[dpdk-dev] [PATCH v7 5/6] igb_uio: use kernel functions for masking MSI-X

[Patrick MacArthur]

Hi, Markus,

This commit appears to cause a regression on CentOS 7.4 with the in-box 
Linux 3.10.0-639-2.2.el7.x86_64 kernel. Although the kernel module 
appears to build correctly, when I attempt to load the module with 
insmod, it fails and I see the following errors in dmesg:

> [620323.805125] igb_uio: Unknown symbol unmask_msi_irq (err 0)
> [620323.805163] igb_uio: Unknown symbol mask_msi_irq (err 0)

It also fails with the same dmesg errors if I copy it into 
/lib/modules/$(uname -r)/extra, run depmod, and try to modprobe it.

Running git bisect points to this commit as the root cause.

This issue was identified as part of setting up the DPDK performance 
test lab CI environment at the University of New Hampshire 
InterOperability Laboratory.

Thanks,
Patrick

On 09/05/2017 08:04 AM, Markus Theil wrote:
> This patch removes the custom MSI-X mask/unmask code and
> uses already existing kernel functions.
> 
> Signed-off-by: Markus Theil <markus.theil at tu-ilmenau.de>
> ---
>   lib/librte_eal/linuxapp/igb_uio/compat.h  | 26 +++++-----------
>   lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 51 ++++++++++++-------------------
>   2 files changed, 28 insertions(+), 49 deletions(-)
> 
> diff --git a/lib/librte_eal/linuxapp/igb_uio/compat.h b/lib/librte_eal/linuxapp/igb_uio/compat.h
> index 3825933..67a7ab3 100644
> --- a/lib/librte_eal/linuxapp/igb_uio/compat.h
> +++ b/lib/librte_eal/linuxapp/igb_uio/compat.h
> @@ -15,24 +15,6 @@
>   #define HAVE_PTE_MASK_PAGE_IOMAP
>   #endif
>   
> -#ifndef PCI_MSIX_ENTRY_SIZE
> -#define PCI_MSIX_ENTRY_SIZE             16
> -#define  PCI_MSIX_ENTRY_LOWER_ADDR      0
> -#define  PCI_MSIX_ENTRY_UPPER_ADDR      4
> -#define  PCI_MSIX_ENTRY_DATA            8
> -#define  PCI_MSIX_ENTRY_VECTOR_CTRL     12
> -#define   PCI_MSIX_ENTRY_CTRL_MASKBIT   1
> -#endif
> -
> -/*
> - * for kernels < 2.6.38 and backported patch that moves MSI-X entry definition
> - * to pci_regs.h Those kernels has PCI_MSIX_ENTRY_SIZE defined but not
> - * PCI_MSIX_ENTRY_CTRL_MASKBIT
> - */
> -#ifndef PCI_MSIX_ENTRY_CTRL_MASKBIT
> -#define PCI_MSIX_ENTRY_CTRL_MASKBIT    1
> -#endif
> -
>   #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) && \
>   	(!(defined(RHEL_RELEASE_CODE) && \
>   	 RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(5, 9)))
> @@ -127,3 +109,11 @@ static bool pci_check_and_mask_intx(struct pci_dev *pdev)
>   #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
>   #define HAVE_ALLOC_IRQ_VECTORS 1
>   #endif
> +
> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0)
> +#define HAVE_PCI_MSI_MASK_IRQ 1
> +#endif
> +
> +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 37)
> +#define HAVE_IRQ_DATA 1
> +#endif
> diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> index c570eed..e4ef817 100644
> --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> @@ -91,27 +91,6 @@ static struct attribute *dev_attrs[] = {
>   static const struct attribute_group dev_attr_grp = {
>   	.attrs = dev_attrs,
>   };
> -/*
> - * It masks the msix on/off of generating MSI-X messages.
> - */
> -static void
> -igbuio_msix_mask_irq(struct msi_desc *desc, int32_t state)
> -{
> -	u32 mask_bits = desc->masked;
> -	unsigned offset = desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
> -						PCI_MSIX_ENTRY_VECTOR_CTRL;
> -
> -	if (state != 0)
> -		mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
> -	else
> -		mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
> -
> -	if (mask_bits != desc->masked) {
> -		writel(mask_bits, desc->mask_base + offset);
> -		readl(desc->mask_base);
> -		desc->masked = mask_bits;
> -	}
> -}
>   
>   /**
>    * This is the irqcontrol callback to be registered to uio_info.
> @@ -132,21 +111,31 @@ igbuio_pci_irqcontrol(struct uio_info *info, s32 irq_state)
>   	struct rte_uio_pci_dev *udev = info->priv;
>   	struct pci_dev *pdev = udev->pdev;
>   
> -	pci_cfg_access_lock(pdev);
> -	if (udev->mode == RTE_INTR_MODE_LEGACY)
> -		pci_intx(pdev, !!irq_state);
> +#ifdef HAVE_IRQ_DATA
> +	struct irq_data *irq = irq_get_irq_data(udev->info.irq);
> +#else
> +	unsigned int irq = udev->info.irq;
> +#endif
>   
> -	else if (udev->mode == RTE_INTR_MODE_MSIX) {
> -		struct msi_desc *desc;
> +	pci_cfg_access_lock(pdev);
>   
> -#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0))
> -		list_for_each_entry(desc, &pdev->msi_list, list)
> -			igbuio_msix_mask_irq(desc, irq_state);
> +	if (udev->mode == RTE_INTR_MODE_MSIX) {
> +#ifdef HAVE_PCI_MSI_MASK_IRQ
> +		if (irq_state == 1)
> +			pci_msi_unmask_irq(irq);
> +		else
> +			pci_msi_mask_irq(irq);
>   #else
> -		list_for_each_entry(desc, &pdev->dev.msi_list, list)
> -			igbuio_msix_mask_irq(desc, irq_state);
> +		if (irq_state == 1)
> +			unmask_msi_irq(irq);
> +		else
> +			mask_msi_irq(irq);
>   #endif
>   	}
> +
> +	if (udev->mode == RTE_INTR_MODE_LEGACY)
> +		pci_intx(pdev, !!irq_state);
> +
>   	pci_cfg_access_unlock(pdev);
>   
>   	return 0;
>