Re: [PATCH] vmw_vmci: switch to pci_irq_alloc_vectors

["Jorgen S. Hansen" <jhansen@vmware.com>]

> On Feb 1, 2017, at 3:42 PM, Christoph Hellwig <hch@lst.de> wrote:
> 
> Cleans up the IRQ management code a lot, including removing a lot of
> state from the per-device structure.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> drivers/misc/vmw_vmci/vmci_guest.c | 75 ++++++++++----------------------------
> include/linux/vmw_vmci_defs.h      |  7 ----
> 2 files changed, 20 insertions(+), 62 deletions(-)
> 
> diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c
> index 189b325..9d65954 100644
> --- a/drivers/misc/vmw_vmci/vmci_guest.c
> +++ b/drivers/misc/vmw_vmci/vmci_guest.c
> @@ -54,10 +54,7 @@ struct vmci_guest_device {
> 	struct device *dev;	/* PCI device we are attached to */
> 	void __iomem *iobase;
> 
> -	unsigned int irq;
> -	unsigned int intr_type;
> 	bool exclusive_vectors;
> -	struct msix_entry msix_entries[VMCI_MAX_INTRS];
> 
> 	struct tasklet_struct datagram_tasklet;
> 	struct tasklet_struct bm_tasklet;
> @@ -369,30 +366,6 @@ static void vmci_process_bitmap(unsigned long data)
> }
> 
> /*
> - * Enable MSI-X.  Try exclusive vectors first, then shared vectors.
> - */
> -static int vmci_enable_msix(struct pci_dev *pdev,
> -			    struct vmci_guest_device *vmci_dev)
> -{
> -	int i;
> -	int result;
> -
> -	for (i = 0; i < VMCI_MAX_INTRS; ++i) {
> -		vmci_dev->msix_entries[i].entry = i;
> -		vmci_dev->msix_entries[i].vector = i;
> -	}
> -
> -	result = pci_enable_msix_exact(pdev,
> -				       vmci_dev->msix_entries, VMCI_MAX_INTRS);
> -	if (result == 0)
> -		vmci_dev->exclusive_vectors = true;
> -	else if (result == -ENOSPC)
> -		result = pci_enable_msix_exact(pdev, vmci_dev->msix_entries, 1);
> -
> -	return result;
> -}
> -
> -/*
>  * Interrupt handler for legacy or MSI interrupt, or for first MSI-X
>  * interrupt (vector VMCI_INTR_DATAGRAM).
>  */
> @@ -406,7 +379,7 @@ static irqreturn_t vmci_interrupt(int irq, void *_dev)
> 	 * Otherwise we must read the ICR to determine what to do.
> 	 */
> 
> -	if (dev->intr_type == VMCI_INTR_TYPE_MSIX && dev->exclusive_vectors) {
> +	if (dev->exclusive_vectors) {
> 		tasklet_schedule(&dev->datagram_tasklet);
> 	} else {
> 		unsigned int icr;
> @@ -491,7 +464,6 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
> 	}
> 
> 	vmci_dev->dev = &pdev->dev;
> -	vmci_dev->intr_type = VMCI_INTR_TYPE_INTX;
> 	vmci_dev->exclusive_vectors = false;
> 	vmci_dev->iobase = iobase;
> 
> @@ -592,26 +564,26 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
> 	 * Enable interrupts.  Try MSI-X first, then MSI, and then fallback on
> 	 * legacy interrupts.
> 	 */
> -	if (!vmci_disable_msix && !vmci_enable_msix(pdev, vmci_dev)) {
> -		vmci_dev->intr_type = VMCI_INTR_TYPE_MSIX;
> -		vmci_dev->irq = vmci_dev->msix_entries[0].vector;
> -	} else if (!vmci_disable_msi && !pci_enable_msi(pdev)) {
> -		vmci_dev->intr_type = VMCI_INTR_TYPE_MSI;
> -		vmci_dev->irq = pdev->irq;
> +	error = pci_alloc_irq_vectors(pdev, VMCI_MAX_INTRS, VMCI_MAX_INTRS,
> +			PCI_IRQ_MSIX);
> +	if (error) {
> +		error = pci_alloc_irq_vectors(pdev, 1, 1,
> +				PCI_IRQ_MSIX | PCI_IRQ_MSI | PCI_IRQ_LEGACY);
