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2011-05-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: arch/tile: more /proc and /sys file support
2011-05-27arch/tile: more /proc and /sys file supportChris Metcalf
This change introduces a few of the less controversial /proc and /proc/sys interfaces for tile, along with sysfs attributes for various things that were originally proposed as /proc/tile files. It also adjusts the "hardwall" proc API. Arnd Bergmann reviewed the initial arch/tile submission, which included a complete set of all the /proc/tile and /proc/sys/tile knobs that we had added in a somewhat ad hoc way during initial development, and provided feedback on where most of them should go. One knob turned out to be similar enough to the existing /proc/sys/debug/exception-trace that it was re-implemented to use that model instead. Another knob was /proc/tile/grid, which reported the "grid" dimensions of a tile chip (e.g. 8x8 processors = 64-core chip). Arnd suggested looking at sysfs for that, so this change moves that information to a pair of sysfs attributes (chip_width and chip_height) in the /sys/devices/system/cpu directory. We also put the "chip_serial" and "chip_revision" information from our old /proc/tile/board file as attributes in /sys/devices/system/cpu. Other information collected via hypervisor APIs is now placed in /sys/hypervisor. We create a /sys/hypervisor/type file (holding the constant string "tilera") to be parallel with the Xen use of /sys/hypervisor/type holding "xen". We create three top-level files, "version" (the hypervisor's own version), "config_version" (the version of the configuration file), and "hvconfig" (the contents of the configuration file). The remaining information from our old /proc/tile/board and /proc/tile/switch files becomes an attribute group appearing under /sys/hypervisor/board/. Finally, after some feedback from Arnd Bergmann for the previous version of this patch, the /proc/tile/hardwall file is split up into two conceptual parts. First, a directory /proc/tile/hardwall/ which contains one file per active hardwall, each file named after the hardwall's ID and holding a cpulist that says which cpus are enclosed by the hardwall. Second, a /proc/PID file "hardwall" that is either empty (for non-hardwall-using processes) or contains the hardwall ID. Finally, this change pushes the /proc/sys/tile/unaligned_fixup/ directory, with knobs controlling the kernel code for handling the fixup of unaligned exceptions. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (26 commits) arch/tile: prefer "tilepro" as the name of the 32-bit architecture compat: include aio_abi.h for aio_context_t arch/tile: cleanups for tilegx compat mode arch/tile: allocate PCI IRQs later in boot arch/tile: support signal "exception-trace" hook arch/tile: use better definitions of xchg() and cmpxchg() include/linux/compat.h: coding-style fixes tile: add an RTC driver for the Tilera hypervisor arch/tile: finish enabling support for TILE-Gx 64-bit chip compat: fixes to allow working with tile arch arch/tile: update defconfig file to something more useful tile: do_hardwall_trap: do not play with task->sighand tile: replace mm->cpu_vm_mask with mm_cpumask() tile,mn10300: add device parameter to dma_cache_sync() audit: support the "standard" <asm-generic/unistd.h> arch/tile: clarify flush_buffer()/finv_buffer() function names arch/tile: kernel-related cleanups from removing static page size arch/tile: various header improvements for building drivers arch/tile: disable GX prefetcher during cache flush arch/tile: tolerate disabling CONFIG_BLK_DEV_INITRD ...
