diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h
index dcc995d..3c11740 100644
--- a/arch/x86/include/asm/mtrr.h
+++ b/arch/x86/include/asm/mtrr.h
@@ -9,94 +9,85 @@
 #ifndef _ASM_MTRR_H
 #define _ASM_MTRR_H
 
-/*  These are the region types  */
-#define MTRR_TYPE_UNCACHEABLE 0
-#define MTRR_TYPE_WRCOMB     1
-/*#define MTRR_TYPE_         2*/
-/*#define MTRR_TYPE_         3*/
-#define MTRR_TYPE_WRTHROUGH  4
-#define MTRR_TYPE_WRPROT     5
-#define MTRR_TYPE_WRBACK     6
-#define MTRR_NUM_TYPES       7
+/* MTRR region types */
+#define MTRR_TYPE_UNCACHEABLE	0
+#define MTRR_TYPE_WRCOMB	1
+#define MTRR_TYPE_WRTHROUGH	4
+#define MTRR_TYPE_WRPROT	5
+#define MTRR_TYPE_WRBACK	6
 
-#define MTRRcap_MSR     0x0fe
-#define MTRRdefType_MSR 0x2ff
+#define MTRR_TYPE_COUNT		7
 
-#define MTRRdefTypeEn		(1 << 11)
-#define MTRRdefTypeFixEn	(1 << 10)
+#define MTRR_CAP_MSR		0x0fe
+#define MTRR_DEF_TYPE_MSR	0x2ff
 
-#define SMRRphysBase_MSR 0x1f2
-#define SMRRphysMask_MSR 0x1f3
+#define MTRR_DEF_TYPE_EN	(1 << 11)
+#define MTRR_DEF_TYPE_FIX_EN	(1 << 10)
 
-#define MTRRphysBase_MSR(reg) (0x200 + 2 * (reg))
-#define MTRRphysMask_MSR(reg) (0x200 + 2 * (reg) + 1)
+#define MTRR_PHYS_BASE_MSR(reg)	(0x200 + 2 * (reg))
+#define MTRR_PHYS_MASK_MSR(reg)	(0x200 + 2 * (reg) + 1)
 
-#define MTRRphysMaskValid	(1 << 11)
+#define MTRR_PHYS_MASK_VALID	(1 << 11)
 
-#define NUM_FIXED_RANGES 88
-#define RANGES_PER_FIXED_MTRR 8
-#define MTRRfix64K_00000_MSR 0x250
-#define MTRRfix16K_80000_MSR 0x258
-#define MTRRfix16K_A0000_MSR 0x259
-#define MTRRfix4K_C0000_MSR 0x268
-#define MTRRfix4K_C8000_MSR 0x269
-#define MTRRfix4K_D0000_MSR 0x26a
-#define MTRRfix4K_D8000_MSR 0x26b
-#define MTRRfix4K_E0000_MSR 0x26c
-#define MTRRfix4K_E8000_MSR 0x26d
-#define MTRRfix4K_F0000_MSR 0x26e
-#define MTRRfix4K_F8000_MSR 0x26f
+#define MTRR_BASE_TYPE_MASK	0x7
+
+/* Number of MTRRs supported */
+#define MTRR_COUNT		8
 
 #if !defined(__ASSEMBLER__)
 
