x86: mtrr cleanup for converting continuous to discrete - auto detect v4

Loop through mtrr chunk_size and gran_size from 1M to 2G to find out
the optimal value so user does not need to add mtrr_chunk_size and
mtrr_gran_size to the kernel command line.

If optimal value is not found, print out all list to help select less
optimal value.

Add mtrr_spare_reg_nr= so user could set 2 instead of 1, if the card
need more entries.

v2: find the one with more spare entries
v3: fix hole_basek offset
v4: tight the compare between range and range_new
    loop stop with 4g

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gabriel C <nix.or.die@googlemail.com>
Cc: Mika Fischer <mika.fischer@zoopnet.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 484 insertions, 148 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 44427607b7c6..2000977af776 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -610,8 +610,17 @@ and is between 256 and 4096 characters. It is defined in the file
                         that could hold holes aka. UC entries.
 
         mtrr_gran_size=nn[KMG] [X86]
-                        used for mtrr cleanup. It is granity of mtrr block.
-                        Big value could prevent small alignment use up MTRRs.
+                        Used for mtrr cleanup. It is granularity of mtrr block.
+                        Default is 1.
+                        Large value could prevent small alignment from
+                        using up MTRRs.
+
+        mtrr_spare_reg_nr=n [X86]
+                        Format: <integer>
+                        Range: 0,7 : spare reg number
+                        Default : 1
+                        Used for mtrr cleanup. It is spare mtrr entries number.
+                        Set to 2 or more if your graphical card needs more.
 
         disable_mtrr_trim [X86, Intel and AMD only]
                         By default the kernel will trim any uncacheable
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f417fe33d852..9e9761504422 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1117,6 +1117,15 @@ config MTRR_SANITIZER_ENABLE_DEFAULT
         help
           Enable mtrr cleanup default value
 
+config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
+        int "MTRR cleanup spare reg num (0-7)"
+        range 0 7
+        default "1"
+        depends on MTRR_SANITIZER
+        help
+          mtrr cleanup spare entries default, it can be changed via
+          mtrr_spare_reg_nr=
+
 config X86_PAT
         bool
         prompt "x86 PAT support"
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 79597d3c3431..e6c162c379ac 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -610,28 +610,6 @@ static struct sysdev_driver mtrr_sysdev_driver = {
         .resume         = mtrr_restore,
 };
 
-#ifdef CONFIG_MTRR_SANITIZER
-static int enable_mtrr_cleanup __initdata = CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT;
-#else
-static int enable_mtrr_cleanup __initdata = -1;
-#endif
-
-static int __init disable_mtrr_cleanup_setup(char *str)
-{
-        if (enable_mtrr_cleanup != -1)
-                enable_mtrr_cleanup = 0;
-        return 0;
-}
-early_param("disable_mtrr_cleanup", disable_mtrr_cleanup_setup);
-
-static int __init enable_mtrr_cleanup_setup(char *str)
-{
-        if (enable_mtrr_cleanup != -1)
-                enable_mtrr_cleanup = 1;
-        return 0;
-}
-early_param("enble_mtrr_cleanup", enable_mtrr_cleanup_setup);
-
 /* should be related to MTRR_VAR_RANGES nums */
 #define RANGE_NUM 256
 
@@ -702,13 +680,15 @@ subtract_range(struct res_range *range, unsigned long start, unsigned long end)
                         continue;
                 }
 
-                if (start <= range[j].start && end < range[j].end && range[j].start < end + 1) {
+                if (start <= range[j].start && end < range[j].end &&
+                    range[j].start < end + 1) {
                         range[j].start = end + 1;
                         continue;
                 }
 
 
-                if (start > range[j].start && end >= range[j].end && range[j].end > start - 1) {
+                if (start > range[j].start && end >= range[j].end &&
+                    range[j].end > start - 1) {
                         range[j].end = start - 1;
                         continue;
                 }
@@ -743,18 +723,123 @@ static int __init cmp_range(const void *x1, const void *x2)
         return start1 - start2;
 }
 
