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2008-07-02avr32: Store virtual addresses in the PGDHaavard Skinnemoen
Instead of storing physical addresses along with page flags in the PGD, store virtual addresses and use NULL to indicate a not present second-level page table. A non-page-aligned page table indicates a bad PMD. This simplifies the TLB miss handler since it no longer has to check the Present bit and no longer has to convert the PGD entry from physical to virtual address. Instead, it has to check for a NULL entry, which is slightly cheaper than either. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02avr32: Remove useless zeroing of swapper_pg_dir at startupHaavard Skinnemoen
swapper_pg_dir is stored in .bss, so it must already be zeroed out when we get there. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02avr32: Clean up and optimize the TLB operationsHaavard Skinnemoen
This and the following patches aim to optimize the code dealing with page tables and TLB operations. Each patch reduces the time it takes to gzip a 16 MB file slightly, but I expect things like fork() and mmap() will improve somewhat more. This patch deals with the low-level TLB operations: * Remove unused _TLBEHI_I define * Use gcc builtins instead of inline assembly * Remove a few unnecessary pipeline flushes and nops * Introduce NR_TLB_ENTRIES define and use it instead of hardcoding it to 32 a few places throughout the code. * Use sysreg bitops instead of hardcoded shifts and masks * Make a few needlessly global functions static Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-28avr32: Rename at32ap.c -> pdc.cHaavard Skinnemoen
The only thing left in at32ap.c is some PDC stuff. Rename the file to reflect what it actually does. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-06-28avr32: Move setup_platform() into chip-specific fileHaavard Skinnemoen
Combine at32_clock_init() and at32_portmux_init() into setup_platform() and remove setup_platform() from at32ap.c. No functional change since all setup_platform() ever did was call those two functions. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-06-27avr32: Kill special exception handler sectionsHaavard Skinnemoen
Kill the special exception handler sections .tlbx.ex.text, .tlbr.ex.text, tlbw.ex.text and .scall.text. Use .org instead to place the handlers at the required offsets from EVBA. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: Clean up time.c #includesHaavard Skinnemoen
Remove lots of unneeded #includes, add #include <linux/kernel.h> and sort alphabetically. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27atmel_pwm: Rename the "mck" clock to "pwm_clk"Sedji Gaouaou
The name "mck" causes a conflict on AT91. Call it "pwm_clk" instead. Signed-off-by: Sedji Gaouaou <sedji.gaouaou@atmel.com> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27at32ap700x spi: enable pullups on MISODavid Brownell
This is a minor tweak to the at32ap700x pin configuration for the SPI input pin (MISO), enabling the on-chip weak pullup (typical 190K) to (a) ensure a fixed data value for missing or input-only slaves; (b) prevent power waste associated with inputs floating near VDDIO/2. Atmel's boards have no external pullup or pulldown on these pins, so it's unlikely other boards would address these issues with external pulldowns. Were there trouble, board-specific code could turn off the relevant pullup(s). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: improve NGW100 I2C/PMBus setupDavid Brownell
Basic I2C initialization for the NGW100 board: - Provide empty i2c device table. Daughtercards may add devices, and the ATtiny24 could do stuff too. - Set up EXTINT(3) so the ATtiny24 can interrupt the AP7000. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: Add PSIF platform devicesHans-Christian Egtvedt
This patch adds the PS/2 interface (PSIF) to the device code, split into two platform devices, one for each port. The function for adding the PSIF platform device is also added to the board header file. Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: Add pin configuration choice to LCDC peripheralHans-Christian Egtvedt
This patch lets the board code choose which pin out to use for the LCD interface. On AT32AP7000 the LCDC is wired to two sets of pins, which lets the user choose between dual ethernet and 32-bit EBI. For the ATNGW100 board it is vital to have the choice to select the alternative pinout since this pinout is routed to the external headers. Update ATSTK1002 and ATSTK1004 to use the new interface. Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: minor GPIO handling updatesDavid Brownell
On the odd chance some code uses a pin as a GPIO IRQ without calling gpio_request() or gpio_direction_input(), the debug dump should still show its pin status. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: Fix wrong I/O access size in __raw_readsbHaavard Skinnemoen
__raw_readsb() should always use byte accesses, never halfword accesses, to I/O memory. Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: Fix sigaltstack behaviourMartin Koegler
A signal handler should be able to change the signal stack used for the next signal by altering the ucontext_t passed as a parameter to the handler. This does not currently work on avr32 since it doesn't update the in-kernel signal context from the ucontext_t upon signal handler return. Fix it by adding a call to do_sigaltstack() from sys_rt_sigreturn(), bringing it in line with most other architectures. Signed-off-by: Martin Koegler <mkoegler@auto.tuwien.ac.at> [haavard.skinnemoen@atmel.com: changed patch description] Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: Allow board to define oscillator ratesAlex
