On 1/10/2024 3:42 PM, Thomas Gleixner wrote:
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On Mon, Jan 08 2024 at 17:35, Vidya Sagar wrote:
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 u32. 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 u64 before left shifting it to
calculate hwirq number.
Fixes: 3878eaefb89a ("PCI/MSI: Enhance core to support hierarchy irqdomain")
Signed-off-by: Vidya Sagar <vidyas@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;
This is not casting to u64. It's casting to unsigned long:
typedef unsigned long irq_hw_number_t;
So this works only correctly on 64bit. On 32bit kernels unsigned long is
still 32bit. It's probably arguable that the 32bit case is not a
problem, but the changelog and the change do not match. This needs a
proper explanation why we don't care about this on 32bit.
Agree that the change and the commit message do not match.
I'll update the commit message to use 'irq_hw_number_t' instead of u64.
Thanks,
Vidya Sagar
Thanks,
tglx
