The CPU identification happens in x86_cpu_init_f() and corresponding fields are saved in the global data for later use.

Signed-off-by: Bin Meng bmeng.cn@gmail.com --- Changes for v2: - Update the patch per review comments from Simon Glass - cpu_vendor_name() and fill_processor_name() are not static now

arch/x86/cpu/cpu.c | 277 +++++++++++++++++++++++++++++++------ arch/x86/include/asm/cpu.h | 168 +++++++++++++++++++++- arch/x86/include/asm/global_data.h | 5 + 3 files changed, 402 insertions(+), 48 deletions(-)

diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c index 6441dde..e3fa21d 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@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 +48,52 @@ 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 + * 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 +166,131 @@ 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 int build_vendor_name(char *vendor_name) +{ + struct cpuid_result result; + result = cpuid(0x00000000); + unsigned int *name_as_ints = (unsigned int *)vendor_name; + + name_as_ints[0] = result.ebx; + name_as_ints[1] = result.edx; + name_as_ints[2] = result.ecx; + + return result.eax; +} + +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; + + cpuid_level = build_vendor_name(vendor_name); + 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 +304,20 @@ 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()) { + 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; }

@@ -277,55 +467,14 @@ 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) @@ -334,9 +483,49 @@ int cpu_has_64bit(void) has_long_mode(); }

+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; +} + +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"); + 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);

return 0; } diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 6c6774a..89b748b 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -1,16 +1,160 @@ /* * 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 +#ifndef _ASM_CPU_H +#define _ASM_CPU_H + +enum { + X86_VENDOR_INVALID = 0, + X86_VENDOR_INTEL, + X86_VENDOR_CYRIX, + X86_VENDOR_AMD, + X86_VENDOR_UMC, + X86_VENDOR_NEXGEN, + X86_VENDOR_CENTAUR, + X86_VENDOR_RISE, + X86_VENDOR_TRANSMETA, + X86_VENDOR_NSC, + X86_VENDOR_SIS, + X86_VENDOR_ANY = 0xfe, + X86_VENDOR_UNKNOWN = 0xff +}; + +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; +} + +/** * cpu_enable_paging_pae() - Enable PAE-paging * - * @pdpt: Value to set in cr3 (PDPT or PML4T) + * @cr3: Value to set in cr3 (PDPT or PML4T) */ void cpu_enable_paging_pae(ulong cr3);

@@ -27,6 +171,22 @@ void cpu_disable_paging_pae(void); int cpu_has_64bit(void);

/** + * cpu_vendor_name() - Get CPU vendor name + * + * @vendor: CPU vendor enumeration number + * + * @return: Address to hold the CPU vendor name string + */ +const char *cpu_vendor_name(int vendor); + +/** + * fill_processor_name() - Get processor name + * + * @processor_name: Address to hold the processor name string + */ +void fill_processor_name(char *processor_name); + +/** * cpu_call64() - Jump to a 64-bit Linux kernel (internal function) * * The kernel is uncompressed and the 64-bit entry point is expected to be diff --git a/arch/x86/include/asm/global_data.h b/arch/x86/include/asm/global_data.h index 9eae228..3e3073a 100644 --- a/arch/x86/include/asm/global_data.h +++ b/arch/x86/include/asm/global_data.h @@ -13,6 +13,11 @@ /* Architecture-specific global data */ struct arch_global_data { struct global_data *gd_addr; /* Location of Global Data */ + uint8_t x86; /* CPU family */ + uint8_t x86_vendor; /* CPU vendor */ + uint8_t x86_model; + uint8_t x86_mask; + uint32_t x86_device; uint64_t tsc_base; /* Initial value returned by rdtsc() */ uint32_t tsc_base_kclocks; /* Initial tsc as a kclocks value */ uint32_t tsc_prev; /* For show_boot_progress() */