[patch 00/11] s390 bug fixes for 2.6.26-rc4

[patch 00/11] s390 bug fixes for 2.6.26-rc4

[Martin Schwidefsky]

Greetings,
another batch of s390 patches for 2.6.26, all of them bug fixes.

The shortlog:

Christian Borntraeger (1):
      [S390] s390 types: make dma_addr_t 64 bit capable

Gerald Schaefer (1):
      [S390] appldata: prevent cpu hotplug when walking cpu_online_map.

Hans-Joachim Picht (1):
      [S390] fix sparsemem related compile error with allnoconfig on s390

Heiko Carstens (3):
      [S390] Fix section mismatch warnings.
      [S390] showmem: Only walk spanned pages.
      [S390] sclp_vt220: fix scheduling while atomic bug.

Martin Schwidefsky (3):
      [S390] 3270: fix race with stack local wait_queue_head_t.
      [S390] tape: fix race with stack local wait_queue_head_t.
      [S390] disassembler: fix idte instruction format.

Michael Holzheu (1):
      [S390] tape: Fix race condition in tape block device driver

Stefan Haberland (1):
      [S390] dasd: use a generic wait_queue for sleep_on

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 01/11] fix sparsemem related compile error with allnoconfig on s390

[Martin Schwidefsky]

[-- Attachment #1: 001-allnoconfig.diff --]
[-- Type: text/plain, Size: 1048 bytes --]

From: Hans-Joachim Picht <hans@linux.vnet.ibm.com>

On s390 make allnoconfig fails with the following build error:

arch/s390/mm/init.c: In function 'show_mem':
arch/s390/mm/init.c:55: error: implicit declaration of function 'pfn_valid'
make[1]: *** [arch/s390/mm/init.o] Error 1
make: *** [arch/s390/mm] Error 2

This problem can by fixed ensuring that ARCH_SELECT_MEMORY_MODEL
is always turned on.

Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/Kconfig |    3 +++
 1 file changed, 3 insertions(+)

Index: quilt-2.6/arch/s390/Kconfig
===================================================================
--- quilt-2.6.orig/arch/s390/Kconfig
+++ quilt-2.6/arch/s390/Kconfig
@@ -308,6 +308,9 @@ config ARCH_SPARSEMEM_ENABLE
 config ARCH_SPARSEMEM_DEFAULT
 	def_bool y
 
+config ARCH_SELECT_MEMORY_MODEL
+       def_bool y
+
 source "mm/Kconfig"
 
 comment "I/O subsystem configuration"

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 02/11] tape: Fix race condition in tape block device driver

[Martin Schwidefsky]

[-- Attachment #1: 002-tape-block.diff --]
[-- Type: text/plain, Size: 1581 bytes --]

From: Michael Holzheu <holzheu@de.ibm.com>

Due to incorrect function call sequence it can happen that a tape block
request is finished before the request is taken from the block request queue.

The following sequence leads to that condition:
 * tapeblock_start_request() -> start CCW program
 * Request finishes -> IO interrupt
 * tapeblock_end_request()
 * end_that_request_last()

If blkdev_dequeue_request() has not been called before end_that_request_last(),
a kernel bug is triggered in end_that_request_last() because the request is
still queued. To solve that problem blkdev_dequeue_request() has to be called
before starting the CCW program.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
---

 drivers/s390/char/tape_block.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: quilt-2.6/drivers/s390/char/tape_block.c
===================================================================
--- quilt-2.6.orig/drivers/s390/char/tape_block.c
+++ quilt-2.6/drivers/s390/char/tape_block.c
@@ -179,11 +179,11 @@ tapeblock_requeue(struct work_struct *wo
 			tapeblock_end_request(req, -EIO);
 			continue;
 		}
+		blkdev_dequeue_request(req);
+		nr_queued++;
 		spin_unlock_irq(&device->blk_data.request_queue_lock);
 		rc = tapeblock_start_request(device, req);
 		spin_lock_irq(&device->blk_data.request_queue_lock);
-		blkdev_dequeue_request(req);
-		nr_queued++;
 	}
 	spin_unlock_irq(&device->blk_data.request_queue_lock);
 	atomic_set(&device->blk_data.requeue_scheduled, 0);

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 03/11] s390 types: make dma_addr_t 64 bit capable

[Martin Schwidefsky]

[-- Attachment #1: 003-dma-64bit.diff --]
[-- Type: text/plain, Size: 1028 bytes --]

From: Christian Borntraeger <borntraeger@de.ibm.com>

virtio tests with guests larger than 4 GB revealed that the dma_addr_t
definition for s390 did not make it into the 64bit world.
This patch changes the definition on s390 to have an u64 on 64bit and
u32 on 32bit systems.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 include/asm-s390/types.h |    6 ++++++
 1 file changed, 6 insertions(+)

