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-rw-r--r--arch/um/Kconfig3
-rw-r--r--arch/um/include/asm/cpufeature.h157
-rw-r--r--arch/um/include/asm/processor-generic.h8
-rw-r--r--arch/um/include/shared/os.h3
-rw-r--r--arch/um/kernel/Makefile13
-rw-r--r--arch/um/kernel/um_arch.c48
-rw-r--r--arch/um/os-Linux/start_up.c32
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;
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-30 10:21:50 +0000