On Mon, Jan 22, 2018 at 10:14 PM, Jeremy Linton [off-list ref] wrote:

Hi,

Thanks for taking a look at this.


On 01/22/2018 09:50 AM, Greg KH wrote:

quoted

On Fri, Jan 12, 2018 at 06:59:15PM -0600, Jeremy Linton wrote:

quoted

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 <redacted>
---
  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.

quoted

quoted

  #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.

I guess adding a comment about that might help.