Index: quilt-2.6/include/asm-s390/types.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/types.h
+++ quilt-2.6/include/asm-s390/types.h
@@ -40,7 +40,13 @@ typedef __signed__ long saddr_t;
 
 #ifndef __ASSEMBLY__
 
+typedef u64 dma64_addr_t;
+#ifdef __s390x__
+/* DMA addresses come in 32-bit and 64-bit flavours. */
+typedef u64 dma_addr_t;
+#else
 typedef u32 dma_addr_t;
+#endif
 
 #ifndef __s390x__
 typedef union {

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 04/11] Fix section mismatch warnings.

[Martin Schwidefsky]

[-- Attachment #1: 004-section.diff --]
[-- Type: text/plain, Size: 3408 bytes --]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

This fixes the last remaining section mismatch warnings in s390
architecture code. It reveals also a real bug introduced by... me
with git commit 2069e978d5a6e7b45d58027e3de7f879b8c5e488
("[S390] sparsemem vmemmap: initialize memmap.")

Calling the generic vmemmap_alloc_block() function to get initialized
memory is a nice idea, however that function is __meminit annotated
and therefore the function might be gone if we try to call it later.
This can happen if a DCSS segment gets added.

So basically revert the patch and clear the memmap explicitly to fix
the original bug.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/kernel/smp.c          |    2 +-
 arch/s390/mm/vmem.c             |   18 +++++++++++++-----
 drivers/s390/char/sclp_config.c |    2 +-
 3 files changed, 15 insertions(+), 7 deletions(-)

Index: quilt-2.6/arch/s390/kernel/smp.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/smp.c
+++ quilt-2.6/arch/s390/kernel/smp.c
@@ -1089,7 +1089,7 @@ out:
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-int smp_rescan_cpus(void)
+int __ref smp_rescan_cpus(void)
 {
 	cpumask_t newcpus;
 	int cpu;
Index: quilt-2.6/arch/s390/mm/vmem.c
===================================================================
--- quilt-2.6.orig/arch/s390/mm/vmem.c
+++ quilt-2.6/arch/s390/mm/vmem.c
@@ -27,12 +27,19 @@ struct memory_segment {
 
 static LIST_HEAD(mem_segs);
 
-static pud_t *vmem_pud_alloc(void)
+static void __ref *vmem_alloc_pages(unsigned int order)
+{
+	if (slab_is_available())
+		return (void *)__get_free_pages(GFP_KERNEL, order);
+	return alloc_bootmem_pages((1 << order) * PAGE_SIZE);
+}
+
+static inline pud_t *vmem_pud_alloc(void)
 {
 	pud_t *pud = NULL;
 
 #ifdef CONFIG_64BIT
-	pud = vmemmap_alloc_block(PAGE_SIZE * 4, 0);
+	pud = vmem_alloc_pages(2);
 	if (!pud)
 		return NULL;
 	clear_table((unsigned long *) pud, _REGION3_ENTRY_EMPTY, PAGE_SIZE * 4);
@@ -40,12 +47,12 @@ static pud_t *vmem_pud_alloc(void)
 	return pud;
 }
 
-static pmd_t *vmem_pmd_alloc(void)
+static inline pmd_t *vmem_pmd_alloc(void)
 {
 	pmd_t *pmd = NULL;
 
 #ifdef CONFIG_64BIT
-	pmd = vmemmap_alloc_block(PAGE_SIZE * 4, 0);
+	pmd = vmem_alloc_pages(2);
 	if (!pmd)
 		return NULL;
 	clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE * 4);
@@ -207,13 +214,14 @@ int __meminit vmemmap_populate(struct pa
 		if (pte_none(*pt_dir)) {
 			unsigned long new_page;
 
-			new_page =__pa(vmemmap_alloc_block(PAGE_SIZE, 0));
+			new_page =__pa(vmem_alloc_pages(0));
 			if (!new_page)
 				goto out;
 			pte = pfn_pte(new_page >> PAGE_SHIFT, PAGE_KERNEL);
 			*pt_dir = pte;
 		}
 	}
+	memset(start, 0, nr * sizeof(struct page));
 	ret = 0;
 out:
 	flush_tlb_kernel_range(start_addr, end_addr);
Index: quilt-2.6/drivers/s390/char/sclp_config.c
===================================================================
--- quilt-2.6.orig/drivers/s390/char/sclp_config.c
+++ quilt-2.6/drivers/s390/char/sclp_config.c
@@ -40,7 +40,7 @@ static void sclp_cpu_capability_notify(s
 	put_online_cpus();
 }
 
-static void sclp_cpu_change_notify(struct work_struct *work)
+static void __ref sclp_cpu_change_notify(struct work_struct *work)
 {
 	smp_rescan_cpus();
 }

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 05/11] appldata: prevent cpu hotplug when walking cpu_online_map.

