i386: move kernel/cpu/mtrr

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

1 files changed, 509 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
new file mode 100644
index 000000000000..56f64e34829f
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -0,0 +1,509 @@
+/* This only handles 32bit MTRR on 32bit hosts. This is strictly wrong
+   because MTRRs can span upto 40 bits (36bits on most modern x86) */ 
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <asm/io.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include <asm/system.h>
+#include <asm/cpufeature.h>
+#include <asm/tlbflush.h>
+#include "mtrr.h"
+
+struct mtrr_state {
+	struct mtrr_var_range *var_ranges;
+	mtrr_type fixed_ranges[NUM_FIXED_RANGES];
+	unsigned char enabled;
+	unsigned char have_fixed;
+	mtrr_type def_type;
+};
+
+struct fixed_range_block {
+	int base_msr; /* start address of an MTRR block */
+	int ranges;   /* number of MTRRs in this block  */
+};
+
+static struct fixed_range_block fixed_range_blocks[] = {
+	{ MTRRfix64K_00000_MSR, 1 }, /* one  64k MTRR  */
+	{ MTRRfix16K_80000_MSR, 2 }, /* two  16k MTRRs */
+	{ MTRRfix4K_C0000_MSR,  8 }, /* eight 4k MTRRs */
+	{}
+};
+
+static unsigned long smp_changes_mask;
+static struct mtrr_state mtrr_state = {};
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "mtrr."
+
+static int mtrr_show;
+module_param_named(show, mtrr_show, bool, 0);
+
+/*  Get the MSR pair relating to a var range  */
+static void
+get_mtrr_var_range(unsigned int index, struct mtrr_var_range *vr)
+{
+	rdmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi);
+	rdmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi);
+}
+
+static void
+get_fixed_ranges(mtrr_type * frs)
+{
+	unsigned int *p = (unsigned int *) frs;
+	int i;
+
+	rdmsr(MTRRfix64K_00000_MSR, p[0], p[1]);
+
+	for (i = 0; i < 2; i++)
+		rdmsr(MTRRfix16K_80000_MSR + i, p[2 + i * 2], p[3 + i * 2]);
+	for (i = 0; i < 8; i++)
+		rdmsr(MTRRfix4K_C0000_MSR + i, p[6 + i * 2], p[7 + i * 2]);
+}
+
+void mtrr_save_fixed_ranges(void *info)
+{
+	if (cpu_has_mtrr)
+		get_fixed_ranges(mtrr_state.fixed_ranges);
+}
+
+static void print_fixed(unsigned base, unsigned step, const mtrr_type*types)
+{
+	unsigned i;
+
+	for (i = 0; i < 8; ++i, ++types, base += step)
+		printk(KERN_INFO "MTRR %05X-%05X %s\n",
+			base, base + step - 1, mtrr_attrib_to_str(*types));
+}
+
+/*  Grab all of the MTRR state for this CPU into *state  */
+void __init get_mtrr_state(void)
+{
+	unsigned int i;
+	struct mtrr_var_range *vrs;
+	unsigned lo, dummy;
+
+	if (!mtrr_state.var_ranges) {
+		mtrr_state.var_ranges = kmalloc(num_var_ranges * sizeof (struct mtrr_var_range), 
+						GFP_KERNEL);
+		if (!mtrr_state.var_ranges)
+			return;
+	} 
+	vrs = mtrr_state.var_ranges;
+
+	rdmsr(MTRRcap_MSR, lo, dummy);
+	mtrr_state.have_fixed = (lo >> 8) & 1;
+
+	for (i = 0; i < num_var_ranges; i++)
+		get_mtrr_var_range(i, &vrs[i]);
+	if (mtrr_state.have_fixed)
+		get_fixed_ranges(mtrr_state.fixed_ranges);
+
+	rdmsr(MTRRdefType_MSR, lo, dummy);
