[PATCH kernel 2/2] powerpc/powernv/pseries: Rework device adding to IOMMU groups
David Gibson
david at gibson.dropbear.id.au
Thu Nov 8 16:18:19 AEDT 2018
On Thu, Oct 18, 2018 at 06:52:43PM +1100, Alexey Kardashevskiy wrote:
> The powernv platform registers IOMMU groups and adds devices to them
> from the pci_controller_ops::setup_bridge() hook except one case when
> virtual functions (SRIOV VFs) are added from a bus notifier.
>
> The pseries platform registers IOMMU groups from
> the pci_controller_ops::dma_bus_setup() hook and adds devices from
> the pci_controller_ops::dma_dev_setup() hook. The very same bus notifier
> used for powernv does not add devices for pseries though as
> __of_scan_bus() adds devices first, then it does the bus/dev DMA setup.
>
> Both platforms use iommu_add_device() which takes a device and expects
> it to have a valid IOMMU table struct with an iommu_table_group pointer
> which in turn points the iommu_group struct (which represents
> an IOMMU group). Although the helper seems easy to use, it relies on
> some pre-existing device configuration and associated data structures
> which it does not really need.
>
> This simplifies iommu_add_device() to take the table_group pointer
> directly. Pseries already has a table_group pointer handy and the bus
> notified is not used anyway. For powernv, this copies the existing bus
> notifier, makes it work for powernv only which means an easy way of
> getting to the table_group pointer. This was tested on VFs but should
> also support physical PCI hotplug.
>
> Since iommu_add_device() receives the table_group pointer directly,
> pseries does not do TCE cache invalidation (the hypervisor does) nor
> allow multiple groups per a VFIO container (in other words sharing
> an IOMMU table between partitionable endpoints), this removes
> iommu_table_group_link from pseries.
>
> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
Reviewed-by: David Gibson <david at gibson.dropbear.id.au>
> ---
> arch/powerpc/include/asm/iommu.h | 12 +++----
> arch/powerpc/kernel/iommu.c | 58 ++-----------------------------
> arch/powerpc/platforms/powernv/pci-ioda.c | 10 +-----
> arch/powerpc/platforms/powernv/pci.c | 43 ++++++++++++++++++++++-
> arch/powerpc/platforms/pseries/iommu.c | 46 ++++++++++++------------
> 5 files changed, 74 insertions(+), 95 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
> index 726f07b..39bee10 100644
> --- a/arch/powerpc/include/asm/iommu.h
> +++ b/arch/powerpc/include/asm/iommu.h
> @@ -220,9 +220,9 @@ struct iommu_table_group {
>
> extern void iommu_register_group(struct iommu_table_group *table_group,
> int pci_domain_number, unsigned long pe_num);
> -extern int iommu_add_device(struct device *dev);
> +extern int iommu_add_device(struct iommu_table_group *table_group,
> + struct device *dev);
> extern void iommu_del_device(struct device *dev);
> -extern int __init tce_iommu_bus_notifier_init(void);
> extern long iommu_tce_xchg(struct mm_struct *mm, struct iommu_table *tbl,
> unsigned long entry, unsigned long *hpa,
> enum dma_data_direction *direction);
> @@ -233,7 +233,8 @@ static inline void iommu_register_group(struct iommu_table_group *table_group,
> {
> }
>
> -static inline int iommu_add_device(struct device *dev)
> +static inline int iommu_add_device(struct iommu_table_group *table_group,
> + struct device *dev)
> {
> return 0;
> }
> @@ -241,11 +242,6 @@ static inline int iommu_add_device(struct device *dev)
