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2013-05-19powerpc: Bring all threads online prior to migration/hibernationRobert Jennings
commit 120496ac2d2d60aee68d3123a68169502a85f4b5 upstream. This patch brings online all threads which are present but not online prior to migration/hibernation. After migration/hibernation those threads are taken back offline. During migration/hibernation all online CPUs must call H_JOIN, this is required by the hypervisor. Without this patch, threads that are offline (H_CEDE'd) will not be woken to make the H_JOIN call and the OS will be deadlocked (all threads either JOIN'd or CEDE'd). Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-11powerpc: fix numa distance for form0 device treeVaidyanathan Srinivasan
commit 7122beeee7bc1757682049780179d7c216dd1c83 upstream. The following commit breaks numa distance setup for old powerpc systems that use form0 encoding in device tree. commit 41eab6f88f24124df89e38067b3766b7bef06ddb powerpc/numa: Use form 1 affinity to setup node distance Device tree node /rtas/ibm,associativity-reference-points would index into /cpus/PowerPCxxxx/ibm,associativity based on form0 or form1 encoding detected by ibm,architecture-vec-5 property. All modern systems use form1 and current kernel code is correct. However, on older systems with form0 encoding, the numa distance will get hard coded as LOCAL_DISTANCE for all nodes. This causes task scheduling anomaly since scheduler will skip building numa level domain (topmost domain with all cpus) if all numa distances are same. (value of 'level' in sched_init_numa() will remain 0) Prior to the above commit: ((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE) Restoring compatible behavior with this patch for old powerpc systems with device tree where numa distance are encoded as form0. Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-11powerpc: Emulate non privileged DSCR read and writeAnton Blanchard
commit 73d2fb758e678c93bc76d40876c2359f0729b0ef upstream. POWER8 allows read and write of the DSCR in userspace. We added kernel emulation so applications could always use the instructions regardless of the CPU type. Unfortunately there are two SPRs for the DSCR and we only added emulation for the privileged one. Add code to match the non privileged one. A simple test was created to verify the fix: http://ozlabs.org/~anton/junkcode/user_dscr_test.c Without the patch we get a SIGILL and it passes with the patch. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07powerpc/spufs: Initialise inode->i_ino in spufs_new_inode()Michael Ellerman
commit 6747e83235caecd30b186d1282e4eba7679f81b7 upstream. In commit 85fe402 (fs: do not assign default i_ino in new_inode), the initialisation of i_ino was removed from new_inode() and pushed down into the callers. However spufs_new_inode() was not updated. This exhibits as no files appearing in /spu, because all our dirents have a zero inode, which readdir() seems to dislike. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-07powerpc: Add isync to copy_and_flushMichael Neuling
commit 29ce3c5073057991217916abc25628e906911757 upstream. In __after_prom_start we copy the kernel down to zero in two calls to copy_and_flush. After the first call (copy from 0 to copy_to_here:) we jump to the newly copied code soon after. Unfortunately there's no isync between the copy of this code and the jump to it. Hence it's possible that stale instructions could still be in the icache or pipeline before we branch to it. We've seen this on real machines and it's results in no console output after: calling quiesce... returning from prom_init The below adds an isync to ensure that the copy and flushing has completed before any branching to the new instructions occurs. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-12powerpc: pSeries_lpar_hpte_remove fails from Adjunct partition being ↵Michael Wolf
performed before the ANDCOND test commit 9fb2640159f9d4f5a2a9d60e490482d4cbecafdb upstream. Some versions of pHyp will perform the adjunct partition test before the ANDCOND test. The result of this is that H_RESOURCE can be returned and cause the BUG_ON condition to occur. The HPTE is not removed. So add a check for H_RESOURCE, it is ok if this HPTE is not removed as pSeries_lpar_hpte_remove is looking for an HPTE to remove and not a specific HPTE to remove. So it is ok to just move on to the next slot and try again. Signed-off-by: Michael Wolf <mjw@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-05signal: Define __ARCH_HAS_SA_RESTORER so we know whether to clear sa_restorerBen Hutchings
Vaguely based on upstream commit 574c4866e33d 'consolidate kernel-side struct sigaction declarations'. flush_signal_handlers() needs to know whether sigaction::sa_restorer is defined, not whether SA_RESTORER is defined. Define the __ARCH_HAS_SA_RESTORER macro to indicate this. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-20powerpc: Fix cputable entry for 970MP rev 1.0Benjamin Herrenschmidt
commit d63ac5f6cf31c8a83170a9509b350c1489a7262b upstream. Commit 44ae3ab3358e962039c36ad4ae461ae9fb29596c forgot to update the entry for the 970MP rev 1.0 processor when moving some CPU features bits to the MMU feature bit mask. This breaks booting on some rare G5 models using that chip revision. Reported-by: Phileas Fogg <phileas-fogg@mail.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-20powerpc: Fix STAB initializationBenjamin Herrenschmidt
commit 13938117a57f88a22f0df9722a5db7271fda85cd upstream. Commit f5339277eb8d3aed37f12a27988366f68ab68930 accidentally removed more than just iSeries bits and took out the call to stab_initialize() thus breaking support for POWER3 processors. Put it back. (Yes, nobody noticed until now