s390/cio: Introduce generic synchronous CHSC IOCTL

This patch adds a new ioctl CHSC_START_SYNC that allows to
execute any synchronous CHSC that is provided by user space.

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

2 files changed, 35 insertions, 7 deletions

diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index e7ef2a683b8f..62d096f11e65 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -10,11 +10,6 @@
 
 #define CHSC_SDA_OC_MSS   0x2
 
-struct chsc_header {
-        u16 length;
-        u16 code;
-} __attribute__ ((packed));
-
 #define NR_MEASUREMENT_CHARS 5
 struct cmg_chars {
         u32 values[NR_MEASUREMENT_CHARS];
diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index facdf809113f..190fc844d814 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -287,11 +287,11 @@ static int chsc_async(struct chsc_async_area *chsc_area,
         return ret;
 }
 
-static void chsc_log_command(struct chsc_async_area *chsc_area)
+static void chsc_log_command(void *chsc_area)
 {
         char dbf[10];
 
-        sprintf(dbf, "CHSC:%x", chsc_area->header.code);
+        sprintf(dbf, "CHSC:%x", ((uint16_t *)chsc_area)[1]);
         CHSC_LOG(0, dbf);
         CHSC_LOG_HEX(0, chsc_area, 32);
 }
@@ -362,6 +362,37 @@ out_free:
         return ret;
 }
 
+static int chsc_ioctl_start_sync(void __user *user_area)
+{
+        struct chsc_sync_area *chsc_area;
+        int ret, ccode;
+
+        chsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+        if (!chsc_area)
+                return -ENOMEM;
+        if (copy_from_user(chsc_area, user_area, PAGE_SIZE)) {
+                ret = -EFAULT;
+                goto out_free;
+        }
+        if (chsc_area->header.code & 0x4000) {
+                ret = -EINVAL;
+                goto out_free;
+        }
+        chsc_log_command(chsc_area);
+        ccode = chsc(chsc_area);
+        if (ccode != 0) {
+                ret = -EIO;
+                goto out_free;
+        }
+        if (copy_to_user(user_area, chsc_area, PAGE_SIZE))
+                ret = -EFAULT;
+        else
+                ret = 0;
+out_free:
+        free_page((unsigned long)chsc_area);
+        return ret;
+}
+
 static int chsc_ioctl_info_channel_path(void __user *user_cd)
 {
         struct chsc_chp_cd *cd;
@@ -795,6 +826,8 @@ static long chsc_ioctl(struct file *filp, unsigned int cmd,
         switch (cmd) {
         case CHSC_START:
                 return chsc_ioctl_start(argp);
+        case CHSC_START_SYNC:
+                return chsc_ioctl_start_sync(argp);
         case CHSC_INFO_CHANNEL_PATH:
                 return chsc_ioctl_info_channel_path(argp);
         case CHSC_INFO_CU: