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2008-12-08AMD IOMMU: fix iommu_map_page functionJoerg Roedel
Impact: bugfix in iommu_map_page function Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2008-12-05MIPS: Fix incorrect use of loose in vpe.cNick Andrew
It should be 'lose', not 'loose'. Signed-off-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-12-04Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/galak/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/galak/powerpc: powerpc/83xx: Enable FIXED_PHY in mpc834x_itx and mpc83xx defconfigs
2008-12-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc64: Sync FPU state in VIS emulation handler. sparc64: Fix VIS emulation bugs sparc: asm/bitops.h should define __fls sparc64: Fix bug in PTRACE_SETFPREGS64 handling.
2008-12-04Merge 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: fix early panic with boot option "nosmp" x86/oprofile: fix Intel cpu family 6 detection oprofile: fix CPU unplug panic in ppro_stop() AMD IOMMU: fix possible race while accessing iommu->need_sync AMD IOMMU: set device table entry for aliased devices AMD IOMMU: struct amd_iommu remove padding on 64 bit x86: fix broken flushing in GART nofullflush path x86: fix dma_mapping_error for 32bit x86
2008-12-04Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: don't export sched_mc_power_savings in laptops
2008-12-04Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linusLinus Torvalds
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: MIPS: Return ENOSYS from sys32_syscall on 64bit kernels like elsewhere. MIPS: 64-bit: vmsplice needs to use the compat wrapper for o32 and N32. MIPS: o32: Fix number of arguments to splice(2). MIPS: Malta: Consolidate platform device code. MIPS: IP22, Fulong, Malta: Update defconfigs. MIPS: Malta: Add back RTC support MIPS: Fix potential DOS by untrusted user app.
2008-12-04powerpc/83xx: Enable FIXED_PHY in mpc834x_itx and mpc83xx defconfigsAnton Vorontsov
This is needed so that Vitesse 7385 5-port switch could work on MPC8349E-mITX boards. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-04MIPS: Return ENOSYS from sys32_syscall on 64bit kernels like elsewhere.David Daney
When the o32 errno was changed to ENOSYS, we forgot to update the code for 64bit kernels. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-12-04MIPS: 64-bit: vmsplice needs to use the compat wrapper for o32 and N32.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-12-04MIPS: o32: Fix number of arguments to splice(2).Ralf Baechle
The syscall code was assuming splice only takes 4 arguments so no stack arguments were being copied from the userspace stack to the kernel stack. As the result splice was likely to fail with EINVAL. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-12-04MIPS: Malta: Consolidate platform device code.Ralf Baechle
After adding the RTC platform device to malta-platform.c malta-mtd.c should get unified with the rest of the platform device code.
2008-12-04MIPS: IP22, Fulong, Malta: Update defconfigs.Ralf Baechle
These haven't seen much attention for too long but particularly important enable RTC_CLASS and CONFIG_RTC_HCTOSYS so the wall clock time is set on kernel startup. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-12-04MIPS: Malta: Add back RTC supportTiejun Chen
With the conversion of MIPS to RTC_LIB the old RTC driver CONFIG_RTC became unselectable. Fix by setting up a platform device. Also enable RTC_CLASS so system time gets set from RTC on kernel initialization. [Ralf: Original patch by Tiejun; polished nice and shiny by me] Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-12-04MIPS: Fix potential DOS by untrusted user app.Vlad Malov
On a 64 bit kernel if an o32 syscall was made with a syscall number less than 4000, we would read the function from outside of the bounds of the syscall table. This led to non-deterministic behavior including system crashes. While we were at it we reworked the 32 bit version as well to use fewer instructions. Both 32 and 64 bit versions are use the same code now. Signed-off-by: Vlad Malov <Vlad.Malov@caviumnetworks.com> Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-12-04sparc64: Sync FPU state in VIS emulation handler.Hong H. Pham
Copy the FPU state to the task's thread_info->fpregs for the VIS emulation functions to access. Signed-off-by: Hong H. Pham <hong.pham@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-04x86: fix early panic with boot option "nosmp"Andi Kleen
Impact: fix boot crash with numcpus=0 on certain systems Fix early exception in __get_smp_config with nosmp. Bail out early when there is no MP table. Reported-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Tested-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-03sparc64: Fix VIS emulation bugsJoseph Myers
