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SubjectRe: [PATCH kernel v10 16/34] powerpc/spapr: vfio: Replace iommu_table with iommu_table_group
On 05/14/2015 11:21 AM, Gavin Shan wrote:
> On Tue, May 12, 2015 at 01:39:05AM +1000, Alexey Kardashevskiy wrote:
>> Modern IBM POWERPC systems support multiple (currently two) TCE tables
>> per IOMMU group (a.k.a. PE). This adds a iommu_table_group container
>> for TCE tables. Right now just one table is supported.
>>
>> This defines iommu_table_group struct which stores pointers to
>> iommu_group and iommu_table(s). This replaces iommu_table with
>> iommu_table_group where iommu_table was used to identify a group:
>> - iommu_register_group();
>> - iommudata of generic iommu_group;
>>
>> This removes @data from iommu_table as it_table_group provides
>> same access to pnv_ioda_pe.
>>
>> For IODA, instead of embedding iommu_table, the new iommu_table_group
>> keeps pointers to those. The iommu_table structs are allocated
>> dynamically.
>>
>> For P5IOC2, both iommu_table_group and iommu_table are embedded into
>> PE struct. As there is no EEH and SRIOV support for P5IOC2,
>> iommu_free_table() should not be called on iommu_table struct pointers
>> so we can keep it embedded in pnv_phb::p5ioc2.
>>
>> For pSeries, this replaces multiple calls of kzalloc_node() with a new
>> iommu_pseries_alloc_group() helper and stores the table group struct
>> pointer into the pci_dn struct. For release, a iommu_table_free_group()
>> helper is added.
>>
>> This moves iommu_table struct allocation from SR-IOV code to
>> the generic DMA initialization code in pnv_pci_ioda_setup_dma_pe and
>> pnv_pci_ioda2_setup_dma_pe as this is where DMA is actually initialized.
>> This change is here because those lines had to be changed anyway.
>>
>> This should cause no behavioural change.
>>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>
> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
>
>> ---
>> Changes:
>> v10:
>> * new to the series, separated from
>> "powerpc/spapr: vfio: Switch from iommu_table to new iommu_table_group"
>> * iommu_table is not embedded into iommu_table_group but allocated
>> dynamically in most cases
>> * iommu_table allocation is moved to a single place for IODA2's
>> pnv_pci_ioda_setup_dma_pe where it belongs to
>> * added list of groups into iommu_table; most of the code just looks at
>> the first item to keep the patch simpler
>> ---
>> arch/powerpc/include/asm/iommu.h | 17 +++--
>> arch/powerpc/include/asm/pci-bridge.h | 2 +-
>> arch/powerpc/kernel/iommu.c | 17 ++---
>> arch/powerpc/platforms/powernv/pci-ioda.c | 55 +++++++-------
>> arch/powerpc/platforms/powernv/pci-p5ioc2.c | 18 +++--
>> arch/powerpc/platforms/powernv/pci.h | 3 +-
>> arch/powerpc/platforms/pseries/iommu.c | 107 +++++++++++++++++++---------
>> drivers/vfio/vfio_iommu_spapr_tce.c | 23 +++---
>> 8 files changed, 152 insertions(+), 90 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
>> index e2a45c3..61bde1a 100644
>> --- a/arch/powerpc/include/asm/iommu.h
>> +++ b/arch/powerpc/include/asm/iommu.h
>> @@ -92,13 +92,10 @@ struct iommu_table {
>> unsigned long *it_map; /* A simple allocation bitmap for now */
>> unsigned long it_page_shift;/* table iommu page size */
>> #ifdef CONFIG_IOMMU_API
>> - struct iommu_group *it_group;
>> + struct iommu_table_group *it_table_group;
>> #endif
>> struct iommu_table_ops *it_ops;
>> void (*set_bypass)(struct iommu_table *tbl, bool enable);
>> -#ifdef CONFIG_PPC_POWERNV
>> - void *data;
>> -#endif
>> };
>>
>> /* Pure 2^n version of get_order */
>> @@ -130,13 +127,21 @@ extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);
>> extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
>> int nid);
>> #ifdef CONFIG_IOMMU_API
>> -extern void iommu_register_group(struct iommu_table *tbl,
>> +
>> +#define IOMMU_TABLE_GROUP_MAX_TABLES 1
>> +
>> +struct iommu_table_group {
>> + struct iommu_group *group;
>> + struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
>> +};
>> +
>> +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 void iommu_del_device(struct device *dev);
>> extern int __init tce_iommu_bus_notifier_init(void);
>> #else
>> -static inline void iommu_register_group(struct iommu_table *tbl,
>> +static inline void iommu_register_group(struct iommu_table_group *table_group,
>> int pci_domain_number,
>> unsigned long pe_num)
>> {
>> diff --git a/arch/powerpc/include/asm/pci-bridge.h b/arch/powerpc/include/asm/pci-bridge.h
>> index 1811c44..e2d7479 100644
>> --- a/arch/powerpc/include/asm/pci-bridge.h
>> +++ b/arch/powerpc/include/asm/pci-bridge.h
>> @@ -185,7 +185,7 @@ struct pci_dn {
>>
>> struct pci_dn *parent;
>> struct pci_controller *phb; /* for pci devices */
>> - struct iommu_table *iommu_table; /* for phb's or bridges */
>> + struct iommu_table_group *table_group; /* for phb's or bridges */
>> struct device_node *node; /* back-pointer to the device_node */
>>
>> int pci_ext_config_space; /* for pci devices */
>> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
>> index 16be6aa..79e8b43 100644
>> --- a/arch/powerpc/kernel/iommu.c
>> +++ b/arch/powerpc/kernel/iommu.c
>> @@ -886,11 +886,12 @@ EXPORT_SYMBOL_GPL(iommu_direction_to_tce_perm);
>> */
>> static void group_release(void *iommu_data)
>> {
>> - struct iommu_table *tbl = iommu_data;
>> - tbl->it_group = NULL;
>> + struct iommu_table_group *table_group = iommu_data;
>> +
>> + table_group->group = NULL;
>> }
>>
>> -void iommu_register_group(struct iommu_table *tbl,
>> +void iommu_register_group(struct iommu_table_group *table_group,
>> int pci_domain_number, unsigned long pe_num)
>> {
>> struct iommu_group *grp;
>> @@ -902,8 +903,8 @@ void iommu_register_group(struct iommu_table *tbl,
>> PTR_ERR(grp));
>> return;
>> }
>> - tbl->it_group = grp;
>> - iommu_group_set_iommudata(grp, tbl, group_release);
>> + table_group->group = grp;
>> + iommu_group_set_iommudata(grp, table_group, group_release);
>> name = kasprintf(GFP_KERNEL, "domain%d-pe%lx",
>> pci_domain_number, pe_num);
>> if (!name)
>> @@ -1091,7 +1092,7 @@ int iommu_add_device(struct device *dev)
>> }
>>
>> tbl = get_iommu_table_base(dev);
>> - if (!tbl || !tbl->it_group) {
>> + if (!tbl || !tbl->it_table_group || !tbl->it_table_group->group) {
>> pr_debug("%s: Skipping device %s with no tbl\n",
>> __func__, dev_name(dev));
>> return 0;
>> @@ -1099,7 +1100,7 @@ int iommu_add_device(struct device *dev)
>>
>> pr_debug("%s: Adding %s to iommu group %d\n",
>> __func__, dev_name(dev),
>> - iommu_group_id(tbl->it_group));
>> + iommu_group_id(tbl->it_table_group->group));
>>
>> if (PAGE_SIZE < IOMMU_PAGE_SIZE(tbl)) {
>> pr_err("%s: Invalid IOMMU page size %lx (%lx) on %s\n",
>> @@ -1108,7 +1109,7 @@ int iommu_add_device(struct device *dev)
>> return -EINVAL;
>> }
>>
>> - return iommu_group_add_device(tbl->it_group, dev);
>> + return iommu_group_add_device(tbl->it_table_group->group, dev);
>> }
>> EXPORT_SYMBOL_GPL(iommu_add_device);
>>
>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>> index 1b43e25..02ed448 100644
>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>> @@ -1087,10 +1087,6 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, int all)
>> return;
>> }
>>
>> - pe->tce32_table = kzalloc_node(sizeof(struct iommu_table),
>> - GFP_KERNEL, hose->node);
>> - pe->tce32_table->data = pe;
>> -
>> /* Associate it with all child devices */
>> pnv_ioda_setup_same_PE(bus, pe);
>>
>> @@ -1292,11 +1288,12 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
>> struct iommu_table *tbl;
>> unsigned long addr;
>> int64_t rc;
>> + struct iommu_table_group *table_group;
>>
>> bus = dev->bus;
>> hose = pci_bus_to_host(bus);
>> phb = hose->private_data;
>> - tbl = pe->tce32_table;
>> + tbl = pe->table_group.tables[0];
>> addr = tbl->it_base;
>>
>> opal_pci_map_pe_dma_window(phb->opal_id, pe->pe_number,
>> @@ -1311,13 +1308,14 @@ static void pnv_pci_ioda2_release_dma_pe(struct pci_dev *dev, struct pnv_ioda_pe
>> if (rc)
>> pe_warn(pe, "OPAL error %ld release DMA window\n", rc);
>>
>> - if (tbl->it_group) {
>> - iommu_group_put(tbl->it_group);
>> - BUG_ON(tbl->it_group);
>> + table_group = tbl->it_table_group;
>> + if (table_group->group) {