+	mtrr_state.def_type = (lo & 0xff);
+	mtrr_state.enabled = (lo & 0xc00) >> 10;
+
+	if (mtrr_show) {
+		int high_width;
+
+		printk(KERN_INFO "MTRR default type: %s\n", mtrr_attrib_to_str(mtrr_state.def_type));
+		if (mtrr_state.have_fixed) {
+			printk(KERN_INFO "MTRR fixed ranges %sabled:\n",
+			       mtrr_state.enabled & 1 ? "en" : "dis");
+			print_fixed(0x00000, 0x10000, mtrr_state.fixed_ranges + 0);
+			for (i = 0; i < 2; ++i)
+				print_fixed(0x80000 + i * 0x20000, 0x04000, mtrr_state.fixed_ranges + (i + 1) * 8);
+			for (i = 0; i < 8; ++i)
+				print_fixed(0xC0000 + i * 0x08000, 0x01000, mtrr_state.fixed_ranges + (i + 3) * 8);
+		}
+		printk(KERN_INFO "MTRR variable ranges %sabled:\n",
+		       mtrr_state.enabled & 2 ? "en" : "dis");
+		high_width = ((size_or_mask ? ffs(size_or_mask) - 1 : 32) - (32 - PAGE_SHIFT) + 3) / 4;
+		for (i = 0; i < num_var_ranges; ++i) {
+			if (mtrr_state.var_ranges[i].mask_lo & (1 << 11))
+				printk(KERN_INFO "MTRR %u base %0*X%05X000 mask %0*X%05X000 %s\n",
+				       i,
+				       high_width,
+				       mtrr_state.var_ranges[i].base_hi,
+				       mtrr_state.var_ranges[i].base_lo >> 12,
+				       high_width,
+				       mtrr_state.var_ranges[i].mask_hi,
+				       mtrr_state.var_ranges[i].mask_lo >> 12,
+				       mtrr_attrib_to_str(mtrr_state.var_ranges[i].base_lo & 0xff));
+			else
+				printk(KERN_INFO "MTRR %u disabled\n", i);
+		}
+	}
+}
+
+/*  Some BIOS's are fucked and don't set all MTRRs the same!  */
+void __init mtrr_state_warn(void)
+{
+	unsigned long mask = smp_changes_mask;
+
+	if (!mask)
+		return;
+	if (mask & MTRR_CHANGE_MASK_FIXED)
+		printk(KERN_WARNING "mtrr: your CPUs had inconsistent fixed MTRR settings\n");
+	if (mask & MTRR_CHANGE_MASK_VARIABLE)
+		printk(KERN_WARNING "mtrr: your CPUs had inconsistent variable MTRR settings\n");
+	if (mask & MTRR_CHANGE_MASK_DEFTYPE)
+		printk(KERN_WARNING "mtrr: your CPUs had inconsistent MTRRdefType settings\n");
+	printk(KERN_INFO "mtrr: probably your BIOS does not setup all CPUs.\n");
+	printk(KERN_INFO "mtrr: corrected configuration.\n");
+}
+
+/* Doesn't attempt to pass an error out to MTRR users
+   because it's quite complicated in some cases and probably not
+   worth it because the best error handling is to ignore it. */
+void mtrr_wrmsr(unsigned msr, unsigned a, unsigned b)
+{
+	if (wrmsr_safe(msr, a, b) < 0)
+		printk(KERN_ERR
+			"MTRR: CPU %u: Writing MSR %x to %x:%x failed\n",
+			smp_processor_id(), msr, a, b);
+}
+
+/**
+ * Enable and allow read/write of extended fixed-range MTRR bits on K8 CPUs
+ * see AMD publication no. 24593, chapter 3.2.1 for more information
+ */
+static inline void k8_enable_fixed_iorrs(void)
+{
+	unsigned lo, hi;
+
+	rdmsr(MSR_K8_SYSCFG, lo, hi);
+	mtrr_wrmsr(MSR_K8_SYSCFG, lo
+				| K8_MTRRFIXRANGE_DRAM_ENABLE
+				| K8_MTRRFIXRANGE_DRAM_MODIFY, hi);
+}
+
+/**
+ * Checks and updates an fixed-range MTRR if it differs from the value it
+ * should have. If K8 extenstions are wanted, update the K8 SYSCFG MSR also.
