On 11/21/24 00:57, 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); > + > + has_align_addr = caps & CAP_HAS_ALIGN_ADDR; > + dev_dbg(dev, "CAP_HAS_ALIGN_ADDR: %d\n", has_align_addr); > + > + if (has_align_addr) Shouldn't this be "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); -- Damien Le Moal Western Digital Research