Re: [PATCHv2 1/2] hmat: Register memory-side cache after parsing

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Wednesday, May 15, 2019 11:54:43 PM CEST Keith Busch wrote:
> Instead of registering the hmat cache attributes in line with parsing
> the table, save the attributes in the memory target and register them
> after parsing completes. This will make it easier to register the
> attributes later when hot add is supported.
> 
> Signed-off-by: Keith Busch <keith.busch@intel.com>
> ---
> v1 -> v2:
> 
>   Fixed multi-level caches, and no caches. v1 incorrectly assumed only a level
>   1 always existed (Brice).
> 
>  drivers/acpi/hmat/hmat.c | 70 +++++++++++++++++++++++++++++++++++++-----------
>  1 file changed, 55 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/acpi/hmat/hmat.c b/drivers/acpi/hmat/hmat.c
> index 96b7d39a97c6..bf23c9a27958 100644
> --- a/drivers/acpi/hmat/hmat.c
> +++ b/drivers/acpi/hmat/hmat.c
> @@ -36,11 +36,17 @@ enum locality_types {
>  
>  static struct memory_locality *localities_types[4];
>  
> +struct target_cache {
> +	struct list_head node;
> +	struct node_cache_attrs cache_attrs;
> +};
> +
>  struct memory_target {
>  	struct list_head node;
>  	unsigned int memory_pxm;
>  	unsigned int processor_pxm;
>  	struct node_hmem_attrs hmem_attrs;
> +	struct list_head caches;
>  };
>  
>  struct memory_initiator {
> @@ -110,6 +116,7 @@ static __init void alloc_memory_target(unsigned int mem_pxm)
>  	target->memory_pxm = mem_pxm;
>  	target->processor_pxm = PXM_INVAL;
>  	list_add_tail(&target->node, &targets);
> +	INIT_LIST_HEAD(&target->caches);
>  }
>  
>  static __init const char *hmat_data_type(u8 type)
> @@ -314,7 +321,8 @@ static __init int hmat_parse_cache(union acpi_subtable_headers *header,
>  				   const unsigned long end)
>  {
>  	struct acpi_hmat_cache *cache = (void *)header;
> -	struct node_cache_attrs cache_attrs;
> +	struct memory_target *target;
> +	struct target_cache *tcache;
>  	u32 attrs;
>  
>  	if (cache->header.length < sizeof(*cache)) {
> @@ -328,37 +336,47 @@ static __init int hmat_parse_cache(union acpi_subtable_headers *header,
>  		cache->memory_PD, cache->cache_size, attrs,
>  		cache->number_of_SMBIOShandles);
>  
> -	cache_attrs.size = cache->cache_size;
> -	cache_attrs.level = (attrs & ACPI_HMAT_CACHE_LEVEL) >> 4;
> -	cache_attrs.line_size = (attrs & ACPI_HMAT_CACHE_LINE_SIZE) >> 16;
> +	target = find_mem_target(cache->memory_PD);
> +	if (!target)
> +		return 0;
> +
> +	tcache = kzalloc(sizeof(*tcache), GFP_KERNEL);
> +	if (!tcache) {
> +		pr_notice_once("Failed to allocate HMAT cache info\n");
> +		return 0;
> +	}
> +
> +	tcache->cache_attrs.size = cache->cache_size;
> +	tcache->cache_attrs.level = (attrs & ACPI_HMAT_CACHE_LEVEL) >> 4;
> +	tcache->cache_attrs.line_size = (attrs & ACPI_HMAT_CACHE_LINE_SIZE) >> 16;
>  
>  	switch ((attrs & ACPI_HMAT_CACHE_ASSOCIATIVITY) >> 8) {
>  	case ACPI_HMAT_CA_DIRECT_MAPPED:
> -		cache_attrs.indexing = NODE_CACHE_DIRECT_MAP;