This patch fixes some bugs in VIS emulation that cause the GCC test failure FAIL: gcc.target/sparc/pdist-3.c execution test for both 32-bit and 64-bit testing on hardware lacking these instructions. The emulation code for the pdist instruction uses RS1(insn) for both source registers rs1 and rs2, which is obviously wrong and leads to the instruction doing nothing (the observed problem), and further inspection of the code shows that RS1 uses a shift of 24 and RD a shift of 25, which clearly cannot both be right; examining SPARC documentation indicates the correct shift for RS1 is 14. This patch fixes the bug if single-stepping over the affected instruction in the debugger, but not if the testcase is run standalone. For that, Wind River has another patch I hope they will send as a followup to this patch submission. Signed-off-by: Joseph Myers <joseph@codesourcery.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-03MN10300: Introduce barriers to replace removed volatiles in gdbstub 16550 driverDavid Howells
Introduce into the MN10300 gdbstub 16550 driver a couple of barrier() calls to replace the removed volatility of the input/output index variables for the Rx ring buffer. A previous patch added them into the on-chip serial port driver. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-03sparc: asm/bitops.h should define __flsRusty Russell
bitops_64.h includes the generic one; pretty sure 32 should too. (Found by using __fls in generic code and breaking sparc defconfig build: thanks Stephen and linux-next!) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-03Merge branch 'oprofile-for-tip' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into x86/urgent
2008-12-03x86/oprofile: fix Intel cpu family 6 detectionWilliam Cohen
Alan Jenkins wrote: > This is on an EeePC 701, /proc/cpuinfo as attached. > > Is this expected? Will the next release work? > > Thanks, Alan > > # opcontrol --setup --no-vmlinux > cpu_type 'unset' is not valid > you should upgrade oprofile or force the use of timer mode > > # opcontrol -v > opcontrol: oprofile 0.9.4 compiled on Nov 29 2008 22:44:10 > > # cat /dev/oprofile/cpu_type > i386/p6 > # uname -r > 2.6.28-rc6eeepc Hi Alan, Looking at the kernel driver code for oprofile it can return the "i386/p6" for the cpu_type. However, looking at the user-space oprofile code there isn't the matching entry in libop/op_cpu_type.c or the events/unit_mask files in events/i386 directory. The Intel AP-485 says this is a "Intel Pentium M processor model D". Seems like the oprofile kernel driver should be identifying the processor as "i386/p6_mobile" The driver identification code doesn't look quite right in nmi_init.c http://git.kernel.org/?p=linux/kernel/git/sfr/linux-next.git;a=blob;f=arch/x86/oprofile/nmi_int.c;h=022cd41ea9b4106e5884277096e80e9088a7c7a9;hb=HEAD has: 409 case 10 ... 13: 410 *cpu_type = "i386/p6"; 411 break; Referring to the Intel AP-485: case 10 and 11 should produce "i386/piii" case 13 should produce "i386/p6_mobile" I didn't see anything for case 12. Something like the attached patch. I don't have a celeron machine to verify that changes in this area of the kernel fix thing. -Will Signed-off-by: William Cohen <wcohen@redhat.com> Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-03powerpc/83xx: Fix MCU support merge issue in mpc8349emitx.dtsAnton Vorontsov
Just found the merge issue in 442746989d92afc125040e0f29b33602ad94da99 ("powerpc/83xx: Add support for MCU microcontroller in .dts files"): the commit adds the MCU controller node into the DMA node, which is wrong because the MCU sits on the I2C bus. Fix this by moving the MCU node into the I2C controller node. The original patch[1] was OK though. ;-) Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2008-12-03oprofile: fix CPU unplug panic in ppro_stop()Eric Dumazet
If oprofile statically compiled in kernel, a cpu unplug triggers a panic in ppro_stop(), because a NULL pointer is dereferenced. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Robert Richter <robert.richter@amd.com>
2008-12-03Merge branch 'iommu-fixes-2.6.28' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent
2008-12-03AMD IOMMU: fix possible race while accessing iommu->need_syncJoerg Roedel
The access to the iommu->need_sync member needs to be protected by the iommu->lock. Otherwise this is a possible race condition. Fix it with this patch. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2008-12-03AMD IOMMU: set device table entry for aliased devicesJoerg Roedel
In some rare cases a request can arrive an IOMMU with its originial requestor id even it is aliased. Handle this by setting the device table entry to the same protection domain for the original and the aliased requestor id. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2008-12-03AMD IOMMU: struct amd_iommu remove padding on 64 bitRichard Kennedy
Remove 16 bytes of padding from struct amd_iommu on 64bit builds reducing its size to 120 bytes, allowing it to span one fewer cachelines. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
2008-12-03x86: fix broken flushing in GART nofullflush pathJoerg Roedel
Impact: remove stale IOTLB entries In the non-default nofullflush case the GART is only flushed when next_bit wraps around. But it can happen that an unmap operation unmaps memory which is behind the current next_bit location. If these addresses are reused it may result in stale GART IO/TLB entries. Fix this by setting the GART next_bit always behind an unmapped location. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-03sparc64: Fix bug in PTRACE_SETFPREGS64 handling.Chris Torek
