s390/sclp: Determine HSA size dynamically for zfcpdump

Currently we have hardcoded the HSA size to 32 MiB. With this patch the
HSA size is determined dynamically via SCLP in early.c.

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

5 files changed, 122 insertions, 17 deletions

diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile
index 17821a026c9..b69ab17f13f 100644
--- a/drivers/s390/char/Makefile
+++ b/drivers/s390/char/Makefile
@@ -3,7 +3,8 @@
 #
 
 obj-y += ctrlchar.o keyboard.o defkeymap.o sclp.o sclp_rw.o sclp_quiesce.o \
-	 sclp_cmd.o sclp_config.o sclp_cpi_sys.o sclp_ocf.o sclp_ctl.o
+	 sclp_cmd.o sclp_config.o sclp_cpi_sys.o sclp_ocf.o sclp_ctl.o \
+	 sclp_early.o
 
 obj-$(CONFIG_TN3270) += raw3270.o
 obj-$(CONFIG_TN3270_CONSOLE) += con3270.o
diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index 40d1406289e..9cb8076f66c 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -172,6 +172,7 @@ int sclp_deactivate(void);
 int sclp_reactivate(void);
 int sclp_service_call(sclp_cmdw_t command, void *sccb);
 int sclp_sync_request(sclp_cmdw_t command, void *sccb);
+int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb);
 
 int sclp_sdias_init(void);
 void sclp_sdias_exit(void);
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 77df9cb0068..5bbe6db988b 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -59,7 +59,7 @@ static u8 sclp_fac84;
 static unsigned long long rzm;
 static unsigned long long rnmax;
 
-static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
+int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
 {
 	int rc;
 
diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c
new file mode 100644
index 00000000000..775112964ee
--- /dev/null
+++ b/drivers/s390/char/sclp_early.c
@@ -0,0 +1,111 @@
+/*
+ * SCLP early driver
+ *
+ * Copyright IBM Corp. 2013
+ */
+
+#define KMSG_COMPONENT "sclp_early"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <asm/sclp.h>
+#include <asm/ipl.h>
+#include "sclp_sdias.h"
+#include "sclp.h"
+
+static __initdata char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE);
+static unsigned long sclp_hsa_size;
+
+static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
+{
+	int rc;
+
+	do {
+		rc = sclp_cmd_sync_early(cmd, sccb);
+	} while (rc == -EBUSY);
+
+	if (rc)
+		return -EIO;
+	if (((struct sccb_header *) sccb)->response_code != 0x0020)
+		return -EIO;
+	return 0;
+}
+
+static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
+{
+	memset(sccb, 0, sizeof(*sccb));
+
+	sccb->hdr.length = sizeof(*sccb);
+	sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
+	sccb->evbuf.hdr.type = EVTYP_SDIAS;
+	sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
+	sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
+	sccb->evbuf.event_id = 4712;
+	sccb->evbuf.dbs = 1;
+}
+
+static int __init sclp_set_event_mask(unsigned long receive_mask,
+				      unsigned long send_mask)
+{
+	struct init_sccb *sccb = (void *) &sccb_early;
+
+	memset(sccb, 0, sizeof(*sccb));
+	sccb->header.length = sizeof(*sccb);
+	sccb->mask_length = sizeof(sccb_mask_t);
+	sccb->receive_mask = receive_mask;
+	sccb->send_mask = send_mask;
+	return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
+}
+
+static long __init sclp_hsa_size_init(void)
+{
+	struct sdias_sccb *sccb = (void *) &sccb_early;
+
+	sccb_init_eq_size(sccb);
+	if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
+		return -EIO;
+	if (sccb->evbuf.blk_cnt != 0)
+		return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
+	return 0;
+}
+
+static long __init sclp_hsa_copy_wait(void)
+{
+	struct sccb_header *sccb = (void *) &sccb_early;
+
+	memset(sccb, 0, PAGE_SIZE);
+	sccb->length = PAGE_SIZE;
+	if (sclp_cmd_early(SCLP_CMDW_READ_EVENT_DATA, sccb))
+		return -EIO;
+	return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
+}
+
+unsigned long sclp_get_hsa_size(void)
+{
+	return sclp_hsa_size;
+}
+
+void __init sclp_hsa_size_detect(void)
+{
+	long size;
+
+	/* First try synchronous interface (LPAR) */
+	if (sclp_set_event_mask(0, 0x40000010))
+		return;
+	size = sclp_hsa_size_init();
+	if (size < 0)
+		return;
+	if (size != 0)
+		goto out;
+	/* Then try asynchronous interface (z/VM) */
+	if (sclp_set_event_mask(0x00000010, 0x40000010))
+		return;
+	size = sclp_hsa_size_init();
+	if (size < 0)
+		return;
+	size = sclp_hsa_copy_wait();
+	if (size < 0)
+		return;
+out:
+	sclp_set_event_mask(0, 0);
+	sclp_hsa_size = size;
+}
diff --git a/drivers/s390/char/zcore.c b/drivers/s390/char/zcore.c
index ffb1fcf0bf5..3d8e4d63f51 100644
--- a/drivers/s390/char/zcore.c
+++ b/drivers/s390/char/zcore.c
@@ -328,9 +328,9 @@ static ssize_t zcore_read(struct file *file, char __user *buf, size_t count,
 	mem_offs = 0;
 
