From 6551fbdfd8b85d1ab5822ac98abb4fb449bcfae0 Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky
Date: Thu, 28 Feb 2013 16:28:41 +0100
Subject: s390: critical section cleanup vs. machine checks

The current machine check code uses the registers stored by the machine
in the lowcore at __LC_GPREGS_SAVE_AREA as the registers of the interrupted
context. The registers 0-7 of a user process can get clobbered if a machine
checks interrupts the execution of a critical section in entry[64].S.

The reason is that the critical section cleanup code may need to modify
the PSW and the registers for the previous context to get to the end of a
critical section. If registers 0-7 have to be replaced the relevant copy
will be in the registers, which invalidates the copy in the lowcore. The
machine check handler needs to explicitly store registers 0-7 to the stack.

Cc: stable@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/kernel/entry.S   | 3 ++-
 arch/s390/kernel/entry64.S | 5 +++--
 2 files changed, 5 insertions(+), 3 deletions(-)

(limited to 'arch')

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 550228523267..94feff7d6132 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -636,7 +636,8 @@ ENTRY(mcck_int_handler)
 	UPDATE_VTIME %r14,%r15,__LC_MCCK_ENTER_TIMER
 mcck_skip:
 	SWITCH_ASYNC __LC_GPREGS_SAVE_AREA+32,__LC_PANIC_STACK,PAGE_SHIFT
-	mvc	__PT_R0(64,%r11),__LC_GPREGS_SAVE_AREA
+	stm	%r0,%r7,__PT_R0(%r11)
+	mvc	__PT_R8(32,%r11),__LC_GPREGS_SAVE_AREA+32
 	stm	%r8,%r9,__PT_PSW(%r11)
 	xc	__SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15)
 	l	%r1,BASED(.Ldo_machine_check)
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 9c837c101297..2e6d60c55f90 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -678,8 +678,9 @@ ENTRY(mcck_int_handler)
 	UPDATE_VTIME %r14,__LC_MCCK_ENTER_TIMER
 	LAST_BREAK %r14
 mcck_skip:
-	lghi	%r14,__LC_GPREGS_SAVE_AREA
-	mvc	__PT_R0(128,%r11),0(%r14)
+	lghi	%r14,__LC_GPREGS_SAVE_AREA+64
+	stmg	%r0,%r7,__PT_R0(%r11)
+	mvc	__PT_R8(64,%r11),0(%r14)
 	stmg	%r8,%r9,__PT_PSW(%r11)
 	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
 	lgr	%r2,%r11		# pass pointer to pt_regs
-- 
cgit v1.2.3


From a7bb1ae749e8051434e54936dcefd37ef1cfa753 Mon Sep 17 00:00:00 2001
From: Heiko Carstens
Date: Thu, 28 Feb 2013 11:16:26 +0100
Subject: s390/mm: fix vmemmap size calculation

The size of the vmemmap must be a multiple of PAGES_PER_SECTION, since the
common code always initializes the vmemmap in such pieces.
So we must round up in order to not have a too small vmemmap.

Fixes an IPL crash on 31 bit with more than 1920MB.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/kernel/setup.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'arch')

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index a5360de85ec7..29268859d8ee 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -571,6 +571,8 @@ static void __init setup_memory_end(void)
 
 	/* Split remaining virtual space between 1:1 mapping & vmemmap array */
 	tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
+	/* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
+	tmp = SECTION_ALIGN_UP(tmp);
 	tmp = VMALLOC_START - tmp * sizeof(struct page);
 	tmp &= ~((vmax >> 11) - 1);	/* align to page table level */
 	tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);
-- 
cgit v1.2.3


From f6a70a07079518280022286a1dceb797d12e1edf Mon Sep 17 00:00:00 2001
From: Heiko Carstens
Date: Mon, 4 Mar 2013 14:14:11 +0100
Subject: s390/mm: fix flush_tlb_kernel_range()

Our flush_tlb_kernel_range() implementation calls __tlb_flush_mm() with
&init_mm as argument. __tlb_flush_mm() however will only flush tlbs
for the passed in mm if its mm_cpumask is not empty.

For the init_mm however its mm_cpumask has never any bits set. Which in
turn means that our flush_tlb_kernel_range() implementation doesn't
work at all.

