[U-Boot] [PATCH 1/4] x86: Display more detailed CPU information on boot
Simon Glass
sjg at chromium.org
Sat Nov 8 19:54:27 CET 2014
Hi Bin,
On 8 November 2014 08:18, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Fri, Nov 7, 2014 at 10:22 AM, Simon Glass <sjg at chromium.org> wrote:
>> Hi Bin,
>>
>> On 4 November 2014 07:58, Bin Meng <bmeng.cn at gmail.com> wrote:
>>> Currently only basic CPU information (x86 or x86_64) is displayed
>>> on boot. This commit adds more detailed information output including
>>> CPU vendor name, device id, family, model and stepping as well as
>>> the CPU brand string, all of which are extracted from CPUID result.
>>>
>>> The CPU identification happens in x86_cpu_init_f() and corresponding
>>> fields are saved in the global data. Later print_cpuinfo() just uses
>>> these fields to display CPU information without the need to probe
>>> again in real time.
>>>
>>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>>> ---
>>> arch/x86/cpu/cpu.c | 282 +++++++++++++++++++++++++++++++------
>>> arch/x86/include/asm/cpu.h | 142 +++++++++++++++++++
>>> arch/x86/include/asm/global_data.h | 5 +
>>> 3 files changed, 385 insertions(+), 44 deletions(-)
>>>
>>> diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
>>> index 2e25253..e9058f7 100644
>>> --- a/arch/x86/cpu/cpu.c
>>> +++ b/arch/x86/cpu/cpu.c
>>> @@ -13,6 +13,9 @@
>>> * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
>>> * Alex Zuepke <azu at sysgo.de>
>>> *
>>> + * Part of this file is adapted from coreboot
>>> + * src/arch/x86/lib/cpu.c
>>> + *
>>> * SPDX-License-Identifier: GPL-2.0+
>>> */
>>>
>>> @@ -27,6 +30,8 @@
>>> #include <asm/interrupt.h>
>>> #include <linux/compiler.h>
>>>
>>> +DECLARE_GLOBAL_DATA_PTR;
>>> +
>>> /*
>>> * Constructor for a conventional segment GDT (or LDT) entry
>>> * This is a macro so it can be used in initialisers
>>> @@ -43,6 +48,51 @@ struct gdt_ptr {
>>> u32 ptr;
>>> } __packed;
>>>
>>> +struct cpu_device_id {
>>> + unsigned vendor;
>>> + unsigned device;
>>> +};
>>> +
>>> +struct cpuinfo_x86 {
>>> + uint8_t x86; /* CPU family */
>>> + uint8_t x86_vendor; /* CPU vendor */
>>> + uint8_t x86_model;
>>> + uint8_t x86_mask;
>>> +};
>>> +
>>> +/* List of cpu vendor strings along with their normalized
>>
>> Can we put /* on its own line?
>>
>> /*
>> * List of CPU vendor strings ...
>> * ...
>> */
>>
>
> Sure.
>
>>> + * id values.