> +		tcache->cache_attrs.indexing = NODE_CACHE_DIRECT_MAP;
>  		break;
>  	case ACPI_HMAT_CA_COMPLEX_CACHE_INDEXING:
> -		cache_attrs.indexing = NODE_CACHE_INDEXED;
> +		tcache->cache_attrs.indexing = NODE_CACHE_INDEXED;
>  		break;
>  	case ACPI_HMAT_CA_NONE:
>  	default:
> -		cache_attrs.indexing = NODE_CACHE_OTHER;
> +		tcache->cache_attrs.indexing = NODE_CACHE_OTHER;
>  		break;
>  	}
>  
>  	switch ((attrs & ACPI_HMAT_WRITE_POLICY) >> 12) {
>  	case ACPI_HMAT_CP_WB:
> -		cache_attrs.write_policy = NODE_CACHE_WRITE_BACK;
> +		tcache->cache_attrs.write_policy = NODE_CACHE_WRITE_BACK;
>  		break;
>  	case ACPI_HMAT_CP_WT:
> -		cache_attrs.write_policy = NODE_CACHE_WRITE_THROUGH;
> +		tcache->cache_attrs.write_policy = NODE_CACHE_WRITE_THROUGH;
>  		break;
>  	case ACPI_HMAT_CP_NONE:
>  	default:
> -		cache_attrs.write_policy = NODE_CACHE_WRITE_OTHER;
> +		tcache->cache_attrs.write_policy = NODE_CACHE_WRITE_OTHER;
>  		break;
>  	}
> +	list_add_tail(&tcache->node, &target->caches);
>  
> -	node_add_cache(pxm_to_node(cache->memory_PD), &cache_attrs);
>  	return 0;
>  }
>  
> @@ -577,20 +595,37 @@ static __init void hmat_register_target_initiators(struct memory_target *target)
>  	}
>  }
>  
> +static __init void hmat_register_target_cache(struct memory_target *target)
> +{
> +	unsigned mem_nid = pxm_to_node(target->memory_pxm);
> +	struct target_cache *tcache;
> +
> +	list_for_each_entry(tcache, &target->caches, node)
> +		node_add_cache(mem_nid, &tcache->cache_attrs);
> +}
> +
>  static __init void hmat_register_target_perf(struct memory_target *target)
>  {
>  	unsigned mem_nid = pxm_to_node(target->memory_pxm);
>  	node_set_perf_attrs(mem_nid, &target->hmem_attrs, 0);
>  }
>  
> +static __init void hmat_register_target(struct memory_target *target)
> +{
> +	if (!node_online(pxm_to_node(target->memory_pxm)))
> +		return;
> +
> +	hmat_register_target_initiators(target);
> +	hmat_register_target_cache(target);
> +	hmat_register_target_perf(target);
> +}
> +
>  static __init void hmat_register_targets(void)
>  {
>  	struct memory_target *target;
>  
> -	list_for_each_entry(target, &targets, node) {
> -		hmat_register_target_initiators(target);
> -		hmat_register_target_perf(target);
> -	}
> +	list_for_each_entry(target, &targets, node)
> +		hmat_register_target(target);
>  }
>  
>  static __init void hmat_free_structures(void)
> @@ -598,8 +633,13 @@ static __init void hmat_free_structures(void)
>  	struct memory_target *target, *tnext;
>  	struct memory_locality *loc, *lnext;
>  	struct memory_initiator *initiator, *inext;
> +	struct target_cache *tcache, *cnext;
>  
>  	list_for_each_entry_safe(target, tnext, &targets, node) {
> +		list_for_each_entry_safe(tcache, cnext, &target->caches, node) {
> +			list_del(&tcache->node);
> +			kfree(tcache);
> +		}
>  		list_del(&target->node);
>  		kfree(target);
>  	}
> 

Not sure what to do with this patch and the next one in the series.

FWIW, they both are fine by me.

Also ISTR seeing them in a series from Dan. (?)