From 9a802431c527f0ef860399f066a9793794cac17b Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Mon, 16 Jan 2017 10:40:44 +0000 Subject: [PATCH] arm64: cacheinfo: add support to override cache levels via device tree The cache hierarchy can be identified through Cache Level ID(CLIDR) architected system register. However in some cases it will provide only the number of cache levels that are integrated into the processor itself. In other words, it can't provide any information about the caches that are external and/or transparent. Some platforms require to export the information about all such external caches to the userspace applications via the sysfs interface. This patch adds support to override the cache levels using device tree to take such external non-architected caches into account. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Tested-by: Tan Xiaojun Signed-off-by: Sudeep Holla Signed-off-by: Will Deacon --- arch/arm64/kernel/cacheinfo.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/cacheinfo.c b/arch/arm64/kernel/cacheinfo.c index 9617301f76b5..3f2250fc391b 100644 --- a/arch/arm64/kernel/cacheinfo.c +++ b/arch/arm64/kernel/cacheinfo.c @@ -84,7 +84,7 @@ static void ci_leaf_init(struct cacheinfo *this_leaf, static int __init_cache_level(unsigned int cpu) { - unsigned int ctype, level, leaves; + unsigned int ctype, level, leaves, of_level; struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); for (level = 1, leaves = 0; level <= MAX_CACHE_LEVEL; level++) { @@ -97,6 +97,17 @@ 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) { + /* + * 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; + } + this_cpu_ci->num_levels = level; this_cpu_ci->num_leaves = leaves; return 0; -- 2.20.1