[Martin Schwidefsky]

[-- Attachment #1: 005-appldate-getcpu.diff --]
[-- Type: text/plain, Size: 2135 bytes --]

From: Gerald Schaefer <gerald.schaefer@de.ibm.com>

Use get_online_cpus() to prevent cpu hotplug in situations where
for_each_online_cpu() is called.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/appldata/appldata_base.c |    8 ++++++++
 1 file changed, 8 insertions(+)

Index: quilt-2.6/arch/s390/appldata/appldata_base.c
===================================================================
--- quilt-2.6.orig/arch/s390/appldata/appldata_base.c
+++ quilt-2.6/arch/s390/appldata/appldata_base.c
@@ -130,6 +130,7 @@ static void appldata_work_fn(struct work
 
 	P_DEBUG("  -= Work Queue =-\n");
 	i = 0;
+	get_online_cpus();
 	spin_lock(&appldata_ops_lock);
 	list_for_each(lh, &appldata_ops_list) {
 		ops = list_entry(lh, struct appldata_ops, list);
@@ -140,6 +141,7 @@ static void appldata_work_fn(struct work
 		}
 	}
 	spin_unlock(&appldata_ops_lock);
+	put_online_cpus();
 }
 
 /*
@@ -266,12 +268,14 @@ appldata_timer_handler(ctl_table *ctl, i
 	len = *lenp;
 	if (copy_from_user(buf, buffer, len > sizeof(buf) ? sizeof(buf) : len))
 		return -EFAULT;
+	get_online_cpus();
 	spin_lock(&appldata_timer_lock);
 	if (buf[0] == '1')
 		__appldata_vtimer_setup(APPLDATA_ADD_TIMER);
 	else if (buf[0] == '0')
 		__appldata_vtimer_setup(APPLDATA_DEL_TIMER);
 	spin_unlock(&appldata_timer_lock);
+	put_online_cpus();
 out:
 	*lenp = len;
 	*ppos += len;
@@ -314,10 +318,12 @@ appldata_interval_handler(ctl_table *ctl
 		return -EINVAL;
 	}
 
+	get_online_cpus();
 	spin_lock(&appldata_timer_lock);
 	appldata_interval = interval;
 	__appldata_vtimer_setup(APPLDATA_MOD_TIMER);
 	spin_unlock(&appldata_timer_lock);
+	put_online_cpus();
 
 	P_INFO("Monitoring CPU interval set to %u milliseconds.\n",
 		 interval);
@@ -556,8 +562,10 @@ static int __init appldata_init(void)
 		return -ENOMEM;
 	}
 
+	get_online_cpus();
 	for_each_online_cpu(i)
 		appldata_online_cpu(i);
+	put_online_cpus();
 
 	/* Register cpu hotplug notifier */
 	register_hotcpu_notifier(&appldata_nb);

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 06/11] showmem: Only walk spanned pages.

[Martin Schwidefsky]

[-- Attachment #1: 006-showmem.diff --]
[-- Type: text/plain, Size: 2398 bytes --]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

Convert show_mem() so its nearly the same as on x86/powerpc.
Gives us proper locking and we get also rid of the only use of max_mapnr.
Also the number of pages was contained in an int which might not be
sufficient not too far in the future.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/mm/init.c |   42 +++++++++++++++++++++++-------------------
 1 file changed, 23 insertions(+), 19 deletions(-)

Index: quilt-2.6/arch/s390/mm/init.c
===================================================================
--- quilt-2.6.orig/arch/s390/mm/init.c
+++ quilt-2.6/arch/s390/mm/init.c
@@ -44,30 +44,34 @@ char  empty_zero_page[PAGE_SIZE] __attri
 
 void show_mem(void)
 {
-	int i, total = 0, reserved = 0;
-	int shared = 0, cached = 0;
+	unsigned long i, total = 0, reserved = 0;
+	unsigned long shared = 0, cached = 0;
+	unsigned long flags;
 	struct page *page;
+	pg_data_t *pgdat;
 