This can be easily verified with a vmalloc/vfree loop which allocates
a page, writes to it and then frees the page again. A crash will follow
almost instantly.

To fix this remove the cpumask_empty() check in __tlb_flush_mm() since
there shouldn't be too many mms with a zero mm_cpumask, besides the
init_mm of course.

Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/include/asm/tlbflush.h | 2 --
 1 file changed, 2 deletions(-)

(limited to 'arch')

diff --git a/arch/s390/include/asm/tlbflush.h b/arch/s390/include/asm/tlbflush.h
index 1d8fe2b17ef6..6b32af30878c 100644
--- a/arch/s390/include/asm/tlbflush.h
+++ b/arch/s390/include/asm/tlbflush.h
@@ -74,8 +74,6 @@ static inline void __tlb_flush_idte(unsigned long asce)
 
 static inline void __tlb_flush_mm(struct mm_struct * mm)
 {
-	if (unlikely(cpumask_empty(mm_cpumask(mm))))
-		return;
 	/*
 	 * If the machine has IDTE we prefer to do a per mm flush
 	 * on all cpus instead of doing a local flush if the mm
-- 
cgit v1.2.3


From 93481c90200c50c7874b6a773acc87095ee3907d Mon Sep 17 00:00:00 2001
From: Sebastian Ott
Date: Thu, 28 Feb 2013 12:07:38 +0100
Subject: s390/scm_drv: extend notify callback

Extend the notify callback of scm_driver by an event parameter
to allow to distinguish between different notifications.

Reviewed-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/include/asm/eadm.h |  4 +++-
 drivers/s390/block/scm_drv.c | 16 ++++++++++------
 drivers/s390/cio/scm.c       |  2 +-
 3 files changed, 14 insertions(+), 8 deletions(-)

(limited to 'arch')

diff --git a/arch/s390/include/asm/eadm.h b/arch/s390/include/asm/eadm.h
index 8d4847191ecc..a4a1ea49003e 100644
--- a/arch/s390/include/asm/eadm.h
+++ b/arch/s390/include/asm/eadm.h
@@ -96,11 +96,13 @@ struct scm_device {
 #define OP_STATE_TEMP_ERR	2
 #define OP_STATE_PERM_ERR	3
 
+enum scm_event {SCM_CHANGE};
+
 struct scm_driver {
 	struct device_driver drv;
 	int (*probe) (struct scm_device *scmdev);
 	int (*remove) (struct scm_device *scmdev);
-	void (*notify) (struct scm_device *scmdev);
+	void (*notify) (struct scm_device *scmdev, enum scm_event event);
 	void (*handler) (struct scm_device *scmdev, void *data, int error);
 };
 
diff --git a/drivers/s390/block/scm_drv.c b/drivers/s390/block/scm_drv.c
index 9fa0a908607b..ff8558c4fe25 100644
--- a/drivers/s390/block/scm_drv.c
+++ b/drivers/s390/block/scm_drv.c
@@ -13,12 +13,16 @@
 #include <asm/eadm.h>
 #include "scm_blk.h"
 
-static void notify(struct scm_device *scmdev)
+static void scm_notify(struct scm_device *scmdev, enum scm_event event)
 {
-	pr_info("%lu: The capabilities of the SCM increment changed\n",
-		(unsigned long) scmdev->address);
-	SCM_LOG(2, "State changed");
-	SCM_LOG_STATE(2, scmdev);
+	switch (event) {
+	case SCM_CHANGE:
+		pr_info("%lu: The capabilities of the SCM increment changed\n",
+			(unsigned long) scmdev->address);
+		SCM_LOG(2, "State changed");
+		SCM_LOG_STATE(2, scmdev);
+		break;
+	}
 }
 
