diff options
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/Kconfig | 3 | ||||
| -rw-r--r-- | arch/um/include/asm/cpufeature.h | 157 | ||||
| -rw-r--r-- | arch/um/include/asm/processor-generic.h | 8 | ||||
| -rw-r--r-- | arch/um/include/shared/os.h | 3 | ||||
| -rw-r--r-- | arch/um/kernel/Makefile | 13 | ||||
| -rw-r--r-- | arch/um/kernel/um_arch.c | 48 | ||||
| -rw-r--r-- | arch/um/os-Linux/start_up.c | 32 |
7 files changed, 258 insertions, 6 deletions
diff --git a/arch/um/Kconfig b/arch/um/Kconfig index fe6d898aeb85..0561b73cfd9a 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -76,6 +76,9 @@ config NR_CPUS range 1 1 default 1 +config ARCH_HAS_CACHE_LINE_SIZE + def_bool y + source "arch/$(HEADER_ARCH)/um/Kconfig" config MAY_HAVE_RUNTIME_DEPS diff --git a/arch/um/include/asm/cpufeature.h b/arch/um/include/asm/cpufeature.h new file mode 100644 index 000000000000..19cd7ed6ec3c --- /dev/null +++ b/arch/um/include/asm/cpufeature.h @@ -0,0 +1,157 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_UM_CPUFEATURE_H +#define _ASM_UM_CPUFEATURE_H + +#include <asm/processor.h> + +#if defined(__KERNEL__) && !defined(__ASSEMBLY__) + +#include <asm/asm.h> +#include <linux/bitops.h> + +extern const char * const x86_cap_flags[NCAPINTS*32]; +extern const char * const x86_power_flags[32]; +#define X86_CAP_FMT "%s" +#define x86_cap_flag(flag) x86_cap_flags[flag] + +/* + * In order to save room, we index into this array by doing + * X86_BUG_<name> - NCAPINTS*32. + */ +extern const char * const x86_bug_flags[NBUGINTS*32]; + +#define test_cpu_cap(c, bit) \ + test_bit(bit, (unsigned long *)((c)->x86_capability)) + +/* + * There are 32 bits/features in each mask word. The high bits + * (selected with (bit>>5) give us the word number and the low 5 + * bits give us the bit/feature number inside the word. + * (1UL<<((bit)&31) gives us a mask for the feature_bit so we can + * see if it is set in the mask word. + */ +#define CHECK_BIT_IN_MASK_WORD(maskname, word, bit) \ + (((bit)>>5)==(word) && (1UL<<((bit)&31) & maskname##word )) + +#define cpu_has(c, bit) \ + test_cpu_cap(c, bit) + +#define this_cpu_has(bit) \ + (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ + x86_this_cpu_test_bit(bit, \ + (unsigned long __percpu *)&cpu_info.x86_capability)) + +/* + * This macro is for detection of features which need kernel + * infrastructure to be used. It may *not* directly test the CPU + * itself. Use the cpu_has() family if you want true runtime + * testing of CPU features, like in hypervisor code where you are + * supporting a possible guest feature where host support for it + * is not relevant. + */ +#define cpu_feature_enabled(bit) \ + (__builtin_constant_p(bit) && DISABLED_MASK_BIT_SET(bit) ? 