 	/* Copy from HSA data */
-	if (*ppos < (ZFCPDUMP_HSA_SIZE + HEADER_SIZE)) {
-		size = min((count - hdr_count), (size_t) (ZFCPDUMP_HSA_SIZE
-			   - mem_start));
+	if (*ppos < sclp_get_hsa_size() + HEADER_SIZE) {
+		size = min((count - hdr_count),
+			   (size_t) (sclp_get_hsa_size() - mem_start));
 		rc = memcpy_hsa_user(buf + hdr_count, mem_start, size);
 		if (rc)
 			goto fail;
@@ -490,7 +490,7 @@ static ssize_t zcore_hsa_read(struct file *filp, char __user *buf,
 	static char str[18];
 
 	if (hsa_available)
-		snprintf(str, sizeof(str), "%lx\n", ZFCPDUMP_HSA_SIZE);
+		snprintf(str, sizeof(str), "%lx\n", sclp_get_hsa_size());
 	else
 		snprintf(str, sizeof(str), "0\n");
 	return simple_read_from_buffer(buf, count, ppos, str, strlen(str));
@@ -584,17 +584,9 @@ static int __init sys_info_init(enum arch_id arch, unsigned long mem_end)
 
 static int __init check_sdias(void)
 {
-	int rc, act_hsa_size;
-
-	rc = sclp_sdias_blk_count();
-	if (rc < 0) {
+	if (!sclp_get_hsa_size()) {
 		TRACE("Could not determine HSA size\n");
-		return rc;
-	}
-	act_hsa_size = (rc - 1) * PAGE_SIZE;
-	if (act_hsa_size < ZFCPDUMP_HSA_SIZE) {
-		TRACE("HSA size too small: %i\n", act_hsa_size);
-		return -EINVAL;
+		return -ENODEV;
 	}
 	return 0;
 }
@@ -662,7 +654,7 @@ static int __init zcore_reipl_init(void)
 	ipl_block = (void *) __get_free_page(GFP_KERNEL);
 	if (!ipl_block)
 		return -ENOMEM;
-	if (ipib_info.ipib < ZFCPDUMP_HSA_SIZE)
+	if (ipib_info.ipib < sclp_get_hsa_size())
 		rc = memcpy_hsa_kernel(ipl_block, ipib_info.ipib, PAGE_SIZE);
 	else
 		rc = memcpy_real(ipl_block, (void *) ipib_info.ipib, PAGE_SIZE);