[PATCH AUTOSEL 5.10 24/39] s390/cio: add dev_busid sysfs entry for each subchannel

[PATCH AUTOSEL 5.10 24/39] 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 cca1a7c4bb33..305db4173dcf 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 5.10 25/39] s390/zcrypt: fix wrong offset index for APKA master key valid state

[Sasha Levin]

From: Harald Freudenberger <freude@linux.ibm.com>

[ Upstream commit 8617bb74006252cb2286008afe7d6575a6425857 ]

Tests showed a mismatch between what the CCA tool reports about
the APKA master key state and what's displayed by the zcrypt dd
in sysfs. After some investigation, we found out that the
documentation which was the source for the zcrypt dd implementation
lacks the listing of 3 fields. So this patch now moves the
evaluation of the APKA master key state to the correct offset.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/s390/crypto/zcrypt_ccamisc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/crypto/zcrypt_ccamisc.c b/drivers/s390/crypto/zcrypt_ccamisc.c
index b1046811450f..ffab935ddd95 100644
--- a/drivers/s390/crypto/zcrypt_ccamisc.c
+++ b/drivers/s390/crypto/zcrypt_ccamisc.c
@@ -1715,10 +1715,10 @@ static int fetch_cca_info(u16 cardnr, u16 domain, struct cca_info *ci)
 	rlen = vlen = PAGE_SIZE/2;
 	rc = cca_query_crypto_facility(cardnr, domain, "STATICSB",
 				       rarray, &rlen, varray, &vlen);
-	if (rc == 0 && rlen >= 10*8 && vlen >= 240) {
-		ci->new_apka_mk_state = (char) rarray[7*8];
-		ci->cur_apka_mk_state = (char) rarray[8*8];
-		ci->old_apka_mk_state = (char) rarray[9*8];
+	if (rc == 0 && rlen >= 13*8 && vlen >= 240) {
+		ci->new_apka_mk_state = (char) rarray[10*8];
+		ci->cur_apka_mk_state = (char) rarray[11*8];
+		ci->old_apka_mk_state = (char) rarray[12*8];
 		if (ci->old_apka_mk_state == '2')
 			memcpy(&ci->old_apka_mkvp, varray + 208, 8);
 		if (ci->cur_apka_mk_state == '2')
-- 
2.30.2

[PATCH AUTOSEL 5.10 35/39] 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 5646b39c728a..e9a9b7b616bc 100644
--- a/arch/s390/mm/kasan_init.c
+++ b/arch/s390/mm/kasan_init.c
@@ -108,6 +108,9 @@ static void __init kasan_early_vmemmap_populate(unsigned long address,
 		sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
 	}
 
+	/*
+	 * 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)) {
@@ -165,30 +168,26 @@ 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 5.10 36/39] s390/pci: fix misleading rc in clp_set_pci_fn()

[Sasha Levin]

From: Niklas Schnelle <schnelle@linux.ibm.com>

[ Upstream commit f7addcdd527a6dddfebe20c358b87bdb95624612 ]

Currently clp_set_pci_fn() always returns 0 as long as the CLP request
itself succeeds even if the operation itself returns a response code
other than CLP_RC_OK or CLP_RC_SETPCIFN_ALRDY. This is highly misleading
because calling code assumes that a zero rc means that the operation was
successful.

Fix this by returning the response code or cc on failure with the
exception of the special handling for CLP_RC_SETPCIFN_ALRDY. Also let's
not assume that the returned function handle for CLP_RC_SETPCIFN_ALRDY
is 0, we don't need it anyway.

Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/s390/pci/pci.c     |  7 ++++---
 arch/s390/pci/pci_clp.c | 33 ++++++++++++++++-----------------
 2 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index ca1a105e3b5d..0ddb1fe353dc 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -659,9 +659,10 @@ int zpci_enable_device(struct zpci_dev *zdev)
 {
 	int rc;
 
-	rc = clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES);
-	if (rc)
+	if (clp_enable_fh(zdev, ZPCI_NR_DMA_SPACES)) {
+		rc = -EIO;
 		goto out;
+	}
 
 	rc = zpci_dma_init_device(zdev);
 	if (rc)
@@ -684,7 +685,7 @@ int zpci_disable_device(struct zpci_dev *zdev)
 	 * The zPCI function may already be disabled by the platform, this is
 	 * detected in clp_disable_fh() which becomes a no-op.
 	 */
-	return clp_disable_fh(zdev);
+	return clp_disable_fh(zdev) ? -EIO : 0;
 }
 EXPORT_SYMBOL_GPL(zpci_disable_device);
 