 	printk("Mem-info:\n");
 	show_free_areas();
-	i = max_mapnr;
-	while (i-- > 0) {
-		if (!pfn_valid(i))
-			continue;
-		page = pfn_to_page(i);
-		total++;
-		if (PageReserved(page))
-			reserved++;
-		else if (PageSwapCache(page))
-			cached++;
-		else if (page_count(page))
-			shared += page_count(page) - 1;
+	for_each_online_pgdat(pgdat) {
+		pgdat_resize_lock(pgdat, &flags);
+		for (i = 0; i < pgdat->node_spanned_pages; i++) {
+			if (!pfn_valid(pgdat->node_start_pfn + i))
+				continue;
+			page = pfn_to_page(pgdat->node_start_pfn + i);
+			total++;
+			if (PageReserved(page))
+				reserved++;
+			else if (PageSwapCache(page))
+				cached++;
+			else if (page_count(page))
+				shared += page_count(page) - 1;
+		}
+		pgdat_resize_unlock(pgdat, &flags);
 	}
-	printk("%d pages of RAM\n", total);
-	printk("%d reserved pages\n", reserved);
-	printk("%d pages shared\n", shared);
-	printk("%d pages swap cached\n", cached);
-
+	printk("%ld pages of RAM\n", total);
+	printk("%ld reserved pages\n", reserved);
+	printk("%ld pages shared\n", shared);
+	printk("%ld pages swap cached\n", cached);
 	printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
 	printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
 	printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

Re: [patch 06/11] showmem: Only walk spanned pages.

[Johannes Weiner]

Hi,

Martin Schwidefsky <schwidefsky@de.ibm.com> writes:

> From: Heiko Carstens <heiko.carstens@de.ibm.com>
>
> Convert show_mem() so its nearly the same as on x86/powerpc.
> Gives us proper locking and we get also rid of the only use of max_mapnr.
> Also the number of pages was contained in an int which might not be
> sufficient not too far in the future.
>
> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> ---
>
>  arch/s390/mm/init.c |   42 +++++++++++++++++++++++-------------------
>  1 file changed, 23 insertions(+), 19 deletions(-)
>
> Index: quilt-2.6/arch/s390/mm/init.c
> ===================================================================
> --- quilt-2.6.orig/arch/s390/mm/init.c
> +++ quilt-2.6/arch/s390/mm/init.c
> @@ -44,30 +44,34 @@ char  empty_zero_page[PAGE_SIZE] __attri
>  
>  void show_mem(void)
>  {
> -	int i, total = 0, reserved = 0;
> -	int shared = 0, cached = 0;
> +	unsigned long i, total = 0, reserved = 0;
> +	unsigned long shared = 0, cached = 0;
> +	unsigned long flags;
>  	struct page *page;
> +	pg_data_t *pgdat;
>  
>  	printk("Mem-info:\n");
>  	show_free_areas();
> -	i = max_mapnr;
> -	while (i-- > 0) {
> -		if (!pfn_valid(i))
> -			continue;
> -		page = pfn_to_page(i);
> -		total++;
> -		if (PageReserved(page))
> -			reserved++;
> -		else if (PageSwapCache(page))
> -			cached++;
> -		else if (page_count(page))
> -			shared += page_count(page) - 1;
> +	for_each_online_pgdat(pgdat) {
> +		pgdat_resize_lock(pgdat, &flags);
> +		for (i = 0; i < pgdat->node_spanned_pages; i++) {
> +			if (!pfn_valid(pgdat->node_start_pfn + i))
> +				continue;
> +			page = pfn_to_page(pgdat->node_start_pfn + i);
> +			total++;
> +			if (PageReserved(page))
> +				reserved++;
> +			else if (PageSwapCache(page))
> +				cached++;
> +			else if (page_count(page))
> +				shared += page_count(page) - 1;
> +		}
> +		pgdat_resize_unlock(pgdat, &flags);
>  	}
> -	printk("%d pages of RAM\n", total);
> -	printk("%d reserved pages\n", reserved);
> -	printk("%d pages shared\n", shared);
> -	printk("%d pages swap cached\n", cached);
> -
> +	printk("%ld pages of RAM\n", total);
> +	printk("%ld reserved pages\n", reserved);
> +	printk("%ld pages shared\n", shared);
> +	printk("%ld pages swap cached\n", cached);

>  	printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
>  	printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
>  	printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));

These are redundant, check show_free_areas().

	Hannes

Re: [patch 06/11] showmem: Only walk spanned pages.

[Heiko Carstens]

On Thu, May 29, 2008 at 07:20:57PM +0200, Johannes Weiner wrote:
> >  	printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
> >  	printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
> >  	printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
> 
> These are redundant, check show_free_areas().

Indeed. Removed them. Thanks!

Btw. what's up with your show_mem() cleanup patch series? I thought it
would be merged before 2.6.26 and now it isn't even in -mm?

Re: [patch 06/11] showmem: Only walk spanned pages.

