[S390] Cleanup struct _lowcore usage and defines.

Use asm offsets to make sure the offset defines to struct _lowcore and
its layout don't get out of sync.
Also add a BUILD_BUG_ON() which checks that the size of the structure
is sane.
And while being at it change those sites which use odd casts to access
the current lowcore. These should use S390_lowcore instead.

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

14 files changed, 95 insertions, 27 deletions

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index a5850a0cfe80..08db736dded0 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -4,8 +4,10 @@
  * and format the required data.
  */
 
-#include <linux/sched.h>
+#define ASM_OFFSETS_C
+
 #include <linux/kbuild.h>
+#include <linux/sched.h>
 #include <asm/vdso.h>
 #include <asm/sigp.h>
 
@@ -22,8 +24,7 @@ int main(void)
         DEFINE(__THREAD_info, offsetof(struct task_struct, stack));
         DEFINE(__THREAD_ksp, offsetof(struct task_struct, thread.ksp));
         DEFINE(__THREAD_per, offsetof(struct task_struct, thread.per_info));
-        DEFINE(__THREAD_mm_segment,
-               offsetof(struct task_struct, thread.mm_segment));
+        DEFINE(__THREAD_mm_segment, offsetof(struct task_struct, thread.mm_segment));
         BLANK();
         DEFINE(__TASK_pid, offsetof(struct task_struct, pid));
         BLANK();
@@ -60,18 +61,94 @@ int main(void)
         DEFINE(__VDSO_WTOM_NSEC, offsetof(struct vdso_data, wtom_clock_nsec));
         DEFINE(__VDSO_TIMEZONE, offsetof(struct vdso_data, tz_minuteswest));
         DEFINE(__VDSO_ECTG_OK, offsetof(struct vdso_data, ectg_available));
-        DEFINE(__VDSO_ECTG_BASE,
-               offsetof(struct vdso_per_cpu_data, ectg_timer_base));
-        DEFINE(__VDSO_ECTG_USER,
-               offsetof(struct vdso_per_cpu_data, ectg_user_time));
+        DEFINE(__VDSO_ECTG_BASE, offsetof(struct vdso_per_cpu_data, ectg_timer_base));
+        DEFINE(__VDSO_ECTG_USER, offsetof(struct vdso_per_cpu_data, ectg_user_time));
         /* constants used by the vdso */
         DEFINE(CLOCK_REALTIME, CLOCK_REALTIME);
         DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC);
         DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC);
+        BLANK();
         /* constants for SIGP */
         DEFINE(__SIGP_STOP, sigp_stop);
         DEFINE(__SIGP_RESTART, sigp_restart);
         DEFINE(__SIGP_SENSE, sigp_sense);
         DEFINE(__SIGP_INITIAL_CPU_RESET, sigp_initial_cpu_reset);
+        BLANK();
+        /* lowcore offsets */
+        DEFINE(__LC_EXT_PARAMS, offsetof(struct _lowcore, ext_params));
+        DEFINE(__LC_CPU_ADDRESS, offsetof(struct _lowcore, cpu_addr));
+        DEFINE(__LC_EXT_INT_CODE, offsetof(struct _lowcore, ext_int_code));
+        DEFINE(__LC_SVC_ILC, offsetof(struct _lowcore, svc_ilc));
+        DEFINE(__LC_SVC_INT_CODE, offsetof(struct _lowcore, svc_code));
+        DEFINE(__LC_PGM_ILC, offsetof(struct _lowcore, pgm_ilc));
+        DEFINE(__LC_PGM_INT_CODE, offsetof(struct _lowcore, pgm_code));
+        DEFINE(__LC_PER_ATMID, offsetof(struct _lowcore, per_perc_atmid));
+        DEFINE(__LC_PER_ADDRESS, offsetof(struct _lowcore, per_address));
+        DEFINE(__LC_PER_ACCESS_ID, offsetof(struct _lowcore, per_access_id));
+        DEFINE(__LC_AR_MODE_ID, offsetof(struct _lowcore, ar_access_id));
+        DEFINE(__LC_SUBCHANNEL_ID, offsetof(struct _lowcore, subchannel_id));
+        DEFINE(__LC_SUBCHANNEL_NR, offsetof(struct _lowcore, subchannel_nr));
+        DEFINE(__LC_IO_INT_PARM, offsetof(struct _lowcore, io_int_parm));
+        DEFINE(__LC_IO_INT_WORD, offsetof(struct _lowcore, io_int_word));
+        DEFINE(__LC_STFL_FAC_LIST, offsetof(struct _lowcore, stfl_fac_list));
+        DEFINE(__LC_MCCK_CODE, offsetof(struct _lowcore, mcck_interruption_code));
+        DEFINE(__LC_DUMP_REIPL, offsetof(struct _lowcore, ipib));
+        BLANK();
+        DEFINE(__LC_RST_NEW_PSW, offsetof(struct _lowcore, restart_psw));
+        DEFINE(__LC_RST_OLD_PSW, offsetof(struct _lowcore, restart_old_psw));
+        DEFINE(__LC_EXT_OLD_PSW, offsetof(struct _lowcore, external_old_psw));
+        DEFINE(__LC_SVC_OLD_PSW, offsetof(struct _lowcore, svc_old_psw));
