[PATCH v2 02/10] PCI/P2PDMA: Add sysfs group to display p2pmem stats

From: Logan Gunthorpe
Date: Wed Feb 28 2018 - 18:41:45 EST


Attributes display the total amount of P2P memory, the amount available
and whether it is published or not.

Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-bus-pci | 25 +++++++++++++++++
drivers/pci/p2pdma.c | 50 +++++++++++++++++++++++++++++++++
2 files changed, 75 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 44d4b2be92fd..f5656dae21be 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -323,3 +323,28 @@ Description:

This is similar to /sys/bus/pci/drivers_autoprobe, but
affects only the VFs associated with a specific PF.
+
+What: /sys/bus/pci/devices/.../p2pmem/available
+Date: November 2017
+Contact: Logan Gunthorpe <logang@xxxxxxxxxxxx>
+Description:
+ If the device has any Peer-to-Peer memory registered, this
+ file contains the amount of memory that has not been
+ allocated (in decimal).
+
+What: /sys/bus/pci/devices/.../p2pmem/size
+Date: November 2017
+Contact: Logan Gunthorpe <logang@xxxxxxxxxxxx>
+Description:
+ If the device has any Peer-to-Peer memory registered, this
+ file contains the total ammount of memory that the device
+ provides (in decimal).
+
+What: /sys/bus/pci/devices/.../p2pmem/published
+Date: November 2017
+Contact: Logan Gunthorpe <logang@xxxxxxxxxxxx>
+Description:
+ If the device has any Peer-to-Peer memory registered, this
+ file contains a '1' if the memory has been published for
+ use inside the kernel or a '0' if it is only intended
+ for use within the driver that published it.
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index ec0a6cb9e500..a57df78f6a32 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -29,6 +29,53 @@ struct pci_p2pdma {
bool published;
};

+static ssize_t size_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ size_t size = 0;
+
+ if (pdev->p2pdma->pool)
+ size = gen_pool_size(pdev->p2pdma->pool);
+
+ return snprintf(buf, PAGE_SIZE, "%zd\n", size);
+}
+static DEVICE_ATTR_RO(size);
+
+static ssize_t available_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+ size_t avail = 0;
+
+ if (pdev->p2pdma->pool)
+ avail = gen_pool_avail(pdev->p2pdma->pool);
+
+ return snprintf(buf, PAGE_SIZE, "%zd\n", avail);
+}
+static DEVICE_ATTR_RO(available);
+
+static ssize_t published_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pci_dev *pdev = to_pci_dev(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", pdev->p2pdma->published);
+}
+static DEVICE_ATTR_RO(published);
+
+static struct attribute *p2pmem_attrs[] = {
+ &dev_attr_size.attr,
+ &dev_attr_available.attr,
+ &dev_attr_published.attr,
+ NULL,
+};
+
+static const struct attribute_group p2pmem_group = {
+ .attrs = p2pmem_attrs,
+ .name = "p2pmem",
+};
+
static void pci_p2pdma_percpu_release(struct percpu_ref *ref)
{
struct pci_p2pdma *p2p =
@@ -55,6 +102,7 @@ static void pci_p2pdma_release(void *data)
percpu_ref_exit(&pdev->p2pdma->devmap_ref);

gen_pool_destroy(pdev->p2pdma->pool);
+ sysfs_remove_group(&pdev->dev.kobj, &p2pmem_group);
pdev->p2pdma = NULL;
}

@@ -83,6 +131,8 @@ static int pci_p2pdma_setup(struct pci_dev *pdev)
if (error)
goto out_pool_destroy;

+ error = sysfs_create_group(&pdev->dev.kobj, &p2pmem_group);
+
pdev->p2pdma = p2p;

return 0;
--
2.11.0