s390/sclp: move sclp_early_read_info to sclp_early_core.c

To enable early online memory detection sclp_early_read_info has
been moved to sclp_early_core.c. sclp_info_sccb has been made a part
of .boot.data, which allows to reuse it later during early kernel
startup and make sclp_early_read_info call just once.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/boot/startup.c

@@ -50,6 +50,7 @@ void startup_kernel(void)
 	void *img;
 
 	rescue_initrd();
+	sclp_early_read_info();
 	if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
 		img = decompress_kernel();
 		memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);

arch/s390/include/asm/sclp.h

@@ -105,6 +105,7 @@ struct zpci_report_error_header {
 	u8 data[0];	/* Subsequent Data passed verbatim to SCLP ET 24 */
 } __packed;
 
+int sclp_early_read_info(void);
 int sclp_early_get_core_info(struct sclp_core_info *info);
 void sclp_early_get_ipl_info(struct sclp_ipl_info *info);
 void sclp_early_detect(void);

drivers/s390/char/sclp.h

@@ -63,6 +63,8 @@
 typedef unsigned int sclp_cmdw_t;
 
 #define SCLP_CMDW_READ_CPU_INFO		0x00010001
+#define SCLP_CMDW_READ_SCP_INFO		0x00020001
+#define SCLP_CMDW_READ_SCP_INFO_FORCED	0x00120001
 #define SCLP_CMDW_READ_EVENT_DATA	0x00770005
 #define SCLP_CMDW_WRITE_EVENT_DATA	0x00760005
 #define SCLP_CMDW_WRITE_EVENT_MASK	0x00780005
@@ -156,6 +158,45 @@ struct read_cpu_info_sccb {
 	u8	reserved[4096 - 16];
 } __attribute__((packed, aligned(PAGE_SIZE)));
 
+struct read_info_sccb {
+	struct	sccb_header header;	/* 0-7 */
+	u16	rnmax;			/* 8-9 */
+	u8	rnsize;			/* 10 */
+	u8	_pad_11[16 - 11];	/* 11-15 */
+	u16	ncpurl;			/* 16-17 */
+	u16	cpuoff;			/* 18-19 */
+	u8	_pad_20[24 - 20];	/* 20-23 */
+	u8	loadparm[8];		/* 24-31 */
+	u8	_pad_32[42 - 32];	/* 32-41 */
+	u8	fac42;			/* 42 */
+	u8	fac43;			/* 43 */
+	u8	_pad_44[48 - 44];	/* 44-47 */
+	u64	facilities;		/* 48-55 */
+	u8	_pad_56[66 - 56];	/* 56-65 */
+	u8	fac66;			/* 66 */
+	u8	_pad_67[76 - 67];	/* 67-83 */
+	u32	ibc;			/* 76-79 */
+	u8	_pad80[84 - 80];	/* 80-83 */
+	u8	fac84;			/* 84 */
+	u8	fac85;			/* 85 */
+	u8	_pad_86[91 - 86];	/* 86-90 */
+	u8	fac91;			/* 91 */
+	u8	_pad_92[98 - 92];	/* 92-97 */
+	u8	fac98;			/* 98 */
+	u8	hamaxpow;		/* 99 */
+	u32	rnsize2;		/* 100-103 */
+	u64	rnmax2;			/* 104-111 */
+	u32	hsa_size;		/* 112-115 */
+	u8	fac116;			/* 116 */
+	u8	fac117;			/* 117 */
+	u8	fac118;			/* 118 */
+	u8	fac119;			/* 119 */
+	u16	hcpua;			/* 120-121 */
+	u8	_pad_122[124 - 122];	/* 122-123 */
+	u32	hmfai;			/* 124-127 */
+	u8	_pad_128[4096 - 128];	/* 128-4095 */
+} __packed __aligned(PAGE_SIZE);
+
 static inline void sclp_fill_core_info(struct sclp_core_info *info,
 				       struct read_cpu_info_sccb *sccb)
 {
@@ -275,6 +316,7 @@ unsigned int sclp_early_con_check_vt220(struct init_sccb *sccb);
 int sclp_early_set_event_mask(struct init_sccb *sccb,
 			      sccb_mask_t receive_mask,
 			      sccb_mask_t send_mask);
+int sclp_early_get_info(struct read_info_sccb *info);
 
 /* useful inlines */
 

drivers/s390/char/sclp_early.c

@@ -15,80 +15,17 @@
 #include "sclp_sdias.h"
 #include "sclp.h"
 
