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Diffstat (limited to 'arch/powerpc/kernel/iommu.c')
-rw-r--r--arch/powerpc/kernel/iommu.c61
1 files changed, 31 insertions, 30 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 30b7736f0896..07093b7cdcb9 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -688,32 +688,24 @@ static void iommu_table_reserve_pages(struct iommu_table *tbl,
if (tbl->it_offset == 0)
set_bit(0, tbl->it_map);
- tbl->it_reserved_start = res_start;
- tbl->it_reserved_end = res_end;
-
- /* Check if res_start..res_end isn't empty and overlaps the table */
- if (res_start && res_end &&
- (tbl->it_offset + tbl->it_size < res_start ||
- res_end < tbl->it_offset))
- return;
+ if (res_start < tbl->it_offset)
+ res_start = tbl->it_offset;
- for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
- set_bit(i - tbl->it_offset, tbl->it_map);
-}
+ if (res_end > (tbl->it_offset + tbl->it_size))
+ res_end = tbl->it_offset + tbl->it_size;
-static void iommu_table_release_pages(struct iommu_table *tbl)
-{
- int i;
+ /* Check if res_start..res_end is a valid range in the table */
+ if (res_start >= res_end) {
+ tbl->it_reserved_start = tbl->it_offset;
+ tbl->it_reserved_end = tbl->it_offset;
+ 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);
+ tbl->it_reserved_start = res_start;
+ tbl->it_reserved_end = res_end;
for (i = tbl->it_reserved_start; i < tbl->it_reserved_end; ++i)
- clear_bit(i - tbl->it_offset, tbl->it_map);
+ set_bit(i - tbl->it_offset, tbl->it_map);
}
/*
@@ -777,6 +769,22 @@ struct iommu_table *iommu_init_table(struct iommu_table *tbl, int nid,
return tbl;
}
+bool iommu_table_in_use(struct iommu_table *tbl)
+{
+ unsigned long start = 0, end;
+
+ /* ignore reserved bit0 */
+ if (tbl->it_offset == 0)
+ start = 1;
+ end = tbl->it_reserved_start - tbl->it_offset;
+ if (find_next_bit(tbl->it_map, end, start) != end)
+ return true;
+
+ start = tbl->it_reserved_end - tbl->it_offset;
+ end = tbl->it_size;
+ return find_next_bit(tbl->it_map, end, start) != end;
+}
+
static void iommu_table_free(struct kref *kref)
{
struct iommu_table *tbl;
@@ -793,10 +801,8 @@ static void iommu_table_free(struct kref *kref)
iommu_debugfs_del(tbl);
- iommu_table_release_pages(tbl);
-
/* verify that table contains no entries */
- if (!bitmap_empty(tbl->it_map, tbl->it_size))
+ if (iommu_table_in_use(tbl))
pr_warn("%s: Unexpected TCEs\n", __func__);
/* free bitmap */
@@ -1097,14 +1103,9 @@ int iommu_take_ownership(struct iommu_table *tbl)
for (i = 0; i < tbl->nr_pools; i++)
spin_lock_nest_lock(&tbl->pools[i].lock, &tbl->large_pool.lock);
- iommu_table_release_pages(tbl);
-
- if (!bitmap_empty(tbl->it_map, tbl->it_size)) {
+ if (iommu_table_in_use(tbl)) {
pr_err("iommu_tce: it_map is not empty");
ret = -EBUSY;
- /* Undo iommu_table_release_pages, i.e. restore bit#0, etc */
- iommu_table_reserve_pages(tbl, tbl->it_reserved_start,
- tbl->it_reserved_end);
} else {
memset(tbl->it_map, 0xff, sz);
}