s390/smp: initialize cpu_present_mask in setup_arch

In order to be able to setup the cpu to node mappings early it is a
prerequisite to know which cpus are present. Therefore cpus must be
detected much earlier than before.

For sclp based cpu detection this requires yet another early sclp
call, since the system is not ready to use the regular interrupt and
memory allocations.

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

3 files changed, 55 insertions, 24 deletions

diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index 7a10c56334bb..e1fc7eb043d6 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -59,6 +59,7 @@
 
 typedef unsigned int sclp_cmdw_t;
 
+#define SCLP_CMDW_READ_CPU_INFO		0x00010001
 #define SCLP_CMDW_READ_EVENT_DATA	0x00770005
 #define SCLP_CMDW_WRITE_EVENT_DATA	0x00760005
 #define SCLP_CMDW_WRITE_EVENT_MASK	0x00780005
@@ -102,6 +103,28 @@ struct init_sccb {
 	sccb_mask_t sclp_send_mask;
 } __attribute__((packed));
 
+struct read_cpu_info_sccb {
+	struct	sccb_header header;
+	u16	nr_configured;
+	u16	offset_configured;
+	u16	nr_standby;
+	u16	offset_standby;
+	u8	reserved[4096 - 16];
+} __attribute__((packed, aligned(PAGE_SIZE)));
+
+static inline void sclp_fill_core_info(struct sclp_core_info *info,
+				       struct read_cpu_info_sccb *sccb)
+{
+	char *page = (char *) sccb;
+
+	memset(info, 0, sizeof(*info));
+	info->configured = sccb->nr_configured;
+	info->standby = sccb->nr_standby;
+	info->combined = sccb->nr_configured + sccb->nr_standby;
+	memcpy(&info->core, page + sccb->offset_configured,
+	       info->combined * sizeof(struct sclp_core_entry));
+}
+
 #define SCLP_HAS_CHP_INFO	(sclp.facilities & 0x8000000000000000ULL)
 #define SCLP_HAS_CHP_RECONFIG	(sclp.facilities & 0x2000000000000000ULL)
 #define SCLP_HAS_CPU_INFO	(sclp.facilities & 0x0800000000000000ULL)
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index e3fc7539116b..b9c5522b8a68 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -80,33 +80,10 @@ out:
  * CPU configuration related functions.
  */
 
-#define SCLP_CMDW_READ_CPU_INFO		0x00010001
 #define SCLP_CMDW_CONFIGURE_CPU		0x00110001
 #define SCLP_CMDW_DECONFIGURE_CPU	0x00100001
 
-struct read_cpu_info_sccb {
-	struct	sccb_header header;
-	u16	nr_configured;
-	u16	offset_configured;
-	u16	nr_standby;
-	u16	offset_standby;
-	u8	reserved[4096 - 16];
-} __attribute__((packed, aligned(PAGE_SIZE)));
-
-static void sclp_fill_core_info(struct sclp_core_info *info,
-				struct read_cpu_info_sccb *sccb)
-{
-	char *page = (char *) sccb;
-
-	memset(info, 0, sizeof(*info));
-	info->configured = sccb->nr_configured;
-	info->standby = sccb->nr_standby;
-	info->combined = sccb->nr_configured + sccb->nr_standby;
-	memcpy(&info->core, page + sccb->offset_configured,
-	       info->combined * sizeof(struct sclp_core_entry));
-}
-
-int sclp_get_core_info(struct sclp_core_info *info)
+int _sclp_get_core_info(struct sclp_core_info *info)
 {
 	int rc;
 	struct read_cpu_info_sccb *sccb;
diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c
index c71df0c7dedc..f8e46c22e641 100644
--- a/drivers/s390/char/sclp_early.c
+++ b/drivers/s390/char/sclp_early.c
@@ -221,6 +221,36 @@ static int __init sclp_set_event_mask(struct init_sccb *sccb,
 	return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
 }
 
+static struct sclp_core_info sclp_core_info_early __initdata;
+static int sclp_core_info_early_valid __initdata;
+
+static void __init sclp_init_core_info_early(struct read_cpu_info_sccb *sccb)
+{
+	int rc;
+
+	if (!SCLP_HAS_CPU_INFO)
+		return;
+	memset(sccb, 0, sizeof(*sccb));
+	sccb->header.length = sizeof(*sccb);
+	do {
+		rc = sclp_cmd_sync_early(SCLP_CMDW_READ_CPU_INFO, sccb);
+	} while (rc == -EBUSY);
+	if (rc)
+		return;
+	if (sccb->header.response_code != 0x0010)
+		return;
+	sclp_fill_core_info(&sclp_core_info_early, sccb);
+	sclp_core_info_early_valid = 1;
+}
+
+int __init _sclp_get_core_info_early(struct sclp_core_info *info)
+{
+	if (!sclp_core_info_early_valid)
+		return -EIO;
+	*info = sclp_core_info_early;
+	return 0;
+}
+
 static long __init sclp_hsa_size_init(struct sdias_sccb *sccb)
 {
 	sccb_init_eq_size(sccb);
@@ -293,6 +323,7 @@ void __init sclp_early_detect(void)
 	void *sccb = &sccb_early;
 
 	sclp_facilities_detect(sccb);
+	sclp_init_core_info_early(sccb);
 	sclp_hsa_size_detect(sccb);
 
 	/* Turn off SCLP event notifications.  Also save remote masks in the