[PATCH] cyrix cpu optimisations

arch/i386/kernel/cpu/cyrix.c

@@ -106,6 +106,89 @@ static void __init check_cx686_slop(struct cpuinfo_x86 *c)
 	}
 }
 
+
+static void __init set_cx86_reorder(void)
+{
+#ifdef CONFIG_OOSTORE
+	u8 ccr3;
+
+	printk(KERN_INFO "Enable Memory access reorder on Cyrix/NSC processor.\n");
+	ccr3 = getCx86(CX86_CCR3);
+	setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */
+
+	/* Load/Store Serialize to mem access disable (=reorder it) */
+	setCx86(CX86_PCR0, getCx86(CX86_PCR0) & ~0x80);
+#ifdef CONFIG_NOHIGHMEM
+	/* set load/store serialize from 1GB to 4GB */
+	ccr3 |= 0xe0;
+#endif
+	setCx86(CX86_CCR3, ccr3);
+#endif	
+}
+
+static void __init set_cx86_memwb(void)
+{
+	u32 cr0;
+
+	printk(KERN_INFO "Enable Memory-Write-back mode on Cyrix/NSC processor.\n");
+
+	/* CCR2 bit 2: unlock NW bit */
+	setCx86(CX86_CCR2, getCx86(CX86_CCR2) & ~0x04);
+	/* set 'Not Write-through' */
+	cr0 = 0x20000000;
+	__asm__("movl %%cr0,%%eax\n\t"
+		"orl %0,%%eax\n\t"
+		"movl %%eax,%%cr0\n"
+		: : "r" (cr0)
+		:"ax");
+	/* CCR2 bit 2: lock NW bit and set WT1 */
+	setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x14 );
+}
+
+static void __init set_cx86_inc(void)
+{
+	unsigned char ccr3;
+
+	printk(KERN_INFO "Enable Incrementor on Cyrix/NSC processor.\n");
+
+	ccr3 = getCx86(CX86_CCR3);
+	setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */
+	/* PCR1 -- Performance Control */
+	/* Incrementor on, whatever that is */
+	setCx86(CX86_PCR1, getCx86(CX86_PCR1) | 0x02);
+	/* PCR0 -- Performance Control */
+	/* Incrementor Margin 10 */
+	setCx86(CX86_PCR0, getCx86(CX86_PCR0) | 0x04); 
+	setCx86(CX86_CCR3, ccr3);	/* disable MAPEN */
+}
+
+/*
+ *	Configure later MediaGX and/or Geode processor.
+ */
+
+static void __init geode_configure(void)
+{
+	unsigned long flags;
+	u8 ccr3, ccr4;
+	unsigned long cr0;
+	local_irq_save(flags);
+	
+	ccr3 = getCx86(CX86_CCR3);
+	setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10);	/* Enable */
+	
+	ccr4 = getCx86(CX86_CCR4);
+	ccr4 |= 0x38;		/* FPU fast, DTE cache, Mem bypass */
+	
+	setCx86(CX86_CCR3, ccr3);
+	
+	set_cx86_memwb();
+	set_cx86_reorder();	
+	set_cx86_inc();
+	
+	local_irq_restore(flags);
+}
+
+
 static void __init init_cyrix(struct cpuinfo_x86 *c)
 {
 	unsigned char dir0, dir0_msn, dir0_lsn, dir1 = 0;
@@ -201,7 +284,10 @@ static void __init init_cyrix(struct cpuinfo_x86 *c)
 		if (c->cpuid_level == 2) {
 			/* Enable cxMMX extensions (GX1 Datasheet 54) */
 			setCx86(CX86_CCR7, getCx86(CX86_CCR7)|1);
-
+			
+			/* GXlv/GXm/GX1 */
+			if((dir1 >= 0x50 && dir1 <= 0x54) || dir1 >= 0x63)
+				geode_configure();
 			get_model_name(c);  /* get CPU marketing name */
 			return;
 		}

include/asm-i386/processor.h

@@ -221,6 +221,9 @@ static inline void clear_in_cr4 (unsigned long mask)
 /*
  *      NSC/Cyrix CPU configuration register indexes
  */
+
+#define CX86_PCR0 0x20
+#define CX86_GCR  0xb8
 #define CX86_CCR0 0xc0
 #define CX86_CCR1 0xc1
 #define CX86_CCR2 0xc2
@@ -229,6 +232,7 @@ static inline void clear_in_cr4 (unsigned long mask)
 #define CX86_CCR5 0xe9
 #define CX86_CCR6 0xea
 #define CX86_CCR7 0xeb
+#define CX86_PCR1 0xf0
 #define CX86_DIR0 0xfe
 #define CX86_DIR1 0xff
 #define CX86_ARR_BASE 0xc4