summaryrefslogtreecommitdiffstats
path: root/arch/s390/lib (follow)
Commit message (Collapse)AuthorAgeFilesLines
* s390/uaccess: add missing page table walk range checkHeiko Carstens2013-11-251-0/+3
| | | | | | | | | | | | | | | When translating a user space address, the address must be checked against the ASCE limit of the process. If the address is larger than the maximum address that is reachable with the ASCE, an ASCE type exception must be generated. The current code simply ignored the higher order bits. This resulted in an address wrap around in user space instead of an exception in user space. Cc: stable@vger.kernel.org # v3.9+ Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: always run the kernel in home spaceMartin Schwidefsky2013-10-244-338/+1
| | | | | | | Simplify the uaccess code by removing the user_mode=home option. The kernel will now always run in the home space mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/bitops: rename find_first_bit_left() to find_first_bit_inv()Heiko Carstens2013-10-241-5/+5
| | | | | | | | | | | | | | | | | | find_first_bit_left() and friends have nothing to do with the normal LSB0 bit numbering for big endian machines used in Linux (least significant bit has bit number 0). Instead they use MSB0 bit numbering, where the most signficant bit has bit number 0. So rename find_first_bit_left() and friends to find_first_bit_inv(), to avoid any confusion. Also provide inv versions of set_bit, clear_bit and test_bit. This also removes the confusing use of e.g. set_bit() in airq.c which uses a "be_to_le" bit number conversion, which could imply that instead set_bit_le() could be used. But that is entirely wrong since the _le bitops variant uses yet another bit numbering scheme. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/bitops: use generic find bit functions / reimplement _left variantHeiko Carstens2013-10-242-1/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just like all other architectures we should use out-of-line find bit operations, since the inline variant bloat the size of the kernel image. And also like all other architecures we should only supply optimized variants of the __ffs, ffs, etc. primitives. Therefore this patch removes the inlined s390 find bit functions and uses the generic out-of-line variants instead. The optimization of the primitives follows with the next patch. With this patch also the functions find_first_bit_left() and find_next_bit_left() have been reimplemented, since logically, they are nothing else but a find_first_bit()/find_next_bit() implementation that use an inverted __fls() instead of __ffs(). Also the restriction that these functions only work on machines which support the "flogr" instruction is gone now. This reduces the size of the kernel image (defconfig, -march=z9-109) by 144,482 bytes. Alone the size of the function build_sched_domains() gets reduced from 7 KB to 3,5 KB. We also git rid of unused functions like find_first_bit_le()... Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time: correct use of store clock fastMartin Schwidefsky2013-10-221-7/+7
| | | | | | | | | | | | | | | | | The result of the store-clock-fast (STCKF) instruction is a bit fuzzy. It can happen that the value stored on one CPU is smaller than the value stored on another CPU, although the order of the stores is the other way around. This can cause deltas of get_tod_clock() values to become negative when they should not be. We need to be more careful with store-clock-fast, this patch partially reverts git commit e4b7b4238e666682555461fa52eecd74652f36bb "time: always use stckf instead of stck if available". The get_tod_clock() function now uses the store-clock-extended (STCKE) instruction. get_tod_clock_fast() can be used if the fuzziness of store-clock-fast is acceptable e.g. for wait loops local to a CPU. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time: return with irqs disabled from psw_idleMartin Schwidefsky2013-08-281-2/+0
| | | | | | | | | Modify the psw_idle waiting logic in entry[64].S to return with interrupts disabled. This avoids potential issues with udelay and interrupt loops as interrupts are not reenabled after clock comparator interrupts. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: cleanup page table definitionsMartin Schwidefsky2013-08-221-8/+8
| | | | | | | | | | | | | Improve the encoding of the different pte types and the naming of the page, segment table and region table bits. Due to the different pte encoding the hugetlbfs primitives need to be adapted as well. To improve compatability with common code make the huge ptes use the encoding of normal ptes. The conversion between the pte and pmd encoding for a huge pte is done with set_huge_pte_at and huge_ptep_get. Overall the code is now easier to understand. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: add "fallthrough" commentsHeiko Carstens2013-05-021-0/+3
