genirq/msi: Do not use pci_msi_[un]mask_irq as default methods

When we create a generic MSI domain, that MSI_FLAG_USE_DEF_CHIP_OPS
is set, and that any of .mask or .unmask are NULL in the irq_chip
structure, we set them to pci_msi_[un]mask_irq.

This is a bad idea for at least two reasons:
- PCI_MSI might not be selected, kernel fails to build (yes, this is
  legitimate, at least on arm64!)
- This may not be a PCI/MSI domain at all (platform MSI, for example)

Either way, this looks wrong. Move the overriding of mask/unmask to
the PCI counterpart, and panic is any of these two methods is not
set in the core code (they really should be present).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1444760085-27857-1-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d4497141d083a71d5d5206496fee58fbddc5cb13..4a7da3c3e0353c3c746e9b10be9a093c8d085920 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1243,6 +1243,10 @@ static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info)
        BUG_ON(!chip);
        if (!chip->irq_write_msi_msg)
                chip->irq_write_msi_msg = pci_msi_domain_write_msg;
+       if (!chip->irq_mask)
+               chip->irq_mask = pci_msi_mask_irq;
+       if (!chip->irq_unmask)
+               chip->irq_unmask = pci_msi_unmask_irq;
 }
 
 /**

diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index 7e6512b9dc1ff2682394cdd0fea9a8c6d01cf6e9..be9149f62eb86e63ac06194d4eeaa4065823ea62 100644 (file)
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -228,11 +228,7 @@ static void msi_domain_update_chip_ops(struct msi_domain_info *info)
 {
        struct irq_chip *chip = info->chip;
 
-       BUG_ON(!chip);
-       if (!chip->irq_mask)
-               chip->irq_mask = pci_msi_mask_irq;
-       if (!chip->irq_unmask)
-               chip->irq_unmask = pci_msi_unmask_irq;
+       BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask);
        if (!chip->irq_set_affinity)
                chip->irq_set_affinity = msi_domain_set_affinity;
 }