Commit cde0fbff authored by Pierre Gondois's avatar Pierre Gondois Committed by Sudeep Holla
Browse files

cacheinfo: Check cache properties are present in DT 



If a Device Tree (DT) is used, the presence of cache properties is
assumed. Not finding any is not considered. For arm64 platforms,
cache information can be fetched from the clidr_el1 register.
Checking whether cache information is available in the DT
allows to switch to using clidr_el1.

init_of_cache_level()
\-of_count_cache_leaves()
will assume there a 2 cache leaves (L1 data/instruction caches), which
can be different from clidr_el1 information.

cache_setup_of_node() tries to read cache properties in the DT.
If there are none, this is considered a success. Knowing no
information was available would allow to switch to using clidr_el1.

Fixes: de0df442 ("cacheinfo: Check 'cache-unified' property to count cache leaves")
Reported-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/all/20230404-hatred-swimmer-6fecdf33b57a@spud/


Signed-off-by: default avatarPierre Gondois <pierre.gondois@arm.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230414081453.244787-3-pierre.gondois@arm.com


Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent 7a306e3e

drivers/base/cacheinfo.c

+32 −0
Original line number Diff line number Diff line
@@ -78,6 +78,9 @@ bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y) 
}



#ifdef CONFIG_OF



static bool of_check_cache_nodes(struct device_node *np);



/* OF properties to query for a given cache type */

struct cache_type_info {

	const char *size_prop;
@@ -205,6 +208,11 @@ static int cache_setup_of_node(unsigned int cpu) 
		return -ENOENT;

	}



	if (!of_check_cache_nodes(np)) {

		of_node_put(np);

		return -ENOENT;

	}



	prev = np;



	while (index < cache_leaves(cpu)) {
@@ -229,6 +237,25 @@ static int cache_setup_of_node(unsigned int cpu) 
	return 0;

}



static bool of_check_cache_nodes(struct device_node *np)

{

	struct device_node *next;



	if (of_property_present(np, "cache-size")   ||

	    of_property_present(np, "i-cache-size") ||

	    of_property_present(np, "d-cache-size") ||

	    of_property_present(np, "cache-unified"))

		return true;



	next = of_find_next_cache_node(np);

	if (next) {

		of_node_put(next);

		return true;

	}



	return false;

}



static int of_count_cache_leaves(struct device_node *np)

{

	unsigned int leaves = 0;
@@ -260,6 +287,11 @@ int init_of_cache_level(unsigned int cpu) 
	struct device_node *prev = NULL;

	unsigned int levels = 0, leaves, level;



	if (!of_check_cache_nodes(np)) {

		of_node_put(np);

		return -ENOENT;

	}



	leaves = of_count_cache_leaves(np);

	if (leaves > 0)

		levels = 1;