Provide a few helper functions to read CPUID leafs or individual registers
into a data structure without requiring unions.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/include/asm/cpuid.h | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
--- a/arch/x86/include/asm/cpuid.h
+++ b/arch/x86/include/asm/cpuid.h
@@ -127,6 +127,38 @@ static inline unsigned int cpuid_edx(uns
return edx;
}
+static inline void __cpuid_read(unsigned int leaf, unsigned int subleaf, u32 *regs)
+{
+ regs[CPUID_EAX] = leaf;
+ regs[CPUID_ECX] = subleaf;
+ __cpuid(regs, regs + 1, regs + 2, regs + 3);
+}
+
+#define cpuid_subleaf(leaf, subleaf, regs) \
+ BUILD_BUG_ON(sizeof(*(regs)) != 16); \
+ __cpuid_read(leaf, subleaf, (u32 *)(regs))
+
+#define cpuid_leaf(leaf, regs) \
+ BUILD_BUG_ON(sizeof(*(regs)) != 16); \
+ __cpuid_read(leaf, 0, (u32 *)(regs))
+
+static inline void __cpuid_read_reg(unsigned int leaf, unsigned int subleaf,
+ enum cpuid_regs_idx regidx, u32 *reg)
+{
+ u32 regs[4];
+
+ __cpuid_read(leaf, subleaf, regs);
+ *reg = regs[regidx];
+}
+
+#define cpuid_subleaf_reg(leaf, subleaf, regidx, reg) \
+ BUILD_BUG_ON(sizeof(*(reg)) != 4); \
+ __cpuid_read_reg(leaf, subleaf, regidx, (u32 *)(reg))
+
+#define cpuid_leaf_reg(leaf, regidx, reg) \
+ BUILD_BUG_ON(sizeof(*(reg)) != 4); \
+ __cpuid_read_reg(leaf, 0, regidx, (u32 *)(reg))
+
static __always_inline bool cpuid_function_is_indexed(u32 function)
{
switch (function) {