2011-05-24Merge branch 'for-2.6.40' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: Unify input section names percpu: Avoid extra NOP in percpu_cmpxchg16b_double percpu: Cast away printk format warning percpu: Always align percpu output section to PAGE_SIZE Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun
2011-05-20arch/tile: cleanups for tilegx compat modeChris Metcalf
These changes make the syscall table line up correctly for tilegx compat mode, and remove the stale sys32_fadvise64() function, which isn't actually used by any syscall table. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-20arch/tile: allocate PCI IRQs later in bootChris Metcalf
This change became required due to some recent reworking in the platform-independent IRQ code. It is required for 2.6.38 and later. Cc: stable@kernel.org Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-20arch/tile: support signal "exception-trace" hookChris Metcalf
This change adds support for /proc/sys/debug/exception-trace to tile. Like x86 and sparc, by default it is set to "1", generating a one-line printk whenever a user process crashes. By setting it to "2", we get a much more complete userspace diagnostic at crash time, including a user-space backtrace, register dump, and memory dump around the address of the crash. Some vestiges of the Tilera-internal version of this support are removed with this patch (the show_crashinfo variable and the arch_coredump_signal function). We retain a "crashinfo" boot parameter which allows you to set the boot-time value of exception-trace. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-12arch/tile: finish enabling support for TILE-Gx 64-bit chipChris Metcalf
This support was partially present in the existing code (look for "__tilegx__" ifdefs) but with this change you can build a working kernel using the TILE-Gx toolchain and ARCH=tilegx. Most of these files are new, generally adding a foo_64.c file where previously there was just a foo_32.c file. The ARCH=tilegx directive redirects to arch/tile, not arch/tilegx, using the existing SRCARCH mechanism in the top-level Makefile. Changes to existing files: - <asm/bitops.h> and <asm/bitops_32.h> changed to factor the include of <asm-generic/bitops/non-atomic.h> in the common header. - <asm/compat.h> and arch/tile/kernel/compat.c changed to remove the "const" markers I had put on compat_sys_execve() when trying to match some recent similar changes to the non-compat execve. It turns out the compat version wasn't "upgraded" to use const. - <asm/opcode-tile_64.h> and <asm/opcode_constants_64.h> were previously included accidentally, with the 32-bit contents. Now they have the proper 64-bit contents. Finally, I had to hack the existing hacky drivers/input/input-compat.h to add yet another "#ifdef" for INPUT_COMPAT_TEST (same as x86_64). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [drivers/input]
2011-05-12compat: fixes to allow working with tile archChris Metcalf
The existing <asm-generic/unistd.h> mechanism doesn't really provide enough to create the 64-bit "compat" ABI properly in a generic way, since the compat ABI is a mix of things were you can re-use the 64-bit versions of syscalls and things where you need a compat wrapper. To provide this in the most direct way possible, I added two new macros to go along with the existing __SYSCALL and __SC_3264 macros: __SC_COMP and SC_COMP_3264. These macros take an additional argument, typically a "compat_sys_xxx" function, which is passed to __SYSCALL if you define __SYSCALL_COMPAT when including the header, resulting in a pointer to the compat function being placed in the generated syscall table. The change also adds some missing definitions to <linux/compat.h> so that it actually has declarations for all the compat syscalls, since the "[nr] = ##call" approach requires proper C declarations for all the functions included in the syscall table. Finally, compat.c defines compat_sys_sigpending() and compat_sys_sigprocmask() even if the underlying architecture doesn't request it, which tries to pull in undefined compat_old_sigset_t defines. We need to guard those compat syscall definitions with appropriate __ARCH_WANT_SYS_xxx ifdefs. Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04tile: do_hardwall_trap: do not play with task->sighandOleg Nesterov
1. do_hardwall_trap() checks ->sighand != NULL and then takes ->siglock. This is unsafe even if the task can't run (I assume it is pinned to the same CPU), its parent can reap the task and set ->sighand = NULL right after this check. Even if the compiler dosn't read ->sighand twice and this memory can't to away __group_send_sig_info() is wrong after that. Use do_send_sig_info(). 2. Send SIGILL to the thread, not to the whole process. Unless it has the handler or blocked this kills the whole thread-group as before. IIUC, different threads can be bound to different rect's. 3. Check PF_EXITING instead of ->sighand. A zombie thread can go away but its ->sighand can be !NULL. Reported-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04tile: replace mm->cpu_vm_mask with mm_cpumask()KOSAKI Motohiro
We plan to change mm->cpu_vm_mask definition later. Thus, this patch convert it into proper macro. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04tile,mn10300: add device parameter to dma_cache_sync()James Hogan
Since v2.6.20 "Pass struct dev pointer to dma_cache_sync()" (d3fa72e4556ec1f04e46a0d561d9e785ecaa173d), dma_cache_sync() takes a struct dev pointer, but these appear to be missing from the tile and mn10300 implementations, so add them. Signed-off-by: James Hogan <james.hogan@imgtec.com> [cmetcalf@tilera.com: took only the "tile" portion as I don't maintain mn10300] Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04arch/tile: various header improvements for building driversChris Metcalf
