Re: [RFC PATCH v3 3/4] mm,memory_hotplug: Enable MHP_MEMMAP_ON_MEMORY when supported

[David Hildenbrand <david@redhat.com>]

On 01.12.20 12:51, Oscar Salvador wrote:
> Let the callers check whether they can use MHP_MEMMAP_ON_MEMORY by
> checking mhp_supports_memmap_on_memory().
> Currently, we only support MHP_MEMMAP_ON_MEMORY in case
> CONFIG_SPARSEMEM_VMEMMAP is enabled, the architecture supports altmap,
> and the range to be added spans a single memory block.
> 
> Signed-off-by: Oscar Salvador <osalvador@suse.de>
> ---
>  arch/powerpc/platforms/pseries/hotplug-memory.c | 5 ++++-
>  drivers/acpi/acpi_memhotplug.c                  | 5 ++++-
>  2 files changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
> index 7efe6ec5d14a..3aba817e729e 100644
> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
> @@ -612,6 +612,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
>  {
>  	unsigned long block_sz;
>  	int nid, rc;
> +	mhp_t mhp_flags = MHP_NONE;
>  
>  	if (lmb->flags & DRCONF_MEM_ASSIGNED)
>  		return -EINVAL;
> @@ -629,8 +630,10 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
>  	if (nid < 0 || !node_possible(nid))
>  		nid = first_online_node;
>  
> +	if (mhp_supports_memmap_on_memory(block_sz))
> +		mhp_flags |= MHP_MEMMAP_ON_MEMORY;
>  	/* Add the memory */
> -	rc = __add_memory(nid, lmb->base_addr, block_sz, MHP_NONE);
> +	rc = __add_memory(nid, lmb->base_addr, block_sz, mhp_flags);
>  	if (rc) {
>  		invalidate_lmb_associativity_index(lmb);
>  		return rc;
> diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
> index b02fd51e5589..1fe645ef0b6c 100644
> --- a/drivers/acpi/acpi_memhotplug.c
> +++ b/drivers/acpi/acpi_memhotplug.c
> @@ -172,6 +172,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
>  	int result, num_enabled = 0;
>  	struct acpi_memory_info *info;
>  	int node;
> +	mhp_t mhp_flags = MHP_NONE;
>  
>  	node = acpi_get_node(handle);
>  	/*
> @@ -194,8 +195,10 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
>  		if (node < 0)
>  			node = memory_add_physaddr_to_nid(info->start_addr);
>  
> +		if (mhp_supports_memmap_on_memory(info->length))
> +			mhp_flags |= MHP_MEMMAP_ON_MEMORY;
>  		result = __add_memory(node, info->start_addr, info->length,
> -				      MHP_NONE);
> +				      mhp_flags);
>  
>  		/*
>  		 * If the memory block has been used by the kernel, add_memory()
> 

Please split that patch into two parts, one for each subsystem.

-- 
Thanks,

David / dhildenb