linux-kernel - Re: [PATCH 1/2] iommu/riscv: Free irq vectors on pci remove

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Message-ID: <CAH2o1u5ttY+0d4v8U=H-PwLUHZo5uMxxCQ5NAXudOQvUUMcpfA@mail.gmail.com>
Date: Wed, 6 Nov 2024 11:00:55 -0800
From: Tomasz Jeznach <tjeznach@...osinc.com>
To: Andrew Jones <ajones@...tanamicro.com>
Cc: iommu@...ts.linux.dev, linux-riscv@...ts.infradead.org, 
	linux-kernel@...r.kernel.org, joro@...tes.org, will@...nel.org, 
	robin.murphy@....com, paul.walmsley@...ive.com, palmer@...belt.com, 
	aou@...s.berkeley.edu
Subject: Re: [PATCH 1/2] iommu/riscv: Free irq vectors on pci remove

On Wed, Nov 6, 2024 at 9:51 AM Andrew Jones <ajones@...tanamicro.com> wrote:
>
> riscv_iommu_pci_probe() calls pci_alloc_irq_vectors() which
> states pci_free_irq_vectors() must be called on cleanup.
>
> Fixes: 68682e9578fb ("iommu/riscv: Add RISC-V IOMMU PCIe device driver")
> Signed-off-by: Andrew Jones <ajones@...tanamicro.com>
> ---
>  drivers/iommu/riscv/iommu-pci.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/iommu/riscv/iommu-pci.c b/drivers/iommu/riscv/iommu-pci.c
> index c7a89143014c..25a27e627a0e 100644
> --- a/drivers/iommu/riscv/iommu-pci.c
> +++ b/drivers/iommu/riscv/iommu-pci.c
> @@ -99,6 +99,7 @@ static void riscv_iommu_pci_remove(struct pci_dev *pdev)
>         struct riscv_iommu_device *iommu = dev_get_drvdata(&pdev->dev);
>
>         riscv_iommu_remove(iommu);
> +       pci_free_irq_vectors(pdev);
>  }
>
>  static const struct pci_device_id riscv_iommu_pci_tbl[] = {
> --
> 2.47.0
>

Andrew, interrupt release call pci_free_irq_vectors() should already
be called by device
managed resources framework, with unwind action callback pcim_msi_release().

Callback is registered during vectors allocation:
 pci_alloc_irq_vectors_affinity()
  __pci_enable_msix_range()
   pci_setup_msi_context()
    pcim_setup_msi_release()

This driver enables device resources management with initial call to
pcim_enable_device().

Are there any conditions / testing sequence the release function is not called?

Thanks,
- Tomasz