+struct var_mtrr_range_state {
+        unsigned long base_pfn;
+        unsigned long size_pfn;
+        mtrr_type type;
+};
+
+struct var_mtrr_range_state __initdata range_state[RANGE_NUM];
+
+static int __init
+x86_get_mtrr_mem_range(struct res_range *range, int nr_range,
+                       unsigned long extra_remove_base,
+                       unsigned long extra_remove_size)
+{
+        unsigned long i, base, size;
+        mtrr_type type;
+
+        for (i = 0; i < num_var_ranges; i++) {
+                type = range_state[i].type;
+                if (type != MTRR_TYPE_WRBACK)
+                        continue;
+                base = range_state[i].base_pfn;
+                size = range_state[i].size_pfn;
+                nr_range = add_range_with_merge(range, nr_range, base,
+                                                base + size - 1);
+        }
+        printk(KERN_DEBUG "After WB checking\n");
+        for (i = 0; i < nr_range; i++)
+                printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
+                                 range[i].start, range[i].end + 1);
+
+        /* take out UC ranges */
+        for (i = 0; i < num_var_ranges; i++) {
+                type = range_state[i].type;
+                if (type != MTRR_TYPE_UNCACHABLE)
+                        continue;
+                size = range_state[i].size_pfn;
+                if (!size)
+                        continue;
+                base = range_state[i].base_pfn;
+                subtract_range(range, base, base + size - 1);
+        }
+        if (extra_remove_size)
+                subtract_range(range, extra_remove_base,
+                                 extra_remove_base + extra_remove_size  - 1);
+
+        /* get new range num */
+        nr_range = 0;
+        for (i = 0; i < RANGE_NUM; i++) {
+                if (!range[i].end)
+                        continue;
+                nr_range++;
+        }
+        printk(KERN_DEBUG "After UC checking\n");
+        for (i = 0; i < nr_range; i++)
+                printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
+                         range[i].start, range[i].end + 1);
+
+        /* sort the ranges */
+        sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);
+        printk(KERN_DEBUG "After sorting\n");
+        for (i = 0; i < nr_range; i++)
+                printk(KERN_DEBUG "MTRR MAP PFN: %016lx - %016lx\n",
+                                 range[i].start, range[i].end + 1);
+
+        /* clear those is not used */
+        for (i = nr_range; i < RANGE_NUM; i++)
+                memset(&range[i], 0, sizeof(range[i]));
+
+        return nr_range;
+}
+
+static struct res_range __initdata range[RANGE_NUM];
+
+#ifdef CONFIG_MTRR_SANITIZER
+
+static unsigned long __init sum_ranges(struct res_range *range, int nr_range)
+{
+        unsigned long sum;
+        int i;
+
+        sum = 0;
+        for (i = 0; i < nr_range; i++)
+                sum += range[i].end + 1 - range[i].start;
+
+        return sum;
+}
+
+static int enable_mtrr_cleanup __initdata =
+        CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT;
+
+static int __init disable_mtrr_cleanup_setup(char *str)
+{
+        if (enable_mtrr_cleanup != -1)
+                enable_mtrr_cleanup = 0;
+        return 0;
+}
+early_param("disable_mtrr_cleanup", disable_mtrr_cleanup_setup);
+
+static int __init enable_mtrr_cleanup_setup(char *str)
+{
+        if (enable_mtrr_cleanup != -1)
+                enable_mtrr_cleanup = 1;
+        return 0;
+}
+early_param("enble_mtrr_cleanup", enable_mtrr_cleanup_setup);
+
 struct var_mtrr_state {
         unsigned long   range_startk;
         unsigned long   range_sizek;
         unsigned long   chunk_sizek;
         unsigned long   gran_sizek;
         unsigned int    reg;
-        unsigned int    address_bits;
 };
 
 static void __init
 set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
-                unsigned char type, unsigned address_bits)
+                unsigned char type, unsigned int address_bits)
 {
         u32 base_lo, base_hi, mask_lo, mask_hi;
         u64 base, mask;
@@ -781,10 +866,34 @@ set_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
         fill_mtrr_var_range(reg, base_lo, base_hi, mask_lo, mask_hi);
 }
 
+static void __init
+save_var_mtrr(unsigned int reg, unsigned long basek, unsigned long sizek,
+                unsigned char type)
+{
+        range_state[reg].base_pfn = basek >> (PAGE_SHIFT - 10);
+        range_state[reg].size_pfn = sizek >> (PAGE_SHIFT - 10);
+        range_state[reg].type = type;
+}
+
+static void __init
+set_var_mtrr_all(unsigned int address_bits)
+{
+        unsigned long basek, sizek;
+        unsigned char type;
+        unsigned int reg;
+
+        for (reg = 0; reg < num_var_ranges; reg++) {
+                basek = range_state[reg].base_pfn << (PAGE_SHIFT - 10);
+                sizek = range_state[reg].size_pfn << (PAGE_SHIFT - 10);
+                type = range_state[reg].type;
+
+                set_var_mtrr(reg, basek, sizek, type, address_bits);
+        }
+}
+
 static unsigned int __init
 range_to_mtrr(unsigned int reg, unsigned long range_startk,
-              unsigned long range_sizek, unsigned char type,
-              unsigned address_bits)
+              unsigned long range_sizek, unsigned char type)
 {
         if (!range_sizek || (reg >= num_var_ranges))
                 return reg;
@@ -803,12 +912,13 @@ range_to_mtrr(unsigned int reg, unsigned long range_startk,
                         align = max_align;
 
