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authorAnton Ivanov <anton.ivanov@cambridgegreys.com>2021-03-12 16:16:07 +0100
committerRichard Weinberger <richard@nod.at>2021-06-17 22:01:26 +0200
commitd8fb32f4790f2a286e58db8548016378ac35fc6f (patch)
tree050c2708dc80d0d61fb6d247a487d02e3c2b6f4f /arch/um/kernel
parentum: allow not setting extra rpaths in the linux binary (diff)
downloadlinux-d8fb32f4790f2a286e58db8548016378ac35fc6f.tar.xz
linux-d8fb32f4790f2a286e58db8548016378ac35fc6f.zip
um: Add support for host CPU flags and alignment
1. Reflect host cpu flags into the UML instance so they can be used to select the correct implementations for xor, crypto, etc. 2. Reflect host cache alignment into UML instance. This is important when running 32 bit on a 64 bit host as 32 bit by default aligns to 32 while the actual alignment should be 64. Ditto for some Xeons which align at 128. Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/kernel')
-rw-r--r--arch/um/kernel/Makefile13
-rw-r--r--arch/um/kernel/um_arch.c48
2 files changed, 55 insertions, 6 deletions
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);
/*