+ * see AMD publication no. 24593, chapter 7.8.1, page 233 for more information
+ * \param msr MSR address of the MTTR which should be checked and updated
+ * \param changed pointer which indicates whether the MTRR needed to be changed
+ * \param msrwords pointer to the MSR values which the MSR should have
+ */
+static void set_fixed_range(int msr, int * changed, unsigned int * msrwords)
+{
+	unsigned lo, hi;
+
+	rdmsr(msr, lo, hi);
+
+	if (lo != msrwords[0] || hi != msrwords[1]) {
+		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+		    boot_cpu_data.x86 == 15 &&
+		    ((msrwords[0] | msrwords[1]) & K8_MTRR_RDMEM_WRMEM_MASK))
+			k8_enable_fixed_iorrs();
+		mtrr_wrmsr(msr, msrwords[0], msrwords[1]);
+		*changed = TRUE;
+	}
+}
+
+int generic_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) {
+		mtrr_if->get(i, &lbase, &lsize, &ltype);
+		if (lsize == 0)
+			return i;
+	}
+	return -ENOSPC;
+}
+
+static void generic_get_mtrr(unsigned int reg, unsigned long *base,
+			     unsigned long *size, mtrr_type *type)
+{
+	unsigned int mask_lo, mask_hi, base_lo, base_hi;
+
+	rdmsr(MTRRphysMask_MSR(reg), mask_lo, mask_hi);
+	if ((mask_lo & 0x800) == 0) {
+		/*  Invalid (i.e. free) range  */
+		*base = 0;
+		*size = 0;
+		*type = 0;
+		return;
+	}
+
+	rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi);
+
+	/* Work out the shifted address mask. */
+	mask_lo = size_or_mask | mask_hi << (32 - PAGE_SHIFT)
+	    | mask_lo >> PAGE_SHIFT;
+
+	/* This works correctly if size is a power of two, i.e. a
+	   contiguous range. */
+	*size = -mask_lo;
+	*base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT;
+	*type = base_lo & 0xff;
+}
+
+/**
+ * Checks and updates the fixed-range MTRRs if they differ from the saved set
+ * \param frs pointer to fixed-range MTRR values, saved by get_fixed_ranges()
+ */
+static int set_fixed_ranges(mtrr_type * frs)
+{
+	unsigned long long *saved = (unsigned long long *) frs;
+	int changed = FALSE;
+	int block=-1, range;
+
+	while (fixed_range_blocks[++block].ranges)
+	    for (range=0; range < fixed_range_blocks[block].ranges; range++)
+		set_fixed_range(fixed_range_blocks[block].base_msr + range,
+		    &changed, (unsigned int *) saved++);
+
+	return changed;
+}
+
+/*  Set the MSR pair relating to a var range. Returns TRUE if
+    changes are made  */
+static int set_mtrr_var_ranges(unsigned int index, struct mtrr_var_range *vr)
+{
+	unsigned int lo, hi;
+	int changed = FALSE;
+
+	rdmsr(MTRRphysBase_MSR(index), lo, hi);
+	if ((vr->base_lo & 0xfffff0ffUL) != (lo & 0xfffff0ffUL)
+	    || (vr->base_hi & (size_and_mask >> (32 - PAGE_SHIFT))) !=
+		(hi & (size_and_mask >> (32 - PAGE_SHIFT)))) {
+		mtrr_wrmsr(MTRRphysBase_MSR(index), vr->base_lo, vr->base_hi);
+		changed = TRUE;
+	}
+
+	rdmsr(MTRRphysMask_MSR(index), lo, hi);
+
+	if ((vr->mask_lo & 0xfffff800UL) != (lo & 0xfffff800UL)
+	    || (vr->mask_hi & (size_and_mask >> (32 - PAGE_SHIFT))) !=
+		(hi & (size_and_mask >> (32 - PAGE_SHIFT)))) {
+		mtrr_wrmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi);
+		changed = TRUE;
+	}
+	return changed;
+}
+
+static u32 deftype_lo, deftype_hi;
+
+static unsigned long set_mtrr_state(void)
+/*  [SUMMARY] Set the MTRR state for this CPU.
