On Thu, 15 Jun 2017 15:11:52 +0200 Joerg Roedel <[email protected]> wrote:
> From: Joerg Roedel <[email protected]> > > 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 <[email protected]> > --- > arch/s390/include/asm/pci.h | 7 +++++++ > arch/s390/pci/pci.c | 5 +++++ > drivers/iommu/s390-iommu.c | 35 +++++++++++++++++++++++++++++++++++ > 3 files changed, 47 insertions(+) > > diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h > index 4e31866..a3f697e 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> > @@ -123,6 +124,8 @@ 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]; > > @@ -173,6 +176,10 @@ int clp_add_pci_device(u32, u32, int); > int clp_enable_fh(struct zpci_dev *, u8); > int clp_disable_fh(struct zpci_dev *); > > +/* 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 8051df1..4c13da6 100644 > --- a/arch/s390/pci/pci.c > +++ b/arch/s390/pci/pci.c > @@ -749,6 +749,7 @@ 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); > @@ -820,6 +821,10 @@ int zpci_create_device(struct zpci_dev *zdev) > if (rc) > goto out; > > + rc = zpci_init_iommu(zdev); > + if (rc) > + goto out_free; > + After this point, there are two options for failure (zpci_enable_device + zpci_scan_bus), but missing error handling with an appropriate call to zpci_destroy_iommu(). I must admit that I do not understand what these sysfs attributes are used for, and by whom and when. Is it really necessary/correct to register them (including the s390_iommu_ops) _before_ the zpci_dev is registered to the bus (zpci_scan_bus -> pci_scan_root_bus/pci_bus_add_devices)? What is the expected life cycle for the attributes, and are they already needed when a device is still under DMA API access, or even before it is added to the PCI bus? > mutex_init(&zdev->lock); > if (zdev->state == ZPCI_FN_STATE_CONFIGURED) { > rc = zpci_enable_device(zdev); > diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c > index 8788640..85f3bc5 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,