| | | | | | | | Add "fallthrough" comments so nobody wonders if a break statement is missing. Reported-by: Joe Perches <joe@perches.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKSStephen Boyd2013-05-012-9/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The help text for this config is duplicated across the x86, parisc, and s390 Kconfig.debug files. Arnd Bergman noted that the help text was slightly misleading and should be fixed to state that enabling this option isn't a problem when using pre 4.4 gcc. To simplify the rewording, consolidate the text into lib/Kconfig.debug and modify it there to be more explicit about when you should say N to this config. Also, make the text a bit more generic by stating that this option enables compile time checks so we can cover architectures which emit warnings vs. ones which emit errors. The details of how an architecture decided to implement the checks isn't as important as the concept of compile time checking of copy_from_user() calls. While we're doing this, remove all the copy_from_user_overflow() code that's duplicated many times and place it into lib/ so that any architecture supporting this option can get the function for free. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Helge Deller <deller@gmx.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390/uaccess: fix page table walkHeiko Carstens2013-04-021-27/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | When translating user space addresses to kernel addresses the follow_table() function had two bugs: - PROT_NONE mappings could be read accessed via the kernel mapping. That is e.g. putting a filename into a user page, then protecting the page with PROT_NONE and afterwards issuing the "open" syscall with a pointer to the filename would incorrectly succeed. - when walking the page tables it used the pgd/pud/pmd/pte primitives which with dynamic page tables give no indication which real level of page tables is being walked (region2, region3, segment or page table). So in case of an exception the translation exception code passed to __handle_fault() is not necessarily correct. This is not really an issue since __handle_fault() doesn't evaluate the code. Only in case of e.g. a SIGBUS this code gets passed to user space. If user space can do something sane with the value is a different question though. To fix these issues don't use any Linux primitives. Only walk the page tables like the hardware would do it, however we leave quite some checks away since we know that we only have full size page tables and each index is within bounds. In theory this should fix all issues... Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: fix clear_user_pt()Heiko Carstens2013-03-211-1/+1
| | | | | | | | | | | | | The page table walker variant of clear_user() is supposed to copy the contents of the empty zero page to user space. However since 238ec4ef "[S390] zero page cache synonyms" empty_zero_page is not anymore the page itself but contains the pointer to the empty zero pages. Therefore the page table walker variant of clear_user() copied the address of the first empty zero page and afterwards more or less random data to user space instead of clearing the given user space range. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: fix kernel ds access for page table walkHeiko Carstens2013-02-281-28/+77
| | | | | | | | | | | | | | | | | | | | | When the kernel resides in home space and the mvcos instruction is not available uaccesses for kernel ds happen via simple strnlen() or memcpy() calls. This however can break badly, since uaccesses in kernel space may fail as well, especially if CONFIG_DEBUG_PAGEALLOC is turned on. To fix this implement strnlen_kernel() and copy_in_kernel() functions which can only be used by the page table uaccess functions. These two functions detect invalid memory accesses and return the correct length of processed data.. Both functions are more or less a copy of the std variants without sacf calls. Fixes ipl crashes on 31 bit machines as well on 64 bit machines without mvcos. Caused by changing the default address space of the kernel being home space. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: fix strncpy_from_user string length checkHeiko Carstens2013-02-282-46/+34
