[PATCH] s390: export ipl device parameters

Sysfs interface to export ipl device parameters.  Dependent on the ipl type
the interface will look like this:

- ccw ipl:

/sys/firmware/ipl/device
		 /ipl_type

- fcp ipl:

/sys/firmware/ipl/binary_parameter
		 /bootprog
		 /br_lba
		 /device
		 /ipl_type
		 /lun
		 /scp_data
		 /wwpn

- otherwise (unknown that is):

/sys/firmware/ipl/ipl_type

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 67 insertions, 5 deletions

diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index 55654b6e16dc..039354d72348 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -485,7 +485,9 @@ start:
 #
         .org  0x10000
 startup:basr  %r13,0                     # get base
-.LPG1:  lctl  %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
+.LPG1:  l     %r1, .Lget_ipl_device_addr-.LPG1(%r13)
+        basr  %r14, %r1
+        lctl  %c0,%c15,.Lctl-.LPG1(%r13) # load control registers
         la    %r12,_pstart-.LPG1(%r13)   # pointer to parameter area
                                          # move IPL device to lowcore
         mvc   __LC_IPLDEV(4),IPL_DEVICE-PARMAREA(%r12)
@@ -560,6 +562,9 @@ startup:basr  %r13,0                     # get base
         mr    %r2,%r1                   # mem size in bytes in %r3
         b     .Lfchunk-.LPG1(%r13)
 
+        .align 4
+.Lget_ipl_device_addr:
+        .long .Lget_ipl_device
 .Lpmask:
         .byte 0
 .align 8
@@ -755,6 +760,63 @@ _pstart:
         .global _pend
 _pend:  
 
+.Lget_ipl_device:
+        basr  %r12,0
+.LPG2:  l     %r1,0xb8                  # get sid
+        sll   %r1,15                    # test if subchannel is enabled
+        srl   %r1,31
+        ltr   %r1,%r1
+        bz    0(%r14)                   # subchannel disabled
+        l     %r1,0xb8
+        la    %r5,.Lipl_schib-.LPG2(%r12)
+        stsch 0(%r5)                    # get schib of subchannel
+        bnz   0(%r14)                   # schib not available
+        tm    5(%r5),0x01               # devno valid?
+        bno   0(%r14)
+        la    %r6,ipl_parameter_flags-.LPG2(%r12)
+        oi    3(%r6),0x01               # set flag
+        la    %r2,ipl_devno-.LPG2(%r12)
+        mvc   0(2,%r2),6(%r5)           # store devno
+        tm    4(%r5),0x80               # qdio capable device?
+        bno   0(%r14)
+        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     0(%r14)
+
+        .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
+
 #ifdef CONFIG_SHARED_KERNEL
         .org   0x100000
 #endif
@@ -764,11 +826,11 @@ _pend:
 #
         .globl _stext
 _stext: basr  %r13,0                    # get base
-.LPG2:
+.LPG3:
 #
 # Setup stack
 #
-        l     %r15,.Linittu-.LPG2(%r13)
+        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
@@ -782,8 +844,8 @@ _stext:	basr  %r13,0                    # get base
         lctl   %c0,%c15,0(%r15)
 
 #
-        lam    0,15,.Laregs-.LPG2(%r13) # load access regs needed by uaccess
-        l      %r14,.Lstart-.LPG2(%r13)
+        lam    0,15,.Laregs-.LPG3(%r13) # load access regs needed by uaccess
+        l      %r14,.Lstart-.LPG3(%r13)
         basr   %r14,%r14                # call start_kernel
 #
 # We returned from start_kernel ?!? PANIK