s390/sclp: convert early sclp console code to C
The 31-bit assembler code for the early sclp console is error
prone as git commit fde24b54d976cc123506695c17db01438a11b673
"s390/sclp: clear upper register halves in _sclp_print_early"
has shown.
Convert the assembler code to C.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 667b1bc..e8d4423 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -33,6 +33,8 @@
mflags-$(CONFIG_MARCH_ZEC12) := -march=zEC12
mflags-$(CONFIG_MARCH_Z13) := -march=z13
+export CC_FLAGS_MARCH := $(mflags-y)
+
aflags-y += $(mflags-y)
cflags-y += $(mflags-y)
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index c417015..085fb0d 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -233,6 +233,17 @@
}
/*
+ * Extract current PSW mask
+ */
+static inline unsigned long __extract_psw(void)
+{
+ unsigned int reg1, reg2;
+
+ asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
+ return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
+}
+
+/*
* Rewind PSW instruction address by specified number of bytes.
*/
static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h
index f6ff060..821dde5 100644
--- a/arch/s390/include/asm/sclp.h
+++ b/arch/s390/include/asm/sclp.h
@@ -79,6 +79,6 @@
int sclp_pci_deconfigure(u32 fid);
int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode);
void sclp_early_detect(void);
-long _sclp_print_early(const char *);
+int _sclp_print_early(const char *);
#endif /* _ASM_S390_SCLP_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index ffb8761..b756c63 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -28,6 +28,17 @@
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
+#
+CFLAGS_REMOVE_sclp.o = $(CC_FLAGS_FTRACE)
+ifneq ($(CC_FLAGS_MARCH),-march=z900)
+CFLAGS_REMOVE_sclp.o += $(CC_FLAGS_MARCH)
+CFLAGS_sclp.o += -march=z900
+endif
+GCOV_PROFILE_sclp.o := n
+
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
diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index 59b7c64..63c77fd 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -370,6 +370,7 @@
xc 0x200(256),0x200 # partially clear lowcore
xc 0x300(256),0x300
xc 0xe00(256),0xe00
+ 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)
diff --git a/arch/s390/kernel/sclp.S b/arch/s390/kernel/sclp.S
deleted file mode 100644
index ada0c07..0000000
--- a/arch/s390/kernel/sclp.S
+++ /dev/null
@@ -1,355 +0,0 @@
-/*
- * Mini SCLP driver.
- *
- * Copyright IBM Corp. 2004, 2009
- *
- * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>,
- * Heiko Carstens <heiko.carstens@de.ibm.com>,
- *
- */
-
-#include <linux/linkage.h>
-#include <asm/irq.h>
-
-LC_EXT_NEW_PSW = 0x58 # addr of ext int handler
-LC_EXT_NEW_PSW_64 = 0x1b0 # addr of ext int handler 64 bit
-LC_EXT_INT_PARAM = 0x80 # addr of ext int parameter
-LC_EXT_INT_CODE = 0x86 # addr of ext int code
-LC_AR_MODE_ID = 0xa3
-
-#
-# Subroutine which waits synchronously until either an external interruption
-# or a timeout occurs.
