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 17821a026c9c..b69ab17f13fa 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 40d1406289ed..9cb8076f66c4 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 77df9cb00688..5bbe6db988b9 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 000000000000..775112964eef
--- /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 ffb1fcf0bf5b..3d8e4d63f514 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);