On our custom board we have other oscillator rates than on atngw100 and atstk100x. Currently these rates are hardcoded in arch/avr32/mach-at32ap/at32ap700x.c. This patch moves them into board specific code. Signed-off-by: Alex Raimondi <raimondi@miromico.ch> Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-27avr32: export empty_zero_pageHaavard Skinnemoen
Fixes one of two ext4 build problems: ERROR: "empty_zero_page" [fs/ext4/ext4dev.ko] undefined! Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-06-24Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] Eliminate NULL test after alloc_bootmem in iosapic_alloc_rte() [IA64] Handle count==0 in sn2_ptc_proc_write() [IA64] Fix boot failure on ia64/sn2
2008-06-24Merge branch 'kvm-updates-2.6.26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm * 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: KVM: Remove now unused structs from kvm_para.h x86: KVM guest: Use the paravirt clocksource structs and functions KVM: Make kvm host use the paravirt clocksource structs x86: Make xen use the paravirt clocksource structs and functions x86: Add structs and functions for paravirt clocksource KVM: VMX: Fix host msr corruption with preemption enabled KVM: ioapic: fix lost interrupt when changing a device's irq KVM: MMU: Fix oops on guest userspace access to guest pagetable KVM: MMU: large page update_pte issue with non-PAE 32-bit guests (resend) KVM: MMU: Fix rmap_write_protect() hugepage iteration bug KVM: close timer injection race window in __vcpu_run KVM: Fix race between timer migration and vcpu migration
2008-06-24Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: xen: remove support for non-PAE 32-bit
2008-06-24x86: KVM guest: Use the paravirt clocksource structs and functionsGerd Hoffmann
This patch updates the kvm host code to use the pvclock structs and functions, thereby making it compatible with Xen. The patch also fixes an initialization bug: on SMP systems the per-cpu has two different locations early at boot and after CPU bringup. kvmclock must take that in account when registering the physical address within the host. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24KVM: Make kvm host use the paravirt clocksource structsGerd Hoffmann
This patch updates the kvm host code to use the pvclock structs. It also makes the paravirt clock compatible with Xen. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24x86: Make xen use the paravirt clocksource structs and functionsGerd Hoffmann
This patch updates the xen guest to use the pvclock structs and helper functions. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24x86: Add structs and functions for paravirt clocksourceGerd Hoffmann
This patch adds structs for the paravirt clocksource ABI used by both xen and kvm (pvclock-abi.h). It also adds some helper functions to read system time and wall clock time from a paravirtual clocksource (pvclock.[ch]). They are based on the xen code. They are enabled using CONFIG_PARAVIRT_CLOCK. Subsequent patches of this series will put the code in use. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24[IA64] Eliminate NULL test after alloc_bootmem in iosapic_alloc_rte()Julia Lawall
As noted by Akinobu Mita alloc_bootmem and related functions never return NULL and always return a zeroed region of memory. Thus a NULL test or memset after calls to these functions is unnecessary. Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-06-24[IA64] Handle count==0 in sn2_ptc_proc_write()Cliff Wickman
The fix applied in e0c6d97c65e0784aade7e97b9411f245a6c543e7 "security hole in sn2_ptc_proc_write" didn't take into account the case where count==0 (which results in a buffer underrun when adding the trailing '\0'). Thanks to Andi Kleen for pointing this out. Signed-off-by: Cliff Wickman <cpw@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-06-24[IA64] Fix boot failure on ia64/sn2Jes Sorensen
Call check_sal_cache_flush() after platform_setup() as check_sal_cache_flush() now relies on being able to call platform vector code. Problem was introduced by: 3463a93def55c309f3c0d0a8aaf216be3be42d64 "Update check_sal_cache_flush to use platform_send_ipi()" Signed-off-by: Jes Sorensen <jes@sgi.com> Tested-by: Alex Chiang: <achiang@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-06-24xen: remove support for non-PAE 32-bitJeremy Fitzhardinge
Non-PAE operation has been deprecated in Xen for a while, and is rarely tested or used. xen-unstable has now officially dropped non-PAE support. Since Xen/pvops' non-PAE support has also been broken for a while, we may as well completely drop it altogether. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-24KVM: VMX: Fix host msr corruption with preemption enabledAvi Kivity
Switching msrs can occur either synchronously as a result of calls to the msr management functions (usually in response to the guest touching virtualized msrs), or asynchronously when preempting a kvm thread that has guest state loaded. If we're unlucky enough to have the two at the same time, host msrs are corrupted and the machine goes kaput on the next syscall. Most easily triggered by Windows Server 2008, as it does a lot of msr switching during bootup. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24KVM: MMU: Fix oops on guest userspace access to guest pagetableAvi Kivity
