diff mbox series

[v11,9/9] ABI: sysfs-bus-pci: add documentation for p2pmem allocate

Message ID 20221021174116.7200-10-logang@deltatee.com (mailing list archive)
State Handled Elsewhere
Headers show
Series Userspace P2PDMA with O_DIRECT NVMe devices | expand

Commit Message

Logan Gunthorpe Oct. 21, 2022, 5:41 p.m. UTC 
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 <logang@deltatee.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 Documentation/ABI/testing/sysfs-bus-pci | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Chaitanya Kulkarni Oct. 25, 2022, 1:29 a.m. UTC | #1 
On 10/21/22 10:41, 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 <logang@deltatee.com>
> Reviewed-by: John Hubbard <jhubbard@nvidia.com>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>

-ck
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index 840727fc75dc..ecf47559f495 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 <logang@deltatee.com>
+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