Commit 5a4e6dcc authored by Roland Dreier's avatar Roland Dreier

IB/mthca: Use IRQ safe locks to protect allocation bitmaps

It is supposed to be OK to call mthca_create_ah() and mthca_destroy_ah()
from any context.  However, for mem-full HCAs, these functions use the
mthca_alloc() and mthca_free() bitmap helpers, and those helpers use
non-IRQ-safe spin_lock() internally.  Lockdep correctly warns that
this could lead to a deadlock.  Fix this by changing mthca_alloc() and
mthca_free() to use spin_lock_irqsave().
Signed-off-by: default avatarRoland Dreier <rolandd@cisco.com>
parent 22db37ec
......@@ -41,9 +41,11 @@
/* Trivial bitmap-based allocator */
u32 mthca_alloc(struct mthca_alloc *alloc)
{
unsigned long flags;
u32 obj;
spin_lock(&alloc->lock);
spin_lock_irqsave(&alloc->lock, flags);
obj = find_next_zero_bit(alloc->table, alloc->max, alloc->last);
if (obj >= alloc->max) {
alloc->top = (alloc->top + alloc->max) & alloc->mask;
......@@ -56,19 +58,24 @@ u32 mthca_alloc(struct mthca_alloc *alloc)
} else
obj = -1;
spin_unlock(&alloc->lock);
spin_unlock_irqrestore(&alloc->lock, flags);
return obj;
}
void mthca_free(struct mthca_alloc *alloc, u32 obj)
{
unsigned long flags;
obj &= alloc->max - 1;
spin_lock(&alloc->lock);
spin_lock_irqsave(&alloc->lock, flags);
clear_bit(obj, alloc->table);
alloc->last = min(alloc->last, obj);
alloc->top = (alloc->top + alloc->max) & alloc->mask;
spin_unlock(&alloc->lock);
spin_unlock_irqrestore(&alloc->lock, flags);
}
int mthca_alloc_init(struct mthca_alloc *alloc, u32 num, u32 mask,
......
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