 static int scm_probe(struct scm_device *scmdev)
@@ -64,7 +68,7 @@ static struct scm_driver scm_drv = {
 		.name = "scm_block",
 		.owner = THIS_MODULE,
 	},
-	.notify = notify,
+	.notify = scm_notify,
 	.probe = scm_probe,
 	.remove = scm_remove,
 	.handler = scm_blk_irq,
diff --git a/drivers/s390/cio/scm.c b/drivers/s390/cio/scm.c
index bcf20f3aa51b..31ac26499979 100644
--- a/drivers/s390/cio/scm.c
+++ b/drivers/s390/cio/scm.c
@@ -211,7 +211,7 @@ static void scmdev_update(struct scm_device *scmdev, struct sale *sale)
 		goto out;
 	scmdrv = to_scm_drv(scmdev->dev.driver);
 	if (changed && scmdrv->notify)
-		scmdrv->notify(scmdev);
+		scmdrv->notify(scmdev, SCM_CHANGE);
 out:
 	device_unlock(&scmdev->dev);
 	if (changed)
-- 
cgit v1.2.3


From 4fa3c019640ef776e393345ed35d9ec5c51aa3c1 Mon Sep 17 00:00:00 2001
From: Sebastian Ott
Date: Thu, 28 Feb 2013 12:07:48 +0100
Subject: s390/scm_blk: suspend writes

Stop writing to scm after certain error conditions such as a concurrent
firmware upgrade. Resume to normal state once scm_blk_set_available is
called (due to an scm availability notification).

Reviewed-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/include/asm/eadm.h |  2 ++
 drivers/s390/block/scm_blk.c | 61 ++++++++++++++++++++++++++++++++++++++++----
 drivers/s390/block/scm_blk.h |  2 ++
 3 files changed, 60 insertions(+), 5 deletions(-)

(limited to 'arch')

diff --git a/arch/s390/include/asm/eadm.h b/arch/s390/include/asm/eadm.h
index a4a1ea49003e..78141be88b3d 100644
--- a/arch/s390/include/asm/eadm.h
+++ b/arch/s390/include/asm/eadm.h
@@ -34,6 +34,8 @@ struct arsb {
 	u32 reserved[4];
 } __packed;
 
+#define EQC_WR_PROHIBIT 22
+
 struct msb {
 	u8 fmt:4;
 	u8 oc:4;
diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c
index d9c7e940fa35..5ac9c935c151 100644
--- a/drivers/s390/block/scm_blk.c
+++ b/drivers/s390/block/scm_blk.c
@@ -135,6 +135,11 @@ static const struct block_device_operations scm_blk_devops = {
 	.release = scm_release,
 };
 
+static bool scm_permit_request(struct scm_blk_dev *bdev, struct request *req)
+{
+	return rq_data_dir(req) != WRITE || bdev->state != SCM_WR_PROHIBIT;
+}
+
 static void scm_request_prepare(struct scm_request *scmrq)
 {
 	struct scm_blk_dev *bdev = scmrq->bdev;
@@ -222,6 +227,10 @@ static void scm_blk_request(struct request_queue *rq)
 		if (req->cmd_type != REQ_TYPE_FS)
 			continue;
 
+		if (!scm_permit_request(bdev, req)) {
+			scm_ensure_queue_restart(bdev);
+			return;
+		}
 		scmrq = scm_request_fetch();
 		if (!scmrq) {
 			SCM_LOG(5, "no request");
@@ -285,6 +294,38 @@ void scm_blk_irq(struct scm_device *scmdev, void *data, int error)
 	tasklet_hi_schedule(&bdev->tasklet);
 }
 
+static void scm_blk_handle_error(struct scm_request *scmrq)
+{
+	struct scm_blk_dev *bdev = scmrq->bdev;
+	unsigned long flags;
+
+	if (scmrq->error != -EIO)
+		goto restart;
+
+	/* For -EIO the response block is valid. */
+	switch (scmrq->aob->response.eqc) {
+	case EQC_WR_PROHIBIT:
+		spin_lock_irqsave(&bdev->lock, flags);
+		if (bdev->state != SCM_WR_PROHIBIT)
+			pr_info("%lu: Write access to the SCM increment is suspended\n",
+				(unsigned long) bdev->scmdev->address);
+		bdev->state = SCM_WR_PROHIBIT;
+		spin_unlock_irqrestore(&bdev->lock, flags);
+		goto requeue;
+	default:
+		break;
+	}
+
+restart:
+	if (!scm_start_aob(scmrq->aob))
+		return;
+
+requeue:
+	spin_lock_irqsave(&bdev->rq_lock, flags);
+	scm_request_requeue(scmrq);
+	spin_unlock_irqrestore(&bdev->rq_lock, flags);
+}
+
 static void scm_blk_tasklet(struct scm_blk_dev *bdev)
 {
 	struct scm_request *scmrq;
@@ -298,11 +339,8 @@ static void scm_blk_tasklet(struct scm_blk_dev *bdev)
 		spin_unlock_irqrestore(&bdev->lock, flags);
 
