x86: add comments to processor.h
add comments to the FPU structures of processor.h.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h
index e49e5e6..1f9501a 100644
--- a/include/asm-x86/processor.h
+++ b/include/asm-x86/processor.h
@@ -289,42 +289,47 @@
#define MXCSR_DEFAULT 0x1f80
struct i387_fsave_struct {
- u32 cwd;
- u32 swd;
- u32 twd;
- u32 fip;
- u32 fcs;
- u32 foo;
- u32 fos;
- /* 8*10 bytes for each FP-reg = 80 bytes: */
+ u32 cwd; /* FPU Control Word */
+ u32 swd; /* FPU Status Word */
+ u32 twd; /* FPU Tag Word */
+ u32 fip; /* FPU IP Offset */
+ u32 fcs; /* FPU IP Selector */
+ u32 foo; /* FPU Operand Pointer Offset */
+ u32 fos; /* FPU Operand Pointer Selector */
+
+ /* 8*10 bytes for each FP-reg = 80 bytes: */
u32 st_space[20];
- /* Software status information: */
+
+ /* Software status information [not touched by FSAVE ]: */
u32 status;
};
struct i387_fxsave_struct {
- u16 cwd;
- u16 swd;
- u16 twd;
- u16 fop;
+ u16 cwd; /* Control Word */
+ u16 swd; /* Status Word */
+ u16 twd; /* Tag Word */
+ u16 fop; /* Last Instruction Opcode */
union {
struct {
- u64 rip;
- u64 rdp;
+ u64 rip; /* Instruction Pointer */
+ u64 rdp; /* Data Pointer */
};
struct {
- u32 fip;
- u32 fcs;
- u32 foo;
- u32 fos;
+ u32 fip; /* FPU IP Offset */
+ u32 fcs; /* FPU IP Selector */
+ u32 foo; /* FPU Operand Offset */
+ u32 fos; /* FPU Operand Selector */
};
};
- u32 mxcsr;
- u32 mxcsr_mask;
- /* 8*16 bytes for each FP-reg = 128 bytes: */
+ u32 mxcsr; /* MXCSR Register State */
+ u32 mxcsr_mask; /* MXCSR Mask */
+
+ /* 8*16 bytes for each FP-reg = 128 bytes: */
u32 st_space[32];
- /* 16*16 bytes for each XMM-reg = 256 bytes: */
+
+ /* 16*16 bytes for each XMM-reg = 256 bytes: */
u32 xmm_space[64];
+
u32 padding[24];
} __attribute__((aligned(16)));