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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2014-02-08 16:34:09 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-19 00:38:37 +0400
commit67bad2fdb754dbef14596c0b5d28b3a12c8dfe84 (patch)
tree05c3cd5f809618319346f9642549460f95149f02 /include/linux/mod_devicetable.h
parent91219a3b20325689eb80f7598cce2dc745db171d (diff)
downloadlinux-67bad2fdb754dbef14596c0b5d28b3a12c8dfe84.tar.xz
cpu: add generic support for CPU feature based module autoloading
This patch adds support for advertising optional CPU features over udev using the modalias, and for declaring compatibility with/dependency upon such a feature in a module. The mapping between feature numbers and actual features should be provided by the architecture in a file called <asm/cpufeature.h> which exports the following functions/macros: - cpu_feature(FEAT), a preprocessor macro that maps token FEAT to a numeric index; - bool cpu_have_feature(n), returning whether this CPU has support for feature #n; - MAX_CPU_FEATURES, an upper bound for 'n' in the previous function. The feature can then be enabled by setting CONFIG_GENERIC_CPU_AUTOPROBE for the architecture. For instance, a module that registers its module init function using module_cpu_feature_match(FEAT_X, module_init_function) will be probed automatically when the CPU's support for the 'FEAT_X' feature is advertised over udev, and will only allow the module to be loaded by hand if the 'FEAT_X' feature is supported. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/mod_devicetable.h')
-rw-r--r--include/linux/mod_devicetable.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 45e921401b06..f2ac87c613a5 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -564,6 +564,15 @@ struct x86_cpu_id {
#define X86_MODEL_ANY 0
#define X86_FEATURE_ANY 0 /* Same as FPU, you can't test for that */
+/*
+ * Generic table type for matching CPU features.
+ * @feature: the bit number of the feature (0 - 65535)
+ */
+
+struct cpu_feature {
+ __u16 feature;
+};
+
#define IPACK_ANY_FORMAT 0xff
#define IPACK_ANY_ID (~0)
struct ipack_device_id {