[Johannes Weiner]

Hi,

Heiko Carstens <heiko.carstens@de.ibm.com> writes:

> On Thu, May 29, 2008 at 07:20:57PM +0200, Johannes Weiner wrote:
>> >  	printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
>> >  	printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
>> >  	printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
>> 
>> These are redundant, check show_free_areas().
>
> Indeed. Removed them. Thanks!
>
> Btw. what's up with your show_mem() cleanup patch series? I thought it
> would be merged before 2.6.26 and now it isn't even in -mm?

It interfered with my stupid `remove free swap space display' series
which is not yet completely in mainline (and no more in -mm).  I wanted
to wait until it trickled in but I think I will include the remaining
patches into the generic show_mem series and send them out soon,
obsoleting the old series...

Remaining unpatched show_mem()s in mainline are are um, sparc, sh, m32r,
alpha, sparc64 and xtensa.

	Hannes

[patch 07/11] sclp_vt220: fix scheduling while atomic bug.

[Martin Schwidefsky]

[-- Attachment #1: 007-sclp_vt220.diff --]
[-- Type: text/plain, Size: 4074 bytes --]

From: Heiko Carstens <heiko.carstens@de.ibm.com>

The driver incorrectly assumed that putchar will only be called from
schedulable process context and therefore blocked and waited if no
free output buffers where available.
Since putchar may also be called from BH context this may lead to
deadlocks.
To fix this just return the number of characters accepted and let the
upper layer handle the rest.

The console write function will busy wait (sclp_sync_wait) until a
buffer is available again.

Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 drivers/s390/char/sclp_vt220.c |   27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

Index: quilt-2.6/drivers/s390/char/sclp_vt220.c
===================================================================
--- quilt-2.6.orig/drivers/s390/char/sclp_vt220.c
+++ quilt-2.6/drivers/s390/char/sclp_vt220.c
@@ -71,9 +71,6 @@ static struct list_head sclp_vt220_outqu
 /* Number of requests in outqueue */
 static int sclp_vt220_outqueue_count;
 
-/* Wait queue used to delay write requests while we've run out of buffers */
-static wait_queue_head_t sclp_vt220_waitq;
-
 /* Timer used for delaying write requests to merge subsequent messages into
  * a single buffer */
 static struct timer_list sclp_vt220_timer;
@@ -133,7 +130,6 @@ sclp_vt220_process_queue(struct sclp_vt2
 	} while (request && __sclp_vt220_emit(request));
 	if (request == NULL && sclp_vt220_flush_later)
 		sclp_vt220_emit_current();
-	wake_up(&sclp_vt220_waitq);
 	/* Check if the tty needs a wake up call */
 	if (sclp_vt220_tty != NULL) {
 		tty_wakeup(sclp_vt220_tty);
@@ -383,7 +379,7 @@ sclp_vt220_timeout(unsigned long data)
  */
 static int
 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
-		   int convertlf, int may_schedule)
+		   int convertlf, int may_fail)
 {
 	unsigned long flags;
 	void *page;
@@ -395,15 +391,14 @@ __sclp_vt220_write(const unsigned char *
 	overall_written = 0;
 	spin_lock_irqsave(&sclp_vt220_lock, flags);
 	do {
-		/* Create a sclp output buffer if none exists yet */
+		/* Create an sclp output buffer if none exists yet */
 		if (sclp_vt220_current_request == NULL) {
 			while (list_empty(&sclp_vt220_empty)) {
 				spin_unlock_irqrestore(&sclp_vt220_lock, flags);
-				if (in_interrupt() || !may_schedule)
-					sclp_sync_wait();
+				if (may_fail)
+					goto out;
 				else
-					wait_event(sclp_vt220_waitq,
-						!list_empty(&sclp_vt220_empty));
+					sclp_sync_wait();
 				spin_lock_irqsave(&sclp_vt220_lock, flags);
 			}
 			page = (void *) sclp_vt220_empty.next;
@@ -437,6 +432,7 @@ __sclp_vt220_write(const unsigned char *
 		add_timer(&sclp_vt220_timer);
 	}
 	spin_unlock_irqrestore(&sclp_vt220_lock, flags);
+out:
 	return overall_written;
 }
 
@@ -520,19 +516,11 @@ sclp_vt220_close(struct tty_struct *tty,
  * character to the tty device.  If the kernel uses this routine,
  * it must call the flush_chars() routine (if defined) when it is
  * done stuffing characters into the driver.
- *
- * NOTE: include/linux/tty_driver.h specifies that a character should be
- * ignored if there is no room in the queue. This driver implements a different
- * semantic in that it will block when there is no more room left.
- *
- * FIXME: putchar can currently be called from BH and other non blocking
- * handlers so  this semantic isn't a good idea.
  */
 static int
 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
 {
-	__sclp_vt220_write(&ch, 1, 0, 0, 1);
-	return 1;
+	return __sclp_vt220_write(&ch, 1, 0, 0, 1);
 }
 