                 sizek = 1 << align;
-                printk(KERN_INFO "Setting variable MTRR %d, base: %ldMB, range: %ldMB, type %s\n",
+                printk(KERN_DEBUG "Setting variable MTRR %d, base: %ldMB, "
+                       "range: %ldMB, type %s\n",
                         reg, range_startk >> 10, sizek >> 10,
                         (type == MTRR_TYPE_UNCACHABLE)?"UC":
                             ((type == MTRR_TYPE_WRBACK)?"WB":"Other")
                         );
-                set_var_mtrr(reg++, range_startk, sizek, type, address_bits);
+                save_var_mtrr(reg++, range_startk, sizek, type);
                 range_startk += sizek;
                 range_sizek -= sizek;
                 if (reg >= num_var_ranges)
@@ -817,10 +927,12 @@ range_to_mtrr(unsigned int reg, unsigned long range_startk,
         return reg;
 }
 
-static void __init
-range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek)
+static unsigned __init
+range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek,
+                        unsigned long sizek)
 {
         unsigned long hole_basek, hole_sizek;
+        unsigned long second_basek, second_sizek;
         unsigned long range0_basek, range0_sizek;
         unsigned long range_basek, range_sizek;
         unsigned long chunk_sizek;
@@ -828,64 +940,95 @@ range_to_mtrr_with_hole(struct var_mtrr_state *state, unsigned long basek)
 
         hole_basek = 0;
         hole_sizek = 0;
+        second_basek = 0;
+        second_sizek = 0;
         chunk_sizek = state->chunk_sizek;
         gran_sizek = state->gran_sizek;
 
         /* align with gran size, prevent small block used up MTRRs */
         range_basek = ALIGN(state->range_startk, gran_sizek);
         if ((range_basek > basek) && basek)
-                return;
-        range_sizek = ALIGN(state->range_sizek - (range_basek - state->range_startk), gran_sizek);
+                return second_sizek;
+        state->range_sizek -= (range_basek - state->range_startk);
+        range_sizek = ALIGN(state->range_sizek, gran_sizek);
 
-        while (range_basek + range_sizek > (state->range_startk + state->range_sizek)) {
+        while (range_sizek > state->range_sizek) {
                 range_sizek -= gran_sizek;
                 if (!range_sizek)
-                        return;
+                        return 0;
         }
-        state->range_startk = range_basek;
         state->range_sizek = range_sizek;
 
         /* try to append some small hole */
         range0_basek = state->range_startk;
         range0_sizek = ALIGN(state->range_sizek, chunk_sizek);
         if (range0_sizek == state->range_sizek) {
-                        printk(KERN_INFO "rangeX: %016lx - %016lx\n", range0_basek<<10, (range0_basek + state->range_sizek)<<10);
-                        state->reg = range_to_mtrr(state->reg, range0_basek,
-                                state->range_sizek, MTRR_TYPE_WRBACK, state->address_bits);
-                return;
-        } else if (basek) {
-            while (range0_basek + range0_sizek - chunk_sizek > basek) {
+                printk(KERN_DEBUG "rangeX: %016lx - %016lx\n", range0_basek<<10,
+                                (range0_basek + state->range_sizek)<<10);
+                state->reg = range_to_mtrr(state->reg, range0_basek,
+                                state->range_sizek, MTRR_TYPE_WRBACK);
+                return 0;
+        }
+
+        range0_sizek -= chunk_sizek;
+        if (range0_sizek && sizek) {
+            while (range0_basek + range0_sizek > (basek + sizek)) {
                 range0_sizek -= chunk_sizek;
                 if (!range0_sizek)
                         break;
             }
         }
 
+        if (range0_sizek) {
+                printk(KERN_DEBUG "range0: %016lx - %016lx\n", range0_basek<<10,
+                                (range0_basek + range0_sizek)<<10);
+                state->reg = range_to_mtrr(state->reg, range0_basek,
+                                range0_sizek, MTRR_TYPE_WRBACK);
 
-        if (range0_sizek > chunk_sizek)
-                range0_sizek -= chunk_sizek;
-        printk(KERN_INFO "range0: %016lx - %016lx\n", range0_basek<<10, (range0_basek + range0_sizek)<<10);
-        state->reg = range_to_mtrr(state->reg, range0_basek,
-                        range0_sizek, MTRR_TYPE_WRBACK, state->address_bits);
+        }
 
         range_basek = range0_basek + range0_sizek;
         range_sizek = chunk_sizek;
 