>>> + */
>>> +static struct {
>>> + int vendor;
>>> + const char *name;
>>> +} x86_vendors[] = {
>>> + { X86_VENDOR_INTEL, "GenuineIntel", },
>>> + { X86_VENDOR_CYRIX, "CyrixInstead", },
>>> + { X86_VENDOR_AMD, "AuthenticAMD", },
>>> + { X86_VENDOR_UMC, "UMC UMC UMC ", },
>>> + { X86_VENDOR_NEXGEN, "NexGenDriven", },
>>> + { X86_VENDOR_CENTAUR, "CentaurHauls", },
>>> + { X86_VENDOR_RISE, "RiseRiseRise", },
>>> + { X86_VENDOR_TRANSMETA, "GenuineTMx86", },
>>> + { X86_VENDOR_TRANSMETA, "TransmetaCPU", },
>>> + { X86_VENDOR_NSC, "Geode by NSC", },
>>> + { X86_VENDOR_SIS, "SiS SiS SiS ", },
>>> +};
>>> +
>>> +static const char *x86_vendor_name[] = {
>>> + [X86_VENDOR_INTEL] = "Intel",
>>> + [X86_VENDOR_CYRIX] = "Cyrix",
>>> + [X86_VENDOR_AMD] = "AMD",
>>> + [X86_VENDOR_UMC] = "UMC",
>>> + [X86_VENDOR_NEXGEN] = "NexGen",
>>> + [X86_VENDOR_CENTAUR] = "Centaur",
>>> + [X86_VENDOR_RISE] = "Rise",
>>> + [X86_VENDOR_TRANSMETA] = "Transmeta",
>>> + [X86_VENDOR_NSC] = "NSC",
>>> + [X86_VENDOR_SIS] = "SiS",
>>> +};
>>> +
>>> static void load_ds(u32 segment)
>>> {
>>> asm volatile("movl %0, %%ds" : : "r" (segment * X86_GDT_ENTRY_SIZE));
>>> @@ -115,6 +165,131 @@ int __weak x86_cleanup_before_linux(void)
>>> return 0;
>>> }
>>>
>>> +/*
>>> + * Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
>>> + * by the fact that they preserve the flags across the division of 5/2.
>>> + * PII and PPro exhibit this behavior too, but they have cpuid available.
>>> + */
>>> +
>>> +/*
>>> + * Perform the Cyrix 5/2 test. A Cyrix won't change
>>> + * the flags, while other 486 chips will.
>>> + */
>>> +static inline int test_cyrix_52div(void)
>>> +{
>>> + unsigned int test;
>>> +
>>> + __asm__ __volatile__(
>>> + "sahf\n\t" /* clear flags (%eax = 0x0005) */
>>> + "div %b2\n\t" /* divide 5 by 2 */
>>> + "lahf" /* store flags into %ah */
>>> + : "=a" (test)
>>> + : "0" (5), "q" (2)
>>> + : "cc");
>>> +
>>> + /* AH is 0x02 on Cyrix after the divide.. */
>>> + return (unsigned char) (test >> 8) == 0x02;
>>> +}
>>> +
>>> +/*
>>> + * Detect a NexGen CPU running without BIOS hypercode new enough
>>> + * to have CPUID. (Thanks to Herbert Oppmann)
>>> + */
>>> +
>>> +static int deep_magic_nexgen_probe(void)
>>> +{
>>> + int ret;
>>> +
>>> + __asm__ __volatile__ (
>>> + " movw $0x5555, %%ax\n"
>>> + " xorw %%dx,%%dx\n"
>>> + " movw $2, %%cx\n"
>>> + " divw %%cx\n"
>>> + " movl $0, %%eax\n"
>>> + " jnz 1f\n"
>>> + " movl $1, %%eax\n"
>>> + "1:\n"
>>> + : "=a" (ret) : : "cx", "dx" );
>>> + return ret;
>>> +}
>>> +
>>> +static bool has_cpuid(void)
>>> +{
>>> + return flag_is_changeable_p(X86_EFLAGS_ID);
>>> +}
>>> +
>>> +static void identify_cpu(struct cpu_device_id *cpu)
>>> +{
>>> + char vendor_name[16];
>>> + int i;
>>> +
>>> + vendor_name[0] = '\0'; /* Unset */
>>> +
>>> + /* Find the id and vendor_name */
>>> + if (!has_cpuid()) {
>>> + /* Its a 486 if we can modify the AC flag */
>>> + if (flag_is_changeable_p(X86_EFLAGS_AC)) {
>>> + cpu->device = 0x00000400; /* 486 */
>>> + } else {
>>> + cpu->device = 0x00000300; /* 386 */
>>> + }
>>> + if ((cpu->device == 0x00000400) && test_cyrix_52div()) {
>>> + memcpy(vendor_name, "CyrixInstead", 13);
>>> + /* If we ever care we can enable cpuid here */
>>> + }
>>> + /* Detect NexGen with old hypercode */
>>> + else if (deep_magic_nexgen_probe()) {
>>> + memcpy(vendor_name, "NexGenDriven", 13);
>>> + }
>>> + }
>>> + if (has_cpuid()) {
>>> + int cpuid_level;
>>> + struct cpuid_result result;
>>
>> blank line between declaration &code
>
> OK.
>
>>> + result = cpuid(0x00000000);
>>> + cpuid_level = result.eax;
>>> + vendor_name[ 0] = (result.ebx >> 0) & 0xff;
>>> + vendor_name[ 1] = (result.ebx >> 8) & 0xff;
>>> + vendor_name[ 2] = (result.ebx >> 16) & 0xff;
>>> + vendor_name[ 3] = (result.ebx >> 24) & 0xff;
>>> + vendor_name[ 4] = (result.edx >> 0) & 0xff;
>>> + vendor_name[ 5] = (result.edx >> 8) & 0xff;
>>> + vendor_name[ 6] = (result.edx >> 16) & 0xff;
>>> + vendor_name[ 7] = (result.edx >> 24) & 0xff;
>>> + vendor_name[ 8] = (result.ecx >> 0) & 0xff;
>>> + vendor_name[ 9] = (result.ecx >> 8) & 0xff;
>>> + vendor_name[10] = (result.ecx >> 16) & 0xff;
>>> + vendor_name[11] = (result.ecx >> 24) & 0xff;
>>
>> I think the byte loop approach is better (see cpu_get_name() in my
>> series). Can it be done? If you put this name bit in a separate
>> function it will be cleaner, too.
>
> Seems you were confused by the codes here. The cpu_get_name() in your
> series is the same function as the fill_processor_name() in my patch,
> but it is not equal to the code logic here. The code here is to
> retrive the correct vendor name string from ebx/ecx/edx as the result
> in ebx/ecx/edx is disordered.
Yes I see that the structure ordering is different. So perhaps you
could put this in a separate function. It could use three 32-bit word
writes to build the name instead of 12 shift and masks, like:
name_word[0] = result.ebx;
name_word[1] = result.edx;
name_word[2] = result.ecx;
The code you have seems a bit verbose given that I think the intent is
that the registers hold four characters each, and in the right order
within each register.
>
>>> + vendor_name[12] = '\0';
>>> +
>>> + /* Intel-defined flags: level 0x00000001 */
>>> + if (cpuid_level >= 0x00000001) {
>>> + cpu->device = cpuid_eax(0x00000001);
>>> + }
>>> + else {
>>> + /* Have CPUID level 0 only unheard of */
>>> + cpu->device = 0x00000400;
>>> + }
>>> + }
>>> + cpu->vendor = X86_VENDOR_UNKNOWN;
>>> + for(i = 0; i < ARRAY_SIZE(x86_vendors); i++) {
>>> + if (memcmp(vendor_name, x86_vendors[i].name, 12) == 0) {
>>> + cpu->vendor = x86_vendors[i].vendor;
>>> + break;
>>> + }
>>> + }
>>> +}
>>> +
>>> +static inline void get_fms(struct cpuinfo_x86 *c, uint32_t tfms)
>>> +{
>>> + c->x86 = (tfms >> 8) & 0xf;
>>> + c->x86_model = (tfms >> 4) & 0xf;
>>> + c->x86_mask = tfms & 0xf;
>>> + if (c->x86 == 0xf)
>>> + c->x86 += (tfms >> 20) & 0xff;
>>> + if (c->x86 >= 0x6)
>>> + c->x86_model += ((tfms >> 16) & 0xF) << 4;
>>> +}
>>> +
>>> int x86_cpu_init_f(void)
>>> {
>>> const u32 em_rst = ~X86_CR0_EM;
>>> @@ -128,6 +303,20 @@ int x86_cpu_init_f(void)
>>> "movl %%eax, %%cr0\n" \
>>> : : "i" (em_rst), "i" (mp_ne_set) : "eax");
>>>
>>> + /* identify CPU via cpuid and store the decoded info into gd->arch */
>>> + if (has_cpuid()) {
>>
>> Why not move this into print_cpuinfo()? Then you can print debug
>> information if the CPU is not known. Or will it always be known? For
>> some reason for me it always says '<invalid cpu vendor>'
>
> The following patch "x86: Do TSC MSR calibration only for
> known/supported CPUs" needs to access gd->arch.x86 and
> gd->arch.x86_model so the cpu identification is put here. I can move
> this into print_cpu_info() but that means only after print_cpu_info()
> is called can TSC timer driver (the udelay API) be available for use.