0 : static_cpu_has(bit)) + +#define boot_cpu_has(bit) cpu_has(&boot_cpu_data, bit) + +#define set_cpu_cap(c, bit) set_bit(bit, (unsigned long *)((c)->x86_capability)) + +extern void setup_clear_cpu_cap(unsigned int bit); + +#define setup_force_cpu_cap(bit) do { \ + set_cpu_cap(&boot_cpu_data, bit); \ + set_bit(bit, (unsigned long *)cpu_caps_set); \ +} while (0) + +#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit) + +#if defined(__clang__) && !defined(CONFIG_CC_HAS_ASM_GOTO) + +/* + * Workaround for the sake of BPF compilation which utilizes kernel + * headers, but clang does not support ASM GOTO and fails the build. + */ +#ifndef __BPF_TRACING__ +#warning "Compiler lacks ASM_GOTO support. Add -D __BPF_TRACING__ to your compiler arguments" +#endif + +#define static_cpu_has(bit) boot_cpu_has(bit) + +#else + +/* + * Static testing of CPU features. Used the same as boot_cpu_has(). It + * statically patches the target code for additional performance. Use + * static_cpu_has() only in fast paths, where every cycle counts. Which + * means that the boot_cpu_has() variant is already fast enough for the + * majority of cases and you should stick to using it as it is generally + * only two instructions: a RIP-relative MOV and a TEST. + */ +static __always_inline bool _static_cpu_has(u16 bit) +{ + asm_volatile_goto("1: jmp 6f\n" + "2:\n" + ".skip -(((5f-4f) - (2b-1b)) > 0) * " + "((5f-4f) - (2b-1b)),0x90\n" + "3:\n" + ".section .altinstructions,\"a\"\n" + " .long 1b - .\n" /* src offset */ + " .long 4f - .\n" /* repl offset */ + " .word %P[always]\n" /* always replace */ + " .byte 3b - 1b\n" /* src len */ + " .byte 5f - 4f\n" /* repl len */ + " .byte 3b - 2b\n" /* pad len */ + ".previous\n" + ".section .altinstr_replacement,\"ax\"\n" + "4: jmp %l[t_no]\n" + "5:\n" + ".previous\n" + ".section .altinstructions,\"a\"\n" + " .long 1b - .\n" /* src offset */ + " .long 0\n" /* no replacement */ + " .word %P[feature]\n" /* feature bit */ + " .byte 3b - 1b\n" /* src len */ + " .byte 0\n" /* repl len */ + " .byte 0\n" /* pad len */ + ".previous\n" + ".section .altinstr_aux,\"ax\"\n" + "6:\n" + " testb %[bitnum],%[cap_byte]\n" + " jnz %l[t_yes]\n" + " jmp %l[t_no]\n" + ".previous\n" + : : [feature] "i" (bit), + [always] "i" (X86_FEATURE_ALWAYS), + [bitnum] "i" (1 << (bit & 7)), + [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3]) + : : t_yes, t_no); +t_yes: + return true; +t_no: + return false; +} + +#define static_cpu_has(bit) \ +( \ + __builtin_constant_p(boot_cpu_has(bit)) ? \ + boot_cpu_has(bit) : \ + _static_cpu_has(bit) \ +) +#endif + +#define cpu_has_bug(c, bit) cpu_has(c, (bit)) +#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit)) + +#define static_cpu_has_bug(bit) static_cpu_has((bit)) +#define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit)) +#define boot_cpu_set_bug(bit) set_cpu_cap(&boot_cpu_data, (bit)) + +#define MAX_CPU_FEATURES (NCAPINTS * 32) +#define cpu_have_feature boot_cpu_has + +#define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X" +#define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \ + boot_cpu_data.x86_model + +#endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */ +#endif /* _ASM_UM_CPUFEATURE_H */ diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h index afd9b267cf81..b5cf0ed116d9 100644 --- a/arch/um/include/asm/processor-generic.h +++ b/arch/um/include/asm/processor-generic.h @@ -16,6 +16,8 @@ struct task_struct; #include <linux/prefetch.h> +#include <asm/cpufeatures.h> + struct mm_struct; struct thread_struct { @@ -90,12 +92,18 @@ extern void