-/*
- * The MTRR code has some side effects that the callers should be aware for.
- * 1. The call sequence matters. x86_setup_mtrrs() calls
- *    x86_setup_fixed_mtrrs_no_enable() then enable_fixed_mtrrs() (equivalent
- *    of x86_setup_fixed_mtrrs()) then x86_setup_var_mtrrs(). If the callers
- *    want to call the components of x86_setup_mtrrs() because of other
- *    rquirements the ordering should still preserved.
- * 2. enable_fixed_mtrr() will enable both variable and fixed MTRRs because
- *    of the nature of the global MTRR enable flag. Therefore, all direct
- *    or indirect callers of enable_fixed_mtrr() should ensure that the
- *    variable MTRR MSRs do not contain bad ranges.
- * 3. If CONFIG_CACHE_ROM is selected an MTRR is allocated for enabling
- *    the caching of the ROM. However, it is set to uncacheable (UC). It
- *    is the responsiblity of the caller to enable it by calling
- *    x86_mtrr_enable_rom_caching().
+/**
+ * Information about the previous MTRR state, set up by mtrr_open()
+ *
+ * @deftype:		Previous value of MTRR_DEF_TYPE_MSR
+ * @enable_cache:	true if cache was enabled
  */
-void x86_setup_mtrrs(void);
-/*
- * x86_setup_var_mtrrs() parameters:
- * address_bits - number of physical address bits supported by cpu
- * above4gb - 2 means dynamically detect number of variable MTRRs available.
- *            non-zero means handle memory ranges above 4GiB.
- *            0 means ignore memory ranges above 4GiB
+struct mtrr_state {
+	uint64_t deftype;
+	bool enable_cache;
+};
+
+/**
+ * mtrr_open() - Prepare to adjust MTRRs
+ *
+ * Use mtrr_open() passing in a structure - this function will init it. Then
+ * when done, pass the same structure to mtrr_close() to re-enable MTRRs and
+ * possibly the cache.
+ *
+ * @state:	Empty structure to pass in to hold settings
  */
-void x86_setup_var_mtrrs(unsigned int address_bits, unsigned int above4gb);
-void enable_fixed_mtrr(void);
-void x86_setup_fixed_mtrrs(void);
-/* Set up fixed MTRRs but do not enable them. */
-void x86_setup_fixed_mtrrs_no_enable(void);
-int x86_mtrr_check(void);
-/* ROM caching can be used after variable MTRRs are set up. Beware that
- * enabling CONFIG_CACHE_ROM will eat through quite a few MTRRs based on
- * one's IO hole size and WRCOMB resources. Be sure to check the console
- * log when enabling CONFIG_CACHE_ROM or adding WRCOMB resources. Beware that
- * on CPUs with core-scoped MTRR registers such as hyperthreaded CPUs the
- * rom caching will be disabled if all threads run the MTRR code. Therefore,
- * one needs to call x86_mtrr_enable_rom_caching() after all threads of the
- * same core have run the MTRR code. */
-#if CONFIG_CACHE_ROM
-void x86_mtrr_enable_rom_caching(void);
-void x86_mtrr_disable_rom_caching(void);
-/* Return the variable range MTRR index of the ROM cache. */
-long x86_mtrr_rom_cache_var_index(void);
-#else
-static inline void x86_mtrr_enable_rom_caching(void) {}
-static inline void x86_mtrr_disable_rom_caching(void) {}
-static inline long x86_mtrr_rom_cache_var_index(void) { return -1; }
-#endif /* CONFIG_CACHE_ROM */
+void mtrr_open(struct mtrr_state *state);
+
+/**
+ * mtrr_open() - Clean up after adjusting MTRRs, and enable them
+ *
+ * This uses the structure containing information returned from mtrr_open().
+ *
+ * @state:	Structure from mtrr_open()
+ */
+/*  */
+void mtrr_close(struct mtrr_state *state);
+
+/**
+ * mtrr_add_request() - Add a new MTRR request
+ *
+ * This adds a request for a memory region to be set up in a particular way.
+ *
+ * @type:	Requested type (MTRR_TYPE_)
+ * @start:	Start address
+ * @size:	Size
+ */
+int mtrr_add_request(int type, uint64_t start, uint64_t size);
+
+/**
+ * mtrr_commit() - set up the MTRR registers based on current requests
+ *
+ * This sets up MTRRs for the available DRAM and the requests received so far.
+ * It must be called with caches disabled.
+ *
+ * @do_caches:	true if caches are currently on
+ */
+int mtrr_commit(bool do_caches);
 
 #endif