| | | | | | | | | | | | | | | The "standard" and page table walk variants of strncpy_from_user() first check the length of the to be copied string in userspace. The string is then copied to kernel space and the length returned to the caller. However userspace can modify the string at any time while the kernel checks for the length of the string or copies the string. In result the returned length of the string is not necessarily correct. Fix this by copying in a loop which mimics the mvcos variant of strncpy_from_user(), which handles this correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: fix strncpy_from_user/strnlen_user zero maxlen caseHeiko Carstens2013-02-283-0/+8
| | | | | | | | | | | | | | | | If the maximum length specified for the to be accessed string for strncpy_from_user() and strnlen_user() is zero the following incorrect values would be returned or incorrect memory accesses would happen: strnlen_user_std() and strnlen_user_pt() incorrectly return "1" strncpy_from_user_pt() would incorrectly access "dst[maxlen - 1]" strncpy_from_user_mvcos() would incorrectly return "-EFAULT" Fix all these oddities by adding early checks. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/uaccess: shorten strncpy_from_user/strnlen_userHeiko Carstens2013-02-281-12/+12
| | | | | | | | | | | | | Always stay within page boundaries when copying from user within strlen_user_mvcos()/strncpy_from_user_mvcos(). This allows to shorten the code a bit and may prevent unnecessary faults, since we copy quite large amounts of memory to kernel space. Also directly call the mvcos variants of copy_from_user() to avoid indirect branches. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: implement software dirty bitsMartin Schwidefsky2013-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The s390 architecture is unique in respect to dirty page detection, it uses the change bit in the per-page storage key to track page modifications. All other architectures track dirty bits by means of page table entries. This property of s390 has caused numerous problems in the past, e.g. see git commit ef5d437f71afdf4a "mm: fix XFS oops due to dirty pages without buffers on s390". To avoid future issues in regard to per-page dirty bits convert s390 to a fault based software dirty bit detection mechanism. All user page table entries which are marked as clean will be hardware read-only, even if the pte is supposed to be writable. A write by the user process will trigger a protection fault which will cause the user pte to be marked as dirty and the hardware read-only bit is removed. With this change the dirty bit in the storage key is irrelevant for Linux as a host, but the storage key is still required for KVM guests. The effect is that page_test_and_clear_dirty and the related code can be removed. The referenced bit in the storage key is still used by the page_test_and_clear_young primitive to provide page age information. For page cache pages of mappings with mapping_cap_account_dirty there will not be any change in behavior as the dirty bit tracking already uses read-only ptes to control the amount of dirty pages. Only for swap cache pages and pages of mappings without mapping_cap_account_dirty there can be additional protection faults. To avoid an excessive number of additional faults the mk_pte primitive checks for PageDirty if the pgprot value allows for writes and pre-dirties the pte. That avoids all additional faults for tmpfs and shmem pages until these pages are added to the swap cache. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/time: rename tod clock access functionsHeiko Carstens2013-02-141-8/+8
| | | | | | | | Fix name clash with some common code device drivers and add "tod" to all tod clock access function names. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: use pmd_large() instead of pmd_huge()Gerald Schaefer2012-10-261-1/+1
| | | | | | | | | Without CONFIG_HUGETLB_PAGE, pmd_huge() will always return 0. So pmd_large() should be used instead in places where both transparent huge pages and hugetlbfs pages can occur. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/string: provide asm lib functions for memcpy and memcmpHeiko Carstens2012-09-264-52/+187
| | | | | | | | | | | | | Our memcpy and memcmp variants were implemented by calling the corresponding gcc builtin variants. However gcc is free to replace a call to __builtin_memcmp with a call to memcmp which, when called, will result in an endless recursion within memcmp. So let's provide asm variants and also fix the variants that are used for uncompressing the kernel image. In addition remove all other occurences of builtin function calls. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/mm: fix user access page-table walk codeGerald Schaefer2012-09-171-79/+63
