s390/facilities: always use lowcore's stfle field for storing facility bits

head.s contains an stfle instruction which stores it result at the
storage location that is assigned to the stfl instruction.

This is currently no problem, since we only care about one double
word. However if the number of double words in the ALS bitfield grows
the current code is not very stable.

E.g. before issuing the stfle command the memory to which it stores
must be cleared, since the instruction may or may not clear memory
contents where no bits are set.

In order to simplify the code a bit always use the storage location
that we reserved for the stfle result.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index ae7b565..d8d18f8 100644 (file)
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -120,6 +120,7 @@ int main(void)
        OFFSET(__LC_IO_INT_PARM, _lowcore, io_int_parm);
        OFFSET(__LC_IO_INT_WORD, _lowcore, io_int_word);
        OFFSET(__LC_STFL_FAC_LIST, _lowcore, stfl_fac_list);
+       OFFSET(__LC_STFLE_FAC_LIST, _lowcore, stfle_fac_list);
        OFFSET(__LC_MCCK_CODE, _lowcore, mcck_interruption_code);
        OFFSET(__LC_MCCK_FAIL_STOR_ADDR, _lowcore, failing_storage_address);
        OFFSET(__LC_LAST_BREAK, _lowcore, breaking_event_addr);

diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index d893d5a..d28a148 100644 (file)
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -300,19 +300,19 @@ ENTRY(startup_kdump)
        xc      0x200(256),0x200        # partially clear lowcore
        xc      0x300(256),0x300
        xc      0xe00(256),0xe00
+       xc      0xf00(256),0xf00
        lctlg   %c0,%c15,0x200(%r0)     # initialize control registers
        stck    __LC_LAST_UPDATE_CLOCK
        spt     6f-.LPG0(%r13)
        mvc     __LC_LAST_UPDATE_TIMER(8),6f-.LPG0(%r13)
-       xc      __LC_STFL_FAC_LIST(8),__LC_STFL_FAC_LIST
-       # check capabilities against MARCH_{G5,Z900,Z990,Z9_109,Z10}
        stfl    0(%r0)                  # store facilities @ __LC_STFL_FAC_LIST
-       tm      __LC_STFL_FAC_LIST,0x01 # stfle available ?
+       mvc     __LC_STFLE_FAC_LIST(4),__LC_STFL_FAC_LIST
+       tm      __LC_STFLE_FAC_LIST,0x01        # stfle available ?
        jz      0f
        la      %r0,1
-       .insn   s,0xb2b00000,__LC_STFL_FAC_LIST # store facility list extended
+       .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_STFL_FAC_LIST
+0:     la      %r1,__LC_STFLE_FAC_LIST
        la      %r2,3f+8-.LPG0(%r13)
        l       %r3,0(%r2)
 1:     l       %r0,0(%r1)

diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index 58b719f..c5febe8 100644 (file)
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -16,7 +16,7 @@
 
 __HEAD
 ENTRY(startup_continue)
-       tm      __LC_STFL_FAC_LIST+6,0x80       # LPP available ?
+       tm      __LC_STFLE_FAC_LIST+6,0x80      # LPP available ?
        jz      0f
        xc      __LC_LPP+1(7,0),__LC_LPP+1      # clear lpp and current_pid
        mvi     __LC_LPP,0x80                   #   and set LPP_MAGIC