[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 a5850a0cfe8..08db736dded 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 dc7e5259770..15e46ca9433 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 e8ef21c51bb..4348f9bc539 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 f33658f09dd..29fd0f1e6ec 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 5a82bc68193..314d8f09cf3 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 c52b4f7742f..9e4dc608487 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 998bde3ec5e..7eedbbcb54a 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 2f481cc3d1c..cb899d9f850 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 774147824c3..5e73dee63ba 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 d9fb98cde0f..77a63ae419f 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 d8a0b115c7c..8b10127c00a 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 c05ee6c221d..469f11b574f 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 c73ede3c1d6..d94aacc898c 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 5f99e66c51c..6bc9c197aa9 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>