+    <state> The MTRR state information to read.
+    <ctxt> Some relevant CPU context.
+    [NOTE] The CPU must already be in a safe state for MTRR changes.
+    [RETURNS] 0 if no changes made, else a mask indication what was changed.
+*/
+{
+	unsigned int i;
+	unsigned long change_mask = 0;
+
+	for (i = 0; i < num_var_ranges; i++)
+		if (set_mtrr_var_ranges(i, &mtrr_state.var_ranges[i]))
+			change_mask |= MTRR_CHANGE_MASK_VARIABLE;
+
+	if (mtrr_state.have_fixed && set_fixed_ranges(mtrr_state.fixed_ranges))
+		change_mask |= MTRR_CHANGE_MASK_FIXED;
+
+	/*  Set_mtrr_restore restores the old value of MTRRdefType,
+	   so to set it we fiddle with the saved value  */
+	if ((deftype_lo & 0xff) != mtrr_state.def_type
+	    || ((deftype_lo & 0xc00) >> 10) != mtrr_state.enabled) {
+		deftype_lo = (deftype_lo & ~0xcff) | mtrr_state.def_type | (mtrr_state.enabled << 10);
+		change_mask |= MTRR_CHANGE_MASK_DEFTYPE;
+	}
+
+	return change_mask;
+}
+
+
+static unsigned long cr4 = 0;
+static DEFINE_SPINLOCK(set_atomicity_lock);
+
+/*
+ * Since we are disabling the cache don't allow any interrupts - they
+ * would run extremely slow and would only increase the pain.  The caller must
+ * ensure that local interrupts are disabled and are reenabled after post_set()
+ * has been called.
+ */
+
+static void prepare_set(void) __acquires(set_atomicity_lock)
+{
+	unsigned long cr0;
+
+	/*  Note that this is not ideal, since the cache is only flushed/disabled
+	   for this CPU while the MTRRs are changed, but changing this requires
+	   more invasive changes to the way the kernel boots  */
+
+	spin_lock(&set_atomicity_lock);
+
+	/*  Enter the no-fill (CD=1, NW=0) cache mode and flush caches. */
+	cr0 = read_cr0() | 0x40000000;	/* set CD flag */
+	write_cr0(cr0);
+	wbinvd();
+
+	/*  Save value of CR4 and clear Page Global Enable (bit 7)  */
+	if ( cpu_has_pge ) {
+		cr4 = read_cr4();
+		write_cr4(cr4 & ~X86_CR4_PGE);
+	}
+
+	/* Flush all TLBs via a mov %cr3, %reg; mov %reg, %cr3 */
+	__flush_tlb();
+
+	/*  Save MTRR state */
+	rdmsr(MTRRdefType_MSR, deftype_lo, deftype_hi);
+
+	/*  Disable MTRRs, and set the default type to uncached  */
+	mtrr_wrmsr(MTRRdefType_MSR, deftype_lo & ~0xcff, deftype_hi);
+}
+
+static void post_set(void) __releases(set_atomicity_lock)
+{
+	/*  Flush TLBs (no need to flush caches - they are disabled)  */
+	__flush_tlb();
+
+	/* Intel (P6) standard MTRRs */
+	mtrr_wrmsr(MTRRdefType_MSR, deftype_lo, deftype_hi);
+		
+	/*  Enable caches  */
+	write_cr0(read_cr0() & 0xbfffffff);
+
+	/*  Restore value of CR4  */
+	if ( cpu_has_pge )
+		write_cr4(cr4);
+	spin_unlock(&set_atomicity_lock);
+}
+
+static void generic_set_all(void)
+{
+	unsigned long mask, count;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	prepare_set();
+
+	/* Actually set the state */
+	mask = set_mtrr_state();
+
+	post_set();
+	local_irq_restore(flags);
+
+	/*  Use the atomic bitops to update the global mask  */
+	for (count = 0; count < sizeof mask * 8; ++count) {
+		if (mask & 0x01)
+			set_bit(count, &smp_changes_mask);
+		mask >>= 1;
+	}
+	
+}
+
+static void generic_set_mtrr(unsigned int reg, unsigned long base,
+			     unsigned long size, mtrr_type type)
+/*  [SUMMARY] Set variable MTRR register on the local CPU.
