Upgrade to 4.4.50-rt62

The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it
to 4.4.50-rt62.
The command to achieve it is:
a) Clone a git repo from
git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git

b) Get the diff between this two changesets:
git diff 640eca2901f3435e616157b11379d3223a44b391
705619beeea1b0b48219a683fd1a901a86fdaf5e

where the two commits are:
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
640eca2901f3435e616157b11379d3223a44b391
640eca2901f3 v4.4.6-rt14
localversion-rt
[yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only
705619beeea1b0b48219a683fd1a901a86fdaf5e
705619beeea1 Linux 4.4.50-rt62
localversion-rt

c) One patch has been backported thus revert the patch before applying.

 filterdiff -p1 -x scripts/package/Makefile
~/tmp/v4.4.6-rt14-4.4.50-rt62.diff  |patch -p1 --dry-run

Upstream status: backport

Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01
Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>

4 files changed, 65 insertions, 50 deletions

diff --git a/kernel/drivers/s390/cio/chp.c b/kernel/drivers/s390/cio/chp.c
index c692dfebd..50597f952 100644
--- a/kernel/drivers/s390/cio/chp.c
+++ b/kernel/drivers/s390/cio/chp.c
@@ -139,11 +139,11 @@ static ssize_t chp_measurement_chars_read(struct file *filp,
 
 	device = container_of(kobj, struct device, kobj);
 	chp = to_channelpath(device);
-	if (!chp->cmg_chars)
+	if (chp->cmg == -1)
 		return 0;
 
-	return memory_read_from_buffer(buf, count, &off,
-				chp->cmg_chars, sizeof(struct cmg_chars));
+	return memory_read_from_buffer(buf, count, &off, &chp->cmg_chars,
+				       sizeof(chp->cmg_chars));
 }
 
 static struct bin_attribute chp_measurement_chars_attr = {
@@ -416,7 +416,8 @@ static void chp_release(struct device *dev)
  * chp_update_desc - update channel-path description
  * @chp - channel-path
  *
- * Update the channel-path description of the specified channel-path.
+ * Update the channel-path description of the specified channel-path
+ * including channel measurement related information.
  * Return zero on success, non-zero otherwise.
  */
 int chp_update_desc(struct channel_path *chp)
@@ -428,8 +429,10 @@ int chp_update_desc(struct channel_path *chp)
 		return rc;
 
 	rc = chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1);
+	if (rc)
+		return rc;
 
-	return rc;
+	return chsc_get_channel_measurement_chars(chp);
 }
 
 /**
@@ -466,14 +469,6 @@ int chp_new(struct chp_id chpid)
 		ret = -ENODEV;
 		goto out_free;
 	}
-	/* Get channel-measurement characteristics. */
-	if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) {
-		ret = chsc_get_channel_measurement_chars(chp);
-		if (ret)
-			goto out_free;
-	} else {
-		chp->cmg = -1;
-	}
 	dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 
 	/* make it known to the system */
diff --git a/kernel/drivers/s390/cio/chp.h b/kernel/drivers/s390/cio/chp.h
index 4efd5b867..af0232290 100644
--- a/kernel/drivers/s390/cio/chp.h
+++ b/kernel/drivers/s390/cio/chp.h
@@ -48,7 +48,7 @@ struct channel_path {
 	/* Channel-measurement related stuff: */
 	int cmg;
 	int shared;
-	void *cmg_chars;
+	struct cmg_chars cmg_chars;
 };
 
 /* Return channel_path struct for given chpid. */
diff --git a/kernel/drivers/s390/cio/chsc.c b/kernel/drivers/s390/cio/chsc.c
index a831d1859..1e1633189 100644
--- a/kernel/drivers/s390/cio/chsc.c
+++ b/kernel/drivers/s390/cio/chsc.c
@@ -14,6 +14,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/device.h>
+#include <linux/mutex.h>
 #include <linux/pci.h>
 
 #include <asm/cio.h>
@@ -94,12 +95,13 @@ struct chsc_ssd_area {
 int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
 {
 	struct chsc_ssd_area *ssd_area;
+	unsigned long flags;
 	int ccode;
 	int ret;
 	int i;
 	int mask;
 
-	spin_lock_irq(&chsc_page_lock);
+	spin_lock_irqsave(&chsc_page_lock, flags);
 	memset(chsc_page, 0, PAGE_SIZE);
 	ssd_area = chsc_page;
 	ssd_area->request.length = 0x0010;
@@ -143,7 +145,7 @@ int chsc_get_ssd_info(struct subchannel_id schid, struct chsc_ssd_info *ssd)
 			ssd->fla[i] = ssd_area->fla[i];
 	}
 out:
-	spin_unlock_irq(&chsc_page_lock);
+	spin_unlock_irqrestore(&chsc_page_lock, flags);
 	return ret;
 }
 