-        if ((range_sizek - (state->range_sizek - range0_sizek) < (chunk_sizek >> 1)) &&
-            (range_basek + range_sizek <= basek)) {
-                hole_sizek = range_sizek - (state->range_sizek - range0_sizek);
-                hole_basek = range_basek + range_sizek - hole_sizek;
-        } else
+        if (range_basek + range_sizek > basek &&
+            range_basek + range_sizek <= (basek + sizek)) {
+                /* one hole */
+                second_basek = basek;
+                second_sizek = range_basek + range_sizek - basek;
+        }
+
+        /* if last piece, only could one hole near end */
+        if ((second_basek || !basek) &&
+            range_sizek - (state->range_sizek - range0_sizek) - second_sizek <
+            (chunk_sizek >> 1)) {
+                /*
+                 * one hole in middle (second_sizek is 0) or at end
+                 * (second_sizek is 0 )
+                 */
+                hole_sizek = range_sizek - (state->range_sizek - range0_sizek)
+                                 - second_sizek;
+                hole_basek = range_basek + range_sizek - hole_sizek
+                                 - second_sizek;
+        } else {
+                /* fallback for big hole, or several holes */
                 range_sizek = state->range_sizek - range0_sizek;
+                second_basek = 0;
+                second_sizek = 0;
+        }
 
-        printk(KERN_INFO "range: %016lx - %016lx\n", range_basek<<10, (range_basek + range_sizek)<<10);
-        state->reg = range_to_mtrr(state->reg, range_basek,
-                        range_sizek, MTRR_TYPE_WRBACK, state->address_bits);
+        printk(KERN_DEBUG "range: %016lx - %016lx\n", range_basek<<10,
+                         (range_basek + range_sizek)<<10);
+        state->reg = range_to_mtrr(state->reg, range_basek, range_sizek,
+                                         MTRR_TYPE_WRBACK);
         if (hole_sizek) {
-                printk(KERN_INFO "hole: %016lx - %016lx\n", hole_basek<<10, (hole_basek + hole_sizek)<<10);
-                state->reg = range_to_mtrr(state->reg, hole_basek,
-                                hole_sizek, MTRR_TYPE_UNCACHABLE, state->address_bits);
+                printk(KERN_DEBUG "hole: %016lx - %016lx\n", hole_basek<<10,
+                                 (hole_basek + hole_sizek)<<10);
+                state->reg = range_to_mtrr(state->reg, hole_basek, hole_sizek,
+                                                 MTRR_TYPE_UNCACHABLE);
+
         }
+
+        return second_sizek;
 }
 
 static void __init
@@ -893,6 +1036,7 @@ set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn,
                    unsigned long size_pfn)
 {
         unsigned long basek, sizek;
+        unsigned long second_sizek = 0;
 
         if (state->reg >= num_var_ranges)
                 return;
@@ -901,21 +1045,19 @@ set_var_mtrr_range(struct var_mtrr_state *state, unsigned long base_pfn,
         sizek = size_pfn << (PAGE_SHIFT - 10);
 
         /* See if I can merge with the last range */
-        if ((basek <= 1024) || (state->range_startk + state->range_sizek == basek)) {
+        if ((basek <= 1024) ||
+            (state->range_startk + state->range_sizek == basek)) {
                 unsigned long endk = basek + sizek;
                 state->range_sizek = endk - state->range_startk;
                 return;
         }
         /* Write the range mtrrs */
-        if (state->range_sizek != 0) {
-                range_to_mtrr_with_hole(state, basek);
+        if (state->range_sizek != 0)
+                second_sizek = range_to_mtrr_with_hole(state, basek, sizek);
 
-                state->range_startk = 0;
-                state->range_sizek = 0;
-        }
         /* Allocate an msr */
-        state->range_startk = basek;
-        state->range_sizek  = sizek;
+        state->range_startk = basek + second_sizek;
+        state->range_sizek  = sizek - second_sizek;
 }
 
 /* mininum size of mtrr block that can take hole */
@@ -931,7 +1073,7 @@ static int __init parse_mtrr_chunk_size_opt(char *p)
 early_param("mtrr_chunk_size", parse_mtrr_chunk_size_opt);
 
 /* granity of mtrr of block */
-static u64 mtrr_gran_size __initdata = (1ULL<<20);
+static u64 mtrr_gran_size __initdata;
 
 static int __init parse_mtrr_gran_size_opt(char *p)
 {
@@ -942,91 +1084,84 @@ static int __init parse_mtrr_gran_size_opt(char *p)
 }
 early_param("mtrr_gran_size", parse_mtrr_gran_size_opt);
 