-#
-# Parameters:
-# R2 = 0 for no timeout, non-zero for timeout in (approximated) seconds
-#
-# Returns:
-# R2 = 0 on interrupt, 2 on timeout
-# R3 = external interruption parameter if R2=0
-#
-
-_sclp_wait_int:
- stm %r6,%r15,24(%r15) # save registers
- basr %r13,0 # get base register
-.LbaseS1:
- ahi %r15,-96 # create stack frame
- la %r8,LC_EXT_NEW_PSW # register int handler
- la %r9,.LextpswS1-.LbaseS1(%r13)
- tm LC_AR_MODE_ID,1
- jno .Lesa1
- la %r8,LC_EXT_NEW_PSW_64 # register int handler 64 bit
- la %r9,.LextpswS1_64-.LbaseS1(%r13)
-.Lesa1:
- mvc .LoldpswS1-.LbaseS1(16,%r13),0(%r8)
- mvc 0(16,%r8),0(%r9)
- epsw %r6,%r7 # set current addressing mode
- nill %r6,0x1 # in new psw (31 or 64 bit mode)
- nilh %r7,0x8000
- stm %r6,%r7,0(%r8)
- lhi %r6,0x0200 # cr mask for ext int (cr0.54)
- ltr %r2,%r2
- jz .LsetctS1
- ahi %r6,0x0800 # cr mask for clock int (cr0.52)
- stck .LtimeS1-.LbaseS1(%r13) # initiate timeout
- al %r2,.LtimeS1-.LbaseS1(%r13)
- st %r2,.LtimeS1-.LbaseS1(%r13)
- sckc .LtimeS1-.LbaseS1(%r13)
-
-.LsetctS1:
- stctl %c0,%c0,.LctlS1-.LbaseS1(%r13) # enable required interrupts
- l %r0,.LctlS1-.LbaseS1(%r13)
- lhi %r1,~(0x200 | 0x800) # clear old values
- nr %r1,%r0
- or %r1,%r6 # set new value
- st %r1,.LctlS1-.LbaseS1(%r13)
- lctl %c0,%c0,.LctlS1-.LbaseS1(%r13)
- st %r0,.LctlS1-.LbaseS1(%r13)
- lhi %r2,2 # return code for timeout
-.LloopS1:
- lpsw .LwaitpswS1-.LbaseS1(%r13) # wait until interrupt
-.LwaitS1:
- lh %r7,LC_EXT_INT_CODE
- chi %r7,EXT_IRQ_CLK_COMP # timeout?
- je .LtimeoutS1
- chi %r7,EXT_IRQ_SERVICE_SIG # service int?
- jne .LloopS1
- sr %r2,%r2
- l %r3,LC_EXT_INT_PARAM
-.LtimeoutS1:
- lctl %c0,%c0,.LctlS1-.LbaseS1(%r13) # restore interrupt setting
- # restore old handler
- mvc 0(16,%r8),.LoldpswS1-.LbaseS1(%r13)
- lm %r6,%r15,120(%r15) # restore registers
- br %r14 # return to caller
-
- .align 8
-.LoldpswS1:
- .long 0, 0, 0, 0 # old ext int PSW
-.LextpswS1:
- .long 0x00080000, 0x80000000+.LwaitS1 # PSW to handle ext int
-.LextpswS1_64:
- .quad 0, .LwaitS1 # PSW to handle ext int, 64 bit
-.LwaitpswS1:
- .long 0x010a0000, 0x00000000+.LloopS1 # PSW to wait for ext int
-.LtimeS1:
- .quad 0 # current time
-.LctlS1:
- .long 0 # CT0 contents
-
-#
-# Subroutine to synchronously issue a service call.
-#
-# Parameters:
-# R2 = command word
-# R3 = sccb address
-#
-# Returns:
-# R2 = 0 on success, 1 on failure
-# R3 = sccb response code if R2 = 0
-#
-
-_sclp_servc:
- stm %r6,%r15,24(%r15) # save registers
- ahi %r15,-96 # create stack frame
- lr %r6,%r2 # save command word
- lr %r7,%r3 # save sccb address
-.LretryS2:
- lhi %r2,1 # error return code
- .insn rre,0xb2200000,%r6,%r7 # servc
- brc 1,.LendS2 # exit if not operational
- brc 8,.LnotbusyS2 # go on if not busy
- sr %r2,%r2 # wait until no longer busy
- bras %r14,_sclp_wait_int
- j .LretryS2 # retry
-.LnotbusyS2:
- sr %r2,%r2 # wait until result
- bras %r14,_sclp_wait_int
- sr %r2,%r2
- lh %r3,6(%r7)
-.LendS2:
- lm %r6,%r15,120(%r15) # restore registers
- br %r14
-
-#
-# Subroutine to set up the SCLP interface.
-#
-# Parameters:
-# R2 = 0 to activate, non-zero to deactivate
-#
-# Returns:
-# R2 = 0 on success, non-zero on failure
-#
-
-_sclp_setup:
- stm %r6,%r15,24(%r15) # save registers
- ahi %r15,-96 # create stack frame
- basr %r13,0 # get base register
-.LbaseS3:
- l %r6,.LsccbS0-.LbaseS3(%r13) # prepare init mask sccb
- mvc 0(.LinitendS3-.LinitsccbS3,%r6),.LinitsccbS3-.LbaseS3(%r13)
- ltr %r2,%r2 # initialization?
- jz .LdoinitS3 # go ahead
- # clear masks
- xc .LinitmaskS3-.LinitsccbS3(8,%r6),.LinitmaskS3-.LinitsccbS3(%r6)
-.LdoinitS3:
- l %r2,.LwritemaskS3-.LbaseS3(%r13)# get command word
- lr %r3,%r6 # get sccb address
- bras %r14,_sclp_servc # issue service call
- ltr %r2,%r2 # servc successful?
- jnz .LerrorS3
- chi %r3,0x20 # write mask successful?
- jne .LerrorS3
- # check masks
- la %r2,.LinitmaskS3-.LinitsccbS3(%r6)
- l %r1,0(%r2) # receive mask ok?
- n %r1,12(%r2)
- cl %r1,0(%r2)
- jne .LerrorS3
- l %r1,4(%r2) # send mask ok?
- n %r1,8(%r2)
- cl %r1,4(%r2)
- sr %r2,%r2
- je .LendS3
-.LerrorS3:
- lhi %r2,1 # error return code
-.LendS3:
- lm %r6,%r15,120(%r15) # restore registers
- br %r14
-.LwritemaskS3:
- .long 0x00780005 # SCLP command for write mask
-.LinitsccbS3:
- .word .LinitendS3-.LinitsccbS3
- .byte 0,0,0,0
- .word 0
- .word 0
- .word 4
-.LinitmaskS3:
- .long 0x80000000
- .long 0x40000000
- .long 0
- .long 0
-.LinitendS3:
-
-#
-# Subroutine which prints a given text to the SCLP console.
-#
-# Parameters:
-# R2 = address of nil-terminated ASCII text
-#
-# Returns:
-# R2 = 0 on success, 1 on failure
-#
-
-_sclp_print:
- stm %r6,%r15,24(%r15) # save registers
- ahi %r15,-96 # create stack frame
- basr %r13,0 # get base register
-.LbaseS4:
- l %r8,.LsccbS0-.LbaseS4(%r13) # prepare write data sccb
- mvc 0(.LmtoS4-.LwritesccbS4,%r8),.LwritesccbS4-.LbaseS4(%r13)
- la %r7,.LmtoS4-.LwritesccbS4(%r8) # current mto addr
- sr %r0,%r0
- l %r10,.Lascebc-.LbaseS4(%r13) # address of translation table
-.LinitmtoS4:
- # initialize mto
- mvc 0(.LmtoendS4-.LmtoS4,%r7),.LmtoS4-.LbaseS4(%r13)
- lhi %r6,.LmtoendS4-.LmtoS4 # current mto length
-.LloopS4:
- ic %r0,0(%r2) # get character
- ahi %r2,1
- ltr %r0,%r0 # end of string?
- jz .LfinalizemtoS4
- chi %r0,0x0a # end of line (NL)?
- jz .LfinalizemtoS4
- stc %r0,0(%r6,%r7) # copy to mto
- la %r11,0(%r6,%r7)
- tr 0(1,%r11),0(%r10) # translate to EBCDIC
- ahi %r6,1
- j .LloopS4
-.LfinalizemtoS4:
- sth %r6,0(%r7) # update mto length
- lh %r9,.LmdbS4-.LwritesccbS4(%r8) # update mdb length
- ar %r9,%r6
- sth %r9,.LmdbS4-.LwritesccbS4(%r8)
- lh %r9,.LevbufS4-.LwritesccbS4(%r8)# update evbuf length
- ar %r9,%r6
- sth %r9,.LevbufS4-.LwritesccbS4(%r8)
- lh %r9,0(%r8) # update sccb length
- ar %r9,%r6
- sth %r9,0(%r8)
- ar %r7,%r6 # update current mto address
- ltr %r0,%r0 # more characters?
- jnz .LinitmtoS4
- l %r2,.LwritedataS4-.LbaseS4(%r13)# write data
- lr %r3,%r8
- bras %r14,_sclp_servc
- ltr %r2,%r2 # servc successful?
- jnz .LendS4
- chi %r3,0x20 # write data successful?
- je .LendS4
- lhi %r2,1 # error return code
-.LendS4:
- lm %r6,%r15,120(%r15) # restore registers
- br %r14
-
-#
-# Function which prints a given text to the SCLP console.
