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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/mtrr/generic.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/i386/kernel/cpu/mtrr/generic.c')
-rw-r--r--arch/i386/kernel/cpu/mtrr/generic.c417
1 files changed, 417 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/mtrr/generic.c b/arch/i386/kernel/cpu/mtrr/generic.c
new file mode 100644
index 000000000000..a4cce454d09b
--- /dev/null
+++ b/arch/i386/kernel/cpu/mtrr/generic.c
@@ -0,0 +1,417 @@
+/* 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 <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;
+ mtrr_type def_type;
+};
+
+static unsigned long smp_changes_mask;
+static struct mtrr_state mtrr_state = {};
+
+/* Get the MSR pair relating to a var range */
+static void __init
+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 __init
+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]);
+}
+
+/* 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;
+
+ for (i = 0; i < num_var_ranges; i++)
+ get_mtrr_var_range(i, &vrs[i]);
+ get_fixed_ranges(mtrr_state.fixed_ranges);
+
+ rdmsr(MTRRdefType_MSR, lo, dummy);
+ mtrr_state.def_type = (lo & 0xff);
+ mtrr_state.enabled = (lo & 0xc00) >> 10;
+}
+
+/* Free resources associated with a struct mtrr_state */
+void __init finalize_mtrr_state(void)
+{
+ if (mtrr_state.var_ranges)
+ kfree(mtrr_state.var_ranges);
+ mtrr_state.var_ranges = NULL;
+}
+
+/* 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);
+}
+
+int generic_get_free_region(unsigned long base, unsigned long size)
+/* [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;
+ unsigned lsize;
+
+ max = num_var_ranges;
+ for (i = 0; i < max; ++i) {
+ mtrr_if->get(i, &lbase, &lsize, &ltype);
+ if (lsize == 0)
+ return i;
+ }
+ return -ENOSPC;
+}
+
+void generic_get_mtrr(unsigned int reg, unsigned long *base,
+ unsigned int *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;
+}
+
+static int set_fixed_ranges(mtrr_type * frs)
+{
+ unsigned int *p = (unsigned int *) frs;
+ int changed = FALSE;
+ int i;
+ unsigned int lo, hi;
+
+ rdmsr(MTRRfix64K_00000_MSR, lo, hi);
+ if (p[0] != lo || p[1] != hi) {
+ mtrr_wrmsr(MTRRfix64K_00000_MSR, p[0], p[1]);
+ changed = TRUE;
+ }
+
+ for (i = 0; i < 2; i++) {
+ rdmsr(MTRRfix16K_80000_MSR + i, lo, hi);
+ if (p[2 + i * 2] != lo || p[3 + i * 2] != hi) {
+ mtrr_wrmsr(MTRRfix16K_80000_MSR + i, p[2 + i * 2],
+ p[3 + i * 2]);
+ changed = TRUE;
+ }
+ }
+
+ for (i = 0; i < 8; i++) {
+ rdmsr(MTRRfix4K_C0000_MSR + i, lo, hi);
+ if (p[6 + i * 2] != lo || p[7 + i * 2] != hi) {
+ mtrr_wrmsr(MTRRfix4K_C0000_MSR + i, p[6 + i * 2],
+ p[7 + i * 2]);
+ changed = TRUE;
+ }
+ }
+ 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 & 0xfUL) != (hi & 0xfUL)) {
+ 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 & 0xfUL) != (hi & 0xfUL)) {
+ mtrr_wrmsr(MTRRphysMask_MSR(index), vr->mask_lo, vr->mask_hi);
+ changed = TRUE;
+ }
+ return changed;
+}
+
+static unsigned long set_mtrr_state(u32 deftype_lo, u32 deftype_hi)
+/* [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 (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 |= (mtrr_state.def_type | mtrr_state.enabled << 10);
+ change_mask |= MTRR_CHANGE_MASK_DEFTYPE;
+ }
+
+ return change_mask;
+}
+
+
+static unsigned long cr4 = 0;
+static u32 deftype_lo, deftype_hi;
+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)
+{
+ 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 & 0xf300UL, deftype_hi);
+}
+
+static void post_set(void)
+{
+ /* 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(deftype_lo,deftype_hi);
+
+ 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;
+
+ 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);
+ } else {
+ mtrr_wrmsr(MTRRphysBase_MSR(reg), base << PAGE_SHIFT | type,
+ (base & size_and_mask) >> (32 - PAGE_SHIFT));
+ mtrr_wrmsr(MTRRphysMask_MSR(reg), -size << PAGE_SHIFT | 0x800,
+ (-size & size_and_mask) >> (32 - PAGE_SHIFT));
+ }
+
+ 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 < 0x70000000 || base > 0x7003FFFF) &&
+ (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;
+ }
+ }
+
+ if (base + size < 0x100) {
+ printk(KERN_WARNING "mtrr: cannot set region below 1 MiB (0x%lx000,0x%lx000)\n",
+ base, size);
+ 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,
+};