KVM has a heuristic to unshadow guest pagetables when userspace accesses them, on the assumption that most guests do not allow userspace to access pagetables directly. Unfortunately, in addition to unshadowing the pagetables, it also oopses. This never triggers on ordinary guests since sane OSes will clear the pagetables before assigning them to userspace, which will trigger the flood heuristic, unshadowing the pagetables before the first userspace access. One particular guest, though (Xenner) will run the kernel in userspace, triggering the oops. Since the heuristic is incorrect in this case, we can simply remove it. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24KVM: MMU: large page update_pte issue with non-PAE 32-bit guests (resend)Marcelo Tosatti
kvm_mmu_pte_write() does not handle 32-bit non-PAE large page backed guests properly. It will instantiate two 2MB sptes pointing to the same physical 2MB page when a guest large pte update is trapped. Instead of duplicating code to handle this, disallow directory level updates to happen through kvm_mmu_pte_write(), so the two 2MB sptes emulating one guest 4MB pte can be correctly created by the page fault handling path. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24KVM: MMU: Fix rmap_write_protect() hugepage iteration bugMarcelo Tosatti
rmap_next() does not work correctly after rmap_remove(), as it expects the rmap chains not to change during iteration. Fix (for now) by restarting iteration from the beginning. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24KVM: close timer injection race window in __vcpu_runMarcelo Tosatti
If a timer fires after kvm_inject_pending_timer_irqs() but before local_irq_disable() the code will enter guest mode and only inject such timer interrupt the next time an unrelated event causes an exit. It would be simpler if the timer->pending irq conversion could be done with IRQ's disabled, so that the above problem cannot happen. For now introduce a new vcpu requests bit to cancel guest entry. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-24KVM: Fix race between timer migration and vcpu migrationMarcelo Tosatti
A guest vcpu instance can be scheduled to a different physical CPU between the test for KVM_REQ_MIGRATE_TIMER and local_irq_disable(). If that happens, the timer will only be migrated to the current pCPU on the next exit, meaning that guest LAPIC timer event can be delayed until a host interrupt is triggered. Fix it by cancelling guest entry if any vcpu request is pending. This has the side effect of nicely consolidating vcpu->requests checks. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-06-23Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: xen: don't drop NX bit xen: mask unwanted pte bits in __supported_pte_mask xen: Use wmb instead of rmb in xen_evtchn_do_upcall(). x86: fix NULL pointer deref in __switch_to
2008-06-20Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] SN2: security hole in sn2_ptc_proc_write
2008-06-20alpha: resurrect Cypress IDE quirkIvan Kokshaysky
Which was removed in the hope that generic legacy IDE quirk in drivers/pci/probe.c is sufficient for Cypress IDE. It isn't, as this controller has non-standard BAR layout: secondary channel registers are in the BAR0-1 of the second PCI function - not in the BAR2-3 of the same function, as the generic quirk routine assumes. Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20alpha: fix compile failures with gcc-4.3 (bug #10438)Ivan Kokshaysky
Vast majority of these build failures are gcc-4.3 warnings about static functions and objects being referenced from non-static (read: "extern inline") functions, in conjunction with our -Werror. We cannot just convert "extern inline" to "static inline", as people keep suggesting all the time, because "extern inline" logic is crucial for generic kernel build. So - just make sure that all callees of critical "extern inline" functions are also "extern inline"; - use "static inline", wherever it's possible. traps.c: work around gcc-4.3 being too smart about array bounds-checking. TODO: add "gnu_inline" attribute to all our "extern inline" functions to ensure desired behaviour with future compilers. Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20alpha: link failure fixIvan Kokshaysky
With built-in scsi disk driver, the final link fails with a following error: `.exit.text' referenced in section `.rodata' of drivers/built-in.o: defined in discarded section `.exit.text' of drivers/built-in.o This happens with -Os (CONFIG_CC_OPTIMIZE_FOR_SIZE=y) with all gcc-4 versions, and also with -O2 and gcc-4.3. The problem is in sd.c:sd_major() being inlined into __exit function exit_sd(), and the compiler generating a jump table in .rodata section for the 'switch' statement in sd_major(). So we have references to discarded section. Fixed with a big hammer in the form of -fno-jump-tables. Note that jump tables vs. discarded sections is a generic problem, other architectures are just lucky not to suffer from it. But with a slightly more complex switch/case statement it can be reproduced on x86 as well. So maybe at some point we should consider -fno-jump-tables as a generic compile option... Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, geode: add a VSA2 ID for General Software x86: use BOOTMEM_EXCLUSIVE on 32-bit x86, 32-bit: fix boot failure on TSC-less processors x86: fix NULL pointer deref in __switch_to x86: set PAE PHYSICAL_MASK_SHIFT to 44 bits.
