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From: Vidya Sagar <vidyas@nvidia.com>
To: <bhelgaas@google.com>, <rdunlap@infradead.org>,
	<ilpo.jarvinen@linux.intel.com>, <tglx@linutronix.de>
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	<sagar.tv@gmail.com>
Subject: [PATCH V1] PCI/MSI: Fix MSI hwirq truncation
Date: Fri, 5 Jan 2024 19:13:39 +0530
Message-ID: <20240105134339.3091497-1-vidyas@nvidia.com>
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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.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
 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