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2008-01-26[S390] vmemmap: allocate struct pages before 1:1 mappingChristian Borntraeger
We have seen an oops in an OOM situation, where show_mem tried to access the struct page of a dcss segment. The vmemmap code has already created the 1:1 mapping but failed allocating the struct pages. In the OOM case, show_mem now walks the memory. It uses pfn_valid to detect if it may access the struct page. In the case described above, the mapping was established and pfn_valid returned true. As the struct pages were not allocated, the kernel oopsed. We have to ensure that we have created the struct pages, before we add a mapping pointing to the pages. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Initialize sclp_ipl_infoMichael Holzheu
The sclp ipl information has not been initialized. Therefore the ipl loadparm and the "has_dump" flag have not been set correctly. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Allocate and free cpu lowcores and stacks when needed/possible.Heiko Carstens
No need to preallocate the per cpu lowcores and stacks. Savings are 28-32k per offline cpu. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] use LIST_HEAD instead of LIST_HEAD_INITDenis Cheng
single list_head variable initialized with LIST_HEAD_INIT could almost always can be replaced with LIST_HEAD declaration, this shrinks the code and looks better. Signed-off-by: Denis Cheng <crquan@gmail.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Load disabled wait psw instead of stopping cpu on halt.Michael Holzheu
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] kernel: Shutdown Actions InterfaceMichael Holzheu
In case of a kernel panic it is currently possible to specify that a dump should be created, the system should be rebooted or stopped. Virtual sysfs files under the directory /sys/firmware/ are used for that configuration. In addition to that, there are kernel parameters 'vmhalt', 'vmpoff' and 'vmpanic', which can be used to specify z/VM commands, which are automatically executed in case of halt, power off or a kernel panic. This patch combines both functionalities and allows to specify the z/VM CP commands also via sysfs attributes. In addition to that, it enhances the existing handling of shutdown triggers (e.g. halt or panic) and associated shutdown actions (e.g. dump or reipl) and makes it more flexible. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] arch/s390: Add missing "space"Joe Perches
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] crypto: move s390 Kconfig options.Jan Glauber
Move s390 crypto Kconfig options to drivers/crypto/Kconfig to have all hardware crypto devices in one place. This also makes messing up the kernel source tree easier for some people. Signed-off-by: Jan Glauber <jan.glauber@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Get rid of additional_cpus kernel parameter.Heiko Carstens
It caused only a lot of confusion. From now on cpu hotplug of up to NR_CPUS will work by default. If somebody wants to limit that then the possible_cpus parameter can be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Remove owner_pc member from raw_spinlock_t.Heiko Carstens
Used to contain the address of the holder of the lock. But since the spinlock code is not inlined anymore all locks contain the same address anyway. And since in addtition nobody complained about that for ages its obviously unused. So remove it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Get rid of HOLES_IN_ZONE requirement.Heiko Carstens
Align everything to MAX_ORDER so we can get rid of the extra checks. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Print kernel version in dump_stack() and show_regs().Heiko Carstens
Also print PREEMPT and/or SMP if the kernel was configured that way. Makes s390 look a bit more like other architectures. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Change vmalloc defintionsChristian Borntraeger
Currently the vmalloc area starts at a dynamic address depending on the memory size. There was also an 8MB security hole after the physical memory to catch out-of-bounds accesses. We can simplify the code by putting the vmalloc area explicitely at the top of the kernel mapping and setting the vmalloc size to a fixed value of 128MB/128GB for 31bit/64bit systems. Part of the vmalloc area will be used for the vmem_map. This leaves an area of 96MB/1GB for normal vmalloc allocations. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Fix tlb flushing with idte.Martin Schwidefsky
