[S390] convert some assembler to C.

Convert GET_IPL_DEVICE assembler macro to C function.

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

7 files changed, 99 insertions, 93 deletions

diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index a6e9bdb53591..0f1db268a8a9 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -481,65 +481,6 @@ start:
         .byte 0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7 
         .byte 0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff
 
-.macro GET_IPL_DEVICE
-.Lget_ipl_device:
-        l     %r1,0xb8                  # get sid
-        sll   %r1,15                    # test if subchannel is enabled
-        srl   %r1,31
-        ltr   %r1,%r1
-        bz    2f-.LPG1(%r13)            # subchannel disabled
-        l     %r1,0xb8
-        la    %r5,.Lipl_schib-.LPG1(%r13)
-        stsch 0(%r5)                    # get schib of subchannel
-        bnz   2f-.LPG1(%r13)            # schib not available
-        tm    5(%r5),0x01               # devno valid?
-        bno   2f-.LPG1(%r13)
-        la    %r6,ipl_parameter_flags-.LPG1(%r13)
-        oi    3(%r6),0x01               # set flag
-        la    %r2,ipl_devno-.LPG1(%r13)
-        mvc   0(2,%r2),6(%r5)           # store devno
-        tm    4(%r5),0x80               # qdio capable device?
-        bno   2f-.LPG1(%r13)
-        oi    3(%r6),0x02               # set flag
-
-        # copy ipl parameters
-
-        lhi   %r0,4096
-        l     %r2,20(%r0)               # get address of parameter list
-        lhi   %r3,IPL_PARMBLOCK_ORIGIN
-        st    %r3,20(%r0)
-        lhi   %r4,1
-        cr    %r2,%r3                   # start parameters < destination ?
-        jl    0f
-        lhi   %r1,1                     # copy direction is upwards
-        j     1f
-0:      lhi   %r1,-1                    # copy direction is downwards
-        ar    %r2,%r0
-        ar    %r3,%r0
-        ar    %r2,%r1
-        ar    %r3,%r1
-1:      mvc   0(1,%r3),0(%r2)           # finally copy ipl parameters
-        ar    %r3,%r1
-        ar    %r2,%r1
-        sr    %r0,%r4
-        jne   1b
-        b     2f-.LPG1(%r13)
-
-        .align 4
-.Lipl_schib:
-        .rept 13
-        .long 0
-        .endr
-
-        .globl ipl_parameter_flags
-ipl_parameter_flags:
-        .long 0
-        .globl ipl_devno
-ipl_devno:
-        .word 0
-2:
-.endm
-
 #ifdef CONFIG_64BIT
 #include "head64.S"
 #else
diff --git a/arch/s390/kernel/head31.S b/arch/s390/kernel/head31.S
index d8bb68a72527..1fa9fa1ca740 100644
--- a/arch/s390/kernel/head31.S
+++ b/arch/s390/kernel/head31.S
@@ -37,13 +37,23 @@ startup:basr	%r13,0			# get base
 
 startup_continue:
         basr    %r13,0                  # get base
-.LPG1:  GET_IPL_DEVICE
-        mvi     __LC_AR_MODE_ID,0       # set ESA flag (mode 0)
+.LPG1:  mvi     __LC_AR_MODE_ID,0       # set ESA flag (mode 0)
         lctl    %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
         l       %r12,.Lparmaddr-.LPG1(%r13) # pointer to parameter area
                                         # move IPL device to lowcore
         mvc     __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
+#
+# Setup stack
+#
+        l       %r15,.Linittu-.LPG1(%r13)
+        mvc     __LC_CURRENT(4),__TI_task(%r15)
+        ahi     %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
+        st      %r15,__LC_KERNEL_STACK  # set end of kernel stack
+        ahi     %r15,-96
+        xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
 
+        l       %r14,.Lipl_save_parameters-.LPG1(%r13)
+        basr    %r14,%r14
 #
 # clear bss memory
 #
@@ -115,6 +125,10 @@ startup_continue:
         b       .Lfchunk-.LPG1(%r13)
 
