On Mon, 11 Jan 2021 14:51:12 -0800
Ben Widawsky <ben.widawsky@xxxxxxxxx> wrote:
> From: Dan Williams <dan.j.williams@xxxxxxxxx>
>
> Create the /sys/bus/cxl hierarchy to enumerate memory devices
> (per-endpoint control devices), memory address space devices (platform
> address ranges with interleaving, performance, and persistence
> attributes), and memory regions (active provisioned memory from an
> address space device that is in use as System RAM or delegated to
> libnvdimm as Persistent Memory regions).
>
> For now, only the per-endpoint control devices are registered on the
> 'cxl' bus.
>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Don't hide the driver core change inside a patch doing other stuff.
(it is a nice change though!)
Otherwise, just a request for units in the sysfs ABI docs.
Jonathan
> ---
> Documentation/ABI/testing/sysfs-bus-cxl | 26 +++
> Documentation/cxl/memory-devices.rst | 3 +
> drivers/base/core.c | 14 ++
> drivers/cxl/Makefile | 2 +
> drivers/cxl/bus.c | 54 +++++
> drivers/cxl/bus.h | 8 +
> drivers/cxl/cxl.h | 3 +
> drivers/cxl/mem.c | 282 +++++++++++++++++++++++-
> include/linux/device.h | 1 +
> 9 files changed, 392 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-cxl
> create mode 100644 drivers/cxl/bus.c
> create mode 100644 drivers/cxl/bus.h
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> new file mode 100644
> index 000000000000..fe7b87eba988
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -0,0 +1,26 @@
> +What: /sys/bus/cxl/devices/memX/firmware_version
> +Date: December, 2020
> +KernelVersion: v5.12
> +Contact: linux-cxl@xxxxxxxxxxxxxxx
> +Description:
> + (RO) "FW Revision" string as reported by the Identify
> + Memory Device Output Payload in the CXL-2.0
> + specification.
> +
> +What: /sys/bus/cxl/devices/memX/ram/size
> +Date: December, 2020
> +KernelVersion: v5.12
> +Contact: linux-cxl@xxxxxxxxxxxxxxx
> +Description:
> + (RO) "Volatile Only Capacity" as reported by the
> + Identify Memory Device Output Payload in the CXL-2.0
> + specification.
Nice to see the format /units of these described in this doc as well as the spec.
Section number etc also good if you can add it to these docs.
> +
> +What: /sys/bus/cxl/devices/memX/pmem/size
> +Date: December, 2020
> +KernelVersion: v5.12
> +Contact: linux-cxl@xxxxxxxxxxxxxxx
> +Description:
> + (RO) "Persistent Only Capacity" as reported by the
> + Identify Memory Device Output Payload in the CXL-2.0
> + specification.
> diff --git a/Documentation/cxl/memory-devices.rst b/Documentation/cxl/memory-devices.rst
> index 134c9b6b4ff4..5f723c25382b 100644
> --- a/Documentation/cxl/memory-devices.rst
> +++ b/Documentation/cxl/memory-devices.rst
> @@ -37,3 +37,6 @@ External Interfaces
>
> .. kernel-doc:: drivers/cxl/acpi.c
> :export:
> +
> +.. kernel-doc:: drivers/cxl/bus.c
> + :export:
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 25e08e5f40bd..33432a4cbe23 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -3179,6 +3179,20 @@ struct device *get_device(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(get_device);
>
> +/**
> + * get_live_device() - increment reference count for device iff !dead
> + * @dev: device.
> + *
> + * Forward the call to get_device() if the device is still alive. If
> + * this is called with the device_lock() held then the device is
> + * guaranteed to not die until the device_lock() is dropped.
> + */
I like the idea of a nice generic wrapper for this but definitely not
deep inside a patch doing something else.
> +struct device *get_live_device(struct device *dev)
> +{
> + return dev && !dev->p->dead ? get_device(dev) : NULL;
> +}
> +EXPORT_SYMBOL_GPL(get_live_device);
> +
...
