On Tue, 12 Aug 2025 15:26:13 +0100
<shiju.jose@xxxxxxxxxx> wrote:
> From: Shiju Jose <shiju.jose@xxxxxxxxxx>
>
> In the numa_memblks, a lookup facility is required to retrieve the
> physical address range of memory in a NUMA node. ACPI RAS2 memory
> features are among the use cases.
>
> Suggested-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
Looks fine to me. Mike, what do you think?
One passing comment inline.
Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
> ---
> include/linux/numa.h | 9 +++++++++
> include/linux/numa_memblks.h | 2 ++
> mm/numa.c | 10 ++++++++++
> mm/numa_memblks.c | 37 ++++++++++++++++++++++++++++++++++++
> 4 files changed, 58 insertions(+)
>
> diff --git a/include/linux/numa.h b/include/linux/numa.h
> index e6baaf6051bc..1d1aabebd26b 100644
> --- a/include/linux/numa.h
> +++ b/include/linux/numa.h
> @@ -41,6 +41,10 @@ int memory_add_physaddr_to_nid(u64 start);
> int phys_to_target_node(u64 start);
> #endif
>
> +#ifndef nid_get_mem_physaddr_range
> +int nid_get_mem_physaddr_range(int nid, u64 *start, u64 *end);
> +#endif
> +
> int numa_fill_memblks(u64 start, u64 end);
>
> #else /* !CONFIG_NUMA */
> @@ -63,6 +67,11 @@ static inline int phys_to_target_node(u64 start)
> return 0;
> }
>
> +static inline int nid_get_mem_physaddr_range(int nid, u64 *start, u64 *end)
> +{
> + return 0;
> +}
> +
> static inline void alloc_offline_node_data(int nid) {}
> #endif
>
> diff --git a/include/linux/numa_memblks.h b/include/linux/numa_memblks.h
> index 991076cba7c5..7b32d96d0134 100644
> --- a/include/linux/numa_memblks.h
> +++ b/include/linux/numa_memblks.h
> @@ -55,6 +55,8 @@ extern int phys_to_target_node(u64 start);
> #define phys_to_target_node phys_to_target_node
> extern int memory_add_physaddr_to_nid(u64 start);
> #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
> +extern int nid_get_mem_physaddr_range(int nid, u64 *start, u64 *end);
> +#define nid_get_mem_physaddr_range nid_get_mem_physaddr_range
> #endif /* CONFIG_NUMA_KEEP_MEMINFO */
>
> #endif /* CONFIG_NUMA_MEMBLKS */
> diff --git a/mm/numa.c b/mm/numa.c
> index 7d5e06fe5bd4..5335af1fefee 100644
> --- a/mm/numa.c
> +++ b/mm/numa.c
> @@ -59,3 +59,13 @@ int phys_to_target_node(u64 start)
> }
> EXPORT_SYMBOL_GPL(phys_to_target_node);
> #endif
> +
> +#ifndef nid_get_mem_physaddr_range
> +int nid_get_mem_physaddr_range(int nid, u64 *start, u64 *end)
> +{
> + pr_info_once("Unknown target phys addr range for node=%d\n", nid);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(nid_get_mem_physaddr_range);
> +#endif
> diff --git a/mm/numa_memblks.c b/mm/numa_memblks.c
> index 541a99c4071a..e1e56b7a3499 100644
> --- a/mm/numa_memblks.c
> +++ b/mm/numa_memblks.c
> @@ -590,4 +590,41 @@ int memory_add_physaddr_to_nid(u64 start)
> }
> EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
>
> +/**
> + * nid_get_mem_physaddr_range - Get the physical address range
> + * of the memblk in the NUMA node.
> + * @nid: NUMA node ID of the memblk
> + * @start: Start address of the memblk
> + * @end: End address of the memblk
> + *
> + * Find the lowest contiguous physical memory address range of the memblk
> + * in the NUMA node with the given nid and return the start and end
> + * addresses.
> + *
> + * RETURNS:
> + * 0 on success, -errno on failure.
> + */
> +int nid_get_mem_physaddr_range(int nid, u64 *start, u64 *end)
> +{
> + struct numa_meminfo *mi = &numa_meminfo;
> + int i;
> +
> + if (!numa_valid_node(nid))
> + return -EINVAL;
> +
> + for (i = 0; i < mi->nr_blks; i++) {
> + if (mi->blk[i].nid == nid) {
> + *start = mi->blk[i].start;
> + /*
> + * Assumption: mi->blk[i].end is the last address
> + * in the range + 1.
This was my fault for asking on internal review if this was documented
anywhere. It's kind of implicitly obvious when reading numa_memblk.c
because there are a bunch of end - 1 prints.
So can probably drop this comment.
> + */
> + *end = mi->blk[i].end;
> + return 0;
> + }
> + }
> +
> + return -ENODEV;
> +}
> +EXPORT_SYMBOL_GPL(nid_get_mem_physaddr_range);
> #endif /* CONFIG_NUMA_KEEP_MEMINFO */