 		if (scmrq->error && scmrq->retries-- > 0) {
-			if (scm_start_aob(scmrq->aob)) {
-				spin_lock_irqsave(&bdev->rq_lock, flags);
-				scm_request_requeue(scmrq);
-				spin_unlock_irqrestore(&bdev->rq_lock, flags);
-			}
+			scm_blk_handle_error(scmrq);
+
 			/* Request restarted or requeued, handle next. */
 			spin_lock_irqsave(&bdev->lock, flags);
 			continue;
@@ -336,6 +374,7 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev)
 	}
 
 	bdev->scmdev = scmdev;
+	bdev->state = SCM_OPER;
 	spin_lock_init(&bdev->rq_lock);
 	spin_lock_init(&bdev->lock);
 	INIT_LIST_HEAD(&bdev->finished_requests);
@@ -400,6 +439,18 @@ void scm_blk_dev_cleanup(struct scm_blk_dev *bdev)
 	put_disk(bdev->gendisk);
 }
 
+void scm_blk_set_available(struct scm_blk_dev *bdev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&bdev->lock, flags);
+	if (bdev->state == SCM_WR_PROHIBIT)
+		pr_info("%lu: Write access to the SCM increment is restored\n",
+			(unsigned long) bdev->scmdev->address);
+	bdev->state = SCM_OPER;
+	spin_unlock_irqrestore(&bdev->lock, flags);
+}
+
 static int __init scm_blk_init(void)
 {
 	int ret = -EINVAL;
diff --git a/drivers/s390/block/scm_blk.h b/drivers/s390/block/scm_blk.h
index 3c1ccf494647..8b387b32fd62 100644
--- a/drivers/s390/block/scm_blk.h
+++ b/drivers/s390/block/scm_blk.h
@@ -21,6 +21,7 @@ struct scm_blk_dev {
 	spinlock_t rq_lock;	/* guard the request queue */
 	spinlock_t lock;	/* guard the rest of the blockdev */
 	atomic_t queued_reqs;
+	enum {SCM_OPER, SCM_WR_PROHIBIT} state;
 	struct list_head finished_requests;
 #ifdef CONFIG_SCM_BLOCK_CLUSTER_WRITE
 	struct list_head cluster_list;
@@ -48,6 +49,7 @@ struct scm_request {
 
 int scm_blk_dev_setup(struct scm_blk_dev *, struct scm_device *);
 void scm_blk_dev_cleanup(struct scm_blk_dev *);
+void scm_blk_set_available(struct scm_blk_dev *);
 void scm_blk_irq(struct scm_device *, void *, int);
 
 void scm_request_finish(struct scm_request *);
-- 
cgit v1.2.3


From aebfa669d9fe77876f120d3d9a28fee240fe5a8e Mon Sep 17 00:00:00 2001
From: Sebastian Ott
Date: Thu, 28 Feb 2013 12:07:55 +0100
Subject: s390/scm: process availability

Let the bus code process scm availability information and
notify scm device drivers about the new state.

Reviewed-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 arch/s390/include/asm/eadm.h |  2 +-
 drivers/s390/block/scm_drv.c |  7 +++++++
 drivers/s390/cio/chsc.c      | 17 +++++++++++++++++
 drivers/s390/cio/chsc.h      |  2 ++
 drivers/s390/cio/scm.c       | 16 ++++++++++++++++
 5 files changed, 43 insertions(+), 1 deletion(-)

(limited to 'arch')

diff --git a/arch/s390/include/asm/eadm.h b/arch/s390/include/asm/eadm.h
index 78141be88b3d..dc9200ca32ed 100644
--- a/arch/s390/include/asm/eadm.h
+++ b/arch/s390/include/asm/eadm.h
@@ -98,7 +98,7 @@ struct scm_device {
 #define OP_STATE_TEMP_ERR	2
 #define OP_STATE_PERM_ERR	3
 
