[S390] rework smp code

Define struct pcpu and merge some of the NR_CPUS arrays into it, including
__cpu_logical_map, current_set and smp_cpu_state. Split smp related
functions to those operating on physical cpus and the functions operating
on a logical cpu number. Make the functions for physical cpus use a
pointer to a struct pcpu. This hides the knowledge about cpu addresses in
smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header.

The PSW restart mechanism is used to start secondary cpus, calling a
function on an online cpu, calling a function on the ipl cpu, and for
the nmi signal. Replace the different assembler functions with a
single function restart_int_handler. The new entry point calls a function
whose pointer is stored in the lowcore of the target cpu and it can wait
for the source cpu to stop. This covers all existing use cases.

Overall the code is now simpler and there are ~380 lines less code.

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

1 files changed, 26 insertions, 30 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 778c100fe314..9a3edb5f2c92 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -2,7 +2,7 @@
  *  arch/s390/kernel/setup.c
  *
  *  S390 version
- *    Copyright (C) IBM Corp. 1999,2010
+ *    Copyright (C) IBM Corp. 1999,2012
  *    Author(s): Hartmut Penner (hp@de.ibm.com),
  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  *
@@ -62,6 +62,7 @@
 #include <asm/ebcdic.h>
 #include <asm/kvm_virtio.h>
 #include <asm/diag.h>
+#include "entry.h"
 
 long psw_kernel_bits	= PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_PRIMARY |
 			  PSW_MASK_EA | PSW_MASK_BA;
@@ -351,8 +352,9 @@ static void setup_addressing_mode(void)
 	}
 }
 
-static void __init
-setup_lowcore(void)
+void *restart_stack __attribute__((__section__(".data")));
+
+static void __init setup_lowcore(void)
 {
 	struct _lowcore *lc;
 
@@ -363,7 +365,7 @@ setup_lowcore(void)
 	lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
 	lc->restart_psw.mask = psw_kernel_bits;
 	lc->restart_psw.addr =
-		PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
+		PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
 	lc->external_new_psw.mask = psw_kernel_bits |
 		PSW_MASK_DAT | PSW_MASK_MCHECK;
 	lc->external_new_psw.addr =
@@ -412,6 +414,24 @@ setup_lowcore(void)
 	lc->last_update_timer = S390_lowcore.last_update_timer;
 	lc->last_update_clock = S390_lowcore.last_update_clock;
 	lc->ftrace_func = S390_lowcore.ftrace_func;
+
+	restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
+	restart_stack += ASYNC_SIZE;
+
+	/*
+	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
+	 * restart data to the absolute zero lowcore. This is necesary if
+	 * PSW restart is done on an offline CPU that has lowcore zero.
+	 */
+	lc->restart_stack = (unsigned long) restart_stack;
+	lc->restart_fn = (unsigned long) do_restart;
+	lc->restart_data = 0;
+	lc->restart_source = -1UL;
+	memcpy(&S390_lowcore.restart_stack, &lc->restart_stack,
+	       4*sizeof(unsigned long));
+	copy_to_absolute_zero(&S390_lowcore.restart_psw,
+			      &lc->restart_psw, sizeof(psw_t));
+
 	set_prefix((u32)(unsigned long) lc);
 	lowcore_ptr[0] = lc;
 }
@@ -572,27 +592,6 @@ static void __init setup_memory_end(void)
 	}
 }
 
-void *restart_stack __attribute__((__section__(".data")));
-
-/*
- * Setup new PSW and allocate stack for PSW restart interrupt
- */
-static void __init setup_restart_psw(void)
-{
-	psw_t psw;
-
-	restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
-	restart_stack += ASYNC_SIZE;
-
-	/*
-	 * Setup restart PSW for absolute zero lowcore. This is necesary
-	 * if PSW restart is done on an offline CPU that has lowcore zero
-	 */
-	psw.mask = PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA | PSW_MASK_BA;
-	psw.addr = PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
-	copy_to_absolute_zero(&S390_lowcore.restart_psw, &psw, sizeof(psw));
-}
-
 static void __init setup_vmcoreinfo(void)
 {
 #ifdef CONFIG_KEXEC
@@ -782,8 +781,7 @@ static void __init reserve_crashkernel(void)
 #endif
 }
 
-static void __init
-setup_memory(void)
+static void __init setup_memory(void)
 {
         unsigned long bootmap_size;
 	unsigned long start_pfn, end_pfn;
@@ -1014,8 +1012,7 @@ static void __init setup_hwcaps(void)
  * was printed.
  */
 
-void __init
-setup_arch(char **cmdline_p)
+void __init setup_arch(char **cmdline_p)
 {
         /*
          * print what head.S has found out about the machine
@@ -1068,7 +1065,6 @@ setup_arch(char **cmdline_p)
 	setup_memory();
 	setup_resources();
 	setup_vmcoreinfo();
-	setup_restart_psw();
 	setup_lowcore();
 
         cpu_init();