powerpc/powernv: Disable interrupts while taking phb->lock

We need to disable interrupts when taking the phb->lock. Otherwise
we could deadlock with pci_lock taken from an interrupt.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index a70bc1e385eba68e49815599eeec52de1492e6d2..f92b9ef7340e85129f4ec801128e307c627273b3 100644 (file)
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -52,32 +52,38 @@ static int pnv_msi_check_device(struct pci_dev* pdev, int nvec, int type)
 
 static unsigned int pnv_get_one_msi(struct pnv_phb *phb)
 {
-       unsigned int id;
+       unsigned long flags;
+       unsigned int id, rc;
+
+       spin_lock_irqsave(&phb->lock, flags);
 
-       spin_lock(&phb->lock);
        id = find_next_zero_bit(phb->msi_map, phb->msi_count, phb->msi_next);
        if (id >= phb->msi_count && phb->msi_next)
                id = find_next_zero_bit(phb->msi_map, phb->msi_count, 0);
        if (id >= phb->msi_count) {
-               spin_unlock(&phb->lock);
-               return 0;
+               rc = 0;
+               goto out;
        }
        __set_bit(id, phb->msi_map);
-       spin_unlock(&phb->lock);
-       return id + phb->msi_base;
+       rc = id + phb->msi_base;
+out:
+       spin_unlock_irqrestore(&phb->lock, flags);
+       return rc;
 }
 
 static void pnv_put_msi(struct pnv_phb *phb, unsigned int hwirq)
 {
+       unsigned long flags;
        unsigned int id;
 
        if (WARN_ON(hwirq < phb->msi_base ||
                    hwirq >= (phb->msi_base + phb->msi_count)))
                return;
        id = hwirq - phb->msi_base;
-       spin_lock(&phb->lock);
+
+       spin_lock_irqsave(&phb->lock, flags);
        __clear_bit(id, phb->msi_map);
-       spin_unlock(&phb->lock);
+       spin_unlock_irqrestore(&phb->lock, flags);
 }
 
 static int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)