Re: [PATCH v4 09/10] pci_endpoint_test: Add 2 ioctl commands

[Kishon Vijay Abraham I]

Hi,

On Monday 18 June 2018 08:30 PM, Gustavo Pimentel wrote:
> Add MSI-X support and update driver documentation accordingly.
> 
> Add 2 new IOCTL commands:
>  - Allow to reconfigure driver IRQ type in runtime.
>  - Allow to retrieve current driver IRQ type configured.
> 
> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> ---
> Change v2->v3:
>  - New patch file created base on the previous patch
> "misc: pci_endpoint_test: Add MSI-X support" patch file following
> Kishon's suggestion.
> Change v3->v4:
>  - Rebased to Lorenzo's master branch v4.18-rc1.
> 
>  Documentation/misc-devices/pci-endpoint-test.txt |   3 +
>  drivers/misc/pci_endpoint_test.c                 | 177 +++++++++++++++++------
>  2 files changed, 132 insertions(+), 48 deletions(-)
> 
> diff --git a/Documentation/misc-devices/pci-endpoint-test.txt b/Documentation/misc-devices/pci-endpoint-test.txt
> index fdfa0f6..58ccca4 100644
> --- a/Documentation/misc-devices/pci-endpoint-test.txt
> +++ b/Documentation/misc-devices/pci-endpoint-test.txt
> @@ -28,6 +28,9 @@ ioctl
>  	      to be tested should be passed as argument.
>   PCITEST_MSIX: Tests message signalled interrupts. The MSI-X number
>  	      to be tested should be passed as argument.
> + PCITEST_SET_IRQTYPE: Changes driver IRQ type configuration. The IRQ type
> +	      should be passed as argument (0: Legacy, 1:MSI, 2:MSI-X).
> + PCITEST_GET_IRQTYPE: Gets driver IRQ type configuration.
>   PCITEST_WRITE: Perform write tests. The size of the buffer should be passed
>  		as argument.
>   PCITEST_READ: Perform read tests. The size of the buffer should be passed
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index 8d15dbe..df2017f 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -157,6 +157,87 @@ static irqreturn_t pci_endpoint_test_irqhandler(int irq, void *dev_id)
>  	return IRQ_HANDLED;
>  }
>  
> +static void pci_endpoint_test_free_irq_vectors(struct pci_endpoint_test *test)
> +{
> +	int i;
> +	struct pci_dev *pdev = test->pdev;
> +	struct device *dev = &pdev->dev;
> +
> +	for (i = 0; i < test->num_irqs; i++)
> +		devm_free_irq(dev, pci_irq_vector(pdev, i), test);
> +
> +	test->num_irqs = 0;
> +}
> +
> +static bool pci_endpoint_test_alloc_irq_vectors(struct pci_endpoint_test *test)
> +{
> +	int irq = -1;
> +	struct pci_dev *pdev = test->pdev;
> +	struct device *dev = &pdev->dev;
> +	bool res = true;
> +
> +	switch (irq_type) {
> +	case IRQ_TYPE_LEGACY:
> +		irq = 0;
> +		break;
> +	case IRQ_TYPE_MSI:
> +		irq = pci_alloc_irq_vectors(pdev, 1, 32, PCI_IRQ_MSI);
> +		if (irq < 0)
> +			dev_err(dev, "Failed to get MSI interrupts\n");
> +		break;
> +	case IRQ_TYPE_MSIX:
> +		irq = pci_alloc_irq_vectors(pdev, 1, 2048, PCI_IRQ_MSIX);
> +		if (irq < 0)
> +			dev_err(dev, "Failed to get MSI-X interrupts\n");
> +		break;
> +	default:
> +		dev_err(dev, "Invalid IRQ type selected\n");
> +	}
> +
> +	if (irq < 0) {
> +		irq = 0;
> +		res = false;
> +	}
> +	test->num_irqs = irq;
> +
> +	return res;
> +}
> +
> +static void pci_endpoint_test_release_irq(struct pci_endpoint_test *test)
> +{
> +	struct pci_dev *pdev = test->pdev;
> +
> +	pci_disable_msi(pdev);
> +	pci_disable_msix(pdev);
> +}
> +
> +static bool pci_endpoint_test_request_irq(struct pci_endpoint_test *test)
> +{
> +	int i;
> +	int err;
> +	struct pci_dev *pdev = test->pdev;
> +	struct device *dev = &pdev->dev;
> +
> +	err = devm_request_irq(dev, pdev->irq, pci_endpoint_test_irqhandler,
> +			       IRQF_SHARED, DRV_MODULE_NAME, test);
> +	if (err) {
> +		dev_err(dev, "Failed to request IRQ %d\n", pdev->irq);
> +		return false;
> +	}
> +
> +	for (i = 1; i < test->num_irqs; i++) {
> +		err = devm_request_irq(dev, pci_irq_vector(pdev, i),
> +				       pci_endpoint_test_irqhandler,
> +				       IRQF_SHARED, DRV_MODULE_NAME, test);
> +		if (err)
> +			dev_err(dev, "Failed to request IRQ %d for MSI%s %d\n",
> +				pci_irq_vector(pdev, i),
> +				irq_type == IRQ_TYPE_MSIX ? "-X" : "", i + 1);
> +	}
> +
> +	return true;
> +}
> +
>  static bool pci_endpoint_test_bar(struct pci_endpoint_test *test,
>  				  enum pci_barno barno)
>  {
> @@ -440,6 +521,38 @@ static bool pci_endpoint_test_read(struct pci_endpoint_test *test, size_t size)
>  	return ret;
>  }
>  
> +static bool pci_endpoint_test_set_irq(struct pci_endpoint_test *test,
> +				      int req_irq_type)
> +{
> +	struct pci_dev *pdev = test->pdev;
> +	struct device *dev = &pdev->dev;
> +
> +	if (req_irq_type < IRQ_TYPE_LEGACY || req_irq_type > IRQ_TYPE_MSIX) {
> +		dev_err(dev, "Invalid IRQ type option\n");
> +		return false;
> +	}
> +
> +	if (irq_type == req_irq_type)
> +		return true;
> +
> +	irq_type = req_irq_type;
> +
> +	pci_endpoint_test_free_irq_vectors(test);
> +	pci_endpoint_test_release_irq(test);
> +
> +	if (!pci_endpoint_test_alloc_irq_vectors(test)) {
> +		pci_endpoint_test_release_irq(test);
> +		return false;
> +	}
> +
> +	if (!pci_endpoint_test_request_irq(test)) {
> +		pci_endpoint_test_release_irq(test);
> +		return false;
> +	}
> +
> +	return true;
> +}
> +
>  static long pci_endpoint_test_ioctl(struct file *file, unsigned int cmd,
>  				    unsigned long arg)
>  {
> @@ -471,6 +584,12 @@ static long pci_endpoint_test_ioctl(struct file *file, unsigned int cmd,
>  	case PCITEST_COPY:
>  		ret = pci_endpoint_test_copy(test, arg);
>  		break;
> +	case PCITEST_SET_IRQTYPE:
> +		ret = pci_endpoint_test_set_irq(test, arg);
> +		break;
> +	case PCITEST_GET_IRQTYPE:
> +		ret = irq_type;

Can't the set_irq be done as part of raise irq itself?

Thanks
Kishon