4.19-stable review patch. If anyone has any objections, please let me know.
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From: Vidya Sagar vidyas@nvidia.com
commit db744ddd59be798c2627efbfc71f707f5a935a40 upstream.
While calculating the hardware interrupt number for a 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 hardware interrupt number for devices 0019:00:00.0 and 0039:00:00.0.
To address this cast the PCI domain number to 'irq_hw_number_t' before left shifting it to calculate the hardware interrupt number.
Please note that this fixes the issue only on 64-bit systems and doesn't change the behavior for 32-bit systems i.e. the 32-bit systems continue to have the issue. Since the issue surfaces only if there are too many PCIe controllers in the system which usually is the case in modern server systems and they don't tend to run 32-bit kernels.
Fixes: 3878eaefb89a ("PCI/MSI: Enhance core to support hierarchy irqdomain") Signed-off-by: Vidya Sagar vidyas@nvidia.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Shanker Donthineni sdonthineni@nvidia.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240115135649.708536-1-vidyas@nvidia.com [ tglx: Backport to linux-4.19.y ] Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pci/msi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1382,7 +1382,7 @@ irq_hw_number_t pci_msi_domain_calc_hwir { return (irq_hw_number_t)desc->msi_attrib.entry_nr | PCI_DEVID(dev->bus->number, dev->devfn) << 11 | - (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27; + ((irq_hw_number_t)(pci_domain_nr(dev->bus) & 0xFFFFFFFF)) << 27; }
static inline bool pci_msi_desc_is_multi_msi(struct msi_desc *desc)