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index d3331596ddbe..0a0e8b8293be 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -213,15 +213,19 @@ int clp_query_pci_fn(struct zpci_dev *zdev)
 }
 
 static int clp_refresh_fh(u32 fid);
-/*
- * Enable/Disable a given PCI function and update its function handle if
- * necessary
+/**
+ * clp_set_pci_fn() - Execute a command on a PCI function
+ * @zdev: Function that will be affected
+ * @nr_dma_as: DMA address space number
+ * @command: The command code to execute
+ *
+ * Returns: 0 on success, < 0 for Linux errors (e.g. -ENOMEM), and
+ * > 0 for non-success platform responses
  */
 static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)
 {
 	struct clp_req_rsp_set_pci *rrb;
 	int rc, retries = 100;
-	u32 fid = zdev->fid;
 
 	rrb = clp_alloc_block(GFP_KERNEL);
 	if (!rrb)
@@ -245,17 +249,16 @@ static int clp_set_pci_fn(struct zpci_dev *zdev, u8 nr_dma_as, u8 command)
 		}
 	} while (rrb->response.hdr.rsp == CLP_RC_SETPCIFN_BUSY);
 
-	if (rc || rrb->response.hdr.rsp != CLP_RC_OK) {
-		zpci_err("Set PCI FN:\n");
-		zpci_err_clp(rrb->response.hdr.rsp, rc);
-	}
-
 	if (!rc && rrb->response.hdr.rsp == CLP_RC_OK) {
 		zdev->fh = rrb->response.fh;
-	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY &&
-			rrb->response.fh == 0) {
+	} else if (!rc && rrb->response.hdr.rsp == CLP_RC_SETPCIFN_ALRDY) {
 		/* Function is already in desired state - update handle */
-		rc = clp_refresh_fh(fid);
+		rc = clp_refresh_fh(zdev->fid);
+	} else {
+		zpci_err("Set PCI FN:\n");
+		zpci_err_clp(rrb->response.hdr.rsp, rc);
+		if (!rc)
+			rc = rrb->response.hdr.rsp;
 	}
 	clp_free_block(rrb);
 	return rc;
@@ -301,17 +304,13 @@ int clp_enable_fh(struct zpci_dev *zdev, u8 nr_dma_as)
 
 	rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_PCI_FN);
 	zpci_dbg(3, "ena fid:%x, fh:%x, rc:%d\n", zdev->fid, zdev->fh, rc);
-	if (rc)
-		goto out;
-
-	if (zpci_use_mio(zdev)) {
+	if (!rc && zpci_use_mio(zdev)) {
 		rc = clp_set_pci_fn(zdev, nr_dma_as, CLP_SET_ENABLE_MIO);
 		zpci_dbg(3, "ena mio fid:%x, fh:%x, rc:%d\n",
 				zdev->fid, zdev->fh, rc);
 		if (rc)
 			clp_disable_fh(zdev);
 	}
-out:
 	return rc;
 }
 
-- 
2.30.2

[PATCH AUTOSEL 5.10 37/39] s390/debug: keep debug data on resize

[Sasha Levin]

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

[ Upstream commit 1204777867e8486a88dbb4793fe256b31ea05eeb ]

Any previously recorded s390dbf debug data is reset when a debug area
is resized using the 'pages' sysfs attribute. This can make
live-debugging unnecessarily complex.

Fix this by copying existing debug data to the newly allocated debug
area when resizing.

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 | 74 ++++++++++++++++++++++++++++------------
 1 file changed, 53 insertions(+), 21 deletions(-)

diff --git a/arch/s390/kernel/debug.c b/arch/s390/kernel/debug.c
index b6619ae9a3e0..e392d3e42b1d 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -24,6 +24,7 @@
 #include <linux/export.h>
 #include <linux/init.h>
 #include <linux/fs.h>
+#include <linux/minmax.h>
 #include <linux/debugfs.h>
 
 #include <asm/debug.h>
@@ -92,6 +93,8 @@ static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
 				     char *out_buf, const char *in_buf);
 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
 				   char *out_buf, debug_sprintf_entry_t *curr_event);
+static void debug_areas_swap(debug_info_t *a, debug_info_t *b);
+static void debug_events_append(debug_info_t *dest, debug_info_t *src);
 