This change adds a number of missing headers in asm (fb.h, parport.h, serial.h, and vga.h) using the minimal generic versions. It also adds a number of missing interfaces that showed up as build failures when trying to build various drivers not normally included in the "tile" distribution: ioremap_wc(), memset_io(), io{read,write}{16,32}be(), virt_to_bus(), bus_to_virt(), irq_canonicalize(), __pte(), __pgd(), and __pmd(). I also added a cast in virt_to_page() since not all callers pass a pointer. I fixed <asm/stat.h> to properly include a __KERNEL__ guard for the __ARCH_WANT_STAT64 symbol, and <asm/swab.h> to use __builtin_bswap32() even for our 64-bit architecture, since the same code is produced. I added an export for get_cycles(), since it's used in some modules. And I made <arch/spr_def.h> properly include the __KERNEL__ guard, even though it's not yet exported, since it likely will be soon. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04arch/tile: tolerate disabling CONFIG_BLK_DEV_INITRDChris Metcalf
The code accidentally was relying on this configuration option being selected. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04arch/tile: properly flush the I$ when unloading kernel modulesChris Metcalf
Otherwise, in principle, there could be stale I$ data present next time the page that previously held the kernel module code was used to run some new code. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04arch/tile: allow nonatomic stores to interoperate with fast atomic syscallsChris Metcalf
This semantic was already true for atomic operations within the kernel, and this change makes it true for the fast atomic syscalls (__NR_cmpxchg and __NR_atomic_update) as well. Previously, user-space had to use the fast atomic syscalls exclusively to update memory, since raw stores could lose a race with the atomic update code even when the atomic update hadn't actually modified the value. With this change, we no longer write back the value to memory if it hasn't changed. This allows certain types of idioms in user space to work as expected, e.g. "atomic exchange" to acquire a spinlock, followed by a raw store of zero to release the lock. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-04arch/tile: improve support for PCI hotplugChris Metcalf
Note that this is not complete hot-plug support; hot-unplug is not included. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-02arch/tile: support TIF_NOTIFY_RESUMEChris Metcalf
This support is required for CONFIG_KEYS, NFSv4 kernel DNS, etc. The change is slightly more complex than the minimal thing, since I took advantage of having to go into the assembly code to just move a bunch of stuff into C code: specifically, the schedule(), do_async_page_fault(), do_signal(), and single_step_once() support, in addition to the TIF_NOTIFY_RESUME support. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-05-02arch/tile: refactor backtracing codeChris Metcalf
This change is the result of some work to make the backtrace code more shareable between kernel, libc, and gdb. For the kernel, some good effects are to eliminate the hacky "VirtualAddress" typedef in favor of "unsigned long", to eliminate a bunch of spurious kernel doc comments, to remove the dead "bt_read_memory" function, and to use "__tilegx__" in #ifdefs instead of "TILE_CHIP". Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-04-14sched: Provide scheduler_ipi() callback in response to smp_send_reschedule()Peter Zijlstra
For future rework of try_to_wake_up() we'd like to push part of that function onto the CPU the task is actually going to run on. In order to do so we need a generic callback from the existing scheduler IPI. This patch introduces such a generic callback: scheduler_ipi() and implements it as a NOP. BenH notes: PowerPC might use this IPI on offline CPUs under rare conditions! Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reviewed-by: Frank Rowand <frank.rowand@am.sony.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110405152728.744338123@chello.nl
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-25tile: Use generic show_interupts()Thomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Chris Metcalf <cmetcalf@tilera.com> LKML-Reference: <20110325142049.536190130@linutronix.de>
2011-03-25tile: Convert to new irq function namesThomas Gleixner
Converted with coccinelle. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Chris Metcalf <cmetcalf@tilera.com> LKML-Reference: <20110325142049.441954268@linutronix.de>
2011-03-24percpu: Always align percpu output section to PAGE_SIZETejun Heo
Percpu allocator honors alignment request upto PAGE_SIZE and both the percpu addresses in the percpu address space and the translated kernel addresses should be aligned accordingly. The calculation of the former depends on the alignment of percpu output section in the kernel image. The linker script macros PERCPU_VADDR() and PERCPU() are used to define this output section and the latter takes @align parameter. Several architectures are using @align smaller than PAGE_SIZE breaking percpu memory alignment. This patch removes @align parameter from PERCPU(), renames it to PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it, add PCPU_SETUP_BUG_ON() checks such that alignment problems are reliably detected and remove percpu alignment comment recently added in workqueue.c as the condition would trigger BUG way before reaching there. For um, this patch raises the alignment of percpu area. As the area is in .init, there shouldn't be any noticeable difference. This problem was discovered by David Howells while debugging boot failure on mn10300. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: uclinux-dist-devel@blackfin.uclinux.org Cc: David Howells <dhowells@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: user-mode-linux-devel@lists.sourceforge.net