| | | | | | | | | | | | | | | | | The s390 page-table walk code, used for user copy and futex, currently cannot handle huge pages. As far as user copy is concerned, that is not really a problem because those functions will only be used on old hardware that has no huge page support. But the futex code will also use pagetable walk functions on current hardware when user space runs in primary space mode. So, if a futex sits in a huge page, the futex operation on it will result in a page fault loop or even data corruption. This patch adds the code for resolving huge page mappings in the user access pagetable walk code on s390. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/vtimer: rework virtual timer interfaceMartin Schwidefsky2012-07-201-1/+1
| | | | | | | | | | | | | | | | | The current virtual timer interface is inherently per-cpu and hard to use. The sole user of the interface is appldata which uses it to execute a function after a specific amount of cputime has been used over all cpus. Rework the virtual timer interface to hook into the cputime accounting. This makes the interface independent from the CPU timer interrupts, and makes the virtual timers global as opposed to per-cpu. Overall the code is greatly simplified. The downside is that the accuracy is not as good as the original implementation, but it is still good enough for appldata. Reviewed-by: Jan Glauber <jang@linux.vnet.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/comments: unify copyright messages and remove file namesHeiko Carstens2012-07-208-18/+6
| | | | | | | | | | | | | | Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* s390/headers: replace __s390x__ with CONFIG_64BIT where possibleHeiko Carstens2012-05-242-2/+2
| | | | | | | | Replace __s390x__ with CONFIG_64BIT in all places that are not exported to userspace or guarded with #ifdef __KERNEL__. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] rework idle codeMartin Schwidefsky2012-03-111-17/+14
| | | | | | | | | | | | | | Whenever the cpu loads an enabled wait PSW it will appear as idle to the underlying host system. The code in default_idle calls vtime_stop_cpu which does the necessary voodoo to get the cpu time accounting right. The udelay code just loads an enabled wait PSW. To correct this rework the vtime_stop_cpu/vtime_start_cpu logic and move the difficult parts to entry[64].S, vtime_stop_cpu can now be called from anywhere and vtime_start_cpu is gone. The correction of the cpu time during wakeup from an enabled wait PSW is done with a critical section in entry[64].S. As vtime_start_cpu is gone, s390_idle_check can be removed as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] rework smp codeMartin Schwidefsky2012-03-111-22/+8
| | | | | | | | | | | | | | | | | | | | | Define struct pcpu and merge some of the NR_CPUS arrays into it, including __cpu_logical_map, current_set and smp_cpu_state. Split smp related functions to those operating on physical cpus and the functions operating on a logical cpu number. Make the functions for physical cpus use a pointer to a struct pcpu. This hides the knowledge about cpu addresses in smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header. The PSW restart mechanism is used to start secondary cpus, calling a function on an online cpu, calling a function on the ipl cpu, and for the nmi signal. Replace the different assembler functions with a single function restart_int_handler. The new entry point calls a function whose pointer is stored in the lowcore of the target cpu and it can wait for the source cpu to stop. This covers all existing use cases. Overall the code is now simpler and there are ~380 lines less code. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] sparse: fix sparse warnings with __user pointersMartin Schwidefsky2011-10-301-2/+4
| | | | | | Use __force to quiet sparse warnings about user address space. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] cleanup psw related bits and piecesMartin Schwidefsky2011-10-301-1/+2
| | | | | | | | | | Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros. Change psw_kernel_bits / psw_user_bits to contain only the bits that are always set in the respective mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] fix s390 assembler code alignmentsJan Glauber2011-07-241-2/+3
| | | | | | | | | | | | The alignment is missing for various global symbols in s390 assembly code. With a recent gcc and an instruction like stgrl this can lead to a specification exception if the instruction uses such a mis-aligned address. Specify the alignment explicitely and while add it define __ALIGN for s390 and use the ENTRY define to save some lines of code. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] delay: implement ndelayHeiko Carstens2011-05-261-0/+15
