From ede9709316f6c4d18d2a3e126879af2816c0b329 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 29 Apr 2015 22:26:02 -0600 Subject: x86: Add a CPU driver for baytrail This driver supports multi-core init and sets up the CPU frequencies correctly. Signed-off-by: Simon Glass Reviewed-by: Bin Meng --- arch/x86/cpu/baytrail/Makefile | 1 + arch/x86/cpu/baytrail/cpu.c | 205 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 206 insertions(+) create mode 100644 arch/x86/cpu/baytrail/cpu.c (limited to 'arch/x86/cpu/baytrail') diff --git a/arch/x86/cpu/baytrail/Makefile b/arch/x86/cpu/baytrail/Makefile index 8914e8b..c78b644 100644 --- a/arch/x86/cpu/baytrail/Makefile +++ b/arch/x86/cpu/baytrail/Makefile @@ -4,6 +4,7 @@ # SPDX-License-Identifier: GPL-2.0+ # +obj-y += cpu.o obj-y += early_uart.o obj-y += fsp_configs.o obj-y += pci.o diff --git a/arch/x86/cpu/baytrail/cpu.c b/arch/x86/cpu/baytrail/cpu.c new file mode 100644 index 0000000..1d48206 --- /dev/null +++ b/arch/x86/cpu/baytrail/cpu.c @@ -0,0 +1,205 @@ +/* + * Copyright (C) 2015 Google, Inc + * + * SPDX-License-Identifier: GPL-2.0+ + * + * Based on code from coreboot + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_SMP +static int enable_smis(struct udevice *cpu, void *unused) +{ + return 0; +} + +static struct mp_flight_record mp_steps[] = { + MP_FR_BLOCK_APS(mp_init_cpu, NULL, mp_init_cpu, NULL), + /* Wait for APs to finish initialization before proceeding. */ + MP_FR_BLOCK_APS(NULL, NULL, enable_smis, NULL), +}; + +static int detect_num_cpus(void) +{ + int ecx = 0; + + /* + * Use the algorithm described in Intel 64 and IA-32 Architectures + * Software Developer's Manual Volume 3 (3A, 3B & 3C): System + * Programming Guide, Jan-2015. Section 8.9.2: Hierarchical Mapping + * of CPUID Extended Topology Leaf. + */ + while (1) { + struct cpuid_result leaf_b; + + leaf_b = cpuid_ext(0xb, ecx); + + /* + * Bay Trail doesn't have hyperthreading so just determine the + * number of cores by from level type (ecx[15:8] == * 2) + */ + if ((leaf_b.ecx & 0xff00) == 0x0200) + return leaf_b.ebx & 0xffff; + ecx++; + } +} + +static int baytrail_init_cpus(void) +{ + struct mp_params mp_params; + + lapic_setup(); + + mp_params.num_cpus = detect_num_cpus(); + mp_params.parallel_microcode_load = 0, + mp_params.flight_plan = &mp_steps[0]; + mp_params.num_records = ARRAY_SIZE(mp_steps); + mp_params.microcode_pointer = 0; + + if (mp_init(&mp_params)) { + printf("Warning: MP init failure\n"); + return -EIO; + } + + return 0; +} +#endif + +int x86_init_cpus(void) +{ +#ifdef CONFIG_SMP + debug("Init additional CPUs\n"); + baytrail_init_cpus(); +#endif + + return 0; +} + +static void set_max_freq(void) +{ + msr_t perf_ctl; + msr_t msr; + + /* Enable speed step */ + msr = msr_read(MSR_IA32_MISC_ENABLES); + msr.lo |= (1 << 16); + msr_write(MSR_IA32_MISC_ENABLES, msr); + + /* + * Set guaranteed ratio [21:16] from IACORE_RATIOS to bits [15:8] of + * the PERF_CTL + */ + msr = msr_read(MSR_IACORE_RATIOS); + perf_ctl.lo = (msr.lo & 0x3f0000) >> 8; + + /* + * Set guaranteed vid [21:16] from IACORE_VIDS to bits [7:0] of + * the PERF_CTL + */ + msr = msr_read(MSR_IACORE_VIDS); + perf_ctl.lo |= (msr.lo & 0x7f0000) >> 16; + perf_ctl.hi = 0; + + msr_write(MSR_IA32_PERF_CTL, perf_ctl); +} + +static int cpu_x86_baytrail_probe(struct udevice *dev) +{ + debug("Init BayTrail core\n"); + + /* + * On BayTrail the turbo disable bit is actually scoped at the + * building-block level, not package. For non-BSP cores that are + * within a building block, enable turbo. The cores within the BSP's + * building block will just see it already enabled and move on. + */ + if (lapicid()) + turbo_enable(); + + /* Dynamic L2 shrink enable and threshold */ + msr_clrsetbits_64(MSR_PMG_CST_CONFIG_CONTROL, 0x3f000f, 0xe0008), + + /* Disable C1E */ + msr_clrsetbits_64(MSR_POWER_CTL, 2, 0); + msr_setbits_64(MSR_POWER_MISC, 0x44); + + /* Set this core to max frequency ratio */ + set_max_freq(); + + return 0; +} + +static unsigned bus_freq(void) +{ + msr_t clk_info = msr_read(MSR_BSEL_CR_OVERCLOCK_CONTROL); + switch (clk_info.lo & 0x3) { + case 0: + return 83333333; + case 1: + return 100000000; + case 2: + return 133333333; + case 3: + return 116666666; + default: + return 0; + } +} + +static unsigned long tsc_freq(void) +{ + msr_t platform_info; + ulong bclk = bus_freq(); + + if (!bclk) + return 0; + + platform_info = msr_read(MSR_PLATFORM_INFO); + + return bclk * ((platform_info.lo >> 8) & 0xff); +} + +static int baytrail_get_info(struct udevice *dev, struct cpu_info *info) +{ + info->cpu_freq = tsc_freq(); + info->features = 1 << CPU_FEAT_L1_CACHE | 1 << CPU_FEAT_MMU; + + return 0; +} + +static int cpu_x86_baytrail_bind(struct udevice *dev) +{ + struct cpu_platdata *plat = dev_get_parent_platdata(dev); + + plat->cpu_id = fdtdec_get_int(gd->fdt_blob, dev->of_offset, + "intel,apic-id", -1); + + return 0; +} + +static const struct cpu_ops cpu_x86_baytrail_ops = { + .get_desc = x86_cpu_get_desc, + .get_info = baytrail_get_info, +}; + +static const struct udevice_id cpu_x86_baytrail_ids[] = { + { .compatible = "intel,baytrail-cpu" }, + { } +}; + +U_BOOT_DRIVER(cpu_x86_baytrail_drv) = { + .name = "cpu_x86_baytrail", + .id = UCLASS_CPU, + .of_match = cpu_x86_baytrail_ids, + .bind = cpu_x86_baytrail_bind, + .probe = cpu_x86_baytrail_probe, + .ops = &cpu_x86_baytrail_ops, +}; -- cgit v1.1