On Fri, 05 May 2023 17:05:34 -0700
Dave Jiang <dave.jiang@xxxxxxxxx> wrote:
> Add helper to retrieve the performance attributes based on the device
> handle. The helper function is exported so the CXL driver can use that
> to acquire the performance data between the CPU and the CXL host bridge.
>
> Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Trivial comment inline. Otherwise LGTM
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
> drivers/acpi/numa/hmat.c | 35 +++++++++++++++++++++++++++++++++++
> include/linux/acpi.h | 9 +++++++++
> 2 files changed, 44 insertions(+)
>
> diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
> index 951579e903cf..73d716e6096e 100644
> --- a/drivers/acpi/numa/hmat.c
> +++ b/drivers/acpi/numa/hmat.c
> @@ -107,6 +107,41 @@ static struct memory_target *find_mem_target(unsigned int mem_pxm)
> return NULL;
> }
>
> +static struct memory_target *acpi_find_genport_target(u8 *device_handle)
> +{
> + struct memory_target *target;
> +
> + list_for_each_entry(target, &targets, node) {
> + if (!strncmp(target->device_handle, device_handle,
> + ACPI_SRAT_DEVICE_HANDLE_SIZE))
Using this for something that isn't a string?
memcmp() ?
Mind you I'm not sure what the nameless author this code was doing
in packing the device handle as a u8 array rather than a union of the two
types it can contain. They probably had a reason lost to the mists of time...
> + return target;
> + }
> +
> + return NULL;
> +}
> +
> +/**
> + * acpi_get_genport_coordinates - Retrieve the access coordinates for a generic port
> + * @device_handle: Device handle string (ACPI or PCI) to match up to the gen port
> + * @coord: The access coordinates written back out for the generic port
> + *
> + * Return: 0 on success. Errno on failure.
> + */
> +int acpi_get_genport_coordinates(u8 *device_handle,
> + struct access_coordinate *coord)
> +{
> + struct memory_target *target;
> +
> + target = acpi_find_genport_target(device_handle);
> + if (!target)
> + return -ENOENT;
> +
> + *coord = target->coord[NODE_ACCESS_CLASS_GENPORT];
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(acpi_get_genport_coordinates, CXL);
> +
> static __init void alloc_memory_initiator(unsigned int cpu_pxm)
> {
> struct memory_initiator *initiator;
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 4c3dfe7587e9..d6a99fa430dd 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -15,6 +15,7 @@
> #include <linux/device.h>
> #include <linux/property.h>
> #include <linux/uuid.h>
> +#include <linux/node.h>
>
> #ifndef _LINUX
> #define _LINUX
> @@ -455,6 +456,8 @@ extern bool acpi_osi_is_win8(void);
> #ifdef CONFIG_ACPI_NUMA
> int acpi_map_pxm_to_node(int pxm);
> int acpi_get_node(acpi_handle handle);
> +int acpi_get_genport_coordinates(u8 *device_handle,
> + struct access_coordinate *coord);
>
> /**
> * pxm_to_online_node - Map proximity ID to online node
> @@ -489,6 +492,12 @@ static inline int acpi_get_node(acpi_handle handle)
> {
> return 0;
> }
> +
> +static inline int acpi_get_genport_coordinates(u8 *device_handle,
> + struct access_coordinate *coord)
> +{
> + return -EOPNOTSUPP;
> +}
> #endif
> extern int acpi_paddr_to_node(u64 start_addr, u64 size);
>
>
>
