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author | Catalin Marinas <catalin.marinas@arm.com> | 2014-04-03 17:48:54 +0100 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2014-05-09 15:47:45 +0100 |
commit | a41dc0e841523efe1df7fa5ad48b5e9027a921df (patch) | |
tree | c162086a45807902dd8c510132f3c3f82603d3e6 /arch/arm64/kernel | |
parent | 89ca3b881987f5a4be4c5dbaa7f0df12bbdde2fd (diff) | |
download | op-kernel-dev-a41dc0e841523efe1df7fa5ad48b5e9027a921df.zip op-kernel-dev-a41dc0e841523efe1df7fa5ad48b5e9027a921df.tar.gz |
arm64: Implement cache_line_size() based on CTR_EL0.CWG
The hardware provides the maximum cache line size in the system via the
CTR_EL0.CWG bits. This patch implements the cache_line_size() function
to read such information, together with a sanity check if the statically
defined L1_CACHE_BYTES is smaller than the hardware value.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r-- | arch/arm64/kernel/setup.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 7ec7846..5b9e046 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -25,6 +25,7 @@ #include <linux/utsname.h> #include <linux/initrd.h> #include <linux/console.h> +#include <linux/cache.h> #include <linux/bootmem.h> #include <linux/seq_file.h> #include <linux/screen_info.h> @@ -198,6 +199,8 @@ static void __init setup_processor(void) { struct cpu_info *cpu_info; u64 features, block; + u32 cwg; + int cls; cpu_info = lookup_processor_type(read_cpuid_id()); if (!cpu_info) { @@ -215,6 +218,18 @@ static void __init setup_processor(void) elf_hwcap = 0; /* + * Check for sane CTR_EL0.CWG value. + */ + cwg = cache_type_cwg(); + cls = cache_line_size(); + if (!cwg) + pr_warn("No Cache Writeback Granule information, assuming cache line size %d\n", + cls); + if (L1_CACHE_BYTES < cls) + pr_warn("L1_CACHE_BYTES smaller than the Cache Writeback Granule (%d < %d)\n", + L1_CACHE_BYTES, cls); + + /* * ID_AA64ISAR0_EL1 contains 4-bit wide signed feature blocks. * The blocks we test below represent incremental functionality * for non-negative values. Negative values are reserved. |