[x86 setup] Make struct ist_info cross-architecture, and use in setup code

Make "struct ist_info" valid on both i386 and x86-64, and use the
structure by name in the setup code.  Additionally, "Intel SpeedStep
IST" is redundant, refer to it as IST consistently.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

arch/i386/boot/main.c

@@ -73,15 +73,15 @@ static void keyboard_set_repeat(void)
 }
 
 /*
- * Get Intel SpeedStep IST information.
+ * Get Intel SpeedStep (IST) information.
  */
-static void query_speedstep_ist(void)
+static void query_ist(void)
 {
 	asm("int $0x15"
-	    : "=a" (boot_params.speedstep_info[0]),
-	      "=b" (boot_params.speedstep_info[1]),
-	      "=c" (boot_params.speedstep_info[2]),
-	      "=d" (boot_params.speedstep_info[3])
+	    : "=a" (boot_params.ist_info.signature),
+	      "=b" (boot_params.ist_info.command),
+	      "=c" (boot_params.ist_info.event),
+	      "=d" (boot_params.ist_info.perf_level)
 	    : "a" (0x0000e980),	 /* IST Support */
 	      "d" (0x47534943)); /* Request value */
 }
@@ -144,8 +144,8 @@ void main(void)
 	query_voyager();
 #endif
 
-	/* Query SpeedStep IST information */
-	query_speedstep_ist();
+	/* Query Intel SpeedStep (IST) information */
+	query_ist();
 
 	/* Query APM information */
 #if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)

include/asm-i386/bootparam.h

@@ -4,8 +4,9 @@
 #include <linux/types.h>
 #include <linux/screen_info.h>
 #include <linux/apm_bios.h>
-#include <asm/e820.h>
 #include <linux/edd.h>
+#include <asm/e820.h>
+#include <asm/ist.h>
 #include <video/edid.h>
 
 struct setup_header {
@@ -59,7 +60,7 @@ struct boot_params {
 	struct screen_info screen_info;			/* 0x000 */
 	struct apm_bios_info apm_bios_info;		/* 0x040 */
 	u8  _pad2[12];					/* 0x054 */
-	u32 speedstep_info[4];				/* 0x060 */
+	struct ist_info ist_info;			/* 0x060 */
 	u8  _pad3[16];					/* 0x070 */
 	u8  hd0_info[16];	/* obsolete! */		/* 0x080 */
 	u8  hd1_info[16];	/* obsolete! */		/* 0x090 */

include/asm-i386/ist.h

@@ -19,11 +19,13 @@
 
 #ifdef __KERNEL__
 
+#include <linux/types.h>
+
 struct ist_info {
-	unsigned long	signature;
-	unsigned long	command;
-	unsigned long	event;
-	unsigned long	perf_level;
+	u32 signature;
+	u32 command;
+	u32 event;
+	u32 perf_level;
 };
 
 extern struct ist_info ist_info;

include/asm-x86_64/ist.h

+#include <asm-i386/ist.h>