| | | | | | | Implement ndelay() on s390 as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* futex: Sanitize futex ops argument typesMichel Lespinasse2011-03-113-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | Change futex_atomic_op_inuser and futex_atomic_cmpxchg_inatomic prototypes to use u32 types for the futex as this is the data type the futex core code uses all over the place. Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Darren Hart <darren@dvhart.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110311025058.GD26122@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* futex: Sanitize cmpxchg_futex_value_locked APIMichel Lespinasse2011-03-113-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cmpxchg_futex_value_locked API was funny in that it returned either the original, user-exposed futex value OR an error code such as -EFAULT. This was confusing at best, and could be a source of livelocks in places that retry the cmpxchg_futex_value_locked after trying to fix the issue by running fault_in_user_writeable(). This change makes the cmpxchg_futex_value_locked API more similar to the get_futex_value_locked one, returning an error code and updating the original value through a reference argument. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> [tile] Acked-by: Tony Luck <tony.luck@intel.com> [ia64] Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michal Simek <monstr@monstr.eu> [microblaze] Acked-by: David Howells <dhowells@redhat.com> [frv] Cc: Darren Hart <darren@dvhart.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <20110311024851.GC26122@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* [S390] missing sacf in uaccessMartin Schwidefsky2011-01-311-6/+4
| | | | | | | | | | | The uaccess functions copy_in_user_std and clear_user_std fail to switch back from secondary space mode to primary space mode with sacf in case of an unresolvable page fault. We need to make sure that the switch back to primary mode is done in all cases, otherwise the code following the uaccess inline assembly will crash. Reported-by: Alexander Graf <agraf@suse.de> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] time: let local_tick_enable/disable() reprogram the clock comparatorHeiko Carstens2011-01-051-2/+0
| | | | | | | | | | | Let local_tick_enable/disable() reprogram the clock comparator so the function names make semantically more sense. Also that way the functions are more symmetric since normally each local_tick_enable() call usually would have a subsequent call to set_clock_comparator() anyway. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] nmi: fix clock comparator revalidationHeiko Carstens2010-11-251-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | On each machine check all registers are revalidated. The save area for the clock comparator however only contains the upper most seven bytes of the former contents, if valid. Therefore the machine check handler uses a store clock instruction to get the current time and writes that to the clock comparator register which in turn will generate an immediate timer interrupt. However within the lowcore the expected time of the next timer interrupt is stored. If the interrupt happens before that time the handler won't be called. In turn the clock comparator won't be reprogrammed and therefore the interrupt condition stays pending which causes an interrupt loop until the expected time is reached. On NOHZ machines this can result in unresponsive machines since the time of the next expected interrupted can be a couple of days in the future. To fix this just revalidate the clock comparator register with the expected value. In addition the special handling for udelay must be changed as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] uaccess: make sure copy_from_user_overflow is builtinHeiko Carstens2010-03-081-1/+2
| | | | | | | | | | | If there is no in kernel image caller modules will suffer: ERROR: "copy_from_user_overflow" [net/core/pktgen.ko] undefined! ERROR: "copy_from_user_overflow" [net/can/can-raw.ko] undefined! ERROR: "copy_from_user_overflow" [fs/cifs/cifs.ko] undefined! Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] spinlock: check virtual cpu running statusGerald Schaefer2010-02-261-16/+37