 /*
@@ -653,7 +641,6 @@ static int __init __sclp_vt220_init(void
 	spin_lock_init(&sclp_vt220_lock);
 	INIT_LIST_HEAD(&sclp_vt220_empty);
 	INIT_LIST_HEAD(&sclp_vt220_outqueue);
-	init_waitqueue_head(&sclp_vt220_waitq);
 	init_timer(&sclp_vt220_timer);
 	sclp_vt220_current_request = NULL;
 	sclp_vt220_buffered_chars = 0;

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 08/11] dasd: use a generic wait_queue for sleep_on

[Martin Schwidefsky]

[-- Attachment #1: 008-dasd-waitqueue.diff --]
[-- Type: text/plain, Size: 4306 bytes --]

From: Stefan Haberland <stefan.haberland@de.ibm.com>

Use a generic wait_queue to prevent the wait_queue in dasd_sleep_on_ 
functions from being referenced by callback_data while it does not
exist any more.

Signed-off-by: Stefan Haberland  <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 drivers/s390/block/dasd.c |   28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

Index: quilt-2.6/drivers/s390/block/dasd.c
===================================================================
--- quilt-2.6.orig/drivers/s390/block/dasd.c
+++ quilt-2.6/drivers/s390/block/dasd.c
@@ -63,6 +63,7 @@ static void dasd_return_cqr_cb(struct da
  */
 static wait_queue_head_t dasd_init_waitq;
 static wait_queue_head_t dasd_flush_wq;
+static wait_queue_head_t generic_waitq;
 
 /*
  * Allocate memory for a new device structure.
@@ -1151,11 +1152,15 @@ static void __dasd_device_process_final_
 	struct list_head *l, *n;
 	struct dasd_ccw_req *cqr;
 	struct dasd_block *block;
+	void (*callback)(struct dasd_ccw_req *, void *data);
+	void *callback_data;
 
 	list_for_each_safe(l, n, final_queue) {
 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
 		list_del_init(&cqr->devlist);
 		block = cqr->block;
+		callback = cqr->callback;
+		callback_data = cqr->callback_data;
 		if (block)
 			spin_lock_bh(&block->queue_lock);
 		switch (cqr->status) {
@@ -1176,7 +1181,7 @@ static void __dasd_device_process_final_
 			BUG();
 		}
 		if (cqr->callback != NULL)
-			(cqr->callback)(cqr, cqr->callback_data);
+			(callback)(cqr, callback_data);
 		if (block)
 			spin_unlock_bh(&block->queue_lock);
 	}
@@ -1406,17 +1411,15 @@ static inline int _wait_for_wakeup(struc
  */
 int dasd_sleep_on(struct dasd_ccw_req *cqr)
 {
-	wait_queue_head_t wait_q;
 	struct dasd_device *device;
 	int rc;
 
 	device = cqr->startdev;
 
-	init_waitqueue_head (&wait_q);
 	cqr->callback = dasd_wakeup_cb;
-	cqr->callback_data = (void *) &wait_q;
+	cqr->callback_data = (void *) &generic_waitq;
 	dasd_add_request_tail(cqr);
-	wait_event(wait_q, _wait_for_wakeup(cqr));
+	wait_event(generic_waitq, _wait_for_wakeup(cqr));
 
 	/* Request status is either done or failed. */
 	rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
@@ -1429,20 +1432,18 @@ int dasd_sleep_on(struct dasd_ccw_req *c
  */
 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
 {
-	wait_queue_head_t wait_q;
 	struct dasd_device *device;
 	int rc;
 
 	device = cqr->startdev;
-	init_waitqueue_head (&wait_q);
 	cqr->callback = dasd_wakeup_cb;
-	cqr->callback_data = (void *) &wait_q;
+	cqr->callback_data = (void *) &generic_waitq;
 	dasd_add_request_tail(cqr);
-	rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
+	rc = wait_event_interruptible(generic_waitq, _wait_for_wakeup(cqr));
 	if (rc == -ERESTARTSYS) {
 		dasd_cancel_req(cqr);
 		/* wait (non-interruptible) for final status */
-		wait_event(wait_q, _wait_for_wakeup(cqr));
+		wait_event(generic_waitq, _wait_for_wakeup(cqr));
 	}
 	rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
 	return rc;
@@ -1466,7 +1467,6 @@ static inline int _dasd_term_running_cqr
 
