[PATCH kernel v9 01/32] powerpc/iommu: Split iommu_free_table into 2 helpers

Alexey Kardashevskiy
2015-04-25T12:16:06Z

The iommu_free_table helper release memory it is using (the TCE table and
@it_map) and release the iommu_table struct as well. We might not want
the very last step as we store iommu_table in parent structures.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
arch/powerpc/include/asm/iommu.h | 1 +
arch/powerpc/kernel/iommu.c | 58 +++++++++++++++++++++++-----------------
2 files changed, 35 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index 1e27d63..e2cef38 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -105,6 +105,7 @@ static inline void *get_iommu_table_base(struct device *dev)
}

/* Frees table for an individual device node */
+extern void iommu_reset_table(struct iommu_table *tbl, const char *node_name);
extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);

/* Initializes an iommu_table based in values set in the passed-in
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index b054f33..5c154e1 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -708,23 +708,44 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid)
return tbl;
}

+void iommu_reset_table(struct iommu_table *tbl, const char *node_name)
+{
+ if (!tbl)
+ return;
+
+ if (tbl->it_map) {
+ unsigned long bitmap_sz;
+ unsigned int order;
+
+ /*
+ * In case we have reserved the first bit, we should not emit
+ * the warning below.
+ */
+ if (tbl->it_offset == 0)
+ clear_bit(0, tbl->it_map);
+
+ /* verify that table contains no entries */
+ if (!bitmap_empty(tbl->it_map, tbl->it_size))
+ pr_warn("%s: Unexpected TCEs for %s\n", __func__,
+ node_name);
+
+ /* calculate bitmap size in bytes */
+ bitmap_sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long);
+
+ /* free bitmap */
+ order = get_order(bitmap_sz);
+ free_pages((unsigned long) tbl->it_map, order);
+ }
+
+ memset(tbl, 0, sizeof(*tbl));
+}
+
void iommu_free_table(struct iommu_table *tbl, const char *node_name)
{
- unsigned long bitmap_sz;
- unsigned int order;
-
- if (!tbl || !tbl->it_map) {
- printk(KERN_ERR "%s: expected TCE map for %s\n", __func__,
- node_name);
+ if (!tbl)
return;
- }

- /*
- * In case we have reserved the first bit, we should not emit
- * the warning below.
- */
- if (tbl->it_offset == 0)
- clear_bit(0, tbl->it_map);
+ iommu_reset_table(tbl, node_name);

#ifdef CONFIG_IOMMU_API
if (tbl->it_group) {
@@ -733,17 +754,6 @@ void iommu_free_table(struct iommu_table *tbl, const char *node_name)
}
#endif

- /* verify that table contains no entries */
- if (!bitmap_empty(tbl->it_map, tbl->it_size))
- pr_warn("%s: Unexpected TCEs for %s\n", __func__, node_name);
-
- /* calculate bitmap size in bytes */
- bitmap_sz = BITS_TO_LONGS(tbl->it_size) * sizeof(unsigned long);
-
- /* free bitmap */
- order = get_order(bitmap_sz);
- free_pages((unsigned long) tbl->it_map, order);
-
/* free table */
kfree(tbl);
}
--
2.0.0