> static inline void iommu_del_device(struct device *dev)
> {
> }
> -
> -static inline int __init tce_iommu_bus_notifier_init(void)
> -{
> - return 0;
> -}
> #endif /* !CONFIG_IOMMU_API */
>
> int dma_iommu_mapping_error(struct device *dev, dma_addr_t dma_addr);
> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> index 47d75c5..fb14fbf 100644
> --- a/arch/powerpc/kernel/iommu.c
> +++ b/arch/powerpc/kernel/iommu.c
> @@ -1094,11 +1094,8 @@ void iommu_release_ownership(struct iommu_table *tbl)
> }
> EXPORT_SYMBOL_GPL(iommu_release_ownership);
>
> -int iommu_add_device(struct device *dev)
> +int iommu_add_device(struct iommu_table_group *table_group, struct device *dev)
> {
> - struct iommu_table *tbl;
> - struct iommu_table_group_link *tgl;
> -
> /*
> * The sysfs entries should be populated before
> * binding IOMMU group. If sysfs entries isn't
> @@ -1114,32 +1111,10 @@ int iommu_add_device(struct device *dev)
> return -EBUSY;
> }
>
> - tbl = get_iommu_table_base(dev);
> - if (!tbl) {
> - pr_debug("%s: Skipping device %s with no tbl\n",
> - __func__, dev_name(dev));
> - return 0;
> - }
> -
> - tgl = list_first_entry_or_null(&tbl->it_group_list,
> - struct iommu_table_group_link, next);
> - if (!tgl) {
> - pr_debug("%s: Skipping device %s with no group\n",
> - __func__, dev_name(dev));
> - return 0;
> - }
> pr_debug("%s: Adding %s to iommu group %d\n",
> - __func__, dev_name(dev),
> - iommu_group_id(tgl->table_group->group));
> + __func__, dev_name(dev), iommu_group_id(table_group->group));
>
> - if (PAGE_SIZE < IOMMU_PAGE_SIZE(tbl)) {
> - pr_err("%s: Invalid IOMMU page size %lx (%lx) on %s\n",
> - __func__, IOMMU_PAGE_SIZE(tbl),
> - PAGE_SIZE, dev_name(dev));
> - return -EINVAL;
> - }
> -
> - return iommu_group_add_device(tgl->table_group->group, dev);
> + return iommu_group_add_device(table_group->group, dev);
> }
> EXPORT_SYMBOL_GPL(iommu_add_device);
>
> @@ -1159,31 +1134,4 @@ void iommu_del_device(struct device *dev)
> iommu_group_remove_device(dev);
> }
> EXPORT_SYMBOL_GPL(iommu_del_device);
> -
> -static int tce_iommu_bus_notifier(struct notifier_block *nb,
> - unsigned long action, void *data)
> -{
> - struct device *dev = data;
> -
> - switch (action) {
> - case BUS_NOTIFY_ADD_DEVICE:
> - return iommu_add_device(dev);
> - case BUS_NOTIFY_DEL_DEVICE:
> - if (dev->iommu_group)
> - iommu_del_device(dev);
> - return 0;
> - default:
> - return 0;
> - }
> -}
> -
> -static struct notifier_block tce_iommu_bus_nb = {
> - .notifier_call = tce_iommu_bus_notifier,
> -};
> -
> -int __init tce_iommu_bus_notifier_init(void)
> -{
> - bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb);
> - return 0;
> -}
> #endif /* CONFIG_IOMMU_API */
> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> index 4dc4a5fed..0228164 100644
> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> @@ -1940,7 +1940,7 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
> set_dma_offset(&dev->dev, pe->tce_bypass_base);
> #ifdef CONFIG_IOMMU_API
> if (add_to_group)
> - iommu_add_device(&dev->dev);
> + iommu_add_device(&pe->table_group, &dev->dev);
> #endif
>
> if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)
> @@ -2369,14 +2369,6 @@ static long pnv_pci_ioda2_setup_default_config(struct pnv_ioda_pe *pe)
> if (!pnv_iommu_bypass_disabled)
> pnv_pci_ioda2_set_bypass(pe, true);
>
> - /*
> - * Setting table base here only for carrying iommu_group
> - * further down to let iommu_add_device() do the job.
> - * pnv_pci_ioda_dma_dev_setup will override it later anyway.
