[patch 5/8] Roll all the cpuid asm into one __cpuid call.

Jeremy Fitzhardinge
2006-08-03T00:26:51Z

[-- Attachment #1: 005-cpuid-cleanup.patch --]
[-- Type: text/plain, Size: 3061 bytes --]

It's a little neater, and also means only one place to patch for
paravirtualization.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>

---
include/asm-i386/processor.h | 74 +++++++++++++++++++-----------------------
1 file changed, 34 insertions(+), 40 deletions(-)

===================================================================
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -143,31 +143,37 @@ static inline void detect_ht(struct cpui
#define X86_EFLAGS_VIP 0x00100000 /* Virtual Interrupt Pending */
#define X86_EFLAGS_ID 0x00200000 /* CPUID detection flag */

-/*
- * Generic CPUID function
- * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
- * resulting in stale register contents being returned.
- */
-static inline void cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx)
-{
+static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
+ unsigned int *ecx, unsigned int *edx)
+{
+ /* ecx is often an input as well as an output. */
__asm__("cpuid"
: "=a" (*eax),
"=b" (*ebx),
"=c" (*ecx),
"=d" (*edx)
- : "0" (op), "c"(0));
+ : "0" (*eax), "2" (*ecx));
+}
+
+/*
+ * Generic CPUID function
+ * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx
+ * resulting in stale register contents being returned.
+ */
+static inline void cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx)
+{
+ *eax = op;
+ *ecx = 0;
+ __cpuid(eax, ebx, ecx, edx);
}

/* Some CPUID calls want 'count' to be placed in ecx */
static inline void cpuid_count(int op, int count, int *eax, int *ebx, int *ecx,
- int *edx)
-{
- __asm__("cpuid"
- : "=a" (*eax),
- "=b" (*ebx),
- "=c" (*ecx),
- "=d" (*edx)
- : "0" (op), "c" (count));
+ int *edx)
+{
+ *eax = op;
+ *ecx = count;
+ __cpuid(eax, ebx, ecx, edx);
}

/*
@@ -175,42 +181,30 @@ static inline void cpuid_count(int op, i
*/
static inline unsigned int cpuid_eax(unsigned int op)
{
- unsigned int eax;
-
- __asm__("cpuid"
- : "=a" (eax)
- : "0" (op)
- : "bx", "cx", "dx");
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return eax;
}
static inline unsigned int cpuid_ebx(unsigned int op)
{
- unsigned int eax, ebx;
-
- __asm__("cpuid"
- : "=a" (eax), "=b" (ebx)
- : "0" (op)
- : "cx", "dx" );
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return ebx;
}
static inline unsigned int cpuid_ecx(unsigned int op)
{
- unsigned int eax, ecx;
-
- __asm__("cpuid"
- : "=a" (eax), "=c" (ecx)
- : "0" (op)
- : "bx", "dx" );
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return ecx;
}
static inline unsigned int cpuid_edx(unsigned int op)
{
- unsigned int eax, edx;
-
- __asm__("cpuid"
- : "=a" (eax), "=d" (edx)
- : "0" (op)
- : "bx", "cx");
+ unsigned int eax, ebx, ecx, edx;
+
+ cpuid(op, &eax, &ebx, &ecx, &edx);
return edx;
}

--