On 05/14/2015 11:21 AM, Gavin Shan wrote:

On Tue, May 12, 2015 at 01:39:05AM +1000, Alexey Kardashevskiy wrote:

quoted

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 <redacted>

Reviewed-by: Gavin Shan <redacted>

quoted

---
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 :)

quoted

	/* 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);

quoted

}

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.

quoted

+{
+	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.

quoted

{
-	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.

quoted

+
+	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