[PATCH AUTOSEL 5.4 20/30] s390/cio: add dev_busid sysfs entry for each subchannel

[PATCH AUTOSEL 5.4 20/30] s390/cio: add dev_busid sysfs entry for each subchannel

[Sasha Levin]

From: Vineeth Vijayan <vneethv@linux.ibm.com>

[ Upstream commit d3683c055212bf910d4e318f7944910ce10dbee6 ]

Introduce dev_busid, which exports the device-id associated with the
io-subchannel (and message-subchannel). The dev_busid indicates that of
the device which may be physically installed on the corrosponding
subchannel. The dev_busid value "none" indicates that the subchannel
is not valid, there is no I/O device currently associated with the
subchannel.

The dev_busid information would be helpful to write device-specific
udev-rules associated with the subchannel. The dev_busid interface would
be available even when the sch is not bound to any driver or if there is
no operational device connected on it. Hence this attribute can be used to
write udev-rules which are specific to the device associated with the
subchannel.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/s390/cio/css.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 5734a78dbb8e..7950ac59b174 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -426,9 +426,26 @@ static ssize_t pimpampom_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(pimpampom);
 
+static ssize_t dev_busid_show(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	struct subchannel *sch = to_subchannel(dev);
+	struct pmcw *pmcw = &sch->schib.pmcw;
+
+	if ((pmcw->st == SUBCHANNEL_TYPE_IO ||
+	     pmcw->st == SUBCHANNEL_TYPE_MSG) && pmcw->dnv)
+		return sysfs_emit(buf, "0.%x.%04x\n", sch->schid.ssid,
+				  pmcw->dev);
+	else
+		return sysfs_emit(buf, "none\n");
+}
+static DEVICE_ATTR_RO(dev_busid);
+
 static struct attribute *io_subchannel_type_attrs[] = {
 	&dev_attr_chpids.attr,
 	&dev_attr_pimpampom.attr,
+	&dev_attr_dev_busid.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(io_subchannel_type);
-- 
2.30.2

[PATCH AUTOSEL 5.4 29/30] s390/kasan: fix large PMD pages address alignment check

[Sasha Levin]

From: Alexander Gordeev <agordeev@linux.ibm.com>

[ Upstream commit ddd63c85ef67ea9ea7282ad35eafb6568047126e ]

It is currently possible to initialize a large PMD page when
the address is not aligned on page boundary.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/s390/mm/kasan_init.c | 41 +++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 21 deletions(-)

diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
index 460f25572940..5182e0836ca7 100644
--- a/arch/s390/mm/kasan_init.c
+++ b/arch/s390/mm/kasan_init.c
@@ -101,6 +101,9 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
 	pgt_prot = pgprot_val(PAGE_KERNEL_EXEC);
 	sgt_prot = pgprot_val(SEGMENT_KERNEL_EXEC);
 
+	/*
+	 * The first 1MB of 1:1 mapping is mapped with 4KB pages
+	 */
 	while (address < end) {
 		pg_dir = pgd_offset_k(address);
 		if (pgd_none(*pg_dir)) {
@@ -146,30 +149,26 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
 
 		pm_dir = pmd_offset(pu_dir, address);
 		if (pmd_none(*pm_dir)) {
-			if (mode == POPULATE_ZERO_SHADOW &&
-			    IS_ALIGNED(address, PMD_SIZE) &&
+			if (IS_ALIGNED(address, PMD_SIZE) &&
 			    end - address >= PMD_SIZE) {
-				pmd_populate(&init_mm, pm_dir,
-						kasan_early_shadow_pte);
-				address = (address + PMD_SIZE) & PMD_MASK;
-				continue;
-			}
-			/* the first megabyte of 1:1 is mapped with 4k pages */
-			if (has_edat && address && end - address >= PMD_SIZE &&
-			    mode != POPULATE_ZERO_SHADOW) {
-				void *page;
-
-				if (mode == POPULATE_ONE2ONE) {
-					page = (void *)address;
-				} else {
-					page = kasan_early_alloc_segment();
-					memset(page, 0, _SEGMENT_SIZE);
+				if (mode == POPULATE_ZERO_SHADOW) {
+					pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte);
+					address = (address + PMD_SIZE) & PMD_MASK;
+					continue;
+				} else if (has_edat && address) {
+					void *page;
+
+					if (mode == POPULATE_ONE2ONE) {
+						page = (void *)address;
+					} else {
+						page = kasan_early_alloc_segment();
+						memset(page, 0, _SEGMENT_SIZE);
+					}
+					pmd_val(*pm_dir) = __pa(page) | sgt_prot;
+					address = (address + PMD_SIZE) & PMD_MASK;
+					continue;
 				}
-				pmd_val(*pm_dir) = __pa(page) | sgt_prot;
-				address = (address + PMD_SIZE) & PMD_MASK;
-				continue;
 			}
-
 			pt_dir = kasan_early_pte_alloc();
 			pmd_populate(&init_mm, pm_dir, pt_dir);
 		} else if (pmd_large(*pm_dir)) {
-- 
2.30.2

[PATCH AUTOSEL 5.4 30/30] s390/debug: fix debug area life cycle

[Sasha Levin]

From: Peter Oberparleiter <oberpar@linux.ibm.com>

[ Upstream commit 9372a82892c2caa6bccab9a4081166fa769699f8 ]

Currently allocation and registration of s390dbf debug areas are tied
together. As a result, a debug area cannot be unregistered and
re-registered while any process has an associated debugfs file open.

