Messages in this thread | | | Date | Wed, 7 Feb 2024 12:29:29 +0530 | Subject | Re: [PATCH V4] PCI/MSI: Fix MSI hwirq truncation | From | Vidya Sagar <> |
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Hi Thomas / Bjorn, Can you please guide me on getting this patch merged?
Thanks, Vidya Sagar
On 1/31/2024 8:45 AM, Vidya Sagar wrote: > Hi Thomas, > Sorry to bother you. > Would you mind giving an Ack to this patch? > > Thanks, > Vidya Sagar > > On 1/23/2024 9:31 PM, Vidya Sagar wrote: >> Hi Thomas, >> Does this patch look fine to you? >> If yes, would you mind giving an Ack? >> >> Thanks, >> Vidya Sagar >> >> On 1/15/2024 7:26 PM, 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 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. Please note that this fixes the issue only >>> on 64-bit systems and doesn't change the behavior in 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") >>> Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> >>> Signed-off-by: Vidya Sagar <vidyas@nvidia.com> >>> --- >>> V4: >>> * Added extra information in the change log about the impact of this >>> patch >>> in a 32-bit system as suggested by Thomas >>> >>> V3: >>> * Addressed review comments from Thomas Gleixner >>> * Added Tested-By: Shanker Donthineni <sdonthineni@nvidia.com> >>> >>> 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,
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