Re: [PATCH v5 4/9] drivers: base cacheinfo: Add support for ACPI based firmware tables

Rafael J. Wysocki
2017-12-12T01:11:52Z

On Friday, December 1, 2017 11:23:25 PM CET Jeremy Linton wrote:
> Add a entry to to struct cacheinfo to maintain a reference to the PPTT
> node which can be used to match identical caches across cores. Also
> stub out cache_setup_acpi() so that individual architectures can
> enable ACPI topology parsing.
>
> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
> ---
> drivers/acpi/pptt.c | 1 +
> drivers/base/cacheinfo.c | 20 ++++++++++++++------
> include/linux/cacheinfo.h | 13 ++++++++++++-
> 3 files changed, 27 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
> index 0f8a1631af33..a35e457cefb7 100644
> --- a/drivers/acpi/pptt.c
> +++ b/drivers/acpi/pptt.c
> @@ -329,6 +329,7 @@ static void update_cache_properties(struct cacheinfo *this_leaf,
> {
> int valid_flags = 0;
>
> + this_leaf->firmware_node = cpu_node;
> if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID) {
> this_leaf->size = found_cache->size;
> valid_flags++;
> diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
> index eb3af2739537..ba89f9310e6f 100644
> --- a/drivers/base/cacheinfo.c
> +++ b/drivers/base/cacheinfo.c
> @@ -86,7 +86,10 @@ static int cache_setup_of_node(unsigned int cpu)
> static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
> struct cacheinfo *sib_leaf)
> {
> - return sib_leaf->of_node == this_leaf->of_node;
> + if (acpi_disabled)
> + return sib_leaf->of_node == this_leaf->of_node;
> + else
> + return sib_leaf->firmware_node == this_leaf->firmware_node;
> }
>
> /* OF properties to query for a given cache type */
> @@ -215,6 +218,11 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
> }
> #endif
>
> +int __weak cache_setup_acpi(unsigned int cpu)
> +{
> + return -ENOTSUPP;
> +}
> +
> static int cache_shared_cpu_map_setup(unsigned int cpu)
> {
> struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
> @@ -225,11 +233,11 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
> if (this_cpu_ci->cpu_map_populated)
> return 0;
>
> - if (of_have_populated_dt())
> + if (!acpi_disabled)
> + ret = cache_setup_acpi(cpu);
> + else if (of_have_populated_dt())
> ret = cache_setup_of_node(cpu);
> - else if (!acpi_disabled)
> - /* No cache property/hierarchy support yet in ACPI */
> - ret = -ENOTSUPP;
> +
> if (ret)
> return ret;
>
> @@ -286,7 +294,7 @@ static void cache_shared_cpu_map_remove(unsigned int cpu)
>
> static void cache_override_properties(unsigned int cpu)
> {
> - if (of_have_populated_dt())
> + if (acpi_disabled && of_have_populated_dt())
> return cache_of_override_properties(cpu);
> }
>
> diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
> index 3d9805297cda..7ebff157ae6c 100644
> --- a/include/linux/cacheinfo.h
> +++ b/include/linux/cacheinfo.h
> @@ -37,6 +37,8 @@ enum cache_type {
> * @of_node: if devicetree is used, this represents either the cpu node in
> * case there's no explicit cache node or the cache node itself in the
> * device tree
> + * @firmware_node: When not using DT, this may contain pointers to other
> + * firmware based values. Particularly ACPI/PPTT unique values.
> * @disable_sysfs: indicates whether this node is visible to the user via
> * sysfs or not
> * @priv: pointer to any private data structure specific to particular
> @@ -65,8 +67,8 @@ struct cacheinfo {
> #define CACHE_ALLOCATE_POLICY_MASK \
> (CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE)
> #define CACHE_ID BIT(4)
> -
> struct device_node *of_node;
> + void *firmware_node;

What about converting this to using struct fwnode instead of adding
fields to it?

> bool disable_sysfs;
> void *priv;
> };
> @@ -99,6 +101,15 @@ int func(unsigned int cpu) \
> struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
> int init_cache_level(unsigned int cpu);
> int populate_cache_leaves(unsigned int cpu);
> +int cache_setup_acpi(unsigned int cpu);
> +int acpi_find_last_cache_level(unsigned int cpu);
> +#ifndef CONFIG_ACPI
> +int acpi_find_last_cache_level(unsigned int cpu)
> +{
> + /*ACPI kernels should be built with PPTT support*/
> + return 0;
> +}
> +#endif
>
> const struct attribute_group *cache_get_priv_group(struct cacheinfo *this_leaf);
>
>

Thanks,
Rafael