> Is this an acceptable limitation?
OK fair enough, let's leave it here and see how things go.
>
> '<invalid cpu vendor>' on you side looks weird to me. Do you make sure
> x86_cpu_init_f() gets called by U-Boot? The print_cpu_info() later
> will use gd->arch.x86_vendor which is initialized here by cpu.vendor.
I am wondering - I thought I was just using your series as it is, but
I'm not sure. Once you rework the patch and I apply it we can talk
about its affect on link.
>
>>> + struct cpu_device_id cpu;
>>> + struct cpuinfo_x86 c;
>>> +
>>> + identify_cpu(&cpu);
>>> + get_fms(&c, cpu.device);
>>> + gd->arch.x86 = c.x86;
>>> + gd->arch.x86_vendor = cpu.vendor;
>>> + gd->arch.x86_model = c.x86_model;
>>> + gd->arch.x86_mask = c.x86_mask;
>>> + gd->arch.x86_device = cpu.device;
>>> + }
>>> +
>>> return 0;
>>> }
>>> int cpu_init_f(void) __attribute__((weak, alias("x86_cpu_init_f")));
>>> @@ -279,55 +468,14 @@ void cpu_disable_paging_pae(void)
>>> : "eax");
>>> }
>>>
>>> -static bool has_cpuid(void)
>>> -{
>>> - unsigned long flag;
>>> -
>>> - asm volatile("pushf\n" \
>>> - "pop %%eax\n"
>>> - "mov %%eax, %%ecx\n" /* ecx = flags */
>>> - "xor %1, %%eax\n"
>>> - "push %%eax\n"
>>> - "popf\n" /* flags ^= $2 */
>>> - "pushf\n"
>>> - "pop %%eax\n" /* eax = flags */
>>> - "push %%ecx\n"
>>> - "popf\n" /* flags = ecx */
>>> - "xor %%ecx, %%eax\n"
>>> - "mov %%eax, %0"
>>> - : "=r" (flag)
>>> - : "i" (1 << 21)
>>> - : "eax", "ecx", "memory");
>>> -
>>> - return flag != 0;
>>> -}
>>> -
>>> static bool can_detect_long_mode(void)
>>> {
>>> - unsigned long flag;
>>> -
>>> - asm volatile("mov $0x80000000, %%eax\n"
>>> - "cpuid\n"
>>> - "mov %%eax, %0"
>>> - : "=r" (flag)
>>> - :
>>> - : "eax", "ebx", "ecx", "edx", "memory");
>>> -
>>> - return flag > 0x80000000UL;
>>> + return cpuid_eax(0x80000000) > 0x80000000UL;
>>> }
>>>
>>> static bool has_long_mode(void)
>>> {
>>> - unsigned long flag;
>>> -
>>> - asm volatile("mov $0x80000001, %%eax\n"
>>> - "cpuid\n"
>>> - "mov %%edx, %0"
>>> - : "=r" (flag)
>>> - :
>>> - : "eax", "ebx", "ecx", "edx", "memory");
>>> -
>>> - return flag & (1 << 29) ? true : false;
>>> + return cpuid_edx(0x80000001) & (1 << 29) ? true : false;
>>> }
>>>
>>> int cpu_has_64bit(void)
>>> @@ -336,9 +484,55 @@ int cpu_has_64bit(void)
>>> has_long_mode();
>>> }
>>>
>>> +static const char *cpu_vendor_name(int vendor)
>>> +{
>>> + const char *name;
>>> + name = "<invalid cpu vendor>";
>>> + if ((vendor < (ARRAY_SIZE(x86_vendor_name))) &&
>>> + (x86_vendor_name[vendor] != 0))
>>> + {
>>> + name = x86_vendor_name[vendor];