@@ -224,8 +226,9 @@ out_unreg:
 
 void chsc_chp_offline(struct chp_id chpid)
 {
-	char dbf_txt[15];
+	struct channel_path *chp = chpid_to_chp(chpid);
 	struct chp_link link;
+	char dbf_txt[15];
 
 	sprintf(dbf_txt, "chpr%x.%02x", chpid.cssid, chpid.id);
 	CIO_TRACE_EVENT(2, dbf_txt);
@@ -236,6 +239,11 @@ void chsc_chp_offline(struct chp_id chpid)
 	link.chpid = chpid;
 	/* Wait until previous actions have settled. */
 	css_wait_for_slow_path();
+
+	mutex_lock(&chp->lock);
+	chp_update_desc(chp);
+	mutex_unlock(&chp->lock);
+
 	for_each_subchannel_staged(s390_subchannel_remove_chpid, NULL, &link);
 }
 
@@ -690,8 +698,9 @@ static void chsc_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
 
 void chsc_chp_online(struct chp_id chpid)
 {
-	char dbf_txt[15];
+	struct channel_path *chp = chpid_to_chp(chpid);
 	struct chp_link link;
+	char dbf_txt[15];
 
 	sprintf(dbf_txt, "cadd%x.%02x", chpid.cssid, chpid.id);
 	CIO_TRACE_EVENT(2, dbf_txt);
@@ -701,6 +710,11 @@ void chsc_chp_online(struct chp_id chpid)
 		link.chpid = chpid;
 		/* Wait until previous actions have settled. */
 		css_wait_for_slow_path();
+
+		mutex_lock(&chp->lock);
+		chp_update_desc(chp);
+		mutex_unlock(&chp->lock);
+
 		for_each_subchannel_staged(__s390_process_res_acc, NULL,
 					   &link);
 		css_schedule_reprobe();
@@ -819,9 +833,10 @@ int __chsc_do_secm(struct channel_subsystem *css, int enable)
 		u32 fmt : 4;
 		u32 : 16;
 	} __attribute__ ((packed)) *secm_area;
+	unsigned long flags;
 	int ret, ccode;
 
-	spin_lock_irq(&chsc_page_lock);
+	spin_lock_irqsave(&chsc_page_lock, flags);
 	memset(chsc_page, 0, PAGE_SIZE);
 	secm_area = chsc_page;
 	secm_area->request.length = 0x0050;
@@ -851,7 +866,7 @@ int __chsc_do_secm(struct channel_subsystem *css, int enable)
 		CIO_CRW_EVENT(2, "chsc: secm failed (rc=%04x)\n",
 			      secm_area->response.code);
 out:
-	spin_unlock_irq(&chsc_page_lock);
+	spin_unlock_irqrestore(&chsc_page_lock, flags);
 	return ret;
 }
 
@@ -967,22 +982,20 @@ static void
 chsc_initialize_cmg_chars(struct channel_path *chp, u8 cmcv,
 			  struct cmg_chars *chars)
 {
-	struct cmg_chars *cmg_chars;
 	int i, mask;
 
-	cmg_chars = chp->cmg_chars;
 	for (i = 0; i < NR_MEASUREMENT_CHARS; i++) {
 		mask = 0x80 >> (i + 3);
 		if (cmcv & mask)
-			cmg_chars->values[i] = chars->values[i];
+			chp->cmg_chars.values[i] = chars->values[i];
 		else
-			cmg_chars->values[i] = 0;
+			chp->cmg_chars.values[i] = 0;
 	}
 }
 
 int chsc_get_channel_measurement_chars(struct channel_path *chp)
 {
-	struct cmg_chars *cmg_chars;
+	unsigned long flags;
 	int ccode, ret;
 
 	struct {
@@ -1006,12 +1019,13 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp)
 		u32 data[NR_MEASUREMENT_CHARS];
 	} __attribute__ ((packed)) *scmc_area;
 
-	chp->cmg_chars = NULL;
-	cmg_chars = kmalloc(sizeof(*cmg_chars), GFP_KERNEL);
-	if (!cmg_chars)
-		return -ENOMEM;
+	chp->shared = -1;
+	chp->cmg = -1;
+
+	if (!css_chsc_characteristics.scmc || !css_chsc_characteristics.secm)
+		return 0;
 