-#
-# Parameters:
-# R2 = address of nil-terminated ASCII text
-#
-# Returns:
-# R2 = 0 on success, 1 on failure
-#
-
-ENTRY(_sclp_print_early)
- stm %r6,%r15,24(%r15) # save registers
- ahi %r15,-96 # create stack frame
- tm LC_AR_MODE_ID,1
- jno .Lesa2
- ahi %r15,-80
- stmh %r6,%r15,96(%r15) # store upper register halves
- basr %r13,0
- lmh %r0,%r15,.Lzeroes-.(%r13) # clear upper register halves
-.Lesa2:
- lr %r10,%r2 # save string pointer
- lhi %r2,0
- bras %r14,_sclp_setup # enable console
- ltr %r2,%r2
- jnz .LendS5
- lr %r2,%r10
- bras %r14,_sclp_print # print string
- ltr %r2,%r2
- jnz .LendS5
- lhi %r2,1
- bras %r14,_sclp_setup # disable console
-.LendS5:
- tm LC_AR_MODE_ID,1
- jno .Lesa3
- lgfr %r2,%r2 # sign extend return value
- lmh %r6,%r15,96(%r15) # restore upper register halves
- ahi %r15,80
-.Lesa3:
- lm %r6,%r15,120(%r15) # restore registers
- br %r14
-.Lzeroes:
- .fill 64,4,0
-
-.LwritedataS4:
- .long 0x00760005 # SCLP command for write data
-.LwritesccbS4:
- # sccb
- .word .LmtoS4-.LwritesccbS4
- .byte 0
- .byte 0,0,0
- .word 0
-
- # evbuf
-.LevbufS4:
- .word .LmtoS4-.LevbufS4
- .byte 0x02
- .byte 0
- .word 0
-
-.LmdbS4:
- # mdb
- .word .LmtoS4-.LmdbS4
- .word 1
- .long 0xd4c4c240
- .long 1
-
- # go
-.LgoS4:
- .word .LmtoS4-.LgoS4
- .word 1
- .long 0
- .byte 0,0,0,0,0,0,0,0
- .byte 0,0,0
- .byte 0
- .byte 0,0,0,0,0,0,0
- .byte 0
- .word 0
- .byte 0,0,0,0,0,0,0,0,0,0
- .byte 0,0,0,0,0,0,0,0
- .byte 0,0,0,0,0,0,0,0
-
-.LmtoS4:
- .word .LmtoendS4-.LmtoS4
- .word 4
- .word 0x1000
- .byte 0
- .byte 0,0,0
-.LmtoendS4:
-
- # Global constants
-.LsccbS0:
- .long _sclp_work_area
-.Lascebc:
- .long _ascebc
-
-.section .data,"aw",@progbits
- .balign 4096
-_sclp_work_area:
- .fill 4096
-.previous
diff --git a/arch/s390/kernel/sclp.c b/arch/s390/kernel/sclp.c
new file mode 100644
index 0000000..fa0bdff
--- /dev/null
+++ b/arch/s390/kernel/sclp.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright IBM Corp. 2015
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+#include <linux/kernel.h>
+#include <asm/ebcdic.h>
+#include <asm/irq.h>
+#include <asm/lowcore.h>
+#include <asm/processor.h>
+#include <asm/sclp.h>
+
+static char _sclp_work_area[4096] __aligned(PAGE_SIZE);
+
+static void _sclp_wait_int(void)
+{
+ unsigned long cr0, cr0_new, psw_mask, addr;
+ psw_t psw_ext_save, psw_wait;
+
+ __ctl_store(cr0, 0, 0);
+ cr0_new = cr0 | 0x200;
+ __ctl_load(cr0_new, 0, 0);
+
+ psw_ext_save = S390_lowcore.external_new_psw;
+ psw_mask = __extract_psw() & (PSW_MASK_EA | PSW_MASK_BA);
+ S390_lowcore.external_new_psw.mask = psw_mask;
+ psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
+ S390_lowcore.ext_int_code = 0;
+
+ do {
+ asm volatile(
+ " larl %[addr],0f\n"
+ " stg %[addr],%[psw_wait_addr]\n"
+ " stg %[addr],%[psw_ext_addr]\n"
+ " lpswe %[psw_wait]\n"
+ "0:\n"
+ : [addr] "=&d" (addr),
+ [psw_wait_addr] "=Q" (psw_wait.addr),
+ [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
+ : [psw_wait] "Q" (psw_wait)