2011-03-23mm: NUMA aware alloc_thread_info_node()Eric Dumazet
Add a node parameter to alloc_thread_info(), and change its name to alloc_thread_info_node() This change is needed to allow NUMA aware kthread_create_on_cpu() Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Andi Kleen <ak@linux.intel.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: (27 commits) arch/tile: support newer binutils assembler shift semantics arch/tile: fix deadlock bugs in rwlock implementation drivers/edac: provide support for tile architecture tile on-chip network driver: sync up with latest fixes arch/tile: support 4KB page size as well as 64KB arch/tile: add some more VMSPLIT options and use consistent naming arch/tile: fix some comments and whitespace arch/tile: export some additional module symbols arch/tile: enhance existing finv_buffer_remote() routine arch/tile: fix two bugs in the backtracer code arch/tile: use extended assembly to inline __mb_incoherent() arch/tile: use a cleaner technique to enable interrupt for cpu_idle() arch/tile: sync up with <arch/sim.h> and <arch/sim_def.h> changes arch/tile: fix reversed test of strict_strtol() return value arch/tile: avoid a simulator warning during bootup arch/tile: export <asm/hardwall.h> to userspace arch/tile: warn and retry if an IPI is not accepted by the target cpu arch/tile: stop disabling INTCTRL_1 interrupts during hypervisor downcalls arch/tile: fix __ndelay etc to work better arch/tile: bug fix: exec'ed task thought it was still single-stepping ... Fix up trivial conflict in arch/tile/kernel/vmlinux.lds.S (percpu alignment vs section naming convention fix)
2011-03-17arch/tile: support newer binutils assembler shift semanticsChris Metcalf
This change supports building the kernel with newer binutils where a shift of greater than the word size is no longer interpreted silently as modulo the word size, but instead generates a warning. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-10arch/tile: support 4KB page size as well as 64KBChris Metcalf
The Tilera architecture traditionally supports 64KB page sizes to improve TLB utilization and improve performance when the hardware is being used primarily to run a single application. For more generic server scenarios, it can be beneficial to run with 4KB page sizes, so this commit allows that to be specified (by modifying the arch/tile/include/hv/pagesize.h header). As part of this change, we also re-worked the PTE management slightly so that PTE writes all go through a __set_pte() function where we can do some additional validation. The set_pte_order() function was eliminated since the "order" argument wasn't being used. One bug uncovered was in the PCI DMA code, which wasn't properly flushing the specified range. This was benign with 64KB pages, but with 4KB pages we were getting some larger flushes wrong. The per-cpu memory reservation code also needed updating to conform with the newer percpu stuff; before it always chose 64KB, and that was always correct, but with 4KB granularity we now have to pay closer attention and reserve the amount of memory that will be requested when the percpu code starts allocating. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-10arch/tile: fix some comments and whitespaceChris Metcalf
This is a grab bag of changes with no actual change to generated code. This includes whitespace and comment typos, plus a couple of stale comments being removed. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: fix two bugs in the backtracer codeChris Metcalf
The first is that we were using an incorrect hand-rolled variant of __kernel_text_address() which didn't handle module PCs. We now just use the standard API. The second was that we weren't accounting for the three-level page table when we were trying to pre-verify the addresses on the 64-bit TILE-Gx processor; we now do that correctly. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: use a cleaner technique to enable interrupt for cpu_idle()Chris Metcalf
Previously we used iret to atomically return to kernel PL with interrupts enabled. However, it turns out that we are architecturally guaranteed that we can just set and clear the "interrupt critical section" and only interrupt on the following instruction, so we now do that instead, since it's cleaner. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: warn and retry if an IPI is not accepted by the target cpuChris Metcalf
Previously we assumed this was impossible, but in fact it can happen. Handle it gracefully by retrying after issuing a warning. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: stop disabling INTCTRL_1 interrupts during hypervisor downcallsChris Metcalf
The problem was that this could lead to IPIs being disabled during the softirq processing after a hypervisor downcall (e.g. for I/O), since both IPI and device interrupts use the INCTRL_1 downcall mechanism. When this happened at the wrong time, it could lead to deadlock. Luckily, we were already maintaining the per-interrupt state we need, and using it in the proper way in the hypervisor, so all we had to do was to change Linux to stop blocking downcall interrupts for the entire length of the downcall. (Now they're blocked while we're executing the downcall routine itself, but not while we're executing any subsequent softirq routines.) The hypervisor is doing a very small amount of work it no longer needs to do (masking INTCTRL_1 on entry to the client interrupt routine), but doing so means that older versions of Tile Linux will continue to work with a current hypervisor, so that seems reasonable. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: fix __ndelay etc to work betterChris Metcalf
