On Sun, Apr 13, 2025 at 05:52:14PM -0500, Ira Weiny wrote:
> Endpoints can now support a single dynamic ram partition following the
> persistent memory partition.
>
> Expand the mode to allow a decoder to point to the first dynamic ram
> partition.
>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
> ---
> Changes:
> [iweiny: completely re-written]
> ---
> Documentation/ABI/testing/sysfs-bus-cxl | 18 +++++++++---------
> drivers/cxl/core/port.c | 4 ++++
> 2 files changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 2b59041bb410..b2754e6047ca 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -358,22 +358,22 @@ Description:
>
>
> What: /sys/bus/cxl/devices/decoderX.Y/mode
> -Date: May, 2022
> -KernelVersion: v6.0
> +Date: May, 2022, May 2025
> +KernelVersion: v6.0, v6.16 (dynamic_ram_a)
> Contact: linux-cxl@vger.kernel.org
> Description:
> (RW) When a CXL decoder is of devtype "cxl_decoder_endpoint" it
> translates from a host physical address range, to a device
> local address range. Device-local address ranges are further
> - split into a 'ram' (volatile memory) range and 'pmem'
> - (persistent memory) range. The 'mode' attribute emits one of
> - 'ram', 'pmem', or 'none'. The 'none' indicates the decoder is
> - not actively decoding, or no DPA allocation policy has been
> - set.
> + split into a 'ram' (volatile memory) range, 'pmem' (persistent
> + memory), and 'dynamic_ram_a' (first Dynamic RAM) range. The
> + 'mode' attribute emits one of 'ram', 'pmem', 'dynamic_ram_a' or
> + 'none'. The 'none' indicates the decoder is not actively
> + decoding, or no DPA allocation policy has been set.
>
> 'mode' can be written, when the decoder is in the 'disabled'
> - state, with either 'ram' or 'pmem' to set the boundaries for the
> - next allocation.
> + state, with either 'ram', 'pmem', or 'dynamic_ram_a' to set the
> + boundaries for the next allocation.
>
>
> What: /sys/bus/cxl/devices/decoderX.Y/dpa_resource
> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> index 0fd6646c1a2e..e98605bd39b4 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -125,6 +125,7 @@ static DEVICE_ATTR_RO(name)
>
> CXL_DECODER_FLAG_ATTR(cap_pmem, CXL_DECODER_F_PMEM);
> CXL_DECODER_FLAG_ATTR(cap_ram, CXL_DECODER_F_RAM);
> +CXL_DECODER_FLAG_ATTR(cap_dynamic_ram_a, CXL_DECODER_F_RAM);
> CXL_DECODER_FLAG_ATTR(cap_type2, CXL_DECODER_F_TYPE2);
> CXL_DECODER_FLAG_ATTR(cap_type3, CXL_DECODER_F_TYPE3);
> CXL_DECODER_FLAG_ATTR(locked, CXL_DECODER_F_LOCK);
> @@ -219,6 +220,8 @@ static ssize_t mode_store(struct device *dev, struct device_attribute *attr,
> mode = CXL_PARTMODE_PMEM;
> else if (sysfs_streq(buf, "ram"))
> mode = CXL_PARTMODE_RAM;
> + else if (sysfs_streq(buf, "dynamic_ram_a"))
> + mode = CXL_PARTMODE_DYNAMIC_RAM_A;
> else
> return -EINVAL;
>
> @@ -324,6 +327,7 @@ static struct attribute_group cxl_decoder_base_attribute_group = {
> static struct attribute *cxl_decoder_root_attrs[] = {
> &dev_attr_cap_pmem.attr,
> &dev_attr_cap_ram.attr,
> + &dev_attr_cap_dynamic_ram_a.attr,
> &dev_attr_cap_type2.attr,
> &dev_attr_cap_type3.attr,
> &dev_attr_target_list.attr,
>
> --
> 2.49.0
>
--
Fan Ni