| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <console/console.h> |
| #include <cpu/intel/haswell/haswell.h> |
| #include <cpu/x86/msr.h> |
| |
| void set_max_freq(void) |
| { |
| msr_t msr, perf_ctl, platform_info; |
| |
| /* Check for configurable TDP option */ |
| platform_info = rdmsr(MSR_PLATFORM_INFO); |
| |
| if ((platform_info.hi >> 1) & 3) { |
| /* Set to nominal TDP ratio */ |
| msr = rdmsr(MSR_CONFIG_TDP_NOMINAL); |
| perf_ctl.lo = (msr.lo & 0xff) << 8; |
| } else { |
| /* Platform Info bits 15:8 give max ratio */ |
| msr = rdmsr(MSR_PLATFORM_INFO); |
| perf_ctl.lo = msr.lo & 0xff00; |
| } |
| |
| perf_ctl.hi = 0; |
| wrmsr(IA32_PERF_CTL, perf_ctl); |
| |
| printk(BIOS_DEBUG, "CPU: frequency set to %d MHz\n", |
| ((perf_ctl.lo >> 8) & 0xff) * CPU_BCLK); |
| } |