+        DEFINE(__LC_PGM_OLD_PSW, offsetof(struct _lowcore, program_old_psw));
+        DEFINE(__LC_MCK_OLD_PSW, offsetof(struct _lowcore, mcck_old_psw));
+        DEFINE(__LC_IO_OLD_PSW, offsetof(struct _lowcore, io_old_psw));
+        DEFINE(__LC_EXT_NEW_PSW, offsetof(struct _lowcore, external_new_psw));
+        DEFINE(__LC_SVC_NEW_PSW, offsetof(struct _lowcore, svc_new_psw));
+        DEFINE(__LC_PGM_NEW_PSW, offsetof(struct _lowcore, program_new_psw));
+        DEFINE(__LC_MCK_NEW_PSW, offsetof(struct _lowcore, mcck_new_psw));
+        DEFINE(__LC_IO_NEW_PSW, offsetof(struct _lowcore, io_new_psw));
+        DEFINE(__LC_SAVE_AREA, offsetof(struct _lowcore, save_area));
+        DEFINE(__LC_RETURN_PSW, offsetof(struct _lowcore, return_psw));
+        DEFINE(__LC_RETURN_MCCK_PSW, offsetof(struct _lowcore, return_mcck_psw));
+        DEFINE(__LC_SYNC_ENTER_TIMER, offsetof(struct _lowcore, sync_enter_timer));
+        DEFINE(__LC_ASYNC_ENTER_TIMER, offsetof(struct _lowcore, async_enter_timer));
+        DEFINE(__LC_EXIT_TIMER, offsetof(struct _lowcore, exit_timer));
+        DEFINE(__LC_USER_TIMER, offsetof(struct _lowcore, user_timer));
+        DEFINE(__LC_SYSTEM_TIMER, offsetof(struct _lowcore, system_timer));
+        DEFINE(__LC_STEAL_TIMER, offsetof(struct _lowcore, steal_timer));
+        DEFINE(__LC_LAST_UPDATE_TIMER, offsetof(struct _lowcore, last_update_timer));
+        DEFINE(__LC_LAST_UPDATE_CLOCK, offsetof(struct _lowcore, last_update_clock));
+        DEFINE(__LC_CURRENT, offsetof(struct _lowcore, current_task));
+        DEFINE(__LC_THREAD_INFO, offsetof(struct _lowcore, thread_info));
+        DEFINE(__LC_KERNEL_STACK, offsetof(struct _lowcore, kernel_stack));
+        DEFINE(__LC_ASYNC_STACK, offsetof(struct _lowcore, async_stack));
+        DEFINE(__LC_PANIC_STACK, offsetof(struct _lowcore, panic_stack));
+        DEFINE(__LC_KERNEL_ASCE, offsetof(struct _lowcore, kernel_asce));
+        DEFINE(__LC_USER_ASCE, offsetof(struct _lowcore, user_asce));
+        DEFINE(__LC_USER_EXEC_ASCE, offsetof(struct _lowcore, user_exec_asce));
+        DEFINE(__LC_CPUID, offsetof(struct _lowcore, cpu_id));
+        DEFINE(__LC_INT_CLOCK, offsetof(struct _lowcore, int_clock));
+        DEFINE(__LC_MACHINE_FLAGS, offsetof(struct _lowcore, machine_flags));
+        DEFINE(__LC_FTRACE_FUNC, offsetof(struct _lowcore, ftrace_func));
+        DEFINE(__LC_IRB, offsetof(struct _lowcore, irb));
+        DEFINE(__LC_CPU_TIMER_SAVE_AREA, offsetof(struct _lowcore, cpu_timer_save_area));
+        DEFINE(__LC_CLOCK_COMP_SAVE_AREA, offsetof(struct _lowcore, clock_comp_save_area));
+        DEFINE(__LC_PSW_SAVE_AREA, offsetof(struct _lowcore, psw_save_area));
+        DEFINE(__LC_PREFIX_SAVE_AREA, offsetof(struct _lowcore, prefixreg_save_area));
+        DEFINE(__LC_AREGS_SAVE_AREA, offsetof(struct _lowcore, access_regs_save_area));
+        DEFINE(__LC_FPREGS_SAVE_AREA, offsetof(struct _lowcore, floating_pt_save_area));
+        DEFINE(__LC_GPREGS_SAVE_AREA, offsetof(struct _lowcore, gpregs_save_area));
+        DEFINE(__LC_CREGS_SAVE_AREA, offsetof(struct _lowcore, cregs_save_area));
+#ifdef CONFIG_32BIT
+        DEFINE(__LC_PFAULT_INTPARM, offsetof(struct _lowcore, ext_params));
+        DEFINE(SAVE_AREA_BASE, offsetof(struct _lowcore, extended_save_area_addr));
+#else /* CONFIG_32BIT */
+        DEFINE(__LC_PFAULT_INTPARM, offsetof(struct _lowcore, ext_params2));
+        DEFINE(__LC_EXT_PARAMS2, offsetof(struct _lowcore, ext_params2));
+        DEFINE(SAVE_AREA_BASE, offsetof(struct _lowcore, floating_pt_save_area));
+        DEFINE(__LC_PASTE, offsetof(struct _lowcore, paste));
+        DEFINE(__LC_FP_CREG_SAVE_AREA, offsetof(struct _lowcore, fpt_creg_save_area));
+        DEFINE(__LC_LAST_BREAK, offsetof(struct _lowcore, breaking_event_addr));
+        DEFINE(__LC_VDSO_PER_CPU, offsetof(struct _lowcore, vdso_per_cpu_data));
+#endif /* CONFIG_32BIT */
         return 0;
 }
diff --git a/arch/s390/kernel/base.S b/arch/s390/kernel/base.S
index dc7e5259770f..15e46ca94335 100644
--- a/arch/s390/kernel/base.S
+++ b/arch/s390/kernel/base.S
@@ -6,8 +6,8 @@
  *               Michael Holzheu <holzheu@de.ibm.com>
  */
 