-enum scm_event {SCM_CHANGE};
+enum scm_event {SCM_CHANGE, SCM_AVAIL};
 
 struct scm_driver {
 	struct device_driver drv;
diff --git a/drivers/s390/block/scm_drv.c b/drivers/s390/block/scm_drv.c
index ff8558c4fe25..5f6180d6ff08 100644
--- a/drivers/s390/block/scm_drv.c
+++ b/drivers/s390/block/scm_drv.c
@@ -15,6 +15,8 @@
 
 static void scm_notify(struct scm_device *scmdev, enum scm_event event)
 {
+	struct scm_blk_dev *bdev = dev_get_drvdata(&scmdev->dev);
+
 	switch (event) {
 	case SCM_CHANGE:
 		pr_info("%lu: The capabilities of the SCM increment changed\n",
@@ -22,6 +24,11 @@ static void scm_notify(struct scm_device *scmdev, enum scm_event event)
 		SCM_LOG(2, "State changed");
 		SCM_LOG_STATE(2, scmdev);
 		break;
+	case SCM_AVAIL:
+		SCM_LOG(2, "Increment available");
+		SCM_LOG_STATE(2, scmdev);
+		scm_blk_set_available(bdev);
+		break;
 	}
 }
 
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 31ceef1beb8b..e16c553f6556 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -433,6 +433,20 @@ static void chsc_process_sei_scm_change(struct chsc_sei_nt0_area *sei_area)
 			      " failed (rc=%d).\n", ret);
 }
 
+static void chsc_process_sei_scm_avail(struct chsc_sei_nt0_area *sei_area)
+{
+	int ret;
+
+	CIO_CRW_EVENT(4, "chsc: scm available information\n");
+	if (sei_area->rs != 7)
+		return;
+
+	ret = scm_process_availability_information();
+	if (ret)
+		CIO_CRW_EVENT(0, "chsc: process availability information"
+			      " failed (rc=%d).\n", ret);
+}
+
 static void chsc_process_sei_nt2(struct chsc_sei_nt2_area *sei_area)
 {
 	switch (sei_area->cc) {
@@ -468,6 +482,9 @@ static void chsc_process_sei_nt0(struct chsc_sei_nt0_area *sei_area)
 	case 12: /* scm change notification */
 		chsc_process_sei_scm_change(sei_area);
 		break;
+	case 14: /* scm available notification */
+		chsc_process_sei_scm_avail(sei_area);
+		break;
 	default: /* other stuff */
 		CIO_CRW_EVENT(2, "chsc: sei nt0 unhandled cc=%d\n",
 			      sei_area->cc);
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 227e05f674b3..349d5fc47196 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -156,8 +156,10 @@ int chsc_scm_info(struct chsc_scm_info *scm_area, u64 token);
 
 #ifdef CONFIG_SCM_BUS
 int scm_update_information(void);
+int scm_process_availability_information(void);
 #else /* CONFIG_SCM_BUS */
 static inline int scm_update_information(void) { return 0; }
+static inline int scm_process_availability_information(void) { return 0; }
 #endif /* CONFIG_SCM_BUS */
 
 
diff --git a/drivers/s390/cio/scm.c b/drivers/s390/cio/scm.c
index 31ac26499979..46ec25632e8b 100644
--- a/drivers/s390/cio/scm.c
+++ b/drivers/s390/cio/scm.c
@@ -297,6 +297,22 @@ int scm_update_information(void)
 	return ret;
 }
 
+static int scm_dev_avail(struct device *dev, void *unused)
+{
+	struct scm_driver *scmdrv = to_scm_drv(dev->driver);
+	struct scm_device *scmdev = to_scm_dev(dev);
+
+	if (dev->driver && scmdrv->notify)
+		scmdrv->notify(scmdev, SCM_AVAIL);
+
+	return 0;
+}
+
+int scm_process_availability_information(void)
+{
+	return bus_for_each_dev(&scm_bus_type, NULL, NULL, scm_dev_avail);
+}
+
 static int __init scm_init(void)
 {
 	int ret;
-- 
cgit v1.2.3