Re: [PATCH v10 06/31] cxl/port: Add 'dynamic_ram_a' to endpoint decoder mode

[Dave Jiang <dave.jiang@intel.com>]

On 5/23/26 2:43 AM, Anisa Su wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> 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>

Need Anisa sign off

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

Just update kver and dates below.

> 
> ---
> Changes:
> [anisa: rebase]
> ---
>  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 3d95c325f6e0..c604c7ca6432 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

A later date

> +KernelVersion:	v6.0, v6.16 (dynamic_ram_a)

7.3 maybe?

DJ

>  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 0c5957d1d329..a7f71f36531f 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -128,6 +128,7 @@ 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);
> @@ -222,6 +223,8 @@ 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;
>  
> @@ -327,6 +330,7 @@ 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,