i386: move kernel/cpu/mtrr

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 224 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/centaur.c b/arch/x86/kernel/cpu/mtrr/centaur.c
new file mode 100644
index 00000000000..cb9aa3a7a7a
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/centaur.c
@@ -0,0 +1,224 @@
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include "mtrr.h"
+
+static struct {
+	unsigned long high;
+	unsigned long low;
+} centaur_mcr[8];
+
+static u8 centaur_mcr_reserved;
+static u8 centaur_mcr_type;	/* 0 for winchip, 1 for winchip2 */
+
+/*
+ *	Report boot time MCR setups 
+ */
+
+static int
+centaur_get_free_region(unsigned long base, unsigned long size, int replace_reg)
+/*  [SUMMARY] Get a free MTRR.
+    <base> The starting (base) address of the region.
+    <size> The size (in bytes) of the region.
+    [RETURNS] The index of the region on success, else -1 on error.
+*/
+{
+	int i, max;
+	mtrr_type ltype;
+	unsigned long lbase, lsize;
+
+	max = num_var_ranges;
+	if (replace_reg >= 0 && replace_reg < max)
+		return replace_reg;
+	for (i = 0; i < max; ++i) {
+		if (centaur_mcr_reserved & (1 << i))
+			continue;
+		mtrr_if->get(i, &lbase, &lsize, &ltype);
+		if (lsize == 0)
+			return i;
+	}
+	return -ENOSPC;
+}
+
+void
+mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
+{
+	centaur_mcr[mcr].low = lo;
+	centaur_mcr[mcr].high = hi;
+}
+
+static void
+centaur_get_mcr(unsigned int reg, unsigned long *base,
+		unsigned long *size, mtrr_type * type)
+{
+	*base = centaur_mcr[reg].high >> PAGE_SHIFT;
+	*size = -(centaur_mcr[reg].low & 0xfffff000) >> PAGE_SHIFT;
+	*type = MTRR_TYPE_WRCOMB;	/*  If it is there, it is write-combining  */
+	if (centaur_mcr_type == 1 && ((centaur_mcr[reg].low & 31) & 2))
+		*type = MTRR_TYPE_UNCACHABLE;
+	if (centaur_mcr_type == 1 && (centaur_mcr[reg].low & 31) == 25)
+		*type = MTRR_TYPE_WRBACK;
+	if (centaur_mcr_type == 0 && (centaur_mcr[reg].low & 31) == 31)
+		*type = MTRR_TYPE_WRBACK;
+
+}
+
+static void centaur_set_mcr(unsigned int reg, unsigned long base,
+			    unsigned long size, mtrr_type type)
+{
+	unsigned long low, high;
+
+	if (size == 0) {
+		/*  Disable  */
+		high = low = 0;
+	} else {
+		high = base << PAGE_SHIFT;
+		if (centaur_mcr_type == 0)
+			low = -size << PAGE_SHIFT | 0x1f;	/* only support write-combining... */
+		else {
+			if (type == MTRR_TYPE_UNCACHABLE)
+				low = -size << PAGE_SHIFT | 0x02;	/* NC */
+			else
+				low = -size << PAGE_SHIFT | 0x09;	/* WWO,WC */
+		}
+	}
+	centaur_mcr[reg].high = high;
+	centaur_mcr[reg].low = low;
+	wrmsr(MSR_IDT_MCR0 + reg, low, high);
+}
+
+#if 0
+/*
+ *	Initialise the later (saner) Winchip MCR variant. In this version
+ *	the BIOS can pass us the registers it has used (but not their values)
+ *	and the control register is read/write
+ */
+
+static void __init
+centaur_mcr1_init(void)
+{
+	unsigned i;
+	u32 lo, hi;
+
+	/* Unfortunately, MCR's are read-only, so there is no way to
+	 * find out what the bios might have done.
+	 */
+
+	rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+	if (((lo >> 17) & 7) == 1) {	/* Type 1 Winchip2 MCR */
+		lo &= ~0x1C0;	/* clear key */
+		lo |= 0x040;	/* set key to 1 */
+		wrmsr(MSR_IDT_MCR_CTRL, lo, hi);	/* unlock MCR */
+	}
+
+	centaur_mcr_type = 1;
+
+	/*
+	 *  Clear any unconfigured MCR's.
+	 */
+
+	for (i = 0; i < 8; ++i) {
+		if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0) {
+			if (!(lo & (1 << (9 + i))))
+				wrmsr(MSR_IDT_MCR0 + i, 0, 0);
+			else
+				/*
+				 *      If the BIOS set up an MCR we cannot see it
+				 *      but we don't wish to obliterate it
+				 */
+				centaur_mcr_reserved |= (1 << i);
+		}
+	}
+	/*  
+	 *  Throw the main write-combining switch... 
+	 *  However if OOSTORE is enabled then people have already done far
+	 *  cleverer things and we should behave. 
+	 */
+
+	lo |= 15;		/* Write combine enables */
+	wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+}
+
+/*
+ *	Initialise the original winchip with read only MCR registers
+ *	no used bitmask for the BIOS to pass on and write only control
+ */
+
+static void __init
+centaur_mcr0_init(void)
+{
+	unsigned i;
+
+	/* Unfortunately, MCR's are read-only, so there is no way to
+	 * find out what the bios might have done.
+	 */
+
+	/* Clear any unconfigured MCR's.
+	 * This way we are sure that the centaur_mcr array contains the actual
+	 * values. The disadvantage is that any BIOS tweaks are thus undone.
+	 *
+	 */
+	for (i = 0; i < 8; ++i) {
+		if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0)
+			wrmsr(MSR_IDT_MCR0 + i, 0, 0);
+	}
+
+	wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0);	/* Write only */
+}
+
+/*
+ *	Initialise Winchip series MCR registers
+ */
+
+static void __init
+centaur_mcr_init(void)
+{
+	struct set_mtrr_context ctxt;
+
+	set_mtrr_prepare_save(&ctxt);
+	set_mtrr_cache_disable(&ctxt);
+
+	if (boot_cpu_data.x86_model == 4)
+		centaur_mcr0_init();
+	else if (boot_cpu_data.x86_model == 8 || boot_cpu_data.x86_model == 9)
+		centaur_mcr1_init();
+
+	set_mtrr_done(&ctxt);
+}
+#endif
+
+static int centaur_validate_add_page(unsigned long base, 
+				     unsigned long size, unsigned int type)
+{
+	/*
+	 *  FIXME: Winchip2 supports uncached
+	 */
+	if (type != MTRR_TYPE_WRCOMB && 
+	    (centaur_mcr_type == 0 || type != MTRR_TYPE_UNCACHABLE)) {
+		printk(KERN_WARNING
+		       "mtrr: only write-combining%s supported\n",
+		       centaur_mcr_type ? " and uncacheable are"
+		       : " is");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static struct mtrr_ops centaur_mtrr_ops = {
+	.vendor            = X86_VENDOR_CENTAUR,
+//	.init              = centaur_mcr_init,
+	.set               = centaur_set_mcr,
+	.get               = centaur_get_mcr,
+	.get_free_region   = centaur_get_free_region,
+	.validate_add_page = centaur_validate_add_page,
+	.have_wrcomb       = positive_have_wrcomb,
+};
+
+int __init centaur_init_mtrr(void)
+{
+	set_mtrr_ops(&centaur_mtrr_ops);
+	return 0;
+}
+
+//arch_initcall(centaur_init_mtrr);