src/include/cpu/x86/mtrr.h

#ifndef CPU_X86_MTRR_H
#define CPU_X86_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

#define MTRRcap_MSR     0x0fe
#define MTRRdefType_MSR 0x2ff

#define MTRRdefTypeEn		(1 << 11)
#define MTRRdefTypeFixEn	(1 << 10)

#define SMRRphysBase_MSR 0x1f2
#define SMRRphysMask_MSR 0x1f3

#define MTRRphysBase_MSR(reg) (0x200 + 2 * (reg))
#define MTRRphysMask_MSR(reg) (0x200 + 2 * (reg) + 1)

#define MTRRphysMaskValid	(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

#if !defined (__ASSEMBLER__) && !defined(__PRE_RAM__)

/*
 * 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
 *    requirements 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.
 */
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
 */
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);
void x86_mtrr_check(void);
#endif

#if !defined(__ASSEMBLER__) && defined(__PRE_RAM__) && !defined(__ROMCC__)
void set_var_mtrr(unsigned reg, unsigned base, unsigned size, unsigned type);
#endif

/* Align up to next power of 2, suitable for ROMCC and assembler too.
 * Range of result 256kB to 128MB is good enough here.
 */
#define _POW2_MASK(x)	((x>>1)|(x>>2)|(x>>3)|(x>>4)|(x>>5)| \
					(x>>6)|(x>>7)|(x>>8)|((1<<18)-1))
#define _ALIGN_UP_POW2(x)	((x + _POW2_MASK(x)) & ~_POW2_MASK(x))

#if !defined(CONFIG_RAMTOP)
# error "CONFIG_RAMTOP not defined"
#endif

#if ((CONFIG_XIP_ROM_SIZE & (CONFIG_XIP_ROM_SIZE -1)) != 0)
# error "CONFIG_XIP_ROM_SIZE is not a power of 2"
#endif

/* Select CACHE_ROM_SIZE to use with MTRR setup. For most cases this
 * resolves to a suitable CONFIG_ROM_SIZE but some odd cases need to
 * use CONFIG_CACHE_ROM_SIZE_OVERRIDE in the mainboard Kconfig.
 */
#if (CONFIG_CACHE_ROM_SIZE_OVERRIDE != 0)
# define CACHE_ROM_SIZE	CONFIG_CACHE_ROM_SIZE_OVERRIDE
#else
# if ((CONFIG_ROM_SIZE & (CONFIG_ROM_SIZE-1)) == 0)
#  define CACHE_ROM_SIZE CONFIG_ROM_SIZE
# else
#  define CACHE_ROM_SIZE _ALIGN_UP_POW2(CONFIG_ROM_SIZE)
#  if (CACHE_ROM_SIZE < CONFIG_ROM_SIZE) || (CACHE_ROM_SIZE >= (2 * CONFIG_ROM_SIZE))
#   error "CACHE_ROM_SIZE is not optimal."
#  endif
# endif
#endif

#if ((CACHE_ROM_SIZE & (CACHE_ROM_SIZE-1)) != 0)
# error "CACHE_ROM_SIZE is not a power of 2."
#endif

#define CACHE_ROM_BASE	(((1<<20) - (CACHE_ROM_SIZE>>12))<<12)

#if (CONFIG_RAMTOP & (CONFIG_RAMTOP - 1)) != 0
# error "CONFIG_RAMTOP must be a power of 2"
#endif

#endif /* CPU_X86_MTRR_H */