Re: [PATCH v2 1/5] cacheinfo: Use RISC-V's init_cache_level() as generic OF implementation

From: Palmer Dabbelt
Date: Fri Dec 02 2022 - 12:58:02 EST


On Mon, 21 Nov 2022 09:12:09 PST (-0800), pierre.gondois@xxxxxxx wrote:
RISC-V's implementation of init_of_cache_level() is following
the Devicetree Specification v0.3 regarding caches, cf.:
- s3.7.3 'Internal (L1) Cache Properties'
- s3.8 'Multi-level and Shared Cache Nodes'

Allow reusing the implementation by moving it.

Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx>
Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
arch/riscv/kernel/cacheinfo.c | 39 +------------------------------
drivers/base/cacheinfo.c | 44 +++++++++++++++++++++++++++++++++++
include/linux/cacheinfo.h | 1 +
3 files changed, 46 insertions(+), 38 deletions(-)

diff --git a/arch/riscv/kernel/cacheinfo.c b/arch/riscv/kernel/cacheinfo.c
index 90deabfe63ea..440a3df5944c 100644
--- a/arch/riscv/kernel/cacheinfo.c
+++ b/arch/riscv/kernel/cacheinfo.c
@@ -115,44 +115,7 @@ static void fill_cacheinfo(struct cacheinfo **this_leaf,

int init_cache_level(unsigned int cpu)
{
- struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
- struct device_node *np = of_cpu_device_node_get(cpu);
- struct device_node *prev = NULL;
- int levels = 0, leaves = 0, level;
-
- if (of_property_read_bool(np, "cache-size"))
- ++leaves;
- if (of_property_read_bool(np, "i-cache-size"))
- ++leaves;
- if (of_property_read_bool(np, "d-cache-size"))
- ++leaves;
- if (leaves > 0)
- levels = 1;
-
- prev = np;
- while ((np = of_find_next_cache_node(np))) {
- of_node_put(prev);
- prev = np;
- if (!of_device_is_compatible(np, "cache"))
- break;
- if (of_property_read_u32(np, "cache-level", &level))
- break;
- if (level <= levels)
- break;
- if (of_property_read_bool(np, "cache-size"))
- ++leaves;
- if (of_property_read_bool(np, "i-cache-size"))
- ++leaves;
- if (of_property_read_bool(np, "d-cache-size"))
- ++leaves;
- levels = level;
- }
-
- of_node_put(np);
- this_cpu_ci->num_levels = levels;
- this_cpu_ci->num_leaves = leaves;
-
- return 0;
+ return init_of_cache_level(cpu);
}

int populate_cache_leaves(unsigned int cpu)
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 4b5cd08c5a65..a4308b48dd3e 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -224,8 +224,52 @@ static int cache_setup_of_node(unsigned int cpu)

return 0;
}
+
+int init_of_cache_level(unsigned int cpu)
+{
+ struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
+ struct device_node *np = of_cpu_device_node_get(cpu);
+ struct device_node *prev = NULL;
+ int levels = 0, leaves = 0, level;
+
+ if (of_property_read_bool(np, "cache-size"))
+ ++leaves;
+ if (of_property_read_bool(np, "i-cache-size"))
+ ++leaves;
+ if (of_property_read_bool(np, "d-cache-size"))
+ ++leaves;
+ if (leaves > 0)
+ levels = 1;
+
+ prev = np;
+ while ((np = of_find_next_cache_node(np))) {
+ of_node_put(prev);
+ prev = np;
+ if (!of_device_is_compatible(np, "cache"))
+ break;
+ if (of_property_read_u32(np, "cache-level", &level))
+ break;
+ if (level <= levels)
+ break;
+ if (of_property_read_bool(np, "cache-size"))
+ ++leaves;
+ if (of_property_read_bool(np, "i-cache-size"))
+ ++leaves;
+ if (of_property_read_bool(np, "d-cache-size"))
+ ++leaves;
+ levels = level;
+ }
+
+ of_node_put(np);
+ this_cpu_ci->num_levels = levels;
+ this_cpu_ci->num_leaves = leaves;
+
+ return 0;
+}
+
#else
static inline int cache_setup_of_node(unsigned int cpu) { return 0; }
+int init_of_cache_level(unsigned int cpu) { return 0; }
#endif

int __weak cache_setup_acpi(unsigned int cpu)
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index 00b7a6ae8617..ff0328f3fbb0 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -80,6 +80,7 @@ struct cpu_cacheinfo {

struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu);
int init_cache_level(unsigned int cpu);
+int init_of_cache_level(unsigned int cpu);
int populate_cache_leaves(unsigned int cpu);
int cache_setup_acpi(unsigned int cpu);
bool last_level_cache_is_valid(unsigned int cpu);

Acked-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>