On Thu, Oct 12, 2017 at 02:48:52PM -0500, Jeremy Linton wrote:
The /sys cache entries should support ACPI/PPTT generated cache
topology information. Lets detect ACPI systems and call
an arch specific cache_setup_acpi() routine to update the hardware
probed cache topology.
For arm64, if ACPI is enabled, determine the max number of cache
levels and populate them using a PPTT table if one is available.
Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
---
arch/arm64/kernel/cacheinfo.c | 23 ++++++++++++++++++-----
drivers/acpi/pptt.c | 1 +
drivers/base/cacheinfo.c | 17 +++++++++++------
include/linux/cacheinfo.h | 11 +++++++++--
4 files changed, 39 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c
index 380f2e2fbed5..2e2cf0d312ba 100644
--- a/arch/arm64/kernel/cacheinfo.c
+++ b/arch/arm64/kernel/cacheinfo.c
@@ -17,6 +17,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/acpi.h>
#include <linux/cacheinfo.h>
#include <linux/of.h>
@@ -44,9 +45,17 @@ static void ci_leaf_init(struct cacheinfo *this_leaf,
this_leaf->type = type;
}
+#ifndef CONFIG_ACPI
+int acpi_find_last_cache_level(unsigned int cpu)
+{
+ /*ACPI kernels should be built with PPTT support*/
+ return 0;
+}
+#endif
+
static int __init_cache_level(unsigned int cpu)
{
- unsigned int ctype, level, leaves, of_level;
+ unsigned int ctype, level, leaves, fw_level;
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) {
@@ -59,15 +68,19 @@ static int __init_cache_level(unsigned int cpu)
leaves += (ctype == CACHE_TYPE_SEPARATE) ? 2 : 1;
}
- of_level = of_find_last_cache_level(cpu);
- if (level < of_level) {
+ if (acpi_disabled)
+ fw_level = of_find_last_cache_level(cpu);
+ else
+ fw_level = acpi_find_last_cache_level(cpu);
+
+ if (level < fw_level) {
/*
* some external caches not specified in CLIDR_EL1
* the information may be available in the device tree
* only unified external caches are considered here
*/
- leaves += (of_level - level);
- level = of_level;
+ leaves += (fw_level - level);
+ level = fw_level;
}
this_cpu_ci->num_levels = level;
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index c86715fed4a7..b5c6de37e328 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -355,6 +355,7 @@ static void update_cache_properties(struct cacheinfo *this_leaf,
struct acpi_pptt_cache *found_cache,
struct acpi_pptt_processor *cpu_node)
{
+ this_leaf->firmware_node = cpu_node;
This pointer comes from an ACPI static table mapping that happens
to be permanent so it should be safe given that the mapping is carried
out at device_initcall (ie cache_setup_acpi()) but it is not that
obvious. More to it below.
if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID)
this_leaf->size = found_cache->size;
if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID)
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index eb3af2739537..8eca279e50d1 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -86,7 +86,7 @@ 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;
+ return sib_leaf->firmware_node == this_leaf->firmware_node;
}
/* OF properties to query for a given cache type */
@@ -215,6 +215,11 @@ 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 +230,11 @@ 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 +291,7 @@ 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 6a524bf6a06d..d1e9b8e01981 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -36,6 +36,9 @@ 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: Shared with of_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
@@ -64,8 +67,10 @@ struct cacheinfo {
#define CACHE_ALLOCATE_POLICY_MASK \
(CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE)
#define CACHE_ID BIT(4)
-
- struct device_node *of_node;
+ union {
+ struct device_node *of_node;
+ void *firmware_node;
+ };
How about turning of_node into a struct fwnode_handle* (and allocate
one for each PPTT cache node - acpi_static_fwnode - to have the
ACPI counterpart) ?