-static void __init
+static int nr_mtrr_spare_reg __initdata =
+                                 CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT;
+
+static int __init parse_mtrr_spare_reg(char *arg)
+{
+        if (arg)
+                nr_mtrr_spare_reg = simple_strtoul(arg, NULL, 0);
+        return 0;
+}
+
+early_param("mtrr_spare_reg_nr", parse_mtrr_spare_reg);
+
+static int __init
 x86_setup_var_mtrrs(struct res_range *range, int nr_range,
-                    unsigned address_bits)
+                    u64 chunk_size, u64 gran_size)
 {
         struct var_mtrr_state var_state;
         int i;
+        int num_reg;
 
         var_state.range_startk  = 0;
         var_state.range_sizek   = 0;
         var_state.reg           = 0;
-        var_state.address_bits  = address_bits;
-        var_state.chunk_sizek   = mtrr_chunk_size >> 10;
-        var_state.gran_sizek    = mtrr_gran_size >> 10;
+        var_state.chunk_sizek   = chunk_size >> 10;
+        var_state.gran_sizek    = gran_size >> 10;
+
+        memset(range_state, 0, sizeof(range_state));
 
         /* Write the range etc */
         for (i = 0; i < nr_range; i++)
-                set_var_mtrr_range(&var_state, range[i].start, range[i].end - range[i].start + 1);
+                set_var_mtrr_range(&var_state, range[i].start,
+                                   range[i].end - range[i].start + 1);
 
         /* Write the last range */
-        range_to_mtrr_with_hole(&var_state, 0);
-        printk(KERN_INFO "DONE variable MTRRs\n");
+        if (var_state.range_sizek != 0)
+                range_to_mtrr_with_hole(&var_state, 0, 0);
+        printk(KERN_DEBUG "DONE variable MTRRs\n");
+
+        num_reg = var_state.reg;
         /* Clear out the extra MTRR's */
         while (var_state.reg < num_var_ranges) {
-                set_var_mtrr(var_state.reg, 0, 0, 0, var_state.address_bits);
+                save_var_mtrr(var_state.reg, 0, 0, 0);
                 var_state.reg++;
         }
-}
-
-static int __init
-x86_get_mtrr_mem_range(struct res_range *range, int nr_range,
-                       unsigned long extra_remove_base,
-                       unsigned long extra_remove_size)
-{
-        unsigned long i, base, size;
-        mtrr_type type;
-
-        for (i = 0; i < num_var_ranges; i++) {
-                mtrr_if->get(i, &base, &size, &type);
-                if (type != MTRR_TYPE_WRBACK)
-                        continue;
-                nr_range = add_range_with_merge(range, nr_range, base, base + size - 1);
-        }
-        printk(KERN_INFO "After WB checking\n");
-        for (i = 0; i < nr_range; i++)
-                printk(KERN_INFO "MTRR MAP PFN: %016lx - %016lx\n", range[i].start, range[i].end + 1);
 
-        /* take out UC ranges */
-        for (i = 0; i < num_var_ranges; i++) {
-                mtrr_if->get(i, &base, &size, &type);
-                if (type != MTRR_TYPE_UNCACHABLE)
-                        continue;
-                if (!size)
-                        continue;
-                subtract_range(range, base, base + size - 1);
-        }
-        if (extra_remove_size)
-                subtract_range(range, extra_remove_base,  extra_remove_base + extra_remove_size  - 1);
+        return num_reg;
+}
 
-        /* get new range num */
-        nr_range = 0;
-        for (i = 0; i < RANGE_NUM; i++) {
-                if (!range[i].end)
-                        continue;
-                nr_range++;
-        }
-        printk(KERN_INFO "After UC checking\n");
-        for (i = 0; i < nr_range; i++)
-                printk(KERN_INFO "MTRR MAP PFN: %016lx - %016lx\n", range[i].start, range[i].end + 1);
+struct mtrr_cleanup_result {
+        unsigned long gran_sizek;
+        unsigned long chunk_sizek;
+        unsigned long lose_cover_sizek;
+        unsigned int num_reg;
+        int bad;
+};
 
-        /* sort the ranges */
-        sort(range, nr_range, sizeof(struct res_range), cmp_range, NULL);
-        printk(KERN_INFO "After sorting\n");
-        for (i = 0; i < nr_range; i++)
-                printk(KERN_INFO "MTRR MAP PFN: %016lx - %016lx\n", range[i].start, range[i].end + 1);
+/*
+ * gran_size: 1M, 2M, ..., 2G
+ * chunk size: gran_size, ..., 4G
+ * so we need (2+13)*6
+ */
+#define NUM_RESULT      90
+#define PSHIFT          (PAGE_SHIFT - 10)
 
