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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2008-09-25 15:35:28 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-09-25 15:35:28 +0100
commitc0e9587841a0fd79bbf8296034faefb9afe72fb4 (patch)
treeb82e0e79706f9f63985b4591e1fa02eaa2df73d2 /arch/arm/kernel/setup.c
parent90f1e084783be9bbff4861fa8e460b76de2787f4 (diff)
[ARM] Introduce new bitmask based cache type macros
Rather than trying to (inaccurately) decode the cache type from the registers each time we need to decide what type of cache we have, use a bitmask initialized early during boot. Since the setup is a one-off initialization, we can be a little more clever and take account of the CPU architecture as well. Note that we continue to achieve the compactness on optimised kernels by forcing tests to always-false or always-true as appropriate, thereby allowing the compiler to do build-time code elimination. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/setup.c')
-rw-r--r--arch/arm/kernel/setup.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 1939c904dae3..5b121d81f9eb 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -67,6 +67,8 @@ unsigned int processor_id;
EXPORT_SYMBOL(processor_id);
unsigned int __machine_arch_type;
EXPORT_SYMBOL(__machine_arch_type);
+unsigned int cacheid;
+EXPORT_SYMBOL(cacheid);
unsigned int __atags_pointer __initdata;
@@ -229,6 +231,25 @@ int cpu_architecture(void)
return cpu_arch;
}
+static void __init cacheid_init(void)
+{
+ unsigned int cachetype = read_cpuid_cachetype();
+ unsigned int arch = cpu_architecture();
+
+ if (arch >= CPU_ARCH_ARMv7) {
+ cacheid = CACHEID_VIPT_NONALIASING;
+ if ((cachetype & (3 << 14)) == 1 << 14)
+ cacheid |= CACHEID_ASID_TAGGED;
+ } else if (arch >= CPU_ARCH_ARMv6) {
+ if (cachetype & (1 << 23))
+ cacheid = CACHEID_VIPT_ALIASING;
+ else
+ cacheid = CACHEID_VIPT_NONALIASING;
+ } else {
+ cacheid = CACHEID_VIVT;
+ }
+}
+
/*
* These functions re-use the assembly code in head.S, which
* already provide the required functionality.
@@ -278,6 +299,7 @@ static void __init setup_processor(void)
elf_hwcap &= ~HWCAP_THUMB;
#endif
+ cacheid_init();
cpu_proc_init();
}