+    <reg> The register to set.
+    <base> The base address of the region.
+    <size> The size of the region. If this is 0 the region is disabled.
+    <type> The type of the region.
+    <do_safe> If TRUE, do the change safely. If FALSE, safety measures should
+    be done externally.
+    [RETURNS] Nothing.
+*/
+{
+	unsigned long flags;
+	struct mtrr_var_range *vr;
+
+	vr = &mtrr_state.var_ranges[reg];
+
+	local_irq_save(flags);
+	prepare_set();
+
+	if (size == 0) {
+		/* The invalid bit is kept in the mask, so we simply clear the
+		   relevant mask register to disable a range. */
+		mtrr_wrmsr(MTRRphysMask_MSR(reg), 0, 0);
+		memset(vr, 0, sizeof(struct mtrr_var_range));
+	} else {
+		vr->base_lo = base << PAGE_SHIFT | type;
+		vr->base_hi = (base & size_and_mask) >> (32 - PAGE_SHIFT);
+		vr->mask_lo = -size << PAGE_SHIFT | 0x800;
+		vr->mask_hi = (-size & size_and_mask) >> (32 - PAGE_SHIFT);
+
+		mtrr_wrmsr(MTRRphysBase_MSR(reg), vr->base_lo, vr->base_hi);
+		mtrr_wrmsr(MTRRphysMask_MSR(reg), vr->mask_lo, vr->mask_hi);
+	}
+
+	post_set();
+	local_irq_restore(flags);
+}
+
+int generic_validate_add_page(unsigned long base, unsigned long size, unsigned int type)
+{
+	unsigned long lbase, last;
+
+	/*  For Intel PPro stepping <= 7, must be 4 MiB aligned 
+	    and not touch 0x70000000->0x7003FFFF */
+	if (is_cpu(INTEL) && boot_cpu_data.x86 == 6 &&
+	    boot_cpu_data.x86_model == 1 &&
+	    boot_cpu_data.x86_mask <= 7) {
+		if (base & ((1 << (22 - PAGE_SHIFT)) - 1)) {
+			printk(KERN_WARNING "mtrr: base(0x%lx000) is not 4 MiB aligned\n", base);
+			return -EINVAL;
+		}
+		if (!(base + size < 0x70000 || base > 0x7003F) &&
+		    (type == MTRR_TYPE_WRCOMB
+		     || type == MTRR_TYPE_WRBACK)) {
+			printk(KERN_WARNING "mtrr: writable mtrr between 0x70000000 and 0x7003FFFF may hang the CPU.\n");
+			return -EINVAL;
+		}
+	}
+
+	/*  Check upper bits of base and last are equal and lower bits are 0
+	    for base and 1 for last  */
+	last = base + size - 1;
+	for (lbase = base; !(lbase & 1) && (last & 1);
+	     lbase = lbase >> 1, last = last >> 1) ;
+	if (lbase != last) {
+		printk(KERN_WARNING "mtrr: base(0x%lx000) is not aligned on a size(0x%lx000) boundary\n",
+		       base, size);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+
+static int generic_have_wrcomb(void)
+{
+	unsigned long config, dummy;
+	rdmsr(MTRRcap_MSR, config, dummy);
+	return (config & (1 << 10));
+}
+
+int positive_have_wrcomb(void)
+{
+	return 1;
+}
+
+/* generic structure...
+ */
+struct mtrr_ops generic_mtrr_ops = {
+	.use_intel_if      = 1,
+	.set_all	   = generic_set_all,
+	.get               = generic_get_mtrr,
+	.get_free_region   = generic_get_free_region,
+	.set               = generic_set_mtrr,
+	.validate_add_page = generic_validate_add_page,
+	.have_wrcomb       = generic_have_wrcomb,
+};