+ : "cc", "memory");
+ } while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
+
+ __ctl_load(cr0, 0, 0);
+ S390_lowcore.external_new_psw = psw_ext_save;
+}
+
+static int _sclp_servc(unsigned int cmd, char *sccb)
+{
+ unsigned int cc;
+
+ do {
+ asm volatile(
+ " .insn rre,0xb2200000,%1,%2\n"
+ " ipm %0\n"
+ : "=d" (cc) : "d" (cmd), "a" (sccb)
+ : "cc", "memory");
+ cc >>= 28;
+ if (cc == 3)
+ return -EINVAL;
+ _sclp_wait_int();
+ } while (cc != 0);
+ return (*(unsigned short *)(sccb + 6) == 0x20) ? 0 : -EIO;
+}
+
+static int _sclp_setup(int disable)
+{
+ static unsigned char init_sccb[] = {
+ 0x00, 0x1c,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x04,
+ 0x80, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+ };
+ unsigned int *masks;
+ int rc;
+
+ memcpy(_sclp_work_area, init_sccb, 28);
+ masks = (unsigned int *)(_sclp_work_area + 12);
+ if (disable)
+ memset(masks, 0, 16);
+ /* SCLP write mask */
+ rc = _sclp_servc(0x00780005, _sclp_work_area);
+ if (rc)
+ return rc;
+ if ((masks[0] & masks[3]) != masks[0] ||
+ (masks[1] & masks[2]) != masks[1])
+ return -EIO;
+ return 0;
+}
+
+static int _sclp_print(const char *str)
+{
+ static unsigned char write_head[] = {
+ /* sccb header */
+ 0x00, 0x52, /* 0 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 2 */
+ /* evbuf */
+ 0x00, 0x4a, /* 8 */
+ 0x02, 0x00, 0x00, 0x00, /* 10 */
+ /* mdb */
+ 0x00, 0x44, /* 14 */
+ 0x00, 0x01, /* 16 */
+ 0xd4, 0xc4, 0xc2, 0x40, /* 18 */
+ 0x00, 0x00, 0x00, 0x01, /* 22 */
+ /* go */
+ 0x00, 0x38, /* 26 */
+ 0x00, 0x01, /* 28 */
+ 0x00, 0x00, 0x00, 0x00, /* 30 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 34 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 42 */
+ 0x00, 0x00, 0x00, 0x00, /* 50 */
+ 0x00, 0x00, /* 54 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 56 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 64 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 72 */
+ 0x00, 0x00, /* 80 */
+ };
+ static unsigned char write_mto[] = {
+ /* mto */
+ 0x00, 0x0a, /* 0 */
+ 0x00, 0x04, /* 2 */
+ 0x10, 0x00, /* 4 */
+ 0x00, 0x00, 0x00, 0x00 /* 6 */
+ };
+ unsigned char *ptr, ch;
+ unsigned int count;
+
+ memcpy(_sclp_work_area, write_head, sizeof(write_head));
+ ptr = _sclp_work_area + sizeof(write_head);
+ do {
+ memcpy(ptr, write_mto, sizeof(write_mto));
+ for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {
+ if (ch == 0x0a)
+ break;
+ ptr[count] = _ascebc[ch];
+ }
+ /* Update length fields in mto, mdb, evbuf and sccb */
+ *(unsigned short *) ptr = count;
+ *(unsigned short *)(_sclp_work_area + 14) += count;
+ *(unsigned short *)(_sclp_work_area + 8) += count;
+ *(unsigned short *)(_sclp_work_area + 0) += count;
+ ptr += count;
+ } while (ch != 0);
+
+ /* SCLP write data */
+ return _sclp_servc(0x00760005, _sclp_work_area);
+}
+
+int _sclp_print_early(const char *str)
+{
+ int rc;
+
+ rc = _sclp_setup(0);
+ if (rc)
+ return rc;
+ rc = _sclp_print(str);
+ if (rc)
+ return rc;
+ return _sclp_setup(1);
+}