+#include <asm/asm-offsets.h>
 #include <asm/ptrace.h>
-#include <asm/lowcore.h>
 
 #ifdef CONFIG_64BIT
 
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index e8ef21c51bbe..4348f9bc5393 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -13,7 +13,6 @@
 #include <linux/linkage.h>
 #include <linux/init.h>
 #include <asm/cache.h>
-#include <asm/lowcore.h>
 #include <asm/errno.h>
 #include <asm/ptrace.h>
 #include <asm/thread_info.h>
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index f33658f09dd7..29fd0f1e6ec4 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -9,11 +9,9 @@
  *               Heiko Carstens <heiko.carstens@de.ibm.com>
  */
 
-#include <linux/sys.h>
 #include <linux/linkage.h>
 #include <linux/init.h>
 #include <asm/cache.h>
-#include <asm/lowcore.h>
 #include <asm/errno.h>
 #include <asm/ptrace.h>
 #include <asm/thread_info.h>
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index 5a82bc68193e..314d8f09cf31 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -13,7 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <trace/syscall.h>
-#include <asm/lowcore.h>
+#include <asm/asm-offsets.h>
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index c52b4f7742fa..9e4dc6084875 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -23,7 +23,6 @@
 
 #include <linux/init.h>
 #include <asm/setup.h>
-#include <asm/lowcore.h>
 #include <asm/asm-offsets.h>
 #include <asm/thread_info.h>
 #include <asm/page.h>
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index 998bde3ec5ea..7eedbbcb54aa 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -1917,7 +1917,6 @@ void __init ipl_update_parameters(void)
 void __init ipl_save_parameters(void)
 {
         struct cio_iplinfo iplinfo;
-        unsigned int *ipl_ptr;
         void *src, *dst;
 
