sparc: fix size argument to find_next_zero_bit()

iommu_alloc_ctx() finds a zero bit in iommu->ctx_bitmap.  It starts
searching from iommu->ctx_lowest_free to the end of the bitmap.
But the size argument to find_next_zero_bit() in iommu_alloc_ctx()
is wrong.  It should be the bitmap size, not the maximum size to
search from the offset argument.

Fortunately iommu->ctx_lowest_free is almost unused and it will not
be more than 1. So the bug wasted only 1-bit at the end of
iommu->ctx_bitmap.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Akinobu Mita 2011-02-08 04:59:50 +00:00 committed by David S. Miller
parent e637804c33
commit 711c71a092

View File

@ -255,10 +255,9 @@ static inline iopte_t *alloc_npages(struct device *dev, struct iommu *iommu,
static int iommu_alloc_ctx(struct iommu *iommu)
{
int lowest = iommu->ctx_lowest_free;
int sz = IOMMU_NUM_CTXS - lowest;
int n = find_next_zero_bit(iommu->ctx_bitmap, sz, lowest);
int n = find_next_zero_bit(iommu->ctx_bitmap, IOMMU_NUM_CTXS, lowest);
if (unlikely(n == sz)) {
if (unlikely(n == IOMMU_NUM_CTXS)) {
n = find_next_zero_bit(iommu->ctx_bitmap, lowest, 1);
if (unlikely(n == lowest)) {
printk(KERN_WARNING "IOMMU: Ran out of contexts.\n");