>> + iommu_group_put(table_group->group);
>> + BUG_ON(table_group->group);
>> }
>> iommu_free_table(tbl, of_node_full_name(dev->dev.of_node));
>> free_pages(addr, get_order(TCE32_TABLE_SIZE));
>> - pe->tce32_table = NULL;
>> + pe->table_group.tables[0] = NULL;
>> }
>>
>> static void pnv_ioda_release_vf_PE(struct pci_dev *pdev, u16 num_vfs)
>> @@ -1465,10 +1463,6 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
>> continue;
>> }
>>
>> - pe->tce32_table = kzalloc_node(sizeof(struct iommu_table),
>> - GFP_KERNEL, hose->node);
>> - pe->tce32_table->data = pe;
>> -
>> /* Put PE to the list */
>> mutex_lock(&phb->ioda.pe_list_mutex);
>> list_add_tail(&pe->list, &phb->ioda.pe_list);
>> @@ -1603,7 +1597,7 @@ static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev
>>
>> pe = &phb->ioda.pe_array[pdn->pe_number];
>> WARN_ON(get_dma_ops(&pdev->dev) != &dma_iommu_ops);
>> - set_iommu_table_base(&pdev->dev, pe->tce32_table);
>> + set_iommu_table_base(&pdev->dev, pe->table_group.tables[0]);
>> /*
>> * Note: iommu_add_device() will fail here as
>> * for physical PE: the device is already added by now;
>> @@ -1636,7 +1630,7 @@ static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,
>> } else {
>> dev_info(&pdev->dev, "Using 32-bit DMA via iommu\n");
>> set_dma_ops(&pdev->dev, &dma_iommu_ops);
>> - set_iommu_table_base(&pdev->dev, pe->tce32_table);
>> + set_iommu_table_base(&pdev->dev, pe->table_group.tables[0]);
>> }
>> *pdev->dev.dma_mask = dma_mask;
>> return 0;
>> @@ -1670,7 +1664,7 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
>> struct pci_dev *dev;
>>
>> list_for_each_entry(dev, &bus->devices, bus_list) {
>> - set_iommu_table_base(&dev->dev, pe->tce32_table);
>> + set_iommu_table_base(&dev->dev, pe->table_group.tables[0]);
>> iommu_add_device(&dev->dev);
>>
>> if (dev->subordinate)
>> @@ -1681,7 +1675,8 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe,
>> static void pnv_pci_ioda1_tce_invalidate(struct iommu_table *tbl,
>> unsigned long index, unsigned long npages, bool rm)
>> {
>> - struct pnv_ioda_pe *pe = tbl->data;
>> + struct pnv_ioda_pe *pe = container_of(tbl->it_table_group,
>> + struct pnv_ioda_pe, table_group);
>> __be64 __iomem *invalidate = rm ?
>> (__be64 __iomem *)pe->tce_inval_reg_phys :
>> (__be64 __iomem *)tbl->it_index;
>> @@ -1758,7 +1753,8 @@ static struct iommu_table_ops pnv_ioda1_iommu_ops = {
>> static void pnv_pci_ioda2_tce_invalidate(struct iommu_table *tbl,
>> unsigned long index, unsigned long npages, bool rm)
>> {
>> - struct pnv_ioda_pe *pe = tbl->data;
>> + struct pnv_ioda_pe *pe = container_of(tbl->it_table_group,
>> + struct pnv_ioda_pe, table_group);
>> unsigned long start, end, inc;
>> __be64 __iomem *invalidate = rm ?
>> (__be64 __iomem *)pe->tce_inval_reg_phys :
>> @@ -1834,8 +1830,12 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
>> if (WARN_ON(pe->tce32_seg >= 0))
>> return;
>>
>> - tbl = pe->tce32_table;
>> - iommu_register_group(tbl, phb->hose->global_number, pe->pe_number);
>> + tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
>> + phb->hose->node);
>> + tbl->it_table_group = &pe->table_group;
>> + pe->table_group.tables[0] = tbl;
>> + iommu_register_group(&pe->table_group, phb->hose->global_number,
>> + pe->pe_number);
>>
>> /* Grab a 32-bit TCE table */
>> pe->tce32_seg = base;
>> @@ -1914,7 +1914,8 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
>>
>> static void pnv_pci_ioda2_set_bypass(struct iommu_table *tbl, bool enable)
>> {
>> - struct pnv_ioda_pe *pe = tbl->data;
>> + struct pnv_ioda_pe *pe = container_of(tbl->it_table_group,
>> + struct pnv_ioda_pe, table_group);
>> uint16_t window_id = (pe->pe_number << 1 ) + 1;
>> int64_t rc;
>>
>> @@ -1948,10 +1949,10 @@ static void pnv_pci_ioda2_setup_bypass_pe(struct pnv_phb *phb,
>> pe->tce_bypass_base = 1ull << 59;
>>
>> /* Install set_bypass callback for VFIO */
>> - pe->tce32_table->set_bypass = pnv_pci_ioda2_set_bypass;
>> + pe->table_group.tables[0]->set_bypass = pnv_pci_ioda2_set_bypass;
>
> It could be simplied as:
>
> tbl->set_bypass = pnv_pci_ioda2_set_bypass;