| | | | | | | | | | | This patch introduces a new function that checks the running status of a cpu in a hypervisor. This status is not virtualized, so the check is only correct if running in an LPAR. On acquiring a spinlock, if the cpu holding the lock is scheduled by the hypervisor, we do a busy wait on the lock. If it is not scheduled, we yield over to that cpu. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] uaccess: implement strict user copy checksHeiko Carstens2010-02-262-1/+9
| | | | | | | | | Same as on x86 and sparc, besides the fact that enabling the option will just emit compile time warnings instead of errors. Keeps allyesconfig kernels compiling. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Move __cpu_logical_map to smp.cHeiko Carstens2010-01-131-1/+1
| | | | | | | | Finally move it to the place where it belongs to and make get rid of it for !CONFIG_SMP. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* locking: Convert raw_rwlock functions to arch_rwlockThomas Gleixner2009-12-141-6/+6
| | | | | | | | | | Name space cleanup for rwlock functions. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* locking: Convert raw_rwlock to arch_rwlockThomas Gleixner2009-12-141-6/+6
| | | | | | | | | | | | | | Not strictly necessary for -rt as -rt does not have non sleeping rwlocks, but it's odd to not have a consistent naming convention. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* locking: Convert __raw_spin* functions to arch_spin*Thomas Gleixner2009-12-141-11/+11
| | | | | | | | | | Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* locking: Convert raw_spinlock to arch_spinlockThomas Gleixner2009-12-141-4/+4
| | | | | | | | | | | | | | | | | | | The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* [S390] Use do_exception() in pagetable walk usercopy functions.Gerald Schaefer2009-12-071-96/+51
| | | | | | | | | | | | The pagetable walk usercopy functions have used a modified copy of the do_exception() function for fault handling. This lead to inconsistencies with recent changes to do_exception(), e.g. performance counters. This patch changes the pagetable walk usercopy code to call do_exception() directly, eliminating the redundancy. A new parameter is added to do_exception() to specify the fault address. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Improve address space mode selection.Martin Schwidefsky2009-12-071-4/+0
| | | | | | | | | | | | | | | | | | Introduce user_mode to replace the two variables switch_amode and s390_noexec. There are three valid combinations of the old values: 1) switch_amode == 0 && s390_noexec == 0 2) switch_amode == 1 && s390_noexec == 0 3) switch_amode == 1 && s390_noexec == 1 They get replaced by 1) user_mode == HOME_SPACE_MODE 2) user_mode == PRIMARY_SPACE_MODE 3) user_mode == SECONDARY_SPACE_MODE The new kernel parameter user_mode=[primary,secondary,home] lets you choose the address space mode the user space processes should use. In addition the CONFIG_S390_SWITCH_AMODE config option is removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Add EX_TABLE for addressing exception in usercopy functions.Gerald Schaefer2009-10-062-12/+14
| | | | | | | | | | | | This patch adds an EX_TABLE entry to mvc{p|s|os} usercopy functions that may be called with KERNEL_DS. In combination with collaborative memory management, kernel pages marked as unused may trigger an adressing exception in the usercopy functions. This fixes an unhandled addressing exception bug where strncpy_from_user() is used with len > strnlen and KERNEL_DS, crossing a page boundary to an unused page. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Provide arch specific mdelay implementation.Heiko Carstens2009-10-061-7/+7
| | | | | | | Use an own implementation instead of the common code udelay loop. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] Fix enabled udelay for short delays.Christian Borntraeger2009-10-061-4/+9
| | | | | | | | | | | | | | | | | When udelay() gets called with a delay that would expire before the next clock event it reprograms the clock comparator. When the interrupt happens the clock comparator won't be resetted therefore the interrupt condition doesn't get cleared. The result is an endless timer interrupt loop until the next clock event would expire (stored in lowcore). So udelay() usually would wait much longer for small delays than it should. Fix this by disabling the local tick which makes sure that the clock comparator will be resetted when a timer interrupt happens. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] add __ucmpdi2() helper functionHeiko Carstens2009-07-072-1/+27