The current implementations of __ndelay and __udelay call a hypervisor service to delay, but the hypervisor service isn't actually implemented very well, and the consensus is that Linux should handle figuring this out natively and not use a hypervisor service. By converting nanoseconds to cycles, and then spinning until the cycle counter reaches the desired cycle, we get several benefits: first, we are sensitive to the actual clock speed; second, we use less power by issuing a slow SPR read once every six cycles while we delay; and third, we properly handle the case of an interrupt by exiting at the target time rather than after some number of cycles. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: bug fix: exec'ed task thought it was still single-steppingChris Metcalf
To handle single-step, tile mmap's a page of memory in the process space for each thread and uses it to construct a version of the instruction that we want to single step. If the process exec's, though, we lose that mapping, and the kernel needs to be aware that it will need to recreate it if the exec'ed process than tries to single-step as well. Also correct some int32_t to s32 for better kernel style. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-03-01arch/tile: catch up with section naming convention in 2.6.35Chris Metcalf
The convention changed to, e.g., ".data..page_aligned". This commit fixes the places in the tile architecture that were still using the old convention. One tile-specific section (.init.page) was dropped in favor of just using an "aligned" attribute. Sam Ravnborg <sam@ravnborg.org> pointed out __PAGE_ALIGNED_BSS, etc. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-02-23tile: Use proper accessor functions in show_interrupt()Thomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-02-23tile: Convert irq_chip to new functionsThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2011-01-25percpu: align percpu readmostly subsection to cachelineTejun Heo
Currently percpu readmostly subsection may share cachelines with other percpu subsections which may result in unnecessary cacheline bounce and performance degradation. This patch adds @cacheline parameter to PERCPU() and PERCPU_VADDR() linker macros, makes each arch linker scripts specify its cacheline size and use it to align percpu subsections. This is based on Shaohua's x86 only patch. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Shaohua Li <shaohua.li@intel.com>
2010-12-17arch/tile: handle rt_sigreturn() more cleanlyChris Metcalf
The current tile rt_sigreturn() syscall pattern uses the common idiom of loading up pt_regs with all the saved registers from the time of the signal, then anticipating the fact that we will clobber the ABI "return value" register (r0) as we return from the syscall by setting the rt_sigreturn return value to whatever random value was in the pt_regs for r0. However, this breaks in our 64-bit kernel when running "compat" tasks, since we always sign-extend the "return value" register to properly handle returned pointers that are in the upper 2GB of the 32-bit compat address space. Doing this to the sigreturn path then causes occasional random corruption of the 64-bit r0 register. Instead, we stop doing the crazy "load the return-value register" hack in sigreturn. We already have some sigreturn-specific assembly code that we use to pass the pt_regs pointer to C code. We extend that code to also set the link register to point to a spot a few instructions after the usual syscall return address so we don't clobber the saved r0. Now it no longer matters what the rt_sigreturn syscall returns, and the pt_regs structure can be cleanly and completely reloaded. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-12-17arch/tile: handle CLONE_SETTLS in copy_thread(), not user spaceChris Metcalf
Previously we were just setting up the "tp" register in the new task as started by clone() in libc. However, this is not quite right, since in principle a signal might be delivered to the new task before it had its TLS set up. (Of course, this race window still exists for resetting the libc getpid() cached value in the new task, in principle. But in any case, we are now doing this exactly the way all other architectures do it.) This change is important for 2.6.37 since the tile glibc we will be submitting upstream will not set TLS in user space any more, so it will only work on a kernel that has this fix. It should also be taken for 2.6.36.x in the stable tree if possible. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Cc: stable <stable@kernel.org>
2010-11-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: arch/tile: fix memchr() not to dereference memory for zero length arch/tile: make glibc's sysconf(_SC_NPROCESSORS_CONF) work correctly arch/tile: fix rwlock so would-be write lockers don't block new readers
2010-11-24Merge branch 'drivers' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile * 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: pci root complex: support for tile architecture drivers/net/tile/: on-chip network drivers for the tile architecture MAINTAINERS: add drivers/char/hvc_tile.c as maintained by tile