-        return nr_range;
-}
+static struct mtrr_cleanup_result __initdata result[NUM_RESULT];
+static struct res_range __initdata range_new[RANGE_NUM];
+static unsigned long __initdata min_loss_pfn[RANGE_NUM];
 
 static int __init mtrr_cleanup(unsigned address_bits)
 {
         unsigned long extra_remove_base, extra_remove_size;
         unsigned long i, base, size, def, dummy;
-        struct res_range range[RANGE_NUM];
         mtrr_type type;
-        int nr_range;
+        int nr_range, nr_range_new;
+        u64 chunk_size, gran_size;
+        unsigned long range_sums, range_sums_new;
+        int index_good;
+        int num_reg_good;
 
         /* extra one for all 0 */
         int num[MTRR_NUM_TYPES + 1];
@@ -1038,10 +1173,20 @@ static int __init mtrr_cleanup(unsigned address_bits)
         if (def != MTRR_TYPE_UNCACHABLE)
                 return 0;
 
+        /* get it and store it aside */
+        memset(range_state, 0, sizeof(range_state));
+        for (i = 0; i < num_var_ranges; i++) {
+                mtrr_if->get(i, &base, &size, &type);
+                range_state[i].base_pfn = base;
+                range_state[i].size_pfn = size;
+                range_state[i].type = type;
+        }
+
         /* check entries number */
         memset(num, 0, sizeof(num));
         for (i = 0; i < num_var_ranges; i++) {
-                mtrr_if->get(i, &base, &size, &type);
+                type = range_state[i].type;
+                size = range_state[i].size_pfn;
                 if (type >= MTRR_NUM_TYPES)
                         continue;
                 if (!size)
@@ -1062,15 +1207,172 @@ static int __init mtrr_cleanup(unsigned address_bits)
         extra_remove_size = 0;
         if (mtrr_tom2) {
                 extra_remove_base = 1 << (32 - PAGE_SHIFT);
-                extra_remove_size = (mtrr_tom2>>PAGE_SHIFT) - extra_remove_base;
+                extra_remove_size =
+                        (mtrr_tom2 >> PAGE_SHIFT) - extra_remove_base;
+        }
+        nr_range = x86_get_mtrr_mem_range(range, 0, extra_remove_base,
+                                          extra_remove_size);
+        range_sums = sum_ranges(range, nr_range);
+        printk(KERN_INFO "total RAM coverred: %ldM\n",
+               range_sums >> (20 - PAGE_SHIFT));
+
+        if (mtrr_chunk_size && mtrr_gran_size) {
+                int num_reg;
+
+                /* convert ranges to var ranges state */
+                num_reg = x86_setup_var_mtrrs(range, nr_range, mtrr_chunk_size,
+                                              mtrr_gran_size);
+
+                /* we got new setting in range_state, check it */
+                memset(range_new, 0, sizeof(range_new));
+                nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
+                                                      extra_remove_base,
+                                                      extra_remove_size);
+                range_sums_new = sum_ranges(range_new, nr_range_new);
+
+                i = 0;
+                result[i].chunk_sizek = mtrr_chunk_size >> 10;
+                result[i].gran_sizek = mtrr_gran_size >> 10;
+                result[i].num_reg = num_reg;
+                if (range_sums < range_sums_new) {
+                        result[i].lose_cover_sizek =
+                                (range_sums_new - range_sums) << PSHIFT;
+                        result[i].bad = 1;
+                } else
+                        result[i].lose_cover_sizek =
+                                (range_sums - range_sums_new) << PSHIFT;
+
+                printk(KERN_INFO " %sgran_size: %ldM  \tchunk_size: %ldM  \t",
+                         result[i].bad?" BAD ":"", result[i].gran_sizek >> 10,
+                         result[i].chunk_sizek >> 10);
+                printk(KERN_CONT "num_reg: %d  \tlose cover RAM: %s%ldM \n",
+                         result[i].num_reg, result[i].bad?"-":"",
+                         result[i].lose_cover_sizek >> 10);
+                if (!result[i].bad) {
+                        set_var_mtrr_all(address_bits);
+                        return 1;
+                }
+                printk(KERN_INFO "invalid mtrr_gran_size or mtrr_chunk_size, "
+                       "will find optimal one\n");
+                memset(result, 0, sizeof(result[0]));
+        }
+
+        i = 0;
+        memset(min_loss_pfn, 0xff, sizeof(min_loss_pfn));
+        memset(result, 0, sizeof(result));
+        for (gran_size = (1ULL<<20); gran_size < (1ULL<<32); gran_size <<= 1) {
+                for (chunk_size = gran_size; chunk_size < (1ULL<<33);
+                     chunk_size <<= 1) {
+                        int num_reg;
+
+                        printk(KERN_INFO
+                               "\ngran_size: %lldM   chunk_size_size: %lldM\n",
+                               gran_size >> 20, chunk_size >> 20);
+                        if (i >= NUM_RESULT)
+                                continue;
+
+                        /* convert ranges to var ranges state */
+                        num_reg = x86_setup_var_mtrrs(range, nr_range,
+                                                         chunk_size, gran_size);
+
+                        /* we got new setting in range_state, check it */
+                        memset(range_new, 0, sizeof(range_new));
+                        nr_range_new = x86_get_mtrr_mem_range(range_new, 0,
+                                         extra_remove_base, extra_remove_size);
+                        range_sums_new = sum_ranges(range_new, nr_range_new);
+
+                        result[i].chunk_sizek = chunk_size >> 10;
+                        result[i].gran_sizek = gran_size >> 10;
+                        result[i].num_reg = num_reg;
+                        if (range_sums < range_sums_new) {
+                                result[i].lose_cover_sizek =
+                                        (range_sums_new - range_sums) << PSHIFT;
+                                result[i].bad = 1;
+                        } else
+                                result[i].lose_cover_sizek =
+                                        (range_sums - range_sums_new) << PSHIFT;
+
+                        /* double check it */
+                        if (!result[i].bad && !result[i].lose_cover_sizek) {
+                                if (nr_range_new != nr_range ||
+                                        memcmp(range, range_new, sizeof(range)))
+                                                result[i].bad = 1;
+                        }
+
+                        if (!result[i].bad && (range_sums - range_sums_new <
+                                               min_loss_pfn[num_reg])) {
+                                min_loss_pfn[num_reg] =
+                                        range_sums - range_sums_new;
+                        }
+                        i++;
+                }
         }
-        nr_range = x86_get_mtrr_mem_range(range, 0, extra_remove_base, extra_remove_size);
 
-        /* convert ranges to var ranges state */
-        x86_setup_var_mtrrs(range, nr_range, address_bits);
+        /* print out all */
+        for (i = 0; i < NUM_RESULT; i++) {
+                printk(KERN_INFO "%sgran_size: %ldM  \tchunk_size: %ldM  \t",
+                       result[i].bad?"*BAD* ":" ", result[i].gran_sizek >> 10,
+                       result[i].chunk_sizek >> 10);
+                printk(KERN_CONT "num_reg: %d  \tlose cover RAM: %s%ldM \n",
+                       result[i].num_reg, result[i].bad?"-":"",
+                       result[i].lose_cover_sizek >> 10);
+        }
 
-        return 1;
+        /* try to find the optimal index */
+        if (nr_mtrr_spare_reg >= num_var_ranges)
+                nr_mtrr_spare_reg = num_var_ranges - 1;
+        num_reg_good = -1;
+        for (i = 1; i < num_var_ranges + 1 - nr_mtrr_spare_reg; i++) {
+                if (!min_loss_pfn[i]) {
+                        num_reg_good = i;
+                        break;
+                }
+        }
+
+        index_good = -1;
+        if (num_reg_good != -1) {
+                for (i = 0; i < NUM_RESULT; i++) {
+                        if (!result[i].bad &&
+                            result[i].num_reg == num_reg_good &&
+                            !result[i].lose_cover_sizek) {
+                                index_good = i;
+                                break;
+                        }
+                }
+        }
+
+        if (index_good != -1) {
+                printk(KERN_INFO "Found optimal setting for mtrr clean up\n");
+                i = index_good;
+                printk(KERN_INFO "gran_size: %ldM  \tchunk_size: %ldM  \t",
+                                result[i].gran_sizek >> 10,
+                                result[i].chunk_sizek >> 10);
+                printk(KERN_CONT "num_reg: %d  \tlose cover RAM: %ldM \n",
+                                result[i].num_reg,
+                                result[i].lose_cover_sizek >> 10);
+                /* convert ranges to var ranges state */
+                chunk_size = result[i].chunk_sizek;
+                chunk_size <<= 10;
+                gran_size = result[i].gran_sizek;
+                gran_size <<= 10;
+                x86_setup_var_mtrrs(range, nr_range, chunk_size, gran_size);
+                set_var_mtrr_all(address_bits);
+                return 1;
+        }
+
+        printk(KERN_INFO "mtrr_cleanup: can not find optimal value\n");
+        printk(KERN_INFO "please specify mtrr_gran_size/mtrr_chunk_size\n");
+
+        return 0;
 }
+#else
+static int __init mtrr_cleanup(unsigned address_bits)
+{
+        return 0;
+}
+#endif
+
+static int __initdata changed_by_mtrr_cleanup;
 
 static int disable_mtrr_trim;
 