 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
 {
-	wait_queue_head_t wait_q;
 	struct dasd_device *device;
 	int rc;
 
@@ -1478,9 +1478,8 @@ int dasd_sleep_on_immediatly(struct dasd
 		return rc;
 	}
 
-	init_waitqueue_head (&wait_q);
 	cqr->callback = dasd_wakeup_cb;
-	cqr->callback_data = (void *) &wait_q;
+	cqr->callback_data = (void *) &generic_waitq;
 	cqr->status = DASD_CQR_QUEUED;
 	list_add(&cqr->devlist, &device->ccw_queue);
 
@@ -1489,7 +1488,7 @@ int dasd_sleep_on_immediatly(struct dasd
 
 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
 
-	wait_event(wait_q, _wait_for_wakeup(cqr));
+	wait_event(generic_waitq, _wait_for_wakeup(cqr));
 
 	/* Request status is either done or failed. */
 	rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
@@ -2430,6 +2429,7 @@ static int __init dasd_init(void)
 
 	init_waitqueue_head(&dasd_init_waitq);
 	init_waitqueue_head(&dasd_flush_wq);
+	init_waitqueue_head(&generic_waitq);
 
 	/* register 'common' DASD debug area, used for all DBF_XXX calls */
 	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 09/11] 3270: fix race with stack local wait_queue_head_t.

[Martin Schwidefsky]

[-- Attachment #1: 009-3270-waitqueue.diff --]
[-- Type: text/plain, Size: 1901 bytes --]

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

A wait_event call with a stack local wait_queue_head_t structure that is
used to do the wake up for the wait_event is inherently racy. After the
wait_event finished the wake_up call might not have completed yet.
Remove the stack local wait_queue_head_t from raw3270_start_init and
use the global raw3270_wait_queue instead.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 drivers/s390/char/raw3270.c |    9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Index: quilt-2.6/drivers/s390/char/raw3270.c
===================================================================
--- quilt-2.6.orig/drivers/s390/char/raw3270.c
+++ quilt-2.6/drivers/s390/char/raw3270.c
@@ -549,7 +549,6 @@ raw3270_start_init(struct raw3270 *rp, s
 		   struct raw3270_request *rq)
 {
 	unsigned long flags;
-	wait_queue_head_t wq;
 	int rc;
 
 #ifdef CONFIG_TN3270_CONSOLE
@@ -566,20 +565,20 @@ raw3270_start_init(struct raw3270 *rp, s
 		return rq->rc;
 	}
 #endif
-	init_waitqueue_head(&wq);
 	rq->callback = raw3270_wake_init;
-	rq->callback_data = &wq;
+	rq->callback_data = &raw3270_wait_queue;
 	spin_lock_irqsave(get_ccwdev_lock(view->dev->cdev), flags);
 	rc = __raw3270_start(rp, view, rq);
 	spin_unlock_irqrestore(get_ccwdev_lock(view->dev->cdev), flags);
 	if (rc)
 		return rc;
 	/* Now wait for the completion. */
-	rc = wait_event_interruptible(wq, raw3270_request_final(rq));
+	rc = wait_event_interruptible(raw3270_wait_queue,
+				      raw3270_request_final(rq));
 	if (rc == -ERESTARTSYS) {	/* Interrupted by a signal. */
 		raw3270_halt_io(view->dev, rq);
 		/* No wait for the halt to complete. */
-		wait_event(wq, raw3270_request_final(rq));
+		wait_event(raw3270_wait_queue, raw3270_request_final(rq));
 		return -ERESTARTSYS;
 	}
 	return rq->rc;

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 10/11] tape: fix race with stack local wait_queue_head_t.

[Martin Schwidefsky]

[-- Attachment #1: 010-tape-waitqueue.diff --]
[-- Type: text/plain, Size: 3498 bytes --]

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

A wait_event call with a stack local wait_queue_head_t structure that is
used to do the wake up for the wait_event is inherently racy. After the
wait_event finished the wake_up call might not have completed yet.
Replace the stack local wait_queue_head_t in tape_do_io and
tape_do_io_interruptible with a per device wait queue.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 drivers/s390/char/tape.h      |    3 +++
 drivers/s390/char/tape_core.c |   16 +++++++---------
 2 files changed, 10 insertions(+), 9 deletions(-)