> - */
> - if (pe->flags & PNV_IODA_PE_DEV)
> - set_iommu_table_base(&pe->pdev->dev, tbl);
> -
> return 0;
> }
>
> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
> index 13aef23..98e02c1 100644
> --- a/arch/powerpc/platforms/powernv/pci.c
> +++ b/arch/powerpc/platforms/powernv/pci.c
> @@ -1127,4 +1127,45 @@ void __init pnv_pci_init(void)
> set_pci_dma_ops(&dma_iommu_ops);
> }
>
> -machine_subsys_initcall_sync(powernv, tce_iommu_bus_notifier_init);
> +static int pnv_tce_iommu_bus_notifier(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
> + struct device *dev = data;
> + struct pci_dev *pdev;
> + struct pci_dn *pdn;
> + struct pnv_ioda_pe *pe;
> + struct pci_controller *hose;
> + struct pnv_phb *phb;
> +
> + switch (action) {
> + case BUS_NOTIFY_ADD_DEVICE:
> + pdev = to_pci_dev(dev);
> + pdn = pci_get_pdn(pdev);
> + hose = pci_bus_to_host(pdev->bus);
> + phb = hose->private_data;
> +
> + WARN_ON_ONCE(!phb);
> + if (!pdn || pdn->pe_number == IODA_INVALID_PE || !phb)
> + return 0;
> +
> + pe = &phb->ioda.pe_array[pdn->pe_number];
> + iommu_add_device(&pe->table_group, dev);
> + return 0;
> + case BUS_NOTIFY_DEL_DEVICE:
> + iommu_del_device(dev);
> + return 0;
> + default:
> + return 0;
> + }
> +}
> +
> +static struct notifier_block pnv_tce_iommu_bus_nb = {
> + .notifier_call = pnv_tce_iommu_bus_notifier,
> +};
> +
> +static int __init pnv_tce_iommu_bus_notifier_init(void)
> +{
> + bus_register_notifier(&pci_bus_type, &pnv_tce_iommu_bus_nb);
> + return 0;
> +}
> +machine_subsys_initcall_sync(powernv, pnv_tce_iommu_bus_notifier_init);
> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
> index eae2578..38b6dd0 100644
> --- a/arch/powerpc/platforms/pseries/iommu.c
> +++ b/arch/powerpc/platforms/pseries/iommu.c
> @@ -60,7 +60,6 @@ static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> {
> struct iommu_table_group *table_group;
> struct iommu_table *tbl;
> - struct iommu_table_group_link *tgl;
>
> table_group = kzalloc_node(sizeof(struct iommu_table_group), GFP_KERNEL,
> node);
> @@ -71,22 +70,13 @@ static struct iommu_table_group *iommu_pseries_alloc_group(int node)
> if (!tbl)
> goto free_group;
>
> - tgl = kzalloc_node(sizeof(struct iommu_table_group_link), GFP_KERNEL,
> - node);
> - if (!tgl)
> - goto free_table;
> -
> INIT_LIST_HEAD_RCU(&tbl->it_group_list);
> kref_init(&tbl->it_kref);
> - tgl->table_group = table_group;
> - list_add_rcu(&tgl->next, &tbl->it_group_list);
>
> table_group->tables[0] = tbl;
>
> return table_group;
>
> -free_table:
> - kfree(tbl);
> free_group:
> kfree(table_group);
> return NULL;
> @@ -96,23 +86,12 @@ static void iommu_pseries_free_group(struct iommu_table_group *table_group,
> const char *node_name)
> {
> struct iommu_table *tbl;
> -#ifdef CONFIG_IOMMU_API
> - struct iommu_table_group_link *tgl;
> -#endif
>
> if (!table_group)
> return;
>
> tbl = table_group->tables[0];
> #ifdef CONFIG_IOMMU_API
> - tgl = list_first_entry_or_null(&tbl->it_group_list,
> - struct iommu_table_group_link, next);
> -
> - WARN_ON_ONCE(!tgl);
> - if (tgl) {
> - list_del_rcu(&tgl->next);
> - kfree(tgl);
> - }
> if (table_group->group) {
> iommu_group_put(table_group->group);
> BUG_ON(table_group->group);
> @@ -1240,7 +1219,7 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
> }
>
> set_iommu_table_base(&dev->dev, pci->table_group->tables[0]);
> - iommu_add_device(&dev->dev);
> + iommu_add_device(pci->table_group, &dev->dev);
> }
>
> static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
> @@ -1455,4 +1434,27 @@ static int __init disable_multitce(char *str)
>
> __setup("multitce=", disable_multitce);
>
> +static int tce_iommu_bus_notifier(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
> + struct device *dev = data;
> +
> + switch (action) {
> + case BUS_NOTIFY_DEL_DEVICE:
> + iommu_del_device(dev);
> + return 0;
> + default:
> + return 0;
> + }
> +}
> +
> +static struct notifier_block tce_iommu_bus_nb = {
> + .notifier_call = tce_iommu_bus_notifier,
> +};
> +
> +static int __init tce_iommu_bus_notifier_init(void)
> +{
> + bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb);
> + return 0;
> +}
> machine_subsys_initcall_sync(pseries, tce_iommu_bus_notifier_init);
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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