 /* globals */
 
@@ -726,35 +729,28 @@ EXPORT_SYMBOL(debug_unregister);
  */
 static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
 {
-	debug_entry_t ***new_areas;
+	debug_info_t *new_id;
 	unsigned long flags;
-	int rc = 0;
 
 	if (!id || (nr_areas <= 0) || (pages_per_area < 0))
 		return -EINVAL;
-	if (pages_per_area > 0) {
-		new_areas = debug_areas_alloc(pages_per_area, nr_areas);
-		if (!new_areas) {
-			pr_info("Allocating memory for %i pages failed\n",
-				pages_per_area);
-			rc = -ENOMEM;
-			goto out;
-		}
-	} else {
-		new_areas = NULL;
+
+	new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
+				  id->level, ALL_AREAS);
+	if (!new_id) {
+		pr_info("Allocating memory for %i pages failed\n",
+			pages_per_area);
+		return -ENOMEM;
 	}
+
 	spin_lock_irqsave(&id->lock, flags);
-	debug_areas_free(id);
-	id->areas = new_areas;
-	id->nr_areas = nr_areas;
-	id->pages_per_area = pages_per_area;
-	id->active_area = 0;
-	memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
-	memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
+	debug_events_append(new_id, id);
+	debug_areas_swap(new_id, id);
+	debug_info_free(new_id);
 	spin_unlock_irqrestore(&id->lock, flags);
 	pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
-out:
-	return rc;
+
+	return 0;
 }
 
 /**
@@ -821,6 +817,42 @@ static inline debug_entry_t *get_active_entry(debug_info_t *id)
 				  id->active_entries[id->active_area]);
 }
 
+/* Swap debug areas of a and b. */
+static void debug_areas_swap(debug_info_t *a, debug_info_t *b)
+{
+	swap(a->nr_areas, b->nr_areas);
+	swap(a->pages_per_area, b->pages_per_area);
+	swap(a->areas, b->areas);
+	swap(a->active_area, b->active_area);
+	swap(a->active_pages, b->active_pages);
+	swap(a->active_entries, b->active_entries);
+}
+
+/* Append all debug events in active area from source to destination log. */
+static void debug_events_append(debug_info_t *dest, debug_info_t *src)
+{
+	debug_entry_t *from, *to, *last;
+
+	if (!src->areas || !dest->areas)
+		return;
+
+	/* Loop over all entries in src, starting with oldest. */
+	from = get_active_entry(src);
+	last = from;
+	do {
+		if (from->clock != 0LL) {
+			to = get_active_entry(dest);
+			memset(to, 0, dest->entry_size);
+			memcpy(to, from, min(src->entry_size,
+					     dest->entry_size));
+			proceed_active_entry(dest);
+		}
+
+		proceed_active_entry(src);
+		from = get_active_entry(src);
+	} while (from != last);
+}
+
 /*
  * debug_finish_entry:
  * - set timestamp, caller address, cpu number etc.
-- 
2.30.2

[PATCH AUTOSEL 5.10 38/39] 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 e392d3e42b1d..89fbfb3b1e01 100644
--- a/arch/s390/kernel/debug.c
+++ b/arch/s390/kernel/debug.c
@@ -314,24 +314,6 @@ 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;
@@ -391,27 +373,10 @@ 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);
-	}
 }
 
 /*
@@ -635,6 +600,31 @@ 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.
  *
@@ -664,19 +654,16 @@ 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);
@@ -705,6 +692,27 @@ 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.
  *
@@ -718,8 +726,10 @@ 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

[PATCH AUTOSEL 5.10 39/39] s390/ap: fix state machine hang after failure to enable irq

[Sasha Levin]

From: Harald Freudenberger <freude@linux.ibm.com>

[ Upstream commit cabebb697c98fb1f05cc950a747a9b6ec61a5b01 ]

If for any reason the interrupt enable for an ap queue fails the
state machine run for the queue returned wrong return codes to the
caller. So the caller assumed interrupt support for this queue in
enabled and thus did not re-establish the high resolution timer used
for polling. In the end this let to a hang for the user space process
waiting "forever" for the reply.

This patch reworks these return codes to return correct indications
for the caller to re-establish the timer when a queue runs without
interrupt support.

Please note that this is fixing a wrong behavior after a first
failure (enable interrupt support for the queue) failed. However,
looks like this occasionally happens on KVM systems.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/s390/crypto/ap_bus.c   | 25 ++++++++-----------------
 drivers/s390/crypto/ap_bus.h   | 10 ++--------
 drivers/s390/crypto/ap_queue.c | 20 +++++++++++---------
 3 files changed, 21 insertions(+), 34 deletions(-)

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index ef738b42a092..c00a288a4eca 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -114,22 +114,13 @@ static struct bus_type ap_bus_type;
 /* Adapter interrupt definitions */
 static void ap_interrupt_handler(struct airq_struct *airq, bool floating);
 
-static int ap_airq_flag;
+static bool ap_irq_flag;
 
 static struct airq_struct ap_airq = {
 	.handler = ap_interrupt_handler,
 	.isc = AP_ISC,
 };
 