> +		if (error)
> +			goto err_remove_bitmap;
> 	} else {
> -		vmci_dev->intr_type = VMCI_INTR_TYPE_INTX;
> -		vmci_dev->irq = pdev->irq;
> +		vmci_dev->exclusive_vectors = true;
> 	}
> 
> 	/*
> 	 * Request IRQ for legacy or MSI interrupts, or for first
> 	 * MSI-X vector.
> 	 */
> -	error = request_irq(vmci_dev->irq, vmci_interrupt, IRQF_SHARED,
> -			    KBUILD_MODNAME, vmci_dev);
> +	error = request_irq(pci_irq_vector(pdev, 0), vmci_interrupt,
> +			    IRQF_SHARED, KBUILD_MODNAME, vmci_dev);
> 	if (error) {
> 		dev_err(&pdev->dev, "Irq %u in use: %d\n",
> -			vmci_dev->irq, error);
> +			pci_irq_vector(pdev, 0), error);
> 		goto err_disable_msi;
> 	}
> 
> @@ -622,13 +594,13 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
> 	 * between the vectors.
> 	 */
> 	if (vmci_dev->exclusive_vectors) {
> -		error = request_irq(vmci_dev->msix_entries[1].vector,
> +		error = request_irq(pci_irq_vector(pdev, 1),
> 				    vmci_interrupt_bm, 0, KBUILD_MODNAME,
> 				    vmci_dev);
> 		if (error) {
> 			dev_err(&pdev->dev,
> 				"Failed to allocate irq %u: %d\n",
> -				vmci_dev->msix_entries[1].vector, error);
> +				pci_irq_vector(pdev, 1), error);
> 			goto err_free_irq;
> 		}
> 	}
> @@ -651,15 +623,12 @@ static int vmci_guest_probe_device(struct pci_dev *pdev,
> 	return 0;
> 
> err_free_irq:
> -	free_irq(vmci_dev->irq, vmci_dev);
> +	free_irq(pci_irq_vector(pdev, 0), vmci_dev);
> 	tasklet_kill(&vmci_dev->datagram_tasklet);
> 	tasklet_kill(&vmci_dev->bm_tasklet);
> 
> err_disable_msi:
> -	if (vmci_dev->intr_type == VMCI_INTR_TYPE_MSIX)
> -		pci_disable_msix(pdev);
> -	else if (vmci_dev->intr_type == VMCI_INTR_TYPE_MSI)
> -		pci_disable_msi(pdev);
> +	pci_free_irq_vectors(pdev);
> 
> 	vmci_err = vmci_event_unsubscribe(ctx_update_sub_id);
> 	if (vmci_err < VMCI_SUCCESS)
> @@ -719,14 +688,10 @@ static void vmci_guest_remove_device(struct pci_dev *pdev)
> 	 * MSI-X, we might have multiple vectors, each with their own
> 	 * IRQ, which we must free too.
> 	 */
> -	free_irq(vmci_dev->irq, vmci_dev);
> -	if (vmci_dev->intr_type == VMCI_INTR_TYPE_MSIX) {
> -		if (vmci_dev->exclusive_vectors)
> -			free_irq(vmci_dev->msix_entries[1].vector, vmci_dev);
> -		pci_disable_msix(pdev);
> -	} else if (vmci_dev->intr_type == VMCI_INTR_TYPE_MSI) {
> -		pci_disable_msi(pdev);
> -	}
> +	if (vmci_dev->exclusive_vectors)
> +		free_irq(pci_irq_vector(pdev, 1), vmci_dev);
> +	free_irq(pci_irq_vector(pdev, 0), vmci_dev);
> +	pci_free_irq_vectors(pdev);
> 
> 	tasklet_kill(&vmci_dev->datagram_tasklet);
> 	tasklet_kill(&vmci_dev->bm_tasklet);
> diff --git a/include/linux/vmw_vmci_defs.h b/include/linux/vmw_vmci_defs.h
> index 1bd31a3..b724ef7 100644
> --- a/include/linux/vmw_vmci_defs.h
> +++ b/include/linux/vmw_vmci_defs.h
> @@ -54,13 +54,6 @@
> #define VMCI_IMR_DATAGRAM      0x1
> #define VMCI_IMR_NOTIFICATION  0x2
> 
> -/* Interrupt type. */
> -enum {
> -	VMCI_INTR_TYPE_INTX = 0,
> -	VMCI_INTR_TYPE_MSI = 1,
> -	VMCI_INTR_TYPE_MSIX = 2,
> -};
> -
> /* Maximum MSI/MSI-X interrupt vectors in the device. */
> #define VMCI_MAX_INTRS 2
> 
> -- 
> 2.1.4
> 

Thanks for the cleanup! Looks great.

Reviewed-by: Jorgen Hansen <jhansen@vmware.com>