From: Chris Torek <chris.torek@windriver.com> >The SPARC64 kernel code for PTRACE_SETFPREGS64 appears to be an exact copy >of that for PTRACE_GETFPREGS64. This means that gdbserver and native >64-bit GDB cannot set floating-point registers. It looks like a simple typo. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-03powerpc: Fix dma_map_sg() cache flushing on non coherent platformsBenjamin Herrenschmidt
On PowerPC 4xx or other non cache-coherent platforms, we lost the appropriate cache flushing in dma_map_sg() when merging the 32 and 64-bit DMA code (commit 4fc665b88a79a45bae8bbf3a05563c27c7337c3d, "powerpc: Merge 32 and 64-bit dma code"). This restores it. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Becky Bruce <beckyb@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-12-02Merge branch 'kvm-updates/2.6.28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm * 'kvm-updates/2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: KVM: MMU: avoid creation of unreachable pages in the shadow KVM: ppc: stop leaking host memory on VM exit KVM: MMU: fix sync of ptes addressed at owner pagetable KVM: ia64: Fix: Use correct calling convention for PAL_VPS_RESUME_HANDLER KVM: ia64: Fix incorrect kbuild CFLAGS override KVM: VMX: Fix interrupt loss during race with NMI KVM: s390: Fix problem state handling in guest sigp handler
2008-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc64: Fix offset calculation in compute_size() rtc: rtc-starfire fixes
2008-12-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k: m68k: Update defconfigs for 2.6.28-rc7 macfb: Do not overflow fb_fix_screeninfo.id
2008-12-02MN10300: Fix application of kernel module relocationsMark Salter
This fixes the MN10300 kernel module linking to match the toolchain. RELA relocs don't use the value at the location being relocated. This has been working because the tools always leave the value at the target location cleared. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-02powerpc: Use physical cpu id when setting the processor affinityKumar Gala
In the CONFIG_SMP case the irq_choose_cpu() code was returning back a logical cpu id not the physical id. We were writing that directly into the HW register. We need to be calling get_hard_smp_processor_id() so irq_choose_cpu() always returns a physical cpu id. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-02m68k: Update defconfigs for 2.6.28-rc7Geert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2008-12-01frv: fix mmap2 error handlingDavid Howells
Fix the error handling in sys_mmap2(). Currently, if the pgoff check fails, fput() might have to be called (which it isn't), so do the pgoff check first, before fget() is called. Signed-off-by: David Howells <dhowells@redhat.com> Reported-by: Julia Lawall <julia@diku.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01spi: fix spi_s3c24xx_gpio num_chipselectBen Dooks
The spi master driver must have num_chipselect set to allow the bus to initialise. Pass this through the platform data. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: powerpc: Fix build for 32-bit SMP configs
2008-12-01Revert "of_platform_driver noise on sparce"Linus Torvalds
This reverts commit e669dae6141ff97d3c7566207f5de3b487dcf837, since it is incomplete, and clashes with fuller patches and the sparc 32/64 unification effort. Requested-by: David Miller <davem@davemloft.net> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-01sparc64: Fix offset calculation in compute_size()David S. Miller
The fault address is somewhere inside of the buffer, not before it. Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-01sched: don't export sched_mc_power_savings in laptopsMahesh Salgaonkar
Impact: do not expose a control that has no effect Fix to prevent sched_mc_power_saving from being exported through sysfs on single-socket systems. (Say multicore single socket (Laptop)) CPU core map of the boot cpu should be equal to possible number of cpus for single socket system. This fix has been developed at FOSS.in kernel workout. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-01powerpc: Fix build for 32-bit SMP configsMilton Miller
attr_smt_snooze_delay is only defined for CONFIG_PPC64, so protect the attribute removal with the same condition. This fixes this build error on 32-bit SMP configurations: /data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c: In function ‘unregister_cpu_online’: /data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: ‘attr_smt_snooze_delay’ undeclared (first use in this function) /data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: (Each undeclared identifier is reported only once /data/home/miltonm/next.git/arch/powerpc/kernel/sysfs.c:722: error: for each function it appears in.) Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-11-30Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: powerpc: Fix system calls on Cell entered with XER.SO=1 powerpc/cell: Fix GDB watchpoints, again powerpc/mpic: Don't reset affinity for secondary MPIC on boot powerpc/cell/axon-msi: Retry on missing interrupt powerpc: Fix boot freeze on machine with empty memory node powerpc: Fix IRQ assignment for some PCIe devices powerpc/spufs: Fix spinning in spufs_ps_fault on signal powerpc/mpc832x_rdb: fix swapped ethernet ids powerpc: Use generic PHY driver for Marvell 88E1111 PHY on GE Fanuc SBC610 powerpc/85xx: L2 cache size wrong in 8572DS dts powerpc/virtex: Update defconfigs powerpc/52xx: update defconfigs xsysace: Fix driver to use resource_size_t instead of unsigned long powerpc/virtex: fix various format/casting printk mismatches powerpc/mpc5200: fix bestcomm Kconfig dependencies powerpc/44x: Fix 460EX/460GT machine check handling powerpc/40x: Limit allocable DRAM during early mapping
2008-11-30Merge master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds
* master.kernel.org:/home/rmk/linux-2.6-arm: Allow architectures to override copy_user_highpage() [ARM] pxa/palmtx: misc fixes to use generic GPIO API ARM: OMAP: Fixes for suspend / resume GPIO wake-up handling [ARM] pxa/corgi: update default config to exclude tosa from being built [ARM] pxa/pcm990: use negative number for an invalid GPIO in camera data ARM: OMAP: Typo fix for clock_allow_idle ARM: OMAP: Remove broken LCD driver for SX1 [ARM] 5335/1: pxa25x_udc: Fix is_vbus_present to return 1 or 0 [ARM] pxa/MioA701: bluetooth resume fix [ARM] pxa/MioA701: fix memory corruption.
2008-12-01powerpc: Fix system calls on Cell entered with XER.SO=1Paul Mackerras
It turns out that on Cell, on a kernel with CONFIG_VIRT_CPU_ACCOUNTING = y, if a program sets the SO (summary overflow) bit in the XER and then does a system call, the SO bit in CR0 will be set on return regardless of whether the system call detected an error. Since CR0.SO is used as the error indication from the system call, this means that all system calls appear to fail. The reason is that the workaround for the timebase bug on Cell uses a compare instruction. With CONFIG_VIRT_CPU_ACCOUNTING = y, the ACCOUNT_CPU_USER_ENTRY macro reads the timebase, so we end up doing a compare instruction, which copies XER.SO to CR0.SO. Since we were doing this in the system call entry patch after clearing CR0.SO but before saving the CR, this meant that the saved CR image had CR0.SO set if XER.SO was set on entry. This fixes it by moving the clearing of CR0.SO to after the ACCOUNT_CPU_USER_ENTRY call in the system call entry path. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-12-01powerpc/cell: Fix GDB watchpoints, againArnd Bergmann
An earlier patch from Jens Osterkamp attempted to fix GDB watchpoints by enabling the DABRX register at boot time. Unfortunately, this did not work on SMP setups, where secondary CPUs were still using the power-on DABRX value. This introduces the same change for secondary CPUs on cell as well. Reported-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Tested-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-12-01powerpc/mpic: Don't reset affinity for secondary MPIC on bootArnd Bergmann
Kexec/kdump currently fails on the IBM QS2x blades when the kexec happens on a CPU other than the initial boot CPU. It turns out that this is the result of mpic_init trying to set affinity of each interrupt vector to the current boot CPU. As far as I can tell, the same problem is likely to exist on any secondary MPIC, because they have to deliver interrupts to the first output all the time. There are two potential solutions for this: either not set up affinity at all for secondary MPICs, or assume that a single CPU output is connected to the upstream interrupt controller and hardcode affinity to that per architecture. This patch implements the second approach, defaulting to the first output. Currently, all known secondary MPICs are routed to their upstream port using the first destination, so we hardcode that. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-12-01powerpc/cell/axon-msi: Retry on missing interruptArnd Bergmann
The MSI capture logic for the axon bridge can sometimes lose interrupts in case of high DMA and interrupt load, when it signals an MSI interrupt to the MPIC interrupt controller while we are already handling another MSI. Each MSI vector gets written into a FIFO buffer in main memory using DMA, and that DMA access is normally flushed by the actual interrupt packet on the IOIF. An MMIO register in the MSIC holds the position of the last entry in the FIFO buffer that was written. However, reading that position does not flush the DMA, so that we can observe stale data in the buffer. In a stress test, we have observed the DMA to arrive up to 14 microseconds after reading the register. This patch works around this problem by retrying the access to the FIFO buffer. We can reliably detect the conditioning by writing an invalid MSI vector into the FIFO buffer after reading from it, assuming that all MSIs we get are valid. After detecting an invalid MSI vector, we udelay(1) in the interrupt cascade for up to 100 times before giving up. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Paul Mackerras <paulus@samba.org>