1 files changed, 50 insertions, 21 deletions

diff --git a/arch/i386/kernel/cpu/mtrr/main.c b/arch/i386/kernel/cpu/mtrr/main.c
index fff90bda4733..16bb7ea87145 100644
--- a/arch/i386/kernel/cpu/mtrr/main.c
+++ b/arch/i386/kernel/cpu/mtrr/main.c
@@ -59,7 +59,11 @@ struct mtrr_ops * mtrr_if = NULL;
 static void set_mtrr(unsigned int reg, unsigned long base,
                      unsigned long size, mtrr_type type);
 
+#ifndef CONFIG_X86_64
 extern int arr3_protected;
+#else
+#define arr3_protected 0
+#endif
 
 void set_mtrr_ops(struct mtrr_ops * ops)
 {
@@ -168,6 +172,13 @@ static void ipi_handler(void *info)
 
 #endif
 
+static inline int types_compatible(mtrr_type type1, mtrr_type type2) {
+        return type1 == MTRR_TYPE_UNCACHABLE ||
+               type2 == MTRR_TYPE_UNCACHABLE ||
+               (type1 == MTRR_TYPE_WRTHROUGH && type2 == MTRR_TYPE_WRBACK) ||
+               (type1 == MTRR_TYPE_WRBACK && type2 == MTRR_TYPE_WRTHROUGH);
+}
+
 /**
  * set_mtrr - update mtrrs on all processors
  * @reg:        mtrr in question
@@ -263,8 +274,8 @@ static void set_mtrr(unsigned int reg, unsigned long base,
 
 /**
  *      mtrr_add_page - Add a memory type region
- *      @base: Physical base address of region in pages (4 KB)
- *      @size: Physical size of region in pages (4 KB)
+ *      @base: Physical base address of region in pages (in units of 4 kB!)
+ *      @size: Physical size of region in pages (4 kB)
  *      @type: Type of MTRR desired
  *      @increment: If this is true do usage counting on the region
  *
@@ -300,11 +311,9 @@ static void set_mtrr(unsigned int reg, unsigned long base,
 int mtrr_add_page(unsigned long base, unsigned long size, 
                   unsigned int type, char increment)
 {
-        int i;
+        int i, replace, error;
         mtrr_type ltype;
-        unsigned long lbase;
-        unsigned int lsize;
-        int error;
+        unsigned long lbase, lsize;
 
         if (!mtrr_if)
                 return -ENXIO;
@@ -324,12 +333,18 @@ int mtrr_add_page(unsigned long base, unsigned long size,
                 return -ENOSYS;
         }
 
+        if (!size) {
+                printk(KERN_WARNING "mtrr: zero sized request\n");
+                return -EINVAL;
+        }
+
         if (base & size_or_mask || size & size_or_mask) {
                 printk(KERN_WARNING "mtrr: base or size exceeds the MTRR width\n");
                 return -EINVAL;
         }
 
         error = -EINVAL;
+        replace = -1;
 
         /* No CPU hotplug when we change MTRR entries */
         lock_cpu_hotplug();
@@ -337,21 +352,28 @@ int mtrr_add_page(unsigned long base, unsigned long size,
         mutex_lock(&mtrr_mutex);
         for (i = 0; i < num_var_ranges; ++i) {
                 mtrr_if->get(i, &lbase, &lsize, &ltype);
-                if (base >= lbase + lsize)
-                        continue;
-                if ((base < lbase) && (base + size <= lbase))
+                if (!lsize || base > lbase + lsize - 1 || base + size - 1 < lbase)
                         continue;
                 /*  At this point we know there is some kind of overlap/enclosure  */
-                if ((base < lbase) || (base + size > lbase + lsize)) {
+                if (base < lbase || base + size - 1 > lbase + lsize - 1) {
+                        if (base <= lbase && base + size - 1 >= lbase + lsize - 1) {
+                                /*  New region encloses an existing region  */
+                                if (type == ltype) {
+                                        replace = replace == -1 ? i : -2;
+                                        continue;
+                                }
+                                else if (types_compatible(type, ltype))
+                                        continue;
+                        }
                         printk(KERN_WARNING
                                "mtrr: 0x%lx000,0x%lx000 overlaps existing"
-                               " 0x%lx000,0x%x000\n", base, size, lbase,
+                               " 0x%lx000,0x%lx000\n", base, size, lbase,
                                lsize);
                         goto out;
                 }
                 /*  New region is enclosed by an existing region  */
                 if (ltype != type) {
-                        if (type == MTRR_TYPE_UNCACHABLE)
+                        if (types_compatible(type, ltype))
                                 continue;
                         printk (KERN_WARNING "mtrr: type mismatch for %lx000,%lx000 old: %s new: %s\n",
                              base, size, mtrr_attrib_to_str(ltype),
@@ -364,10 +386,18 @@ int mtrr_add_page(unsigned long base, unsigned long size,
                 goto out;
         }
         /*  Search for an empty MTRR  */
-        i = mtrr_if->get_free_region(base, size);
+        i = mtrr_if->get_free_region(base, size, replace);
         if (i >= 0) {
                 set_mtrr(i, base, size, type);
-                usage_table[i] = 1;
+                if (likely(replace < 0))
+                        usage_table[i] = 1;
+                else {
+                        usage_table[i] = usage_table[replace] + !!increment;
+                        if (unlikely(replace != i)) {
+                                set_mtrr(replace, 0, 0, 0);
+                                usage_table[replace] = 0;
+                        }
+                }
         } else
                 printk(KERN_INFO "mtrr: no more MTRRs available\n");
         error = i;
@@ -455,8 +485,7 @@ int mtrr_del_page(int reg, unsigned long base, unsigned long size)
 {
         int i, max;
         mtrr_type ltype;
-        unsigned long lbase;
-        unsigned int lsize;
+        unsigned long lbase, lsize;
         int error = -EINVAL;
 
         if (!mtrr_if)
@@ -544,9 +573,11 @@ extern void centaur_init_mtrr(void);
 
 static void __init init_ifs(void)
 {
+#ifndef CONFIG_X86_64
         amd_init_mtrr();
         cyrix_init_mtrr();
         centaur_init_mtrr();
+#endif
 }
 
 /* The suspend/resume methods are only for CPU without MTRR. CPU using generic
@@ -555,7 +586,7 @@ static void __init init_ifs(void)
 struct mtrr_value {
         mtrr_type       ltype;
         unsigned long   lbase;
-        unsigned int    lsize;
+        unsigned long   lsize;
 };
 
 static struct mtrr_value * mtrr_state;
@@ -565,10 +596,8 @@ static int mtrr_save(struct sys_device * sysdev, pm_message_t state)
         int i;
         int size = num_var_ranges * sizeof(struct mtrr_value);
 
-        mtrr_state = kmalloc(size,GFP_ATOMIC);
-        if (mtrr_state)
-                memset(mtrr_state,0,size);
-        else
+        mtrr_state = kzalloc(size,GFP_ATOMIC);
+        if (!mtrr_state)
                 return -ENOMEM;
 
         for (i = 0; i < num_var_ranges; i++) {