| | | | | | | | | | | Provide __ucmpdi2() helper function on 31 bit so we don't run again and again in compile errors like this one: kernel/built-in.o: In function `T.689': perf_counter.c:(.text+0x56c86): undefined reference to `__ucmpdi2' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* [S390] udelay: disable lockdep to avoid false positivesHeiko Carstens2009-07-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Our udelay implementation enables interrupts to receive a special timer interrupt regardless of the context it is called from. This might lead to false positive lockdep reports. Since lockdep isn't aware of the fact that only a single interrupt source is enabled it warns about possible deadlocks that in reality won't happen, like the one below. To fix this disable lockdep before enabling interrupts. [ 254.040888] ================================= [ 254.040904] [ INFO: inconsistent lock state ] [ 254.040910] 2.6.30 #9 [ 254.040914] --------------------------------- [ 254.040920] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. [ 254.040927] swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes: [ 254.040934] (sch->lock){?.-...}, at: [<00000000002e4778>] ccw_device_timeout+0x48/0x2f0 [ 254.040961] {IN-HARDIRQ-W} state was registered at: [ 254.040969] [<0000000000096f74>] __lock_acquire+0x9d4/0x188c [ 254.040985] [<0000000000097f68>] lock_acquire+0x13c/0x16c [ 254.040998] [<00000000004527e0>] _spin_lock+0x74/0xb8 [ 254.041016] [<0000000000457eb2>] do_IRQ+0xde/0x208 [ 254.041031] [<000000000002d190>] io_return+0x0/0x8 [ 254.041049] [<0000000000029faa>] vtime_stop_cpu+0xbe/0x114 [ 254.041066] irq event stamp: 259629 [ 254.041076] hardirqs last enabled at (259628): [<000000000045238e>] _spin_unlock_irq+0x5e/0x9c [ 254.041095] hardirqs last disabled at (259629): [<000000000045292e>] _spin_lock_irq+0x4a/0xc4 [ 254.041126] softirqs last enabled at (259614): [<000000000006500e>] __do_softirq+0x296/0x2b0 [ 254.041137] softirqs last disabled at (259619): [<0000000000024cf6>] do_softirq+0x102/0x108 [ 254.041147] [ 254.041148] other info that might help us debug this: [ 254.041153] 2 locks held by swapper/0: [ 254.041157] #0: (&priv->timer){+.-...}, at: [<000000000006bf9a>] run_timer_softirq+0x19a/0x340 [ 254.041170] #1: (sch->lock){?.-...}, at: [<00000000002e4778>] ccw_device_timeout+0x48/0x2f0 [ 254.041182] [ 254.041310] Call Trace: [ 254.041313] ([<00000000000174fc>] show_trace+0x16c/0x170) [ 254.041321] [<0000000000017578>] show_stack+0x78/0x104 [ 254.041327] [<000000000044d0ca>] dump_stack+0xc6/0xd4 [ 254.041342] [<00000000000949b4>] print_usage_bug+0x1c8/0x1fc [ 254.041353] [<0000000000094e8a>] mark_lock+0x4a2/0x670 [ 254.041364] [<00000000000950e2>] mark_held_locks+0x8a/0xb4 [ 254.041375] [<0000000000095398>] trace_hardirqs_on_caller+0x74/0x1ac [ 254.041388] [<00000000000954fa>] trace_hardirqs_on+0x2a/0x38 [ 254.041402] [<000000000025f1ec>] __udelay_disabled+0xac/0xfc [ 254.041419] [<000000000025f432>] __udelay+0x12a/0x148 [ 254.041433] [<00000000002d64d8>] cio_commit_config+0x170/0x290 [ 254.041451] [<00000000002d6978>] cio_disable_subchannel+0x120/0x1cc [ 254.041468] [<00000000002e32a4>] ccw_device_recog_done+0x54/0x2f4 [ 254.041485] [<00000000002e3638>] ccw_device_sense_id_done+0x50/0x90 [ 254.041508] [<00000000002e615a>] snsid_callback+0xfa/0x3a8 [ 254.041515] [<00000000002dd96c>] ccwreq_stop+0x80/0x90 [ 254.041523] [<00000000002dda8e>] ccw_request_timeout+0xc2/0xd0 [ 254.041530] [<00000000002e2f70>] ccw_device_request_event+0x58/0x90 [ 254.041537] [<00000000002e47ae>] ccw_device_timeout+0x7e/0x2f0 [ 254.041555] [<000000000006c02a>] run_timer_softirq+0x22a/0x340 [ 254.041566] [<0000000000064eb0>] __do_softirq+0x138/0x2b0 [ 254.041578] [<0000000000024cf6>] do_softirq+0x102/0x108 [ 254.041590] [<00000000000647ce>] irq_exit+0xee/0x114 [ 254.041603] [<0000000000457d88>] do_extint+0x130/0x17c [ 254.041617] [<000000000002d41e>] ext_no_vtime+0x1e/0x22 [ 254.041631] [<0000000000029faa>] vtime_stop_cpu+0xbe/0x114 [ 254.041646] ([<0000000000029f58>] vtime_stop_cpu+0x6c/0x114) [ 254.041662] [<000000000001d842>] cpu_idle+0x122/0x1c0 [ 254.041679] [<00000000004482c6>] start_secondary+0xce/0xe0 [ 254.041696] [<0000000000000000>] 0x0 [ 254.041715] [<0000000000000000>] 0x0 [ 254.041745] INFO: lockdep is turned off. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* Move FAULT_FLAG_xyz into handle_mm_fault() callersLinus Torvalds2009-06-211-1/+1
| | | | | | | | | | This allows the callers to now pass down the full set of FAULT_FLAG_xyz flags to handle_mm_fault(). All callers have been (mechanically) converted to the new calling convention, there's almost certainly room for architectures to clean up their code and then add FAULT_FLAG_RETRY when that support is added. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 23:00:40 +0100