-/**
- * ap_using_interrupts() - Returns non-zero if interrupt support is
- * available.
- */
-static inline int ap_using_interrupts(void)
-{
-	return ap_airq_flag;
-}
-
 /**
  * ap_airq_ptr() - Get the address of the adapter interrupt indicator
  *
@@ -139,7 +130,7 @@ static inline int ap_using_interrupts(void)
  */
 void *ap_airq_ptr(void)
 {
-	if (ap_using_interrupts())
+	if (ap_irq_flag)
 		return ap_airq.lsi_ptr;
 	return NULL;
 }
@@ -369,7 +360,7 @@ void ap_wait(enum ap_sm_wait wait)
 	switch (wait) {
 	case AP_SM_WAIT_AGAIN:
 	case AP_SM_WAIT_INTERRUPT:
-		if (ap_using_interrupts())
+		if (ap_irq_flag)
 			break;
 		if (ap_poll_kthread) {
 			wake_up(&ap_poll_wait);
@@ -444,7 +435,7 @@ static void ap_tasklet_fn(unsigned long dummy)
 	 * be received. Doing it in the beginning of the tasklet is therefor
 	 * important that no requests on any AP get lost.
 	 */
-	if (ap_using_interrupts())
+	if (ap_irq_flag)
 		xchg(ap_airq.lsi_ptr, 0);
 
 	spin_lock_bh(&ap_queues_lock);
@@ -514,7 +505,7 @@ static int ap_poll_thread_start(void)
 {
 	int rc;
 
-	if (ap_using_interrupts() || ap_poll_kthread)
+	if (ap_irq_flag || ap_poll_kthread)
 		return 0;
 	mutex_lock(&ap_poll_thread_mutex);
 	ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
@@ -1014,7 +1005,7 @@ static BUS_ATTR_RO(ap_adapter_mask);
 static ssize_t ap_interrupts_show(struct bus_type *bus, char *buf)
 {
 	return scnprintf(buf, PAGE_SIZE, "%d\n",
-			 ap_using_interrupts() ? 1 : 0);
+			 ap_irq_flag ? 1 : 0);
 }
 
 static BUS_ATTR_RO(ap_interrupts);
@@ -1687,7 +1678,7 @@ static int __init ap_module_init(void)
 	/* enable interrupts if available */
 	if (ap_interrupts_available()) {
 		rc = register_adapter_interrupt(&ap_airq);
-		ap_airq_flag = (rc == 0);
+		ap_irq_flag = (rc == 0);
 	}
 
 	/* Create /sys/bus/ap. */
@@ -1737,7 +1728,7 @@ static int __init ap_module_init(void)
 		bus_remove_file(&ap_bus_type, ap_bus_attrs[i]);
 	bus_unregister(&ap_bus_type);
 out:
-	if (ap_using_interrupts())
+	if (ap_irq_flag)
 		unregister_adapter_interrupt(&ap_airq);
 	kfree(ap_qci_info);
 	return rc;
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 5029b80132aa..ccdbd95cab70 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -77,12 +77,6 @@ static inline int ap_test_bit(unsigned int *ptr, unsigned int nr)
 #define AP_FUNC_EP11  5
 #define AP_FUNC_APXA  6
 
-/*
- * AP interrupt states
- */
-#define AP_INTR_DISABLED	0	/* AP interrupt disabled */
-#define AP_INTR_ENABLED		1	/* AP interrupt enabled */
-
 /*
  * AP queue state machine states
  */
@@ -109,7 +103,7 @@ enum ap_sm_event {
  * AP queue state wait behaviour
  */
 enum ap_sm_wait {
-	AP_SM_WAIT_AGAIN,	/* retry immediately */
+	AP_SM_WAIT_AGAIN = 0,	/* retry immediately */
 	AP_SM_WAIT_TIMEOUT,	/* wait for timeout */
 	AP_SM_WAIT_INTERRUPT,	/* wait for thin interrupt (if available) */
 	AP_SM_WAIT_NONE,	/* no wait */
@@ -182,7 +176,7 @@ struct ap_queue {
 	enum ap_dev_state dev_state;	/* queue device state */
 	bool config;			/* configured state */
 	ap_qid_t qid;			/* AP queue id. */
-	int interrupt;			/* indicate if interrupts are enabled */
+	bool interrupt;			/* indicate if interrupts are enabled */
 	int queue_count;		/* # messages currently on AP queue. */
 	int pendingq_count;		/* # requests on pendingq list. */
 	int requestq_count;		/* # requests on requestq list. */
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 337353c9655e..639f8d25679c 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -19,7 +19,7 @@
 static void __ap_flush_queue(struct ap_queue *aq);
 
