src/cpu/amd/car/disable_cache_as_ram.c

/*
 * This file is part of the coreboot project.
 *
 * original idea yhlu 6.2005 (assembler code)
 *
 * Copyright (C) 2010 Rudolf Marek <r.marek@assembler.cz>
 * Copyright (C) 2015 Timothy Pearson <tpearson@raptorengineeringinc.com>, Raptor Engineering
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * WARNING: this file will be used by both any AP cores and core 0 / node 0
 */

#include <cpu/x86/cache.h>

static inline __attribute__((always_inline)) uint32_t amd_fam1x_cpu_family(void)
{
	uint32_t family;

	family = cpuid_eax(0x80000001);
	family = ((family & 0xf00000) >> 16) | ((family & 0xf00) >> 8);

	return family;
}

static inline __attribute__((always_inline)) void disable_cache_as_ram(uint8_t skip_sharedc_config)
{
	msr_t msr;
	uint32_t family;

	if (!skip_sharedc_config) {
		/* disable cache */
		write_cr0(read_cr0() | CR0_CacheDisable);

		msr.lo = 0;
		msr.hi = 0;
		wrmsr(MTRR_FIX_4K_C8000, msr);
#if CONFIG_DCACHE_RAM_SIZE > 0x8000
		wrmsr(MTRR_FIX_4K_C0000, msr);
#endif
#if CONFIG_DCACHE_RAM_SIZE > 0x10000
		wrmsr(MTRR_FIX_4K_D0000, msr);
#endif
#if CONFIG_DCACHE_RAM_SIZE > 0x18000
		wrmsr(MTRR_FIX_4K_D8000, msr);
#endif
		/* disable fixed mtrr from now on, it will be enabled by ramstage again */
		msr = rdmsr(SYSCFG_MSR);
		msr.lo &= ~(SYSCFG_MSR_MtrrFixDramEn | SYSCFG_MSR_MtrrFixDramModEn);
		wrmsr(SYSCFG_MSR, msr);

		/* Set the default memory type and disable fixed and enable variable MTRRs */
		msr.hi = 0;
		msr.lo = (1 << 11);

		wrmsr(MTRR_DEF_TYPE_MSR, msr);

		enable_cache();
	}

	/* INVDWBINVD = 1 */
	msr = rdmsr(0xc0010015);
	msr.lo |= (0x1 << 4);
	wrmsr(0xc0010015, msr);

	family = amd_fam1x_cpu_family();

#if IS_ENABLED(CPU_AMD_MODEL_10XXX)
	if (family >= 0x6f) {
		/* Family 15h or later */

		/* DisSS = 0 */
		msr = rdmsr(0xc0011020);
		msr.lo &= ~(0x1 << 28);
		wrmsr(0xc0011020, msr);

		if (!skip_sharedc_config) {
			/* DisSpecTlbRld = 0 */
			msr = rdmsr(0xc0011021);
			msr.lo &= ~(0x1 << 9);
			wrmsr(0xc0011021, msr);

			/* Erratum 714: SpecNbReqDis = 0 */
			msr = rdmsr(BU_CFG2_MSR);
			msr.lo &= ~(0x1 << 8);
			wrmsr(BU_CFG2_MSR, msr);
		}

		/* DisSpecTlbRld = 0 */
		/* DisHwPf = 0 */
		msr = rdmsr(0xc0011022);
		msr.lo &= ~(0x1 << 4);
		msr.lo &= ~(0x1 << 13);
		wrmsr(0xc0011022, msr);
	}
#endif
}

static void disable_cache_as_ram_bsp(void)
{
	disable_cache_as_ram(0);
}