2022-09-22 16:58:58

by Logan Gunthorpe

[permalink] [raw]
Subject: [PATCH v10 8/8] ABI: sysfs-bus-pci: add documentation for p2pmem allocate

Add documentation for the p2pmem/allocate binary file which allows
for allocating p2pmem buffers in userspace for passing to drivers
that support them. (Currently only O_DIRECT to NVMe devices.)

Signed-off-by: Logan Gunthorpe <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
---
Documentation/ABI/testing/sysfs-bus-pci | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 6fc2c2efe8ab..f4602b8d6e11 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -407,6 +407,16 @@ Description:
file contains a '1' if the memory has been published for
use outside the driver that owns the device.

+What: /sys/bus/pci/devices/.../p2pmem/allocate
+Date: August 2022
+Contact: Logan Gunthorpe <[email protected]>
+Description:
+ This file allows mapping p2pmem into userspace. For each
+ mmap() call on this file, the kernel will allocate a chunk
+ of Peer-to-Peer memory for use in Peer-to-Peer transactions.
+ This memory can be used in O_DIRECT calls to NVMe backed
+ files for Peer-to-Peer copies.
+
What: /sys/bus/pci/devices/.../link/clkpm
/sys/bus/pci/devices/.../link/l0s_aspm
/sys/bus/pci/devices/.../link/l1_aspm
--
2.30.2


2022-09-23 08:41:31

by Greg KH

[permalink] [raw]
Subject: Re: [PATCH v10 8/8] ABI: sysfs-bus-pci: add documentation for p2pmem allocate

On Thu, Sep 22, 2022 at 10:39:26AM -0600, Logan Gunthorpe wrote:
> Add documentation for the p2pmem/allocate binary file which allows
> for allocating p2pmem buffers in userspace for passing to drivers
> that support them. (Currently only O_DIRECT to NVMe devices.)
>
> Signed-off-by: Logan Gunthorpe <[email protected]>
> Reviewed-by: John Hubbard <[email protected]>
> ---
> Documentation/ABI/testing/sysfs-bus-pci | 10 ++++++++++
> 1 file changed, 10 insertions(+)

Reviewed-by: Greg Kroah-Hartman <[email protected]>