-	spin_lock_irq(&chsc_page_lock);
+	spin_lock_irqsave(&chsc_page_lock, flags);
 	memset(chsc_page, 0, PAGE_SIZE);
 	scmc_area = chsc_page;
 	scmc_area->request.length = 0x0010;
@@ -1031,25 +1045,19 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp)
 			      scmc_area->response.code);
 		goto out;
 	}
-	if (scmc_area->not_valid) {
-		chp->cmg = -1;
-		chp->shared = -1;
+	if (scmc_area->not_valid)
 		goto out;
-	}
+
 	chp->cmg = scmc_area->cmg;
 	chp->shared = scmc_area->shared;
 	if (chp->cmg != 2 && chp->cmg != 3) {
 		/* No cmg-dependent data. */
 		goto out;
 	}
-	chp->cmg_chars = cmg_chars;
 	chsc_initialize_cmg_chars(chp, scmc_area->cmcv,
 				  (struct cmg_chars *) &scmc_area->data);
 out:
-	spin_unlock_irq(&chsc_page_lock);
-	if (!chp->cmg_chars)
-		kfree(cmg_chars);
-
+	spin_unlock_irqrestore(&chsc_page_lock, flags);
 	return ret;
 }
 
@@ -1130,6 +1138,7 @@ struct css_chsc_char css_chsc_characteristics;
 int __init
 chsc_determine_css_characteristics(void)
 {
+	unsigned long flags;
 	int result;
 	struct {
 		struct chsc_header request;
@@ -1142,7 +1151,7 @@ chsc_determine_css_characteristics(void)
 		u32 chsc_char[508];
 	} __attribute__ ((packed)) *scsc_area;
 
-	spin_lock_irq(&chsc_page_lock);
+	spin_lock_irqsave(&chsc_page_lock, flags);
 	memset(chsc_page, 0, PAGE_SIZE);
 	scsc_area = chsc_page;
 	scsc_area->request.length = 0x0010;
@@ -1164,7 +1173,7 @@ chsc_determine_css_characteristics(void)
 		CIO_CRW_EVENT(2, "chsc: scsc failed (rc=%04x)\n",
 			      scsc_area->response.code);
 exit:
-	spin_unlock_irq(&chsc_page_lock);
+	spin_unlock_irqrestore(&chsc_page_lock, flags);
 	return result;
 }
 
diff --git a/kernel/drivers/s390/cio/cmf.c b/kernel/drivers/s390/cio/cmf.c
index b2afad5a5..2a34eb5f6 100644
--- a/kernel/drivers/s390/cio/cmf.c
+++ b/kernel/drivers/s390/cio/cmf.c
@@ -753,6 +753,17 @@ static void reset_cmb(struct ccw_device *cdev)
 	cmf_generic_reset(cdev);
 }
 
+static int cmf_enabled(struct ccw_device *cdev)
+{
+	int enabled;
+
+	spin_lock_irq(cdev->ccwlock);
+	enabled = !!cdev->private->cmb;
+	spin_unlock_irq(cdev->ccwlock);
+
+	return enabled;
+}
+
 static struct attribute_group cmf_attr_group;
 
 static struct cmb_operations cmbops_basic = {
@@ -1153,13 +1164,8 @@ static ssize_t cmb_enable_show(struct device *dev,
 			       char *buf)
 {
 	struct ccw_device *cdev = to_ccwdev(dev);
-	int enabled;
 
-	spin_lock_irq(cdev->ccwlock);
-	enabled = !!cdev->private->cmb;
-	spin_unlock_irq(cdev->ccwlock);
-
-	return sprintf(buf, "%d\n", enabled);
+	return sprintf(buf, "%d\n", cmf_enabled(cdev));
 }
 
 static ssize_t cmb_enable_store(struct device *dev,
@@ -1199,15 +1205,20 @@ int ccw_set_cmf(struct ccw_device *cdev, int enable)
  *  @cdev:	The ccw device to be enabled
  *
  *  Returns %0 for success or a negative error value.
- *
+ *  Note: If this is called on a device for which channel measurement is already
+ *	  enabled a reset of the measurement data is triggered.
  *  Context:
  *    non-atomic
  */
 int enable_cmf(struct ccw_device *cdev)
 {
-	int ret;
+	int ret = 0;
 
 	device_lock(&cdev->dev);
+	if (cmf_enabled(cdev)) {
+		cmbops->reset(cdev);
+		goto out_unlock;
+	}
 	get_device(&cdev->dev);
 	ret = cmbops->alloc(cdev);
 	if (ret)
@@ -1226,7 +1237,7 @@ int enable_cmf(struct ccw_device *cdev)
 out:
 	if (ret)
 		put_device(&cdev->dev);
-
+out_unlock:
 	device_unlock(&cdev->dev);
 	return ret;
 }