MTRR: add alternate allocation method for odd memory maps

[coreboot.git] / src / cpu / x86 / mtrr / mtrr.c

diff --git a/src/cpu/x86/mtrr/mtrr.c b/src/cpu/x86/mtrr/mtrr.c
index 9015ad4d97c9dd96a99333b784e6bbea71a58593..8dccfefa042f1a43b8cbea6e1a394a541ae63e46 100644 (file)
--- a/src/cpu/x86/mtrr/mtrr.c
+++ b/src/cpu/x86/mtrr/mtrr.c
@@ -179,6 +179,18 @@ static inline unsigned int fls(unsigned int x)
 #endif
 #define MTRRS        (BIOS_MTRRS + OS_MTRRS)
 
+static int total_mtrrs = MTRRS;
+static int bios_mtrrs = BIOS_MTRRS;
+
+static void detect_var_mtrrs(void)
+{
+       msr_t msr;
+
+       msr = rdmsr(MTRRcap_MSR);
+
+       total_mtrrs = msr.lo & 0xff;
+       bios_mtrrs = total_mtrrs - 2;
+}
 
 static void set_fixed_mtrrs(unsigned int first, unsigned int last, unsigned char type)
 {
@@ -235,6 +247,8 @@ static unsigned int range_to_mtrr(unsigned int reg,
        unsigned long next_range_startk, unsigned char type,
        unsigned int address_bits, unsigned int above4gb)
 {
+       unsigned long hole_startk = 0, hole_sizek = 0;
+
        if (!range_sizek) {
                /* If there's no MTRR hole, this function will bail out
                 * here when called for the hole.
@@ -243,7 +257,7 @@ static unsigned int range_to_mtrr(unsigned int reg,
                return reg;
        }
 
-       if (reg >= BIOS_MTRRS) {
+       if (reg >= bios_mtrrs) {
                printk(BIOS_ERR, "Warning: Out of MTRRs for base: %4ldMB, range: %ldMB, type %s\n",
                                range_startk >>10, range_sizek >> 10,
                                (type==MTRR_TYPE_UNCACHEABLE)?"UC":
@@ -251,6 +265,16 @@ static unsigned int range_to_mtrr(unsigned int reg,
                return reg;
        }
 
+       if (above4gb == 2 && type == MTRR_TYPE_WRBACK && range_sizek % 0x4000) {
+               /*
+                * If this range is not divisible by 16MB then instead
+                * make a larger range and carve out an uncached hole.
+                */
+               hole_startk = range_startk + range_sizek;
+               hole_sizek = 0x4000 - (range_sizek % 0x4000);
+               range_sizek += hole_sizek;
+       }
+
        while(range_sizek) {
                unsigned long max_align, align;
                unsigned long sizek;
@@ -274,11 +298,20 @@ static unsigned int range_to_mtrr(unsigned int reg,
                        set_var_mtrr(reg++, range_startk, sizek, type, address_bits);
                range_startk += sizek;
                range_sizek -= sizek;
-               if (reg >= BIOS_MTRRS) {
+               if (reg >= bios_mtrrs) {
                        printk(BIOS_ERR, "Running out of variable MTRRs!\n");
                        break;
                }
        }
+
+       if (hole_sizek) {
+               printk(BIOS_DEBUG, "Adding hole at %ldMB-%ldMB\n",
+                      hole_startk, hole_startk + hole_sizek);
+               reg = range_to_mtrr(reg, hole_startk, hole_sizek,
+                             next_range_startk, MTRR_TYPE_UNCACHEABLE,
+                             address_bits, above4gb);
+       }
+
        return reg;
 }
 
@@ -325,7 +358,7 @@ void set_var_mtrr_resource(void *gp, struct device *dev, struct resource *res)
 {
        struct var_mtrr_state *state = gp;
        unsigned long basek, sizek;
-       if (state->reg >= BIOS_MTRRS)
+       if (state->reg >= bios_mtrrs)
                return;
        basek = resk(res->base);
        sizek = resk(res->size);
@@ -341,7 +374,7 @@ void set_var_mtrr_resource(void *gp, struct device *dev, struct resource *res)
        /* Write the range mtrrs */
        if (state->range_sizek != 0) {
 #if CONFIG_VAR_MTRR_HOLE
-               if (state->hole_sizek == 0) {
+               if (state->hole_sizek == 0 && state->above4gb != 2) {
                        /* We need to put that on to hole */
                        unsigned long endk = basek + sizek;
                        state->hole_startk = state->range_startk + state->range_sizek;
@@ -424,6 +457,10 @@ void x86_setup_var_mtrrs(unsigned int address_bits, unsigned int above4gb)
        var_state.address_bits = address_bits;
        var_state.above4gb = above4gb;
 
+       /* Detect number of variable MTRRs */
+       if (above4gb == 2)
+               detect_var_mtrrs();
+
        search_global_resources(
                IORESOURCE_MEM | IORESOURCE_CACHEABLE, IORESOURCE_MEM | IORESOURCE_CACHEABLE,
                set_var_mtrr_resource, &var_state);
@@ -435,7 +472,8 @@ void x86_setup_var_mtrrs(unsigned int address_bits, unsigned int above4gb)
        } else {
 #if CONFIG_VAR_MTRR_HOLE
                // Increase the base range and set up UMA as an UC hole instead
-               var_state.range_sizek += (uma_memory_size >> 10);
+               if (above4gb != 2)
+                       var_state.range_sizek += (uma_memory_size >> 10);
 
                var_state.hole_startk = (uma_memory_base >> 10);
                var_state.hole_sizek = (uma_memory_size >> 10);
@@ -454,7 +492,7 @@ void x86_setup_var_mtrrs(unsigned int address_bits, unsigned int above4gb)
        printk(BIOS_DEBUG, "DONE variable MTRRs\n");
        printk(BIOS_DEBUG, "Clear out the extra MTRR's\n");
        /* Clear out the extra MTRR's */
-       while(var_state.reg < MTRRS) {
+       while(var_state.reg < total_mtrrs) {
                set_var_mtrr(var_state.reg++, 0, 0, 0, var_state.address_bits);
        }
 
@@ -463,7 +501,7 @@ void x86_setup_var_mtrrs(unsigned int address_bits, unsigned int above4gb)
         * complete ROM now that we actually have RAM.
         */
        if (boot_cpu() && (acpi_slp_type != 3)) {
-               set_var_mtrr(7, (4096-4)*1024, 4*1024,
+               set_var_mtrr(total_mtrrs-1, (4096-4)*1024, 4*1024,
                        MTRR_TYPE_WRPROT, address_bits);
        }
 #endif