         .align 4
+.Lipl_save_parameters:
+        .long   ipl_save_parameters
+.Linittu:
+        .long   init_thread_union
 .Lpmask:
         .byte   0
 .align 8
@@ -274,6 +288,20 @@ startup_continue:
 .Lbss_end:  .long _end
 .Lparmaddr: .long PARMAREA
 .Lsccbaddr: .long .Lsccb
+
+        .globl ipl_schib
+ipl_schib:
+        .rept 13
+        .long 0
+        .endr
+
+        .globl ipl_flags
+ipl_flags:
+        .long 0
+        .globl ipl_devno
+ipl_devno:
+        .word 0
+
         .org    0x12000
 .globl s390_readinfo_sccb
 s390_readinfo_sccb:
@@ -305,16 +333,6 @@ s390_readinfo_sccb:
         .globl  _stext
 _stext: basr    %r13,0                  # get base
 .LPG3:
-#
-# Setup stack
-#
-        l       %r15,.Linittu-.LPG3(%r13)
-        mvc     __LC_CURRENT(4),__TI_task(%r15)
-        ahi     %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union+THREAD_SIZE
-        st      %r15,__LC_KERNEL_STACK  # set end of kernel stack
-        ahi     %r15,-96
-        xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
-
 # check control registers
         stctl   %c0,%c15,0(%r15)
         oi      2(%r15),0x40            # enable sigp emergency signal
@@ -333,6 +351,5 @@ _stext:	basr	%r13,0			# get base
 #
         .align  8
 .Ldw:   .long   0x000a0000,0x00000000
-.Linittu:.long  init_thread_union
 .Lstart:.long   start_kernel
 .Laregs:.long   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index c2005101fee1..1ebaa338aa7e 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -39,7 +39,6 @@ startup_continue:
         basr  %r13,0                     # get base
 .LPG1:  sll   %r13,1                     # remove high order bit
         srl   %r13,1
-        GET_IPL_DEVICE
         lhi   %r1,1                      # mode 1 = esame
         mvi   __LC_AR_MODE_ID,1          # set esame flag
         slr   %r0,%r0                    # set cpuid to zero
@@ -49,7 +48,18 @@ startup_continue:
         lg    %r12,.Lparmaddr-.LPG1(%r13)# pointer to parameter area
                                          # move IPL device to lowcore
         mvc   __LC_IPLDEV(4),IPL_DEVICE+4-PARMAREA(%r12)
+#
+# Setup stack
+#
+        larl  %r15,init_thread_union
+        lg    %r14,__TI_task(%r15)      # cache current in lowcore
+        stg   %r14,__LC_CURRENT
+        aghi  %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
+        stg   %r15,__LC_KERNEL_STACK    # set end of kernel stack
+        aghi  %r15,-160
+        xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
 
+        brasl %r14,ipl_save_parameters
 #
 # clear bss memory
 #
@@ -269,6 +279,19 @@ startup_continue:
 .Lparmaddr:
         .quad   PARMAREA
 
+        .globl ipl_schib
+ipl_schib:
+        .rept 13
+        .long 0
+        .endr
+
+        .globl ipl_flags
+ipl_flags:
+        .long 0
+        .globl ipl_devno
+ipl_devno:
+        .word 0
+
         .org    0x12000
 .globl s390_readinfo_sccb
 s390_readinfo_sccb:
@@ -300,24 +323,12 @@ s390_readinfo_sccb:
         .globl _stext
 _stext: basr  %r13,0                    # get base
 .LPG3:
-#
-# Setup stack
-#
-        larl  %r15,init_thread_union
-        lg    %r14,__TI_task(%r15)      # cache current in lowcore
-        stg   %r14,__LC_CURRENT
-        aghi  %r15,1<<(PAGE_SHIFT+THREAD_ORDER) # init_task_union + THREAD_SIZE
-        stg   %r15,__LC_KERNEL_STACK    # set end of kernel stack
-        aghi  %r15,-160
-        xc    __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # clear backchain
-
 # check control registers
         stctg  %c0,%c15,0(%r15)
         oi     6(%r15),0x40             # enable sigp emergency signal
         oi     4(%r15),0x10             # switch on low address proctection
         lctlg  %c0,%c15,0(%r15)
 
-#
         lam    0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
         brasl  %r14,start_kernel        # go to C code
 #
@@ -325,7 +336,7 @@ _stext:	basr  %r13,0                    # get base
 #
         basr  %r13,0
         lpswe .Ldw-.(%r13)           # load disabled wait psw
-#
+
             .align 8
 .Ldw:       .quad  0x0002000180000000,0x0000000000000000
 .Laregs:    .long  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 105ee15a2b31..6555cc48e28f 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -189,9 +189,9 @@ static enum ipl_type ipl_get_type(void)
 {
         struct ipl_parameter_block *ipl = IPL_PARMBLOCK_START;
 
