Re: [RFC PATCH v2 1/5] acpi: numa: Add support to enumerate and store extended linear address mode

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Tue, 12 Nov 2024 15:12:33 -0700
Dave Jiang <dave.jiang@intel.com> wrote:

> Store the address mode as part of the cache attriutes. Export the mode
> attribute to sysfs as all other cache attributes.
> 
> Link: https://lore.kernel.org/linux-cxl/668333b17e4b2_5639294fd@dwillia2-xfh.jf.intel.com.notmuch/
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
One trivial suggestion that I don't care that much about.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> v2:
> - Fix spelling errors (Jonathan)
> - Change UNKNOWN to RESERVED (Jonathan)
> ---
>  Documentation/ABI/stable/sysfs-devices-node | 6 ++++++
>  drivers/acpi/numa/hmat.c                    | 3 +++
>  drivers/base/node.c                         | 2 ++
>  include/linux/node.h                        | 7 +++++++
>  4 files changed, 18 insertions(+)
> 
> diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node
> index 402af4b2b905..725ef0e1e01f 100644
> --- a/Documentation/ABI/stable/sysfs-devices-node
> +++ b/Documentation/ABI/stable/sysfs-devices-node
> @@ -177,6 +177,12 @@ Description:
>  		The cache write policy: 0 for write-back, 1 for write-through,
>  		other or unknown.
>  
> +What:		/sys/devices/system/node/nodeX/memory_side_cache/indexY/mode

Mode feels perhaps a bit to vague.  Maybe address_mode?

> +Date:		September 2024
> +Contact:	Dave Jiang <dave.jiang@intel.com>
> +Description:
> +		The address mode: 0 for reserved, 1 for extended-linear.
> +
>  What:		/sys/devices/system/node/nodeX/x86/sgx_total_bytes
>  Date:		November 2021
>  Contact:	Jarkko Sakkinen <jarkko@kernel.org>
> diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
> index 1a902a02390f..39524f36be5b 100644
> --- a/drivers/acpi/numa/hmat.c
> +++ b/drivers/acpi/numa/hmat.c
> @@ -506,6 +506,9 @@ static __init int hmat_parse_cache(union acpi_subtable_headers *header,
>  	switch ((attrs & ACPI_HMAT_CACHE_ASSOCIATIVITY) >> 8) {
>  	case ACPI_HMAT_CA_DIRECT_MAPPED:
>  		tcache->cache_attrs.indexing = NODE_CACHE_DIRECT_MAP;
> +		/* Extended Linear mode is only valid if cache is direct mapped */
> +		if (cache->address_mode == ACPI_HMAT_CACHE_MODE_EXTENDED_LINEAR)
> +			tcache->cache_attrs.mode = NODE_CACHE_MODE_EXTENDED_LINEAR;
>  		break;
>  	case ACPI_HMAT_CA_COMPLEX_CACHE_INDEXING:
>  		tcache->cache_attrs.indexing = NODE_CACHE_INDEXED;