2008-06-20[IA64] SN2: security hole in sn2_ptc_proc_writeCliff Wickman
Security hole in sn2_ptc_proc_write It is possible to overrun a buffer with a write to this /proc file. Signed-off-by: Cliff Wickman <cpw@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-06-20Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIPLinus Torvalds
KAMEZAWA Hiroyuki and Oleg Nesterov point out that since the commit 557ed1fa2620dc119adb86b34c614e152a629a80 ("remove ZERO_PAGE") removed the ZERO_PAGE from the VM mappings, any users of get_user_pages() will generally now populate the VM with real empty pages needlessly. We used to get the ZERO_PAGE when we did the "handle_mm_fault()", but since fault handling no longer uses ZERO_PAGE for new anonymous pages, we now need to handle that special case in follow_page() instead. In particular, the removal of ZERO_PAGE effectively removed the core file writing optimization where we would skip writing pages that had not been populated at all, and increased memory pressure a lot by allocating all those useless newly zeroed pages. This reinstates the optimization by making the unmapped PTE case the same as for a non-existent page table, which already did this correctly. While at it, this also fixes the XIP case for follow_page(), where the caller could not differentiate between the case of a page that simply could not be used (because it had no "struct page" associated with it) and a page that just wasn't mapped. We do that by simply returning an error pointer for pages that could not be turned into a "struct page *". The error is arbitrarily picked to be EFAULT, since that was what get_user_pages() already used for the equivalent IO-mapped page case. [ Also removed an impossible test for pte_offset_map_lock() failing: that's not how that function works ] Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Nick Piggin <npiggin@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-06-20xen: don't drop NX bitJeremy Fitzhardinge
Because NX is now enforced properly, we must put the hypercall page into the .text segment so that it is executable. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org> Cc: the arch/x86 maintainers <x86@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20xen: mask unwanted pte bits in __supported_pte_maskJeremy Fitzhardinge
[ Stable: this isn't a bugfix in itself, but it's a pre-requiste for "xen: don't drop NX bit" ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org> Cc: the arch/x86 maintainers <x86@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19x86, geode: add a VSA2 ID for General SoftwareJordan Crouse
General Software writes their own VSA2 module for their version of the Geode BIOS, which returns a different ID then the standard VSA2. This was causing the framebuffer driver to break for most GSW boards. Signed-off-by: Jordan Crouse <jordan.crouse@amd.com> Cc: tglx@linutronix.de Cc: linux-geode@lists.infradead.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19x86: use BOOTMEM_EXCLUSIVE on 32-bitBernhard Walle
This patch uses the BOOTMEM_EXCLUSIVE for crashkernel reservation also for i386 and prints a error message on failure. The patch is still for 2.6.26 since it is only bug fixing. The unification of reserve_crashkernel() between i386 and x86_64 should be done for 2.6.27. Signed-off-by: Bernhard Walle <bwalle@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org>
2008-06-19x86, 32-bit: fix boot failure on TSC-less processorsMikael Pettersson
Booting 2.6.26-rc6 on my 486 DX/4 fails with a "BUG: Int 6" (invalid opcode) and a kernel halt immediately after the kernel has been uncompressed. The BUG shows EIP pointing to an rdtsc instruction in native_read_tsc(), invoked from native_sched_clock(). (This error occurs so early that not even the serial console can capture it.) A bisection showed that this bug first occurs in 2.6.26-rc3-git7, via commit 9ccc906c97e34fd91dc6aaf5b69b52d824386910: >x86: distangle user disabled TSC from unstable > >tsc_enabled is set to 0 from the command line switch "notsc" and from >the mark_tsc_unstable code. Seperate those functionalities and replace >tsc_enable with tsc_disable. This makes also the native_sched_clock() >decision when to use TSC understandable. > >Preparatory patch to solve the sched_clock() issue on 32 bit. > >Signed-off-by: Thomas Gleixner <tglx@linutronix.de> The core reason for this bug is that native_sched_clock() gets called before tsc_init(). Before the commit above, tsc_32.c used a "tsc_enabled" variable which defaulted to 0 == disabled, and which only got enabled late in tsc_init(). Thus early calls to native_sched_clock() would skip the TSC and use jiffies instead. After the commit above, tsc_32.c uses a "tsc_disabled" variable which defaults to 