start_thread(struct pt_regs *regs, unsigned long entry, struct cpuinfo_um { unsigned long loops_per_jiffy; int ipi_pipe[2]; + int cache_alignment; + union { + __u32 x86_capability[NCAPINTS + NBUGINTS]; + unsigned long x86_capability_alignment; + }; }; extern struct cpuinfo_um boot_cpu_data; #define cpu_data (&boot_cpu_data) #define current_cpu_data boot_cpu_data +#define cache_line_size() (boot_cpu_data.cache_alignment) #define KSTK_REG(tsk, reg) get_thread_reg(reg, &tsk->thread.switch_buf) extern unsigned long get_wchan(struct task_struct *p); diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index 453b13369533..8e9e05d3b419 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -187,6 +187,9 @@ int os_poll(unsigned int n, const int *fds); extern void os_early_checks(void); extern void os_check_bugs(void); extern void check_host_supports_tls(int *supports_tls, int *tls_min); +extern void get_host_cpu_features( + void (*flags_helper_func)(char *line), + void (*cache_helper_func)(char *line)); /* mem.c */ extern int create_mem_file(unsigned long long len); diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile index 2fdd00de5a72..1d18e4e46989 100644 --- a/arch/um/kernel/Makefile +++ b/arch/um/kernel/Makefile @@ -17,7 +17,7 @@ extra-y := vmlinux.lds obj-y = config.o exec.o exitcode.o irq.o ksyms.o mem.o \ physmem.o process.o ptrace.o reboot.o sigio.o \ signal.o syscall.o sysrq.o time.o tlb.o trap.o \ - um_arch.o umid.o maccess.o kmsg_dump.o skas/ + um_arch.o umid.o maccess.o kmsg_dump.o capflags.o skas/ obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o obj-$(CONFIG_GPROF) += gprof_syms.o @@ -29,7 +29,7 @@ USER_OBJS := config.o include arch/um/scripts/Makefile.rules -targets := config.c config.tmp +targets := config.c config.tmp capflags.c # Be careful with the below Sed code - sed is pitfall-rich! # We use sed to lower build requirements, for "embedded" builders for instance. @@ -44,6 +44,15 @@ quiet_cmd_quote1 = QUOTE $@ $(obj)/config.c: $(src)/config.c.in $(obj)/config.tmp FORCE $(call if_changed,quote2) +quiet_cmd_mkcapflags = MKCAP $@ + cmd_mkcapflags = $(CONFIG_SHELL) $(srctree)/$(src)/../../x86/kernel/cpu/mkcapflags.sh $@ $^ + +cpufeature = $(src)/../../x86/include/asm/cpufeatures.h +vmxfeature = $(src)/../../x86/include/asm/vmxfeatures.h + +$(obj)/capflags.c: $(cpufeature) $(vmxfeature) $(src)/../../x86/kernel/cpu/mkcapflags.sh FORCE + $(call if_changed,mkcapflags) + quiet_cmd_quote2 = QUOTE $@ cmd_quote2 = sed -e '/CONFIG/{' \ -e 's/"CONFIG"//' \ diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c index 74e07e748a9b..20cce10bde51 100644 --- a/arch/um/kernel/um_arch.c +++ b/arch/um/kernel/um_arch.c @@ -6,6 +6,7 @@ #include <linux/delay.h> #include <linux/init.h> #include <linux/mm.h> +#include <linux/ctype.h> #include <linux/module.h> #include <linux/seq_file.h> #include <linux/string.h> @@ -16,6 +17,7 @@ #include <linux/suspend.h> #include <asm/processor.h> +#include <asm/cpufeature.h> #include <asm/sections.h> #include <asm/setup.h> #include <as-layout.h> @@ -50,9 +52,13 @@ static void __init add_arg(char *arg) */ struct cpuinfo_um boot_cpu_data = { .loops_per_jiffy = 0, - .ipi_pipe = { -1, -1 } + .ipi_pipe = { -1, -1 }, + .cache_alignment = L1_CACHE_BYTES, + .x86_capability = { 0 } }; +EXPORT_SYMBOL(boot_cpu_data); + union thread_union cpu0_irqstack __section(".data..init_irqstack") = { .thread_info = INIT_THREAD_INFO(init_task) }; @@ -62,17 +68,25 @@ static char host_info[(__NEW_UTS_LEN + 1) * 5]; static int show_cpuinfo(struct seq_file *m, void *v) { - int index = 0; + int i = 0; - seq_printf(m, "processor\t: %d\n", index); + seq_printf(m, "processor\t: %d\n", i); seq_printf(m, "vendor_id\t: User Mode Linux\n"); seq_printf(m, "model name\t: UML\n"); seq_printf(m, "mode\t\t: skas\n"); seq_printf(m, "host\t\t: %s\n", host_info); - seq_printf(m, "bogomips\t: %lu.%02lu\n\n", + seq_printf(m, "fpu\t\t: %s\n", cpu_has(&boot_cpu_data, X86_FEATURE_FPU) ? "yes" : "no"); + seq_printf(m, "flags\t\t:"); + for (i = 0; i < 32*NCAPINTS; i++) + if (cpu_has(&boot_cpu_data, i) && (x86_cap_flags[i] != NULL)) + seq_printf(m, " %s", x86_cap_flags[i]); + seq_printf(m, "\n"); + seq_printf(m, "cache_alignment\t: %d\n", boot_cpu_data.cache_alignment); + seq_printf(m, "bogomips\t: %lu.%02lu\n", loops_per_jiffy/(500000/HZ), (loops_per_jiffy/(5000/HZ)) % 100); + return 0; } @@ -261,6 +275,30 @@ EXPORT_SYMBOL(end_iomem); #define MIN_VMALLOC (32 * 1024 * 1024) +static void parse_host_cpu_flags(char *line) +{ + int i; + for (i = 0; i < 32*NCAPINTS; i++) { + if ((x86_cap_flags[i] != NULL) && strstr(line, x86_cap_flags[i])) + set_cpu_cap(&boot_cpu_data, i);; + } +} +static void parse_cache_line(char *line) +{ + long res; + char *to_parse = strstr(line, ":"); + if (to_parse) { + to_parse++; + while (*to_parse != 0 && isspace(*to_parse)) { + to_parse++; + } + if (kstrtoul(to_parse, 10, &res) == 0 && is_power_of_2(res)) + boot_cpu_data.cache_alignment = res; + else + boot_cpu_data.cache_alignment = L1_CACHE_BYTES; + } +} + int __init linux_main(int argc, char **argv) { unsigned long avail, diff; @@ -297,6 +335,8 @@ int __init linux_main(int argc, char **argv) /* OS sanity checks that need to happen before the kernel runs */ os_early_checks(); + get_host_cpu_features(parse_host_cpu_flags, parse_cache_line); + brk_start = (unsigned long) sbrk(0); /* diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c index f79dc338279e..8a72c99994eb 100644 --- a/arch/um/os-Linux/start_up.c +++ b/arch/um/os-Linux/start_up.c @@ -321,6 +321,38 @@ static void __init check_coredump_limit(void) os_info("%llu\n", (unsigned long long)lim.rlim_max); } +void __init get_host_cpu_features( + void (*flags_helper_func)(char *line), + void (*cache_helper_func)(char *line)) +{ + FILE *cpuinfo; + char *line = NULL; + size_t len = 0; + int done_parsing = 0; + + cpuinfo = fopen("/proc/cpuinfo", "r"); + if (cpuinfo == NULL) { + os_info("Failed to get host CPU features\n"); + } else { + while ((getline(&line, &len, cpuinfo)) != -1) { + if (strstr(line, "flags")) { + flags_helper_func(line); + done_parsing++; + } + if (strstr(line, "cache_alignment")) { + cache_helper_func(line); + done_parsing++; + } + free(line); + line = NULL; + if (done_parsing > 1) + break; + } + fclose(cpuinfo); + } +} + + void __init os_early_checks(void) { int pid; |