s390/als: convert architecture level set code to C
There is no reason to have this code in assembly language. Therefore
convert it to C.
Note that this code needs special treatment: it is called very early
and one of the side effects is that e.g. the bss section is not
cleared. Therefore the preferred way for static variables is to put
them on the stack which has a size of 16KB.
There is no functional change with this patch.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/boot/compressed/Makefile b/arch/s390/boot/compressed/Makefile
index 98ec652..13723c3 100644
--- a/arch/s390/boot/compressed/Makefile
+++ b/arch/s390/boot/compressed/Makefile
@@ -18,7 +18,7 @@
GCOV_PROFILE := n
-OBJECTS := $(addprefix $(objtree)/arch/s390/kernel/, head.o sclp.o ebcdic.o)
+OBJECTS := $(addprefix $(objtree)/arch/s390/kernel/, head.o sclp.o ebcdic.o als.o)
OBJECTS += $(obj)/head.o $(obj)/misc.o $(obj)/piggy.o
LDFLAGS_vmlinux := --oformat $(LD_BFD) -e startup -T
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index f37be37..07fca5e 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -4,6 +4,7 @@
KCOV_INSTRUMENT_early.o := n
KCOV_INSTRUMENT_sclp.o := n
+KCOV_INSTRUMENT_als.o := n
ifdef CONFIG_FUNCTION_TRACER
# Don't trace early setup code and tracing code
@@ -32,13 +33,16 @@
CFLAGS_sysinfo.o += -w
#
-# Use -march=z900 for sclp.c to be able to print an error message if
-# the kernel is started on a machine which is too old
+# Use -march=z900 for sclp.c and als.c to be able to print an error
+# message if the kernel is started on a machine which is too old
#
CFLAGS_REMOVE_sclp.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_als.o = $(CC_FLAGS_FTRACE)
ifneq ($(CC_FLAGS_MARCH),-march=z900)
CFLAGS_REMOVE_sclp.o += $(CC_FLAGS_MARCH)
CFLAGS_sclp.o += -march=z900
+CFLAGS_REMOVE_als.o += $(CC_FLAGS_MARCH)
+CFLAGS_als.o += -march=z900
AFLAGS_REMOVE_head.o += $(CC_FLAGS_MARCH)
AFLAGS_head.o += -march=z900
endif
@@ -46,7 +50,7 @@
obj-y := traps.o time.o process.o base.o early.o setup.o idle.o vtime.o
obj-y += processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
-obj-y += debug.o irq.o ipl.o dis.o diag.o sclp.o vdso.o
+obj-y += debug.o irq.o ipl.o dis.o diag.o sclp.o vdso.o als.o
obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o
obj-y += entry.o reipl.o relocate_kernel.o
diff --git a/arch/s390/kernel/als.c b/arch/s390/kernel/als.c
new file mode 100644
index 0000000..f96a577
--- /dev/null
+++ b/arch/s390/kernel/als.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright IBM Corp. 2016
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <asm/processor.h>
+#include <asm/facility.h>
+#include <asm/lowcore.h>
+#include <asm/sclp.h>
+#include "entry.h"
+
+/*
+ * The code within this file will be called very early. It may _not_
+ * access anything within the bss section, since that is not cleared
+ * yet and may contain data (e.g. initrd) that must be saved by other
+ * code.
+ * For temporary objects the stack (16k) should be used.
+ */
+
+static unsigned long als[] __initdata = { FACILITIES_ALS };
+
+void __init verify_facilities(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(S390_lowcore.stfle_fac_list); i++)
+ S390_lowcore.stfle_fac_list[i] = 0;
+ asm volatile(
+ " stfl 0(0)\n"
+ : "=m" (S390_lowcore.stfl_fac_list));
+ S390_lowcore.stfle_fac_list[0] = (u64)S390_lowcore.stfl_fac_list << 32;
+ if (S390_lowcore.stfl_fac_list & 0x01000000) {
+ register unsigned long reg0 asm("0") = ARRAY_SIZE(als) - 1;
+
+ asm volatile(".insn s,0xb2b00000,0(%1)" /* stfle */
+ : "+d" (reg0)
+ : "a" (&S390_lowcore.stfle_fac_list)
+ : "memory", "cc");
+ }
+ for (i = 0; i < ARRAY_SIZE(als); i++) {
+ if ((S390_lowcore.stfle_fac_list[i] & als[i]) == als[i])
+ continue;
+ _sclp_print_early("The Linux kernel requires more recent processor hardware");
+ disabled_wait(0x8badcccc);
+ }
+}
diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index bedd2f5..e79f030 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -79,4 +79,6 @@
DECLARE_PER_CPU(u64, mt_cycles[8]);
+void verify_facilities(void);
+
#endif /* _ENTRY_H */
diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index fcaefb0..56e4d82 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -306,49 +306,14 @@
stck __LC_LAST_UPDATE_CLOCK
spt 6f-.LPG0(%r13)
mvc __LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
- stfl 0(%r0) # store facilities @ __LC_STFL_FAC_LIST
- mvc __LC_STFLE_FAC_LIST(4),__LC_STFL_FAC_LIST
- tm __LC_STFLE_FAC_LIST,0x01 # stfle available ?
- jz 0f
- lghi %r0,FACILITIES_ALS_DWORDS-1
- .insn s,0xb2b00000,__LC_STFLE_FAC_LIST # store facility list extended
- # verify if all required facilities are supported by the machine
-0: la %r1,__LC_STFLE_FAC_LIST
- la %r2,3f+8-.LPG0(%r13)
- lhi %r3,FACILITIES_ALS_DWORDS
-1: lg %r0,0(%r1)
- ng %r0,0(%r2)
- clg %r0,0(%r2)
- jne 2f
- la %r1,8(%r1)
- la %r2,8(%r2)
- ahi %r3,-1
- jnz 1b
- j 4f
-2: l %r15,.Lstack-.LPG0(%r13)
+ l %r15,.Lstack-.LPG0(%r13)
ahi %r15,-STACK_FRAME_OVERHEAD
- la %r2,.Lals_string-.LPG0(%r13)
- l %r3,.Lsclp_print-.LPG0(%r13)
- basr %r14,%r3
- lpsw 3f-.LPG0(%r13) # machine type not good enough, crash
-.Lals_string:
- .asciz "The Linux kernel requires more recent processor hardware"
-.Lsclp_print:
- .long _sclp_print_early
-.Lstack:
- .long 0x8000 + (1<<(PAGE_SHIFT+THREAD_ORDER))
- .align 16
-3: .long 0x000a0000,0x8badcccc
-
-# List of facilities that are required. If not all facilities are present
-# the kernel will crash.
-
- .quad FACILITIES_ALS
-
-4:
+ brasl %r14,verify_facilities
/* Continue with startup code in head64.S */
jg startup_continue
+.Lstack:
+ .long 0x8000 + (1<<(PAGE_SHIFT+THREAD_ORDER))
.align 8
6: .long 0x7fffffff,0xffffffff