The clear-by-asce operation of the idte instruction gets an asce (address-space-control-element) as argument to specify which TLBs need to get flushed. The current code passes a plain pointer to the start of the pgd without the additional bits which would make the pointer an asce. The current machines don't mind the difference but a future model might want to use the designation type control bits in the asce as a filter for the TLBs to flush. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-26[S390] Standby cpu activation/deactivation.Heiko Carstens
Add a new interface so that cpus can be put into standby state and configured state. Only offline cpus can be put into standby state or configured state. For that the new percpu sysfs attribute "configure" must be used. To put a cpu in standby state a "0" must be written to the attribute. In order to switch it into configured state a "1" must be written to the attribute. Only cpus in configured state can be brought online. In addition this patch introduces a static mapping of physical to logical cpus. As a result only the sysfs directories of present cpus will be created. To scan for new cpus the new sysfs attribute "rescan" must be used. Writing to /sys/devices/system/cpu/rescan will trigger a rescan of cpus and will create directories for new cpus. On IPL only configured cpus will be used. And on reboot/shutdown all cpus will remain in their current state (configured/standby). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-01-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (125 commits) [CRYPTO] twofish: Merge common glue code [CRYPTO] hifn_795x: Fixup container_of() usage [CRYPTO] cast6: inline bloat-- [CRYPTO] api: Set default CRYPTO_MINALIGN to unsigned long long [CRYPTO] tcrypt: Make xcbc available as a standalone test [CRYPTO] xcbc: Remove bogus hash/cipher test [CRYPTO] xcbc: Fix algorithm leak when block size check fails [CRYPTO] tcrypt: Zero axbuf in the right function [CRYPTO] padlock: Only reset the key once for each CBC and ECB operation [CRYPTO] api: Include sched.h for cond_resched in scatterwalk.h [CRYPTO] salsa20-asm: Remove unnecessary dependency on CRYPTO_SALSA20 [CRYPTO] tcrypt: Add select of AEAD [CRYPTO] salsa20: Add x86-64 assembly version [CRYPTO] salsa20_i586: Salsa20 stream cipher algorithm (i586 version) [CRYPTO] gcm: Introduce rfc4106 [CRYPTO] api: Show async type [CRYPTO] chainiv: Avoid lock spinning where possible [CRYPTO] seqiv: Add select AEAD in Kconfig [CRYPTO] scatterwalk: Handle zero nbytes in scatterwalk_map_and_copy [CRYPTO] null: Allow setkey on digest_null ...
2008-01-24Driver core: change sysdev classes to use dynamic kobject namesKay Sievers
All kobjects require a dynamically allocated name now. We no longer need to keep track if the name is statically assigned, we can just unconditionally free() all kobject names on cleanup. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24Kobject: convert arch/* from kobject_unregister() to kobject_put()Greg Kroah-Hartman
There is no need for kobject_unregister() anymore, thanks to Kay's kobject cleanup changes, so replace all instances of it with kobject_put(). Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24firmware: change firmware_kset to firmware_kobjGreg Kroah-Hartman
There is no firmware "subsystem" it's just a directory in /sys that other portions of the kernel want to hook into. So make it a kobject not a kset to help alivate anyone who tries to do some odd kset-like things with this. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kset: convert s390 ipl.c to use kset_createGreg Kroah-Hartman
Dynamically create the kset instead of declaring it statically. This makes the kobject attributes now work properly that I broke in the previous patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Michael Holzheu <holzheu@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Volker Sameske <sameske@de.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kobject: convert s390 ipl.c to kobj_attr interfaceGreg Kroah-Hartman
This makes the code a bit simpler and and gets us one step closer to deleting the deprecated subsys_attr code. NOTE, this needs the next patch in the series in order to work properly. This will build, but the sysfs files will not properly operate. Thanks to Cornelia for the build fix on this patch. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Michael Holzheu <holzheu@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Volker Sameske <sameske@de.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kobject: convert s390 hypervisor to use kobject_createGreg Kroah-Hartman