Index: quilt-2.6/drivers/s390/char/tape_core.c
===================================================================
--- quilt-2.6.orig/drivers/s390/char/tape_core.c
+++ quilt-2.6/drivers/s390/char/tape_core.c
@@ -449,6 +449,7 @@ tape_alloc_device(void)
 	INIT_LIST_HEAD(&device->req_queue);
 	INIT_LIST_HEAD(&device->node);
 	init_waitqueue_head(&device->state_change_wq);
+	init_waitqueue_head(&device->wait_queue);
 	device->tape_state = TS_INIT;
 	device->medium_state = MS_UNKNOWN;
 	*device->modeset_byte = 0;
@@ -954,21 +955,19 @@ __tape_wake_up(struct tape_request *requ
 int
 tape_do_io(struct tape_device *device, struct tape_request *request)
 {
-	wait_queue_head_t wq;
 	int rc;
 
-	init_waitqueue_head(&wq);
 	spin_lock_irq(get_ccwdev_lock(device->cdev));
 	/* Setup callback */
 	request->callback = __tape_wake_up;
-	request->callback_data = &wq;
+	request->callback_data = &device->wait_queue;
 	/* Add request to request queue and try to start it. */
 	rc = __tape_start_request(device, request);
 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
 	if (rc)
 		return rc;
 	/* Request added to the queue. Wait for its completion. */
-	wait_event(wq, (request->callback == NULL));
+	wait_event(device->wait_queue, (request->callback == NULL));
 	/* Get rc from request */
 	return request->rc;
 }
@@ -989,20 +988,19 @@ int
 tape_do_io_interruptible(struct tape_device *device,
 			 struct tape_request *request)
 {
-	wait_queue_head_t wq;
 	int rc;
 
-	init_waitqueue_head(&wq);
 	spin_lock_irq(get_ccwdev_lock(device->cdev));
 	/* Setup callback */
 	request->callback = __tape_wake_up_interruptible;
-	request->callback_data = &wq;
+	request->callback_data = &device->wait_queue;
 	rc = __tape_start_request(device, request);
 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
 	if (rc)
 		return rc;
 	/* Request added to the queue. Wait for its completion. */
-	rc = wait_event_interruptible(wq, (request->callback == NULL));
+	rc = wait_event_interruptible(device->wait_queue,
+				      (request->callback == NULL));
 	if (rc != -ERESTARTSYS)
 		/* Request finished normally. */
 		return request->rc;
@@ -1015,7 +1013,7 @@ tape_do_io_interruptible(struct tape_dev
 		/* Wait for the interrupt that acknowledges the halt. */
 		do {
 			rc = wait_event_interruptible(
-				wq,
+				device->wait_queue,
 				(request->callback == NULL)
 			);
 		} while (rc == -ERESTARTSYS);
Index: quilt-2.6/drivers/s390/char/tape.h
===================================================================
--- quilt-2.6.orig/drivers/s390/char/tape.h
+++ quilt-2.6/drivers/s390/char/tape.h
@@ -231,6 +231,9 @@ struct tape_device {
 	/* Request queue. */
 	struct list_head		req_queue;
 
+	/* Request wait queue. */
+	wait_queue_head_t		wait_queue;
+
 	/* Each tape device has (currently) two minor numbers. */
 	int				first_minor;
 

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

[patch 11/11] disassembler: fix idte instruction format.

[Martin Schwidefsky]

[-- Attachment #1: 011-idte-dis.diff --]
[-- Type: text/plain, Size: 1223 bytes --]

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

The correct instruction format of idte is "idte r1,r3,r2" with
r1 at bit 24, r3 at bit 16 and r2 at bit 28. 

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

 arch/s390/kernel/dis.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: quilt-2.6/arch/s390/kernel/dis.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/dis.c
+++ quilt-2.6/arch/s390/kernel/dis.c
@@ -208,7 +208,7 @@ static const unsigned char formats[][7] 
 	[INSTR_RRF_F0FF]  = { 0xff, F_16,F_24,F_28,0,0,0 },    /* e.g. madbr */
 	[INSTR_RRF_FUFF]  = { 0xff, F_24,F_16,F_28,U4_20,0,0 },/* e.g. didbr */
 	[INSTR_RRF_RURR]  = { 0xff, R_24,R_28,R_16,U4_20,0,0 },/* e.g. .insn */
-	[INSTR_RRF_R0RR]  = { 0xff, R_24,R_28,R_16,0,0,0 },    /* e.g. idte  */
+	[INSTR_RRF_R0RR]  = { 0xff, R_24,R_16,R_28,0,0,0 },    /* e.g. idte  */
 	[INSTR_RRF_U0FF]  = { 0xff, F_24,U4_16,F_28,0,0,0 },   /* e.g. fixr  */
 	[INSTR_RRF_U0RF]  = { 0xff, R_24,U4_16,F_28,0,0,0 },   /* e.g. cfebr */
 	[INSTR_RRF_M0RR]  = { 0xff, R_24,R_28,M_16,0,0,0 },    /* e.g. sske  */

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.