-#define SCLP_CMDW_READ_SCP_INFO		0x00020001
-#define SCLP_CMDW_READ_SCP_INFO_FORCED	0x00120001
-
-struct read_info_sccb {
-	struct	sccb_header header;	/* 0-7 */
-	u16	rnmax;			/* 8-9 */
-	u8	rnsize;			/* 10 */
-	u8	_pad_11[16 - 11];	/* 11-15 */
-	u16	ncpurl;			/* 16-17 */
-	u16	cpuoff;			/* 18-19 */
-	u8	_pad_20[24 - 20];	/* 20-23 */
-	u8	loadparm[8];		/* 24-31 */
-	u8	_pad_32[42 - 32];	/* 32-41 */
-	u8	fac42;			/* 42 */
-	u8	fac43;			/* 43 */
-	u8	_pad_44[48 - 44];	/* 44-47 */
-	u64	facilities;		/* 48-55 */
-	u8	_pad_56[66 - 56];	/* 56-65 */
-	u8	fac66;			/* 66 */
-	u8	_pad_67[76 - 67];	/* 67-83 */
-	u32	ibc;			/* 76-79 */
-	u8	_pad80[84 - 80];	/* 80-83 */
-	u8	fac84;			/* 84 */
-	u8	fac85;			/* 85 */
-	u8	_pad_86[91 - 86];	/* 86-90 */
-	u8	fac91;			/* 91 */
-	u8	_pad_92[98 - 92];	/* 92-97 */
-	u8	fac98;			/* 98 */
-	u8	hamaxpow;		/* 99 */
-	u32	rnsize2;		/* 100-103 */
-	u64	rnmax2;			/* 104-111 */
-	u32	hsa_size;		/* 112-115 */
-	u8	fac116;			/* 116 */
-	u8	fac117;			/* 117 */
-	u8	fac118;			/* 118 */
-	u8	fac119;			/* 119 */
-	u16	hcpua;			/* 120-121 */
-	u8	_pad_122[124 - 122];	/* 122-123 */
-	u32	hmfai;			/* 124-127 */
-	u8	_pad_128[4096 - 128];	/* 128-4095 */
-} __packed __aligned(PAGE_SIZE);
-
 static struct sclp_ipl_info sclp_ipl_info;
 
 struct sclp_info sclp;
 EXPORT_SYMBOL(sclp);
 
-static int __init sclp_early_read_info(struct read_info_sccb *sccb)
-{
-	int i;
-	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
-				  SCLP_CMDW_READ_SCP_INFO};
-
-	for (i = 0; i < ARRAY_SIZE(commands); i++) {
-		memset(sccb, 0, sizeof(*sccb));
-		sccb->header.length = sizeof(*sccb);
-		sccb->header.function_code = 0x80;
-		sccb->header.control_mask[2] = 0x80;
-		if (sclp_early_cmd(commands[i], sccb))
-			break;
-		if (sccb->header.response_code == 0x10)
-			return 0;
-		if (sccb->header.response_code != 0x1f0)
-			break;
-	}
-	return -EIO;
-}
-
 static void __init sclp_early_facilities_detect(struct read_info_sccb *sccb)
 {
 	struct sclp_core_entry *cpue;
 	u16 boot_cpu_address, cpu;
 
-	if (sclp_early_read_info(sccb))
+	if (sclp_early_get_info(sccb))
 		return;
 
 	sclp.facilities = sccb->facilities;

drivers/s390/char/sclp_early_core.c

@@ -9,9 +9,12 @@
 #include <asm/lowcore.h>
 #include <asm/ebcdic.h>
 #include <asm/irq.h>
+#include <asm/sections.h>
 #include "sclp.h"
 #include "sclp_rw.h"
 
+static struct read_info_sccb __bootdata(sclp_info_sccb);
+static int __bootdata(sclp_info_sccb_valid);
 char sclp_early_sccb[PAGE_SIZE] __aligned(PAGE_SIZE) __section(.data);
 int sclp_init_state __section(.data) = sclp_init_state_uninitialized;
 /*
@@ -234,3 +237,36 @@ void sclp_early_printk_force(const char *str)
 {
 	__sclp_early_printk(str, strlen(str), 1);
 }
+
+int __init sclp_early_read_info(void)
+{
+	int i;
+	struct read_info_sccb *sccb = &sclp_info_sccb;
+	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
+				  SCLP_CMDW_READ_SCP_INFO};
+
+	for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		memset(sccb, 0, sizeof(*sccb));
+		sccb->header.length = sizeof(*sccb);
+		sccb->header.function_code = 0x80;
+		sccb->header.control_mask[2] = 0x80;
+		if (sclp_early_cmd(commands[i], sccb))
+			break;
+		if (sccb->header.response_code == 0x10) {
+			sclp_info_sccb_valid = 1;
+			return 0;
+		}
+		if (sccb->header.response_code != 0x1f0)
+			break;
+	}
+	return -EIO;
+}
+
+int __init sclp_early_get_info(struct read_info_sccb *info)
+{
+	if (!sclp_info_sccb_valid)
+		return -EIO;
+
+	*info = sclp_info_sccb;
+	return 0;
+}