u-boot/arch/x86/include/asm/mtrr.h
Bin Meng 3b621ccabd x86: Test mtrr support flag before accessing mtrr msr
On some x86 processors (like Intel Quark) the MTRR registers are not
supported. This is reflected by the CPUID (EAX 01H) result EDX[12].
Accessing the MTRR registers on such processors will cause #GP so we
must test the support flag before accessing MTRR MSRs.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-01-23 17:24:55 -07:00

107 lines
2.5 KiB
C

/*
* Copyright (c) 2014 Google, Inc
*
* From Coreboot file of the same name
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _ASM_MTRR_H
#define _ASM_MTRR_H
/* 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 MTRR_TYPE_COUNT 7
#define MTRR_CAP_MSR 0x0fe
#define MTRR_DEF_TYPE_MSR 0x2ff
#define MTRR_DEF_TYPE_EN (1 << 11)
#define MTRR_DEF_TYPE_FIX_EN (1 << 10)
#define MTRR_PHYS_BASE_MSR(reg) (0x200 + 2 * (reg))
#define MTRR_PHYS_MASK_MSR(reg) (0x200 + 2 * (reg) + 1)
#define MTRR_PHYS_MASK_VALID (1 << 11)
#define MTRR_BASE_TYPE_MASK 0x7
/* Number of MTRRs supported */
#define MTRR_COUNT 8
#if !defined(__ASSEMBLER__)
/**
* 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
*/
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 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
*
* @return: 0 on success, non-zero on failure
*/
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
*
* @return: 0 on success, non-zero on failure
*/
int mtrr_commit(bool do_caches);
#endif
#if ((CONFIG_XIP_ROM_SIZE & (CONFIG_XIP_ROM_SIZE - 1)) != 0)
# error "CONFIG_XIP_ROM_SIZE is not a power of 2"
#endif
#if ((CONFIG_CACHE_ROM_SIZE & (CONFIG_CACHE_ROM_SIZE - 1)) != 0)
# error "CONFIG_CACHE_ROM_SIZE is not a power of 2"
#endif
#define CACHE_ROM_BASE (((1 << 20) - (CONFIG_CACHE_ROM_SIZE >> 12)) << 12)
#endif