On Wed, Nov 20, 2024 at 04:57:33PM +0100, Niklas Cassel wrote:
> If running pci_endpoint_test.c (host side) against a version of
> pci-epf-test.c (EP side), we will not see any capabilities being set.
>
> For now, only add the CAP_HAS_ALIGN_ADDR capability.
>
> If the CAP_HAS_ALIGN_ADDR is set, that means that the EP side supports
> reading/writing to an address without any alignment requirements.
>
> Thus, if CAP_HAS_ALIGN_ADDR is set, make sure that we do not add any
> specific padding to the buffers that we allocate (which was only made
> in order to get the buffers to satisfy certain alignment requirements).
>
> Signed-off-by: Niklas Cassel <cassel@xxxxxxxxxx>
> ---
> drivers/misc/pci_endpoint_test.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c
> index 3aaaf47fa4ee..ab2b322410fb 100644
> --- a/drivers/misc/pci_endpoint_test.c
> +++ b/drivers/misc/pci_endpoint_test.c
> @@ -69,6 +69,9 @@
> #define PCI_ENDPOINT_TEST_FLAGS 0x2c
> #define FLAG_USE_DMA BIT(0)
>
> +#define PCI_ENDPOINT_TEST_CAPS 0x30
> +#define CAP_HAS_ALIGN_ADDR BIT(0)
> +
> #define PCI_DEVICE_ID_TI_AM654 0xb00c
> #define PCI_DEVICE_ID_TI_J7200 0xb00f
> #define PCI_DEVICE_ID_TI_AM64 0xb010
> @@ -805,6 +808,22 @@ static const struct file_operations pci_endpoint_test_fops = {
> .unlocked_ioctl = pci_endpoint_test_ioctl,
> };
>
> +static void pci_endpoint_test_get_capabilities(struct pci_endpoint_test *test)
> +{
> + struct pci_dev *pdev = test->pdev;
> + struct device *dev = &pdev->dev;
> + u32 caps;
> + bool has_align_addr;
> +
> + caps = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_CAPS);
I worry about if there are problem if EP have not such register. for
example, if reg's space size is 64, but host try to read pos 68. I think it
is original design problem, it should have one 'version' or 'size' in
register list.
Frank
> +
> + has_align_addr = caps & CAP_HAS_ALIGN_ADDR;
> + dev_dbg(dev, "CAP_HAS_ALIGN_ADDR: %d\n", has_align_addr);
> +
> + if (has_align_addr)
> + test->alignment = 0;
> +}
> +
> static int pci_endpoint_test_probe(struct pci_dev *pdev,
> const struct pci_device_id *ent)
> {
> @@ -906,6 +925,8 @@ static int pci_endpoint_test_probe(struct pci_dev *pdev,
> goto err_kfree_test_name;
> }
>
> + pci_endpoint_test_get_capabilities(test);
> +
> misc_device = &test->miscdev;
> misc_device->minor = MISC_DYNAMIC_MINOR;
> misc_device->name = kstrdup(name, GFP_KERNEL);
> --
> 2.47.0
>