 /**
- * ap_queue_enable_interruption(): Enable interruption on an AP queue.
+ * ap_queue_enable_irq(): Enable interrupt support on this AP queue.
  * @qid: The AP queue number
  * @ind: the notification indicator byte
  *
@@ -27,7 +27,7 @@ static void __ap_flush_queue(struct ap_queue *aq);
  * value it waits a while and tests the AP queue if interrupts
  * have been switched on using ap_test_queue().
  */
-static int ap_queue_enable_interruption(struct ap_queue *aq, void *ind)
+static int ap_queue_enable_irq(struct ap_queue *aq, void *ind)
 {
 	struct ap_queue_status status;
 	struct ap_qirq_ctrl qirqctrl = { 0 };
@@ -198,7 +198,8 @@ static enum ap_sm_wait ap_sm_read(struct ap_queue *aq)
 		return AP_SM_WAIT_NONE;
 	case AP_RESPONSE_NO_PENDING_REPLY:
 		if (aq->queue_count > 0)
-			return AP_SM_WAIT_INTERRUPT;
+			return aq->interrupt ?
+				AP_SM_WAIT_INTERRUPT : AP_SM_WAIT_TIMEOUT;
 		aq->sm_state = AP_SM_STATE_IDLE;
 		return AP_SM_WAIT_NONE;
 	default:
@@ -252,7 +253,8 @@ static enum ap_sm_wait ap_sm_write(struct ap_queue *aq)
 		fallthrough;
 	case AP_RESPONSE_Q_FULL:
 		aq->sm_state = AP_SM_STATE_QUEUE_FULL;
-		return AP_SM_WAIT_INTERRUPT;
+		return aq->interrupt ?
+			AP_SM_WAIT_INTERRUPT : AP_SM_WAIT_TIMEOUT;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		aq->sm_state = AP_SM_STATE_RESET_WAIT;
 		return AP_SM_WAIT_TIMEOUT;
@@ -302,7 +304,7 @@ static enum ap_sm_wait ap_sm_reset(struct ap_queue *aq)
 	case AP_RESPONSE_NORMAL:
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		aq->sm_state = AP_SM_STATE_RESET_WAIT;
-		aq->interrupt = AP_INTR_DISABLED;
+		aq->interrupt = false;
 		return AP_SM_WAIT_TIMEOUT;
 	default:
 		aq->dev_state = AP_DEV_STATE_ERROR;
@@ -335,7 +337,7 @@ static enum ap_sm_wait ap_sm_reset_wait(struct ap_queue *aq)
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		lsi_ptr = ap_airq_ptr();
-		if (lsi_ptr && ap_queue_enable_interruption(aq, lsi_ptr) == 0)
+		if (lsi_ptr && ap_queue_enable_irq(aq, lsi_ptr) == 0)
 			aq->sm_state = AP_SM_STATE_SETIRQ_WAIT;
 		else
 			aq->sm_state = (aq->queue_count > 0) ?
@@ -376,7 +378,7 @@ static enum ap_sm_wait ap_sm_setirq_wait(struct ap_queue *aq)
 
 	if (status.irq_enabled == 1) {
 		/* Irqs are now enabled */
-		aq->interrupt = AP_INTR_ENABLED;
+		aq->interrupt = true;
 		aq->sm_state = (aq->queue_count > 0) ?
 			AP_SM_STATE_WORKING : AP_SM_STATE_IDLE;
 	}
@@ -566,7 +568,7 @@ static ssize_t interrupt_show(struct device *dev,
 	spin_lock_bh(&aq->lock);
 	if (aq->sm_state == AP_SM_STATE_SETIRQ_WAIT)
 		rc = scnprintf(buf, PAGE_SIZE, "Enable Interrupt pending.\n");
-	else if (aq->interrupt == AP_INTR_ENABLED)
+	else if (aq->interrupt)
 		rc = scnprintf(buf, PAGE_SIZE, "Interrupts enabled.\n");
 	else
 		rc = scnprintf(buf, PAGE_SIZE, "Interrupts disabled.\n");
@@ -747,7 +749,7 @@ struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type)
 	aq->ap_dev.device.type = &ap_queue_type;
 	aq->ap_dev.device_type = device_type;
 	aq->qid = qid;
-	aq->interrupt = AP_INTR_DISABLED;
+	aq->interrupt = false;
 	spin_lock_init(&aq->lock);
 	INIT_LIST_HEAD(&aq->pendingq);
 	INIT_LIST_HEAD(&aq->requestq);
-- 
2.30.2