[PATCH V3] PCI/MSI: Fix MSI hwirq truncation

[Vidya Sagar]

While calculating the hwirq number for an MSI interrupt, the higher
bits (i.e. from bit-5 onwards a.k.a domain_nr >= 32) of the PCI domain
number gets truncated because of the shifted value casting to return
type of pci_domain_nr() which is 'int'. This for example is resulting
in same hwirq number for devices 0019:00:00.0 and 0039:00:00.0.

So, cast the PCI domain number to 'irq_hw_number_t' before left shifting
it to calculate hwirq number.

Fixes: 3878eaefb89a ("PCI/MSI: Enhance core to support hierarchy irqdomain")
Tested-By: Shanker Donthineni <sdonthineni@xxxxxxxxxx>
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
---
V3:
* Addressed review comments from Thomas Gleixner
* Added Tested-By: Shanker Donthineni <sdonthineni@xxxxxxxxxx>

V2:
* Added Fixes tag

 drivers/pci/msi/irqdomain.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index c8be056c248d..cfd84a899c82 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -61,7 +61,7 @@ static irq_hw_number_t pci_msi_domain_calc_hwirq(struct msi_desc *desc)
 
 	return (irq_hw_number_t)desc->msi_index |
 		pci_dev_id(dev) << 11 |
-		(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
+		((irq_hw_number_t)(pci_domain_nr(dev->bus) & 0xFFFFFFFF)) << 27;
 }
 
 static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,
-- 
2.25.1