No, this is worse in this case. The whole idea of the patch to be
mechanical as much as we can. That means:
s/tce32_table/table_group.tables[0]/
If I do what you suggest, the reviewers will have to look further if "tbl"
has been initialized properly, etc.

And later in this patchset I am getting rid of
pnv_pci_ioda2_setup_bypass_pe so there is no point to try making it look
nice :)

>>
>> /* Enable bypass by default */
>> - pnv_pci_ioda2_set_bypass(pe->tce32_table, true);
>> + pnv_pci_ioda2_set_bypass(pe->table_group.tables[0], true);
>
> Similar to above:
>
> tbl->set_bypass(tbl, true);
>
>> }
>>
>> static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>> @@ -1968,8 +1969,12 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
>> if (WARN_ON(pe->tce32_seg >= 0))
>> return;
>>
>> - tbl = pe->tce32_table;
>> - iommu_register_group(tbl, phb->hose->global_number, pe->pe_number);
>> + tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
>> + phb->hose->node);
>> + tbl->it_table_group = &pe->table_group;
>> + pe->table_group.tables[0] = tbl;
>> + iommu_register_group(&pe->table_group, phb->hose->global_number,
>> + pe->pe_number);
>>
>> /* The PE will reserve all possible 32-bits space */
>> pe->tce32_seg = 0;
>> diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
>> index 2722c1a..4ea9def 100644
>> --- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
>> +++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
>> @@ -92,14 +92,16 @@ static struct iommu_table_ops pnv_p5ioc2_iommu_ops = {
>> static void pnv_pci_p5ioc2_dma_dev_setup(struct pnv_phb *phb,
>> struct pci_dev *pdev)
>> {
>> - if (phb->p5ioc2.iommu_table.it_map == NULL) {
>> - phb->p5ioc2.iommu_table.it_ops = &pnv_p5ioc2_iommu_ops;
>> - iommu_init_table(&phb->p5ioc2.iommu_table, phb->hose->node);
>> - iommu_register_group(&phb->p5ioc2.iommu_table,
>> + struct iommu_table *tbl = phb->p5ioc2.table_group.tables[0];
>> +
>> + if (!tbl->it_map) {
>> + tbl->it_ops = &pnv_p5ioc2_iommu_ops;
>> + iommu_init_table(tbl, phb->hose->node);
>> + iommu_register_group(&phb->p5ioc2.table_group,
>> pci_domain_nr(phb->hose->bus), phb->opal_id);
>> }
>>
>> - set_iommu_table_base(&pdev->dev, &phb->p5ioc2.iommu_table);
>> + set_iommu_table_base(&pdev->dev, tbl);
>> iommu_add_device(&pdev->dev);
>> }
>>
>> @@ -180,6 +182,12 @@ static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
>> pnv_pci_setup_iommu_table(&phb->p5ioc2.iommu_table,
>> tce_mem, tce_size, 0,
>> IOMMU_PAGE_SHIFT_4K);
>> + /*
>> + * We do not allocate iommu_table as we do not support
>> + * hotplug or SRIOV on P5IOC2 and therefore iommu_free_table()
>> + * should not be called for phb->p5ioc2.table_group.tables[0] ever.
>> + */
>> + phb->p5ioc2.table_group.tables[0] = &phb->p5ioc2.iommu_table;
>> }
>>
>> void __init pnv_pci_init_p5ioc2_hub(struct device_node *np)
>> diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
>> index ec26afd..720cc99 100644
>> --- a/arch/powerpc/platforms/powernv/pci.h
>> +++ b/arch/powerpc/platforms/powernv/pci.h
>> @@ -57,7 +57,7 @@ struct pnv_ioda_pe {
>> /* "Base" iommu table, ie, 4K TCEs, 32-bit DMA */
>> int tce32_seg;
>> int tce32_segcount;
>> - struct iommu_table *tce32_table;
>> + struct iommu_table_group table_group;
>> phys_addr_t tce_inval_reg_phys;
>>
>> /* 64-bit TCE bypass region */
>> @@ -123,6 +123,7 @@ struct pnv_phb {
>> union {
>> struct {
>> struct iommu_table iommu_table;
>> + struct iommu_table_group table_group;
>> } p5ioc2;
>>
>> struct {
>> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
>> index 4f2ab90..ad5ac6d 100644
>> --- a/arch/powerpc/platforms/pseries/iommu.c
>> +++ b/arch/powerpc/platforms/pseries/iommu.c
>> @@ -52,14 +52,49 @@
>>
>> #include "pseries.h"
>>
>> -static void iommu_pseries_free_table(struct iommu_table *tbl,
>> +static struct iommu_table_group *iommu_pseries_alloc_group(int node)
>
> Since it's a static function, the name could be simplied to
> iommu_group_alloc(), or alloc_iommu_group(). But it might
> not the style you like :-)