>>> + }
>>> + return name;
>>> +}
>>> +
>>> +static void fill_processor_name(char *processor_name)
>>> +{
>>> + struct cpuid_result regs;
>>> + char temp_processor_name[49];
>>> + char *processor_name_start;
>>> + unsigned int *name_as_ints = (unsigned int *)temp_processor_name;
>>> + int i;
>>> +
>>> + for (i = 0; i < 3; i++) {
>>> + regs = cpuid(0x80000002 + i);
>>> + name_as_ints[i * 4 + 0] = regs.eax;
>>> + name_as_ints[i * 4 + 1] = regs.ebx;
>>> + name_as_ints[i * 4 + 2] = regs.ecx;
>>> + name_as_ints[i * 4 + 3] = regs.edx;
>>> + }
>>> +
>>> + temp_processor_name[48] = 0;
>>> +
>>> + /* Skip leading spaces. */
>>> + processor_name_start = temp_processor_name;
>>> + while (*processor_name_start == ' ')
>>> + processor_name_start++;
>>> +
>>> + memset(processor_name, 0, 49);
>>> + strcpy(processor_name, processor_name_start);
>>> +}
>>> +
>>> int print_cpuinfo(void)
>>> {
>>> - printf("CPU: %s\n", cpu_has_64bit() ? "x86_64" : "x86");
>>> + char processor_name[49];
>>> +
>>> + printf("CPU: %s, vendor %s, device %xh\n", cpu_has_64bit() ? "x86_64" : "x86",
>>> + cpu_vendor_name(gd->arch.x86_vendor), gd->arch.x86_device);
>>> + printf("CPU: family %02xh, model %02xh, stepping %02xh\n",
>>> + gd->arch.x86, gd->arch.x86_model, gd->arch.x86_mask);
>>> + fill_processor_name(processor_name);
>>> + printf("CPU: %s\n", processor_name);
Not sure if I mentioned this before, but we should only have one line
of CPU information. The rest could be debug() and/or available through
a command like 'cpuinfo' on the cmdline.
>>>
>>> return 0;
>>> }
>>> diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
>>> index 6c6774a..6cd9f5b 100644
>>> --- a/arch/x86/include/asm/cpu.h
>>> +++ b/arch/x86/include/asm/cpu.h
>>> @@ -1,12 +1,154 @@
>>> /*
>>> * Copyright (c) 2014 The Chromium OS Authors.
>>> *
>>> + * Part of this file is adapted from coreboot
>>> + * src/arch/x86/include/arch/cpu.h and
>>> + * src/arch/x86/lib/cpu.c
>>> + *
>>> * SPDX-License-Identifier: GPL-2.0+
>>> */
>>>
>>> #ifndef __X86_CPU_H
>>> #define __X86_CPU_H
>>
>> _ASM_CPU_H
>
> OK
>
>>> +#define X86_VENDOR_INVALID 0
>>> +#define X86_VENDOR_INTEL 1
>>> +#define X86_VENDOR_CYRIX 2
>>> +#define X86_VENDOR_AMD 3
>>> +#define X86_VENDOR_UMC 4
>>> +#define X86_VENDOR_NEXGEN 5
>>> +#define X86_VENDOR_CENTAUR 6
>>> +#define X86_VENDOR_RISE 7
>>> +#define X86_VENDOR_TRANSMETA 8
>>> +#define X86_VENDOR_NSC 9
>>> +#define X86_VENDOR_SIS 10
>>> +#define X86_VENDOR_ANY 0xfe
>>> +#define X86_VENDOR_UNKNOWN 0xff
>>
>> Can we use an enum for this?
>
> Sure.