         if (cio_get_iplinfo(&iplinfo))
@@ -1928,11 +1927,10 @@ void __init ipl_save_parameters(void)
         if (!iplinfo.is_qdio)
                 return;
         ipl_flags |= IPL_PARMBLOCK_VALID;
-        ipl_ptr = (unsigned int *)__LC_IPL_PARMBLOCK_PTR;
-        src = (void *)(unsigned long)*ipl_ptr;
+        src = (void *)(unsigned long)S390_lowcore.ipl_parmblock_ptr;
         dst = (void *)IPL_PARMBLOCK_ORIGIN;
         memmove(dst, src, PAGE_SIZE);
-        *ipl_ptr = IPL_PARMBLOCK_ORIGIN;
+        S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
 }
 
 static LIST_HEAD(rcall);
diff --git a/arch/s390/kernel/reipl.S b/arch/s390/kernel/reipl.S
index 2f481cc3d1c9..cb899d9f8505 100644
--- a/arch/s390/kernel/reipl.S
+++ b/arch/s390/kernel/reipl.S
@@ -6,7 +6,7 @@
  *    Author(s): Holger Smolinski (Holger.Smolinski@de.ibm.com)
  */
 
-#include <asm/lowcore.h>
+#include <asm/asm-offsets.h>
 
 #
 # do_reipl_asm
diff --git a/arch/s390/kernel/reipl64.S b/arch/s390/kernel/reipl64.S
index 774147824c3d..5e73dee63baa 100644
--- a/arch/s390/kernel/reipl64.S
+++ b/arch/s390/kernel/reipl64.S
@@ -4,7 +4,7 @@
  *               Denis Joseph Barrow,
  */
 
-#include <asm/lowcore.h>
+#include <asm/asm-offsets.h>
 
 #
 # do_reipl_asm
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index d9fb98cde0fa..77a63ae419f0 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -396,15 +396,12 @@ static void __init
 setup_lowcore(void)
 {
         struct _lowcore *lc;
-        int lc_pages;
 
         /*
          * Setup lowcore for boot cpu
          */
-        lc_pages = sizeof(void *) == 8 ? 2 : 1;
-        lc = (struct _lowcore *)
-                __alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
-        memset(lc, 0, lc_pages * PAGE_SIZE);
+        BUILD_BUG_ON(sizeof(struct _lowcore) != LC_PAGES * 4096);
+        lc = __alloc_bootmem(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
         lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
         lc->restart_psw.addr =
                 PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index d8a0b115c7c1..8b10127c00ad 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -36,6 +36,7 @@
 #include <linux/cpu.h>
 #include <linux/timex.h>
 #include <linux/bootmem.h>
+#include <asm/asm-offsets.h>
 #include <asm/ipl.h>
 #include <asm/setup.h>
 #include <asm/sigp.h>
@@ -121,7 +122,7 @@ void smp_switch_to_ipl_cpu(void (*func)(void *), void *data)
         sp -= sizeof(struct pt_regs);
         regs = (struct pt_regs *) sp;
         memcpy(&regs->gprs, &current_lc->gpregs_save_area, sizeof(regs->gprs));
-        memcpy(&regs->psw, &current_lc->st_status_fixed_logout, sizeof(psw_t));
+        regs->psw = lc->psw_save_area;
         sp -= STACK_FRAME_OVERHEAD;
         sf = (struct stack_frame *) sp;
         sf->back_chain = regs->gprs[15];
diff --git a/arch/s390/kernel/switch_cpu.S b/arch/s390/kernel/switch_cpu.S
index c05ee6c221d8..469f11b574fa 100644
--- a/arch/s390/kernel/switch_cpu.S
+++ b/arch/s390/kernel/switch_cpu.S
@@ -6,7 +6,6 @@
  */
 
 #include <asm/asm-offsets.h>
-#include <asm/lowcore.h>
 #include <asm/ptrace.h>
 
 # smp_switch_to_cpu switches to destination cpu and executes the passed function
diff --git a/arch/s390/kernel/switch_cpu64.S b/arch/s390/kernel/switch_cpu64.S
index c73ede3c1d68..d94aacc898cb 100644
--- a/arch/s390/kernel/switch_cpu64.S
+++ b/arch/s390/kernel/switch_cpu64.S
@@ -6,7 +6,6 @@
  */
 
 #include <asm/asm-offsets.h>
-#include <asm/lowcore.h>
 #include <asm/ptrace.h>
 
 # smp_switch_to_cpu switches to destination cpu and executes the passed function
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 5f99e66c51c3..6bc9c197aa91 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -23,6 +23,7 @@
 #include <linux/security.h>
 #include <linux/bootmem.h>
 #include <linux/compat.h>
+#include <asm/asm-offsets.h>
 #include <asm/pgtable.h>
 #include <asm/system.h>
 #include <asm/processor.h>