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PCI/MSI: Prevent MSI hardware interrupt number truncation
jira LE-1907 Rebuild_History Non-Buildable kernel-5.14.0-427.18.1.el9_4 commit-author Vidya Sagar <vidyas@nvidia.com> commit db744dd 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: 3878eae ("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 (cherry picked from commit db744dd) Signed-off-by: Jonathan Maple <jmaple@ciq.com>
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drivers/pci/msi/irqdomain.c

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -61,7 +61,7 @@ static irq_hw_number_t pci_msi_domain_calc_hwirq(struct msi_desc *desc)
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return (irq_hw_number_t)desc->msi_index |
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pci_dev_id(dev) << 11 |
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(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 27;
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((irq_hw_number_t)(pci_domain_nr(dev->bus) & 0xFFFFFFFF)) << 27;
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}
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static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,

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