We don't need a kset here, a simple kobject will do just fine, so dynamically create the kobject and use it. Thanks to Cornelia for the build fix. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Michael Holzheu <holzheu@de.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kobject: convert /sys/hypervisor to use kobject_createGreg Kroah-Hartman
We don't need a kset here, a simple kobject will do just fine, so dynamically create the kobject and use it. We also rename hypervisor_subsys to hypervisor_kset to catch all users of the variable. Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24kobject: remove struct kobj_type from struct ksetGreg Kroah-Hartman
We don't need a "default" ktype for a kset. We should set this explicitly every time for each kset. This change is needed so that we can make ksets dynamic, and cleans up one of the odd, undocumented assumption that the kset/kobject/ktype model has. This patch is based on a lot of help from Kay Sievers. Nasty bug in the block code was found by Dave Young <hidave.darkstar@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-11[CRYPTO] s390-aes: Use correct encrypt/decrypt function in fallbackSebastian Siewior
crypto_blkcipher_decrypt is wrong because it does not care about the IV. Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] aes_s390: Add fallback driverSebastian Siewior
Some CPUs support only 128 bit keys in HW. This patch adds SW fallback support for the other keys which may be required. The generic algorithm (and the block mode) must be availble in case of a fallback. Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc> Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] aes: Move common defines into a header fileSebastian Siewior
This three defines are used in all AES related hardware. Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-12-04[S390] Make sure the restore psw masks are initialized.Heiko Carstens
In case of TRACE_IRQFLAGS the restore psw masks will not be initialized if noexec is turned on. This will lead to an immediate system crash. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-12-04[S390] Fix compile error on 31bit without preemptionChristian Borntraeger
Commit b8e7a54cd06b0b0174029ef3a7f5a1415a2c28f2 introduced a compile error if CONFIG_PREEMPT is not set: arch/s390/kernel/built-in.o: In function `cleanup_io_leave_insn': /space/kvm/arch/s390/kernel/entry.S:(.text+0xbfce): undefined reference to `preempt_schedule_irq' This patch hides preempt_schedule_irq if CONFIG_PREEMPT is not set. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] Add missing die_notifier() call to die().Heiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] Fix memory detection.Heiko Carstens
Before we're getting short on memory detection fixes here is the next one: if neither sclp nor diag260 report the storage size the detection loop will return immediately without detecting anything. Fix this by breaking the detection loop only if the memory end is known. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] Dont overwrite lowcores on smp_send_stop().Heiko Carstens
Don't perform a sigp store-status-at-address on smp_send_stop(). It will overwrite the lowcores of other cpus and destroys valueable debug informations. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] Fix kernel preemption.Heiko Carstens
When returning from IRQ handling and TIF_NEED_RESCHED is set we must call preempt_schedule_irq() instead of schedule(). Otherwise the BKL might be unlocked in schedule() and therfore everything that relies on the BKL is broken. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] appldata: remove unused binary sysctls.Heiko Carstens
Remove binary sysctls that never worked due to missing strategy functions. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] cmm: remove unused binary sysctls.Heiko Carstens
Remove binary sysctls that never worked due to missing strategy functions. Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] Fix irq tracing and lockdep_sys_exit calls.Heiko Carstens
Current support for TRACE_IRQFLAGS and lockdep_sys_exit is broken. IRQ flag tracing is broken for program checks. Even worse is that the newly introduced calls to lockdep_sys_exit are in the critical section code which is not supposed to call any C functions. In addition the checks if locks are still held are also done when returning to kernel code which is broken as well. Fix all this by disabling interrupts and machine checks at the exit paths and then do the appropriate checks and calls. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-20[S390] magic sysrq: check for in_atomic before doing an console_unblankChristian Borntraeger