@@ -1111,7 +1413,8 @@ int __init amd_special_default_mtrr(void)
         return 0;
 }
 
-static u64 __init real_trim_memory(unsigned long start_pfn, unsigned long limit_pfn)
+static u64 __init real_trim_memory(unsigned long start_pfn,
+                                   unsigned long limit_pfn)
 {
         u64 trim_start, trim_size;
         trim_start = start_pfn;
@@ -1138,9 +1441,8 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
 {
         unsigned long i, base, size, highest_pfn = 0, def, dummy;
         mtrr_type type;
-        struct res_range range[RANGE_NUM];
         int nr_range;
-        u64 total_real_trim_size;
+        u64 total_trim_size;
 
         /* extra one for all 0 */
         int num[MTRR_NUM_TYPES + 1];
@@ -1155,11 +1457,22 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
         if (def != MTRR_TYPE_UNCACHABLE)
                 return 0;
 
-        /* Find highest cached pfn */
+        /* get it and store it aside */
+        memset(range_state, 0, sizeof(range_state));
         for (i = 0; i < num_var_ranges; i++) {
                 mtrr_if->get(i, &base, &size, &type);
+                range_state[i].base_pfn = base;
+                range_state[i].size_pfn = size;
+                range_state[i].type = type;
+        }
+
+        /* Find highest cached pfn */
+        for (i = 0; i < num_var_ranges; i++) {
+                type = range_state[i].type;
                 if (type != MTRR_TYPE_WRBACK)
                         continue;
+                base = range_state[i].base_pfn;
+                size = range_state[i].size_pfn;
                 if (highest_pfn < base + size)
                         highest_pfn = base + size;
         }
@@ -1177,9 +1490,10 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
         /* check entries number */
         memset(num, 0, sizeof(num));
         for (i = 0; i < num_var_ranges; i++) {
-                mtrr_if->get(i, &base, &size, &type);
+                type = range_state[i].type;
                 if (type >= MTRR_NUM_TYPES)
                         continue;
+                size = range_state[i].size_pfn;
                 if (!size)
                         type = MTRR_NUM_TYPES;
                 num[type]++;
@@ -1205,26 +1519,28 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
         }
         nr_range = x86_get_mtrr_mem_range(range, nr_range, 0, 0);
 
-        total_real_trim_size = 0;
+        total_trim_size = 0;
         /* check the head */
         if (range[0].start)
-                total_real_trim_size += real_trim_memory(0, range[0].start);
+                total_trim_size += real_trim_memory(0, range[0].start);
         /* check the holes */
         for (i = 0; i < nr_range - 1; i++) {
                 if (range[i].end + 1 < range[i+1].start)
-                        total_real_trim_size += real_trim_memory(range[i].end + 1, range[i+1].start);
+                        total_trim_size += real_trim_memory(range[i].end + 1,
+                                                            range[i+1].start);
         }
         /* check the top */
         i = nr_range - 1;
         if (range[i].end + 1 < end_pfn)
-                total_real_trim_size += real_trim_memory(range[i].end + 1, end_pfn);
+                total_trim_size += real_trim_memory(range[i].end + 1,
+                                                         end_pfn);
 
-        if (total_real_trim_size) {
+        if (total_trim_size) {
                 printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
                         " all of memory, losing %lluMB of RAM.\n",
-                        total_real_trim_size >> 20);
+                        total_trim_size >> 20);
 
-                if (enable_mtrr_cleanup < 1)
+                if (!changed_by_mtrr_cleanup)
                         WARN_ON(1);
 
                 printk(KERN_INFO "update e820 for mtrr\n");
@@ -1314,8 +1630,10 @@ void __init mtrr_bp_init(void)
                 if (use_intel()) {
                         get_mtrr_state();
 
-                        if (mtrr_cleanup(phys_addr))
+                        if (mtrr_cleanup(phys_addr)) {
+                                changed_by_mtrr_cleanup = 1;
                                 mtrr_if->set_all();
+                        }
 
                 }
         }
@@ -1355,7 +1673,7 @@ static int __init mtrr_init_finialize(void)
         if (!mtrr_if)
                 return 0;
         if (use_intel()) {
-                if (enable_mtrr_cleanup < 1)
+                if (!changed_by_mtrr_cleanup)
                         mtrr_state_warn();
         } else {
                 /* The CPUs haven't MTRR and seem to not support SMP. They have