On Fri, Apr 17, 2015 at 01:48:13AM +1000, Alexey Kardashevskiy wrote:

On 04/16/2015 03:55 PM, David Gibson wrote:

quoted

On Fri, Apr 10, 2015 at 04:30:54PM +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.

Signed-off-by: Alexey Kardashevskiy <redacted>
---
 arch/powerpc/include/asm/iommu.h            |  18 +++--
 arch/powerpc/kernel/iommu.c                 |  34 ++++----
 arch/powerpc/platforms/powernv/pci-ioda.c   |  38 +++++----
 arch/powerpc/platforms/powernv/pci-p5ioc2.c |  17 ++--
 arch/powerpc/platforms/powernv/pci.c        |   2 +-
 arch/powerpc/platforms/powernv/pci.h        |   4 +-
 arch/powerpc/platforms/pseries/iommu.c      |   9 ++-
 drivers/vfio/vfio_iommu_spapr_tce.c         | 120 ++++++++++++++++++++--------
 8 files changed, 160 insertions(+), 82 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index eb75726..667aa1a 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h

@@ -90,9 +90,7 @@ struct iommu_table {
 	struct iommu_pool pools[IOMMU_NR_POOLS];
 	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;
-#endif
+	struct iommu_table_group *it_group;
 	struct iommu_table_ops *it_ops;
 	void (*set_bypass)(struct iommu_table *tbl, bool enable);
 };

@@ -126,14 +124,24 @@ 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);
+
+#define IOMMU_TABLE_GROUP_MAX_TABLES	1
+
+struct iommu_table_group {
 #ifdef CONFIG_IOMMU_API
-extern void iommu_register_group(struct iommu_table *tbl,
+	struct iommu_group *group;
+#endif
+	struct iommu_table tables[IOMMU_TABLE_GROUP_MAX_TABLES];

There's nothing to indicate which of the tables are in use at the
current time.  I mean, it doesn't matter now because there's only one,
but the patch doesn't make a whole lot of sense without that.

quoted

+};
+
+#ifdef CONFIG_IOMMU_API
+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/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index b39d00a..fd49c8e 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c

@@ -712,17 +712,20 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)

 struct iommu_table *iommu_table_alloc(int node)
 {
-	struct iommu_table *tbl;
+	struct iommu_table_group *table_group;

-	tbl = kzalloc_node(sizeof(struct iommu_table), GFP_KERNEL, node);
+	table_group = kzalloc_node(sizeof(struct iommu_table_group), GFP_KERNEL,
+			   node);
+	table_group->tables[0].it_group = table_group;

-	return tbl;
+	return &table_group->tables[0];
 }

 void iommu_free_table(struct iommu_table *tbl, const char *node_name)

Surely the free function should take a table group rather than a table
as argument.

No, it should not. Tables lifetime is not the same even within the
same group.

If that's so, then this function shouldn't free the group...

-- 
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