When doing an magic sysrq reboot on s390 the following bug message appears: SysRq : Resetting BUG: sleeping function called from invalid context at include/asm/semaphore.h:61 in_atomic():1, irqs_disabled():0 07000000004002a8 000000000fe6bc48 0000000000000002 0000000000000000 000000000fe6bce8 000000000fe6bc60 000000000fe6bc60 000000000012a79a 0000000000000000 07000000004002a8 0000000000000006 0000000000000000 0000000000000000 000000000fe6bc48 000000000000000d 000000000fe6bcb8 00000000004000c8 0000000000103234 000000000fe6bc48 000000000fe6bc90 Call Trace: (¬<00000000001031b2>| show_trace+0x12e/0x148) ¬<000000000011ffca>| __might_sleep+0x10a/0x118 ¬<0000000000129fba>| acquire_console_sem+0x92/0xf4 ¬<000000000012a2ca>| console_unblank+0xc2/0xc8 ¬<0000000000107bb4>| machine_restart+0x54/0x6c ¬<000000000028e806>| sysrq_handle_reboot+0x26/0x30 ¬<000000000028e52a>| __handle_sysrq+0xa6/0x180 ¬<0000000000140134>| run_workqueue+0xcc/0x18c ¬<000000000014029a>| worker_thread+0xa6/0x108 ¬<00000000001458e4>| kthread+0x64/0x9c ¬<0000000000106f0e>| kernel_thread_starter+0x6/0xc ¬<0000000000106f08>| kernel_thread_starter+0x0/0xc The only reason for doing a console_unblank on s390 is to flush the log buffer. We have to check for in_atomic before doing a console_unblank as the console is otherwise filled with an unrelated bug message. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-09sched: restore deterministic CPU accounting on powerpcPaul Mackerras
Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been broken on powerpc, because we end up counting user time twice: once in timer_interrupt() and once in update_process_times(). This fixes the problem by pulling the code in update_process_times that updates utime and stime into a separate function called account_process_tick. If CONFIG_VIRT_CPU_ACCOUNTING is not defined, there is a version of account_process_tick in kernel/timer.c that simply accounts a whole tick to either utime or stime as before. If CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to implement account_process_tick. This also lets us simplify the s390 code a bit; it means that the s390 timer interrupt can now call update_process_times even when CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a suitable account_process_tick(). account_process_tick() now takes the task_struct * as an argument. Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-05[S390] tod clock: announce clocksource as perfectChristian Borntraeger
The Time of Day clock is the standard time source for s390. It is - monotonic - allows very fast reading - architecture guarantees at least microsecond stepping - available as part of the architecture We should announce the rate of tod as 400 to be in sync with the description found in clocksource.h: "400-499:Perfect The ideal clocksource. A must-use where available." This change will prefer tod over less reliable clock sources. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-05[S390] Rename "idle_time" attribute to "idle_time_us".Heiko Carstens
Seems that people prefer to have the unit encoded in the attribute name. Also makes parsing easier. Now we have: # cat /sys/devices/system/cpu/cpu0/idle_time_us 131473592 instead of # cat /sys/devices/system/cpu/cpu0/idle_time 131473592 us Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-05[S390] Fix memory detection.Heiko Carstens
Yet another patch in the countless series of memory detection fixes: if the last area of the reported storage size is a hole the detection loop will loop forever. Just break chunk detection loop if its end is going to be larger than reported storage size. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-11-05[S390] Fix compile on !CONFIG_SMP.Heiko Carstens
Commit fae8b22d3e3e3a3d317a7746493997af02a3f35c "[S390] Add per-cpu idle time / idle count sysfs attributes" causes a link error on !CONFIG_SMP. Fix this by adding some #ifdef's. Real fix would be to cleanup the code since we don't register a cpu on !CONFIG_SMP. But that would be quite a big patch. For the time being this is good enough. arch/s390/kernel/built-in.o: In function `do_monitor_call': (.text+0x50d4): undefined reference to `per_cpu__s390_idle' arch/s390/kernel/built-in.o: In function `cpu_idle': (.text+0x518c): undefined reference to `per_cpu__s390_idle' make: *** [.tmp_vmlinux1] Error 1 Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-30Kbuild/doc: fix links to Documentation filesDirk Hohndel
Fix links to files in Documentation/* in various Kconfig files Signed-off-by: Dirk Hohndel <hohndel@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-22[S390] 4level-fixup cleanupMartin Schwidefsky