-        if (!IPL_DEVNO_VALID)
+        if (!(ipl_flags & IPL_DEVNO_VALID))
                 return IPL_TYPE_UNKNOWN;
-        if (!IPL_PARMBLOCK_VALID)
+        if (!(ipl_flags & IPL_PARMBLOCK_VALID))
                 return IPL_TYPE_CCW;
         if (ipl->hdr.version > IPL_MAX_SUPPORTED_VERSION)
                 return IPL_TYPE_UNKNOWN;
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 050963f15802..61eb7caa1567 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -16,11 +16,10 @@
 #include <linux/device.h>
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h>
-
 #include <asm/cio.h>
 #include <asm/delay.h>
 #include <asm/irq.h>
-
+#include <asm/setup.h>
 #include "airq.h"
 #include "cio.h"
 #include "css.h"
@@ -909,3 +908,38 @@ void reipl_ccw_dev(struct ccw_dev_id *devid)
         cio_reset_channel_paths();
         do_reipl_asm(*((__u32*)&schid));
 }
+
+extern struct schib ipl_schib;
+
+/*
+ * ipl_save_parameters gets called very early. It is not allowed to access
+ * anything in the bss section at all. The bss section is not cleared yet,
+ * but may contain some ipl parameters written by the firmware.
+ * These parameters (if present) are copied to 0x2000.
+ * To avoid corruption of the ipl parameters, all variables used by this
+ * function must reside on the stack or in the data section.
+ */
+void ipl_save_parameters(void)
+{
+        struct subchannel_id schid;
+        unsigned int *ipl_ptr;
+        void *src, *dst;
+
+        schid = *(struct subchannel_id *)__LC_SUBCHANNEL_ID;
+        if (!schid.one)
+                return;
+        if (stsch(schid, &ipl_schib))
+                return;
+        if (!ipl_schib.pmcw.dnv)
+                return;
+        ipl_devno = ipl_schib.pmcw.dev;
+        ipl_flags |= IPL_DEVNO_VALID;
+        if (!ipl_schib.pmcw.qf)
+                return;
+        ipl_flags |= IPL_PARMBLOCK_VALID;
+        ipl_ptr = (unsigned int *)__LC_IPL_PARMBLOCK_PTR;
+        src = (void *)(unsigned long)*ipl_ptr;
+        dst = (void *)IPL_PARMBLOCK_ORIGIN;
+        memmove(dst, src, PAGE_SIZE);
+        *ipl_ptr = IPL_PARMBLOCK_ORIGIN;
+}
diff --git a/include/asm-s390/lowcore.h b/include/asm-s390/lowcore.h
index 2e3d4cca5e21..18695d10dedf 100644
--- a/include/asm-s390/lowcore.h
+++ b/include/asm-s390/lowcore.h
@@ -35,6 +35,7 @@
 #define __LC_IO_NEW_PSW                 0x01f0
 #endif /* !__s390x__ */
 
+#define __LC_IPL_PARMBLOCK_PTR          0x014
 #define __LC_EXT_PARAMS                 0x080
 #define __LC_CPU_ADDRESS                0x084
 #define __LC_EXT_INT_CODE               0x086
diff --git a/include/asm-s390/setup.h b/include/asm-s390/setup.h
index 4a1126d8439a..00c03e46689b 100644
--- a/include/asm-s390/setup.h
+++ b/include/asm-s390/setup.h
@@ -125,13 +125,15 @@ struct ipl_parameter_block {
 /*
  * IPL validity flags and parameters as detected in head.S
  */
-extern u32 ipl_parameter_flags;
+extern u32 ipl_flags;
 extern u16 ipl_devno;
 
 void do_reipl(void);
 
-#define IPL_DEVNO_VALID         (ipl_parameter_flags & 1)
-#define IPL_PARMBLOCK_VALID     (ipl_parameter_flags & 2)
+enum {
+        IPL_DEVNO_VALID = 1,
+        IPL_PARMBLOCK_VALID = 2,
+};
 
 #define IPL_PARMBLOCK_START     ((struct ipl_parameter_block *) \
                                  IPL_PARMBLOCK_ORIGIN)