2010-11-24arch/tile: make glibc's sysconf(_SC_NPROCESSORS_CONF) work correctlyChris Metcalf
glibc assumes that it can count /sys/devices/system/cpu/cpu* to get the number of configured cpus. For this to be valid on tile, we need to generate a "cpu" entry for all cpus, including the ones that are not currently allocated for Linux's use. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-24pci root complex: support for tile architectureChris Metcalf
This change enables PCI root complex support for TILEPro. Unlike TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI support consists of hypervisor upcalls for PIO, DMA, etc. However, the performance is fine for the devices we have tested with so far (1Gb Ethernet, SATA, etc.). The <asm/io.h> header was tweaked to be a little bit more aggressive about disabling attempts to map/unmap IO port space. The hacky <asm/pci-bridge.h> header was rolled into the <asm/pci.h> header and the result was simplified. Both of the latter two headers were preliminary versions not meant for release before now - oh well. There is one quirk for our TILEmpower platform, which accidentally negotiates up to 5GT and needs to be kicked down to 2.5GT. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-17BKL: remove extraneous #include <smp_lock.h>Arnd Bergmann
The big kernel lock has been removed from all these files at some point, leaving only the #include. Remove this too as a cleanup. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-01arch/tile: mark "hardwall" device as non-seekableChris Metcalf
Arnd's recent patch series tagged this device with noop_llseek, conservatively. In fact, it should be no_llseek, which we arrange for by opening the device with nonseekable_open(). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01asm-generic/stat.h: support 64-bit file time_t for stat()Chris Metcalf
The existing asm-generic/stat.h specifies st_mtime, etc., as a 32-value, and works well for 32-bit architectures (currently microblaze, score, and 32-bit tile). However, for 64-bit architectures it isn't sufficient to return 32 bits of time_t; this isn't good insurance against the 2037 rollover. (It also makes glibc support less convenient, since we can't use glibc's handy STAT_IS_KERNEL_STAT mode.) This change extends the two "timespec" fields for each of the three atime, mtime, and ctime fields from "int" to "long". As a result, on 32-bit platforms nothing changes, and 64-bit platforms will now work as expected. The only wrinkle is 32-bit userspace under 64-bit kernels taking advantage of COMPAT mode. For these, we leave the "struct stat64" definitions with the "int" versions of the time_t and nsec fields, so that architectures can implement compat_sys_stat64() and friends with sys_stat64(), etc., and get the expected 32-bit structure layout. This requires a field-by-field copy in the kernel, implemented by the code guarded under __ARCH_WANT_STAT64. This does mean that the shape of the "struct stat" and "struct stat64" structures is different on a 64-bit kernel, but only one of the two structures should ever be used by any given process: "struct stat" is meant for 64-bit userspace only, and "struct stat64" for 32-bit userspace only. (On a 32-bit kernel the two structures continue to have the same shape, since "long" is 32 bits.) The alternative is keeping the two structures the same shape on 64-bit kernels, which means a 64-bit time_t in "struct stat64" for 32-bit processes. This is a little unnatural since 32-bit userspace can't do anything with 64 bits of time_t information, since time_t is just "long", not "int64_t"; and in any case 32-bit userspace might expect to be running under a 32-bit kernel, which can't provide the high 32 bits anyway. In the case of a 32-bit kernel we'd then be extending the kernel's 32-bit time_t to 64 bits, then truncating it back to 32 bits again in userspace, for no particular reason. And, as mentioned above, if we have 64-bit time_t for 32-bit processes we can't easily use glibc's STAT_IS_KERNEL_STAT, since glibc's stat structure requires an embedded "struct timespec", which is a pair of "long" (32-bit) values in a 32-bit userspace. "Inventive" solutions are possible, but are pretty hacky. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2010-11-01arch/tile: don't allow user code to set the PL via ptrace or signal returnChris Metcalf
The kernel was allowing any component of the pt_regs to be updated either by signal handlers writing to the stack, or by processes writing via PTRACE_POKEUSR or PTRACE_SETREGS, which meant they could set their PL up from 0 to 1 and get access to kernel code and data (or, in practice, cause a kernel panic). We now always reset the ex1 field, allowing the user to set their ICS bit only. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2010-11-01arch/tile: correct double syscall restart for nested signalsChris Metcalf
This change is modelled on similar fixes for other architectures. The pt_regs "faultnum" member is set to the trap (fault) number that caused us to enter the kernel, and is INT_SWINT_1 for the syscall software interrupt. We already supported a pseudo value, INT_SWINT_1_SIGRETURN, that we used for the rt_sigreturn syscall; it avoided the case where one signal was handled, then we "tail-called" to another handler. This change avoids the similar case where we start to call one handler, then are preempted into another handler when we start trying to run the first handler. We clear ->faultnum after calling handle_signal(), and to be paranoid also in the case where there was no signal to deliver. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>