s390: Remove zfcpdump NR_CPUS dependency

Currently zfpcdump can only collect registers for up to CONFIG_NR_CPUS
CPUss. This dependency is not necessary. So remove it by dynamically
allocating the save area array.

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

4 files changed, 40 insertions, 15 deletions

diff --git a/arch/s390/include/asm/ipl.h b/arch/s390/include/asm/ipl.h
index 2bd6cb897b90..ea7d9d6ab06e 100644
--- a/arch/s390/include/asm/ipl.h
+++ b/arch/s390/include/asm/ipl.h
@@ -7,6 +7,7 @@
 #ifndef _ASM_S390_IPL_H
 #define _ASM_S390_IPL_H
 
+#include <asm/lowcore.h>
 #include <asm/types.h>
 #include <asm/cio.h>
 #include <asm/setup.h>
@@ -88,6 +89,14 @@ extern u32 ipl_flags;
 extern u32 dump_prefix_page;
 extern unsigned int zfcpdump_prefix_array[];
 
+struct dump_save_areas {
+	struct save_area **areas;
+	int count;
+};
+
+extern struct dump_save_areas dump_save_areas;
+struct save_area *dump_save_area_create(int cpu);
+
 extern void do_reipl(void);
 extern void do_halt(void);
 extern void do_poff(void);
diff --git a/arch/s390/include/asm/smp.h b/arch/s390/include/asm/smp.h
index b64f15c3b4cc..ac9bed8e103f 100644
--- a/arch/s390/include/asm/smp.h
+++ b/arch/s390/include/asm/smp.h
@@ -14,7 +14,6 @@
 #define raw_smp_processor_id()	(S390_lowcore.cpu_nr)
 
 extern struct mutex smp_cpu_state_mutex;
-extern struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
 
 extern int __cpu_up(unsigned int cpu, struct task_struct *tidle);
 
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 3db6af0601a5..f45b2ab0cb81 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -22,6 +22,32 @@
 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
 #define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
 
+struct dump_save_areas dump_save_areas;
+
+/*
+ * Allocate and add a save area for a CPU
+ */
+struct save_area *dump_save_area_create(int cpu)
+{
+	struct save_area **save_areas, *save_area;
+
+	save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
+	if (!save_area)
+		return NULL;
+	if (cpu + 1 > dump_save_areas.count) {
+		dump_save_areas.count = cpu + 1;
+		save_areas = krealloc(dump_save_areas.areas,
+				      dump_save_areas.count * sizeof(void *),
+				      GFP_KERNEL | __GFP_ZERO);
+		if (!save_areas) {
+			kfree(save_area);
+			return NULL;
+		}
+		dump_save_areas.areas = save_areas;
+	}
+	dump_save_areas.areas[cpu] = save_area;
+	return save_area;
+}
 
 /*
  * Return physical address for virtual address
@@ -450,8 +476,8 @@ static int get_cpu_cnt(void)
 {
 	int i, cpus = 0;
 
-	for (i = 0; zfcpdump_save_areas[i]; i++) {
-		if (zfcpdump_save_areas[i]->pref_reg == 0)
+	for (i = 0; i < dump_save_areas.count; i++) {
+		if (dump_save_areas.areas[i]->pref_reg == 0)
 			continue;
 		cpus++;
 	}
@@ -522,8 +548,8 @@ static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
 
 	ptr = nt_prpsinfo(ptr);
 
-	for (i = 0; zfcpdump_save_areas[i]; i++) {
-		sa = zfcpdump_save_areas[i];
+	for (i = 0; i < dump_save_areas.count; i++) {
+		sa = dump_save_areas.areas[i];
 		if (sa->pref_reg == 0)
 			continue;
 		ptr = fill_cpu_elf_notes(ptr, sa);
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index cca6cf6abacc..739313db71e5 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -533,9 +533,6 @@ EXPORT_SYMBOL(smp_ctl_clear_bit);
 
 #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
 
-struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
-EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
-
 static void __init smp_get_save_area(int cpu, u16 address)
 {
 	void *lc = pcpu_devices[0].lowcore;
@@ -546,15 +543,9 @@ static void __init smp_get_save_area(int cpu, u16 address)
 	if (!OLDMEM_BASE && (address == boot_cpu_address ||
 			     ipl_info.type != IPL_TYPE_FCP_DUMP))
 		return;
-	if (cpu >= NR_CPUS) {
-		pr_warning("CPU %i exceeds the maximum %i and is excluded "
-			   "from the dump\n", cpu, NR_CPUS - 1);
-		return;
-	}
-	save_area = kmalloc(sizeof(struct save_area), GFP_KERNEL);
+	save_area = dump_save_area_create(cpu);
 	if (!save_area)
 		panic("could not allocate memory for save area\n");
-	zfcpdump_save_areas[cpu] = save_area;
 #ifdef CONFIG_CRASH_DUMP
 	if (address == boot_cpu_address) {
 		/* Copy the registers of the boot cpu. */