| Felix Held | a90854d | 2021-02-10 04:05:27 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
| 2 | |
| 3 | #include <amdblocks/smm.h> |
| 4 | #include <console/console.h> |
| 5 | #include <cpu/x86/msr.h> |
| 6 | #include <cpu/amd/msr.h> |
| 7 | |
| 8 | /* |
| 9 | * For data stored in TSEG, ensure TValid is clear so R/W access can reach |
| 10 | * the DRAM when not in SMM. |
| 11 | */ |
| 12 | void clear_tvalid(void) |
| 13 | { |
| 14 | msr_t hwcr = rdmsr(HWCR_MSR); |
| 15 | msr_t mask = rdmsr(SMM_MASK_MSR); |
| 16 | int tvalid = !!(mask.lo & SMM_TSEG_VALID); |
| 17 | |
| 18 | if (hwcr.lo & SMM_LOCK) { |
| 19 | if (!tvalid) /* not valid but locked means still accessible */ |
| 20 | return; |
| 21 | |
| 22 | printk(BIOS_ERR, "Error: can't clear TValid, already locked\n"); |
| 23 | return; |
| 24 | } |
| 25 | |
| 26 | mask.lo &= ~SMM_TSEG_VALID; |
| 27 | wrmsr(SMM_MASK_MSR, mask); |
| 28 | } |