Fix this by splitting alloc/release from register/unregister.

Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/s390/kernel/debug.c | 102 +++++++++++++++++++++------------------
 1 file changed, 56 insertions(+), 46 deletions(-)

diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index 7184d55d87aa..b1aadc3ad065 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -327,24 +327,6 @@ static debug_info_t *debug_info_create(const char *name, int pages_per_area,
 		goto out;
 
 	rc->mode = mode & ~S_IFMT;
-
-	/* create root directory */
-	rc->debugfs_root_entry = debugfs_create_dir(rc->name,
-						    debug_debugfs_root_entry);
-
-	/* append new element to linked list */
-	if (!debug_area_first) {
-		/* first element in list */
-		debug_area_first = rc;
-		rc->prev = NULL;
-	} else {
-		/* append element to end of list */
-		debug_area_last->next = rc;
-		rc->prev = debug_area_last;
-	}
-	debug_area_last = rc;
-	rc->next = NULL;
-
 	refcount_set(&rc->ref_count, 1);
 out:
 	return rc;
@@ -404,27 +386,10 @@ static void debug_info_get(debug_info_t *db_info)
  */
 static void debug_info_put(debug_info_t *db_info)
 {
-	int i;
-
 	if (!db_info)
 		return;
-	if (refcount_dec_and_test(&db_info->ref_count)) {
-		for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
-			if (!db_info->views[i])
-				continue;
-			debugfs_remove(db_info->debugfs_entries[i]);
-		}
-		debugfs_remove(db_info->debugfs_root_entry);
-		if (db_info == debug_area_first)
-			debug_area_first = db_info->next;
-		if (db_info == debug_area_last)
-			debug_area_last = db_info->prev;
-		if (db_info->prev)
-			db_info->prev->next = db_info->next;
-		if (db_info->next)
-			db_info->next->prev = db_info->prev;
+	if (refcount_dec_and_test(&db_info->ref_count))
 		debug_info_free(db_info);
-	}
 }
 
 /*
@@ -648,6 +613,31 @@ static int debug_close(struct inode *inode, struct file *file)
 	return 0; /* success */
 }
 
+/* Create debugfs entries and add to internal list. */
+static void _debug_register(debug_info_t *id)
+{
+	/* create root directory */
+	id->debugfs_root_entry = debugfs_create_dir(id->name,
+						    debug_debugfs_root_entry);
+
+	/* append new element to linked list */
+	if (!debug_area_first) {
+		/* first element in list */
+		debug_area_first = id;
+		id->prev = NULL;
+	} else {
+		/* append element to end of list */
+		debug_area_last->next = id;
+		id->prev = debug_area_last;
+	}
+	debug_area_last = id;
+	id->next = NULL;
+
+	debug_register_view(id, &debug_level_view);
+	debug_register_view(id, &debug_flush_view);
+	debug_register_view(id, &debug_pages_view);
+}
+
 /**
  * debug_register_mode() - creates and initializes debug area.
  *
@@ -677,19 +667,16 @@ debug_info_t *debug_register_mode(const char *name, int pages_per_area,
 	if ((uid != 0) || (gid != 0))
 		pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
 	BUG_ON(!initialized);
-	mutex_lock(&debug_mutex);
 
 	/* create new debug_info */
 	rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
-	if (!rc)
-		goto out;
-	debug_register_view(rc, &debug_level_view);
-	debug_register_view(rc, &debug_flush_view);
-	debug_register_view(rc, &debug_pages_view);
-out:
-	if (!rc)
+	if (rc) {
+		mutex_lock(&debug_mutex);
+		_debug_register(rc);
+		mutex_unlock(&debug_mutex);
+	} else {
 		pr_err("Registering debug feature %s failed\n", name);
-	mutex_unlock(&debug_mutex);
+	}
 	return rc;
 }
 EXPORT_SYMBOL(debug_register_mode);
@@ -718,6 +705,27 @@ debug_info_t *debug_register(const char *name, int pages_per_area,
 }
 EXPORT_SYMBOL(debug_register);
 
+/* Remove debugfs entries and remove from internal list. */
+static void _debug_unregister(debug_info_t *id)
+{
+	int i;
+
+	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
+		if (!id->views[i])
+			continue;
+		debugfs_remove(id->debugfs_entries[i]);
+	}
+	debugfs_remove(id->debugfs_root_entry);
+	if (id == debug_area_first)
+		debug_area_first = id->next;
+	if (id == debug_area_last)
+		debug_area_last = id->prev;
+	if (id->prev)
+		id->prev->next = id->next;
+	if (id->next)
+		id->next->prev = id->prev;
+}
+
 /**
  * debug_unregister() - give back debug area.
  *
@@ -731,8 +739,10 @@ void debug_unregister(debug_info_t *id)
 	if (!id)
 		return;
 	mutex_lock(&debug_mutex);
-	debug_info_put(id);
+	_debug_unregister(id);
 	mutex_unlock(&debug_mutex);
+
+	debug_info_put(id);
 }
 EXPORT_SYMBOL(debug_unregister);
 
-- 
2.30.2