rc)
@@ -869,6 +874,8 @@ int zpci_create_device(struct zpci_dev *zdev)
out_disable:
if (zdev->state == ZPCI_FN_STATE_ONLINE)
zpci_disable_device(zdev);
+out_destroy_iommu:
+ zpci_destroy_iommu(zdev);
out_free:
zpci_free_domain(zdev);
out:
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 8788640756a7..85f3bc52efc2 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -18,6 +18,8 @@
*/
#define S390_IOMMU_PGSIZES (~0xFFFUL)

+static struct iommu_ops s390_iommu_ops;
+
struct s390_domain {
struct iommu_domain domain;
struct list_head devices;
@@ -166,11 +168,13 @@ static void s390_iommu_detach_device(struct iommu_domain *domain,
static int s390_iommu_add_device(struct device *dev)
{
struct iommu_group *group = iommu_group_get_for_dev(dev);
+ struct zpci_dev *zdev = to_pci_dev(dev)->sysdata;

if (IS_ERR(group))
return PTR_ERR(group);

iommu_group_put(group);
+ iommu_device_link(&zdev->iommu_dev, dev);

return 0;
}
@@ -197,6 +201,7 @@ static void s390_iommu_remove_device(struct device *dev)
s390_iommu_detach_device(domain, dev);
}

+ iommu_device_unlink(&zdev->iommu_dev, dev);
iommu_group_remove_device(dev);
}

@@ -327,6 +332,36 @@ static size_t s390_iommu_unmap(struct iommu_domain *domain,
return size;
}

+int zpci_init_iommu(struct zpci_dev *zdev)
+{
+ int rc = 0;
+
+ rc = iommu_device_sysfs_add(&zdev->iommu_dev, NULL, NULL,
+ "s390-iommu.%08x", zdev->fid);
+ if (rc)
+ goto out_err;
+
+ iommu_device_set_ops(&zdev->iommu_dev, &s390_iommu_ops);
+
+ rc = iommu_device_register(&zdev->iommu_dev);
+ if (rc)
+ goto out_sysfs;
+
+ return 0;
+
+out_sysfs:
+ iommu_device_sysfs_remove(&zdev->iommu_dev);
+
+out_err:
+ return rc;
+}
+
+void zpci_destroy_iommu(struct zpci_dev *zdev)
+{
+ iommu_device_unregister(&zdev->iommu_dev);
+ iommu_device_sysfs_remove(&zdev->iommu_dev);
+}
+
static struct iommu_ops s390_iommu_ops = {
.capable = s390_iommu_capable,
.domain_alloc = s390_domain_alloc,
--
2.12.3