0, meaning that the TSC is Ok to use. Early calls to native_sched_clock() now erroneously try to use the TSC on !cpu_has_tsc processors, leading to invalid opcode exceptions. My proposed fix is to initialise tsc_disabled to a "soft disabled" state distinct from the hard disabled state set up by the "notsc" kernel option. This fixes the native_sched_clock() problem. It also allows tsc_init() to be simplified: instead of setting tsc_disabled = 1 on every error return, we just set tsc_disabled = 0 once when all checks have succeeded. I've verified that this lets my 486 boot again. I've also verified that a Core2 machine still uses the TSC as clocksource after the patch. Signed-off-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-19x86: fix NULL pointer deref in __switch_toSuresh Siddha
Patrick McHardy reported a crash: > > I get this oops once a day, its apparently triggered by something > > run by cron, but the process is a different one each time. > > > > Kernel is -git from yesterday shortly before the -rc6 release > > (last commit is the usb-2.6 merge, the x86 patches are missing), > > .config is attached. > > > > I'll retry with current -git, but the patches that have gone in > > since I last updated don't look related. > > > > [62060.043009] BUG: unable to handle kernel NULL pointer dereference at > > 000001ff > > [62060.043009] IP: [<c0102a9b>] __switch_to+0x2f/0x118 > > [62060.043009] *pde = 00000000 > > [62060.043009] Oops: 0002 [#1] PREEMPT Vegard Nossum analyzed it: > This decodes to > > 0: 0f ae 00 fxsave (%eax) > > so it's related to the floating-point context. This is the exact > location of the crash: > > $ addr2line -e arch/x86/kernel/process_32.o -i ab0 > include/asm/i387.h:232 > include/asm/i387.h:262 > arch/x86/kernel/process_32.c:595 > > ...so it looks like prev_task->thread.xstate->fxsave has become NULL. > Or maybe it never had any other value. Somehow (as described below) TS_USEDFPU is set but the fpu is not allocated or freed. Another possible FPU pre-emption issue with the sleazy FPU optimization which was benign before but not so anymore, with the dynamic FPU allocation patch. New task is getting exec'd and it is prempted at the below point. flush_thread() { ... /* * Forget coprocessor state.. */ clear_fpu(tsk); <----- Preemption point clear_used_math(); ... } Now when it context switches in again, as the used_math() is still set and fpu_counter can be > 5, we will do a math_state_restore() which sets the task's TS_USEDFPU. After it continues from the above preemption point it does clear_used_math() and much later free_thread_xstate(). Now, at the next context switch, it is quite possible that xstate is null, used_math() is not set and TS_USEDFPU is still set. This will trigger unlazy_fpu() causing kernel oops. Fix this by clearing tsk's fpu_counter before clearing task's fpu. Reported-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-18[POWERPC] Clear sub-page HPTE present bits when demoting page sizePaul Mackerras
When we demote a slice from 64k to 4k, and we are about to insert an HPTE for a 4k subpage and we notice that there is an existing 64k HPTE, we first invalidate that HPTE before inserting the new 4k subpage HPTE. Since the bits that encode which hash bucket the old HPTE was in overlap with the bits that encode which of the 16 subpages have HPTEs, we need to clear out the subpage HPTE-present bits before starting to insert HPTEs for the 4k subpages. If we don't do that, we can erroneously think that a subpage already has an HPTE when it doesn't. That in itself wouldn't be such a problem except that when we go to update the HPTE that we think is present on machines with a hypervisor, the hypervisor can tell us that the HPTE we think is there is actually there even though it isn't, which can lead to a process getting stuck in a loop, continually faulting. The reason for the confusion is that the AVPN (abbreviated virtual page number) we are looking for in the HPTE for a 4k subpage can actually match the AVPN in a stale HPTE for another 64k page. For example, the HPTE for the 4k subpage at 0x84000f000 will be in the same hash bucket and have the same AVPN as the HPTE for the 64k page at 0x8400f0000. This fixes the code to clear out the subpage HPTE-present bits. Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-06-18[POWERPC] 4xx: Clear new TLB cache attribute bits in Data Storage vectorJosh Boyer
A recent commit added support for the new 440x6 and 464 cores that have the added WL1, IL1I, IL1D, IL2I, and ILD2 bits for the caching attributes in the TLBs. The new bits were cleared in the finish_tlb_load function, however a similar bit of code was missed in the DataStorage interrupt vector. Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>