Get independent from asm-generic/4level-fixup.h Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22[S390] Cleanup page table definitions.Martin Schwidefsky
- De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22[S390] Introduce follow_table in uaccess_pt.cMartin Schwidefsky
Define and use follow_table inline in uaccess_pt.c to simplify the code. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22[S390] Remove unused user_seg from thread structure.Martin Schwidefsky
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22[S390] tlb flush fix.Martin Schwidefsky
The current tlb flushing code for page table entries violates the s390 architecture in a small detail. The relevant section from the principles of operation (SA22-7832-02 page 3-47): "A valid table entry must not be changed while it is attached to any CPU and may be used for translation by that CPU except to (1) invalidate the entry by using INVALIDATE PAGE TABLE ENTRY or INVALIDATE DAT TABLE ENTRY, (2) alter bits 56-63 of a page-table entry, or (3) make a change by means of a COMPARE AND SWAP AND PURGE instruction that purges the TLB." That means if one thread of a multithreaded applciation uses a vma while another thread does an unmap on it, the page table entries of that vma needs to get removed with IPTE, IDTE or CSP. In some strange and rare situations a cpu could check-stop (die) because a entry has been pushed out of the TLB that is still needed to complete a (milli-coded) instruction. I've never seen it happen with the current code on any of the supported machines, so right now this is a theoretical problem. But I want to fix it nevertheless, to avoid headaches in the futures. To get this implemented correctly without changing common code the primitives ptep_get_and_clear, ptep_get_and_clear_full and ptep_set_wrprotect need to use the IPTE instruction to invalidate the pte before the new pte value gets stored. If IPTE is always used for the three primitives three important operations will have a performace hit: fork, mprotect and exit_mmap. Time for some workarounds: * 1: ptep_get_and_clear_full is used in unmap_vmas to remove page tables entries in a batched tlb gather operation. If the mmu_gather context passed to unmap_vmas has been started with full_mm_flush==1 or if only one cpu is online or if the only user of a mm_struct is the current process then the fullmm indication in the mmu_gather context is set to one. All TLBs for mm_struct are flushed by the tlb_gather_mmu call. No new TLBs can be created while the unmap is in progress. In this case ptep_get_and_clear_full clears the ptes with a simple store. * 2: ptep_get_and_clear is used in change_protection to clear the ptes from the page tables before they are reentered with the new access flags. At the end of the update flush_tlb_range clears the remaining TLBs. In general the ptep_get_and_clear has to issue IPTE for each pte and flush_tlb_range is a nop. But if there is only one user of the mm_struct then ptep_get_and_clear uses simple stores to do the update and flush_tlb_range will flush the TLBs. * 3: Similar to 2, ptep_set_wrprotect is used in copy_page_range for a fork to make all ptes of a cow mapping read-only. At the end of of copy_page_range dup_mmap will flush the TLBs with a call to flush_tlb_mm. Check for mm->mm_users and if there is only one user avoid using IPTE in ptep_set_wrprotect and let flush_tlb_mm clear the TLBs. Overall for single threaded programs the tlb flush code now performs better, for multi threaded programs it is slightly worse. In particular exit_mmap() now does a single IDTE for the mm and then just frees every page cache reference and every page table page directly without a delay over the mmu_gather structure. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22[S390] kernel: Fix dump on panic for DASDs under LPAR.Michael Holzheu
Currently the ccw method is used to ipl the DASD dump record under LPAR. This mechanism is not reliable, which can cause dump failures. This fix now uses the diag 308 ipl method for all machines, which have diag308 subcode 5 and 4 support. Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-10-22[S390] Add per-cpu idle time / idle count sysfs attributes.Heiko Carstens
Add two new sysfs entries per cpu: idle_count and idle_time. idle_count contains the number of times a cpu went into idle state. idle_time contains the time a cpu spent in idle state in microseconds. This can be used e.g. by powertop to tell how often idle state is entered and left. # cat /sys/devices/system/cpu/cpu0/idle_count 504 # cat /sys/devices/system/cpu/cpu0/idle_time 469734037 us Cc: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>