[PATCH v6 07/12] drivers: base cacheinfo: Add support for ACPI based firmware tables

Jeremy Linton
2018-01-22T21:14:37Z

Hi,

Thanks for taking a look at this.

On 01/22/2018 09:50 AM, Greg KH wrote:
> On Fri, Jan 12, 2018 at 06:59:15PM -0600, 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 | 9 +++++++++
>> 3 files changed, 23 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
>> index 2c4b3ed862a8..4f5ab19c3a08 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->fw_unique = 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 217aa90fb036..ee51e33cc37c 100644
>> --- a/drivers/base/cacheinfo.c
>> +++ b/drivers/base/cacheinfo.c
>> @@ -208,16 +208,16 @@ static int cache_setup_of_node(unsigned int cpu)
>>
>> if (index != cache_leaves(cpu)) /* not all OF nodes populated */
>> return -ENOENT;
>> -
>> return 0;
>> }
>> +
>
> Whitespace changes not needed for this patch :(

Sure.

>
>
>> #else
>> static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
>> static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf,
>> struct cacheinfo *sib_leaf)
>> {
>> /*
>> - * For non-DT systems, assume unique level 1 cache, system-wide
>> + * For non-DT/ACPI systems, assume unique level 1 caches, system-wide
>> * shared caches for all other levels. This will be used only if
>> * arch specific code has not populated shared_cpu_map
>> */
>> @@ -225,6 +225,11 @@ 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);
>> @@ -235,11 +240,11 @@ 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);
>
> Why does acpi go first? :)

This sounds like a joke i heard...

OTOH, given that we have machines with both ACPI and DT tables, it
seemed a little clearer and a little more robust to code that so that if
ACPI is enabled to prefer it over DT information. As long as the
routines which set of of_root are protected by if (acpi_disabled) checks
it should be safe to do it either way.

>
>> + 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;
>>
>> +int acpi_find_last_cache_level(unsigned int cpu)
>> +{
>> + /*ACPI kernels should be built with PPTT support*/
>
> Here are some extra ' ' characters, you need them...

Oh ok, thanks! :)