Giving it the name like this I am telling people not to try reusing it for
anything else + easier to grep.


>
>> +{
>> + struct iommu_table_group *table_group = NULL;
>> + struct iommu_table *tbl = NULL;
>> +
>> + table_group = kzalloc_node(sizeof(struct iommu_table_group), GFP_KERNEL,
>> + node);
>> + if (!table_group)
>> + goto fail_exit;
>> +
>> + tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL, node);
>> + if (!tbl)
>> + goto fail_exit;
>> +
>> + tbl->it_table_group = table_group;
>> + table_group->tables[0] = tbl;
>> +
>> + return table_group;
>> +
>> +fail_exit:
>> + kfree(table_group);
>> + kfree(tbl);
>> +
>> + return NULL;
>> +}
>> +
>> +static void iommu_pseries_free_group(struct iommu_table_group *table_group,
>> const char *node_name)
>
> Same suggestion as above.
>
>> {
>> - if (tbl->it_group) {
>> - iommu_group_put(tbl->it_group);
>> - BUG_ON(tbl->it_group);
>> + struct iommu_table *tbl;
>> +
>> + if (!table_group)
>> + return;
>> +
>> + if (table_group->group) {
>> + iommu_group_put(table_group->group);
>> + BUG_ON(table_group->group);
>> }
>> +
>> + tbl = table_group->tables[0];
>> iommu_free_table(tbl, node_name);
>
> It might worthy to have one check:
>
> if (table_group->tables[0])
> iommu_free_table(table_group->tables[0], node_name);


BUG_ON() - may be. (table_group->tables[0] == NULL) cannot happen normally
(no memory corruption, etc) as iommu_pseries_alloc_group() allocated both
table_group and table or nothing.


>
>> +
>> + kfree(table_group);
>> }
>>
>> static void tce_invalidate_pSeries_sw(struct iommu_table *tbl,
>> @@ -629,13 +664,13 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
>> pci->phb->dma_window_size = 0x8000000ul;
>> pci->phb->dma_window_base_cur = 0x8000000ul;
>>
>> - tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL,
>> - pci->phb->node);
>> + pci->table_group = iommu_pseries_alloc_group(pci->phb->node);
>> + tbl = pci->table_group->tables[0];
>
> The orginal code isn't checking "!pci->table_group". If this function is
> called only at bootup time, it would be nice to see kernel crash. Otherwise,
> I guess it's still worthy to have the check :-)


kzalloc_node() is supposed to print something when fails.



--
Alexey


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