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/* SPDX-License-Identifier: GPL-2.0-only */
#include <amdblocks/smm.h>
#include <console/console.h>
#include <cpu/x86/msr.h>
#include <cpu/amd/msr.h>
/*
* For data stored in TSEG, ensure TValid is clear so R/W access can reach
* the DRAM when not in SMM.
*/
void clear_tvalid(void)
{
msr_t hwcr = rdmsr(HWCR_MSR);
msr_t mask = rdmsr(SMM_MASK_MSR);
int tvalid = !!(mask.lo & SMM_TSEG_VALID);
if (hwcr.lo & SMM_LOCK) {
if (!tvalid) /* not valid but locked means still accessible */
return;
printk(BIOS_ERR, "can't clear TValid, already locked\n");
return;
}
mask.lo &= ~SMM_TSEG_VALID;
wrmsr(SMM_MASK_MSR, mask);
}
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