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 00000000000..56f64e34829
--- /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,
+};