>
>>> +
>>> +struct cpuid_result {
>>> + uint32_t eax;
>>> + uint32_t ebx;
>>> + uint32_t ecx;
>>> + uint32_t edx;
>>> +};
>>> +
>>> +/*
>>> + * Generic CPUID function
>>> + */
>>> +static inline struct cpuid_result cpuid(int op)
>>> +{
>>> + struct cpuid_result result;
>>> + asm volatile(
>>> + "mov %%ebx, %%edi;"
>>> + "cpuid;"
>>> + "mov %%ebx, %%esi;"
>>> + "mov %%edi, %%ebx;"
>>> + : "=a" (result.eax),
>>> + "=S" (result.ebx),
>>> + "=c" (result.ecx),
>>> + "=d" (result.edx)
>>> + : "0" (op)
>>> + : "edi");
>>> + return result;
>>> +}
>>> +
>>> +/*
>>> + * Generic Extended CPUID function
>>> + */
>>> +static inline struct cpuid_result cpuid_ext(int op, unsigned ecx)
>>> +{
>>> + struct cpuid_result result;
>>> + asm volatile(
>>> + "mov %%ebx, %%edi;"
>>> + "cpuid;"
>>> + "mov %%ebx, %%esi;"
>>> + "mov %%edi, %%ebx;"
>>> + : "=a" (result.eax),
>>> + "=S" (result.ebx),
>>> + "=c" (result.ecx),
>>> + "=d" (result.edx)
>>> + : "0" (op), "2" (ecx)
>>> + : "edi");
>>> + return result;
>>> +}
>>> +
>>> +/*
>>> + * CPUID functions returning a single datum
>>> + */
>>> +static inline unsigned int cpuid_eax(unsigned int op)
>>> +{
>>> + unsigned int eax;
>>> +
>>> + __asm__("mov %%ebx, %%edi;"
>>> + "cpuid;"
>>> + "mov %%edi, %%ebx;"
>>> + : "=a" (eax)
>>> + : "0" (op)
>>> + : "ecx", "edx", "edi");
>>> + return eax;
>>> +}
>>> +
>>> +static inline unsigned int cpuid_ebx(unsigned int op)
>>> +{
>>> + unsigned int eax, ebx;
>>> +
>>> + __asm__("mov %%ebx, %%edi;"
>>> + "cpuid;"
>>> + "mov %%ebx, %%esi;"
>>> + "mov %%edi, %%ebx;"
>>> + : "=a" (eax), "=S" (ebx)
>>> + : "0" (op)
>>> + : "ecx", "edx", "edi");
>>> + return ebx;
>>> +}
>>> +
>>> +static inline unsigned int cpuid_ecx(unsigned int op)
>>> +{
>>> + unsigned int eax, ecx;
>>> +
>>> + __asm__("mov %%ebx, %%edi;"
>>> + "cpuid;"
>>> + "mov %%edi, %%ebx;"
>>> + : "=a" (eax), "=c" (ecx)
>>> + : "0" (op)
>>> + : "edx", "edi");
>>> + return ecx;
>>> +}
>>> +
>>> +static inline unsigned int cpuid_edx(unsigned int op)
>>> +{
>>> + unsigned int eax, edx;
>>> +
>>> + __asm__("mov %%ebx, %%edi;"
>>> + "cpuid;"
>>> + "mov %%edi, %%ebx;"
>>> + : "=a" (eax), "=d" (edx)
>>> + : "0" (op)
>>> + : "ecx", "edi");
>>> + return edx;
>>> +}
>>> +
>>> +/* Standard macro to see if a specific flag is changeable */
>>> +static inline int flag_is_changeable_p(uint32_t flag)
>>> +{
>>> + uint32_t f1, f2;
>>> +
>>> + asm(
>>> + "pushfl\n\t"
>>> + "pushfl\n\t"
>>> + "popl %0\n\t"
>>> + "movl %0,%1\n\t"
>>> + "xorl %2,%0\n\t"
>>> + "pushl %0\n\t"
>>> + "popfl\n\t"
>>> + "pushfl\n\t"
>>> + "popl %0\n\t"
>>> + "popfl\n\t"
>>> + : "=&r" (f1), "=&r" (f2)
>>> + : "ir" (flag));
>>> + return ((f1^f2) & flag) != 0;
>>> +}
>>
>> Does this have to be inline?
>
> I don't think so, but both coreboot and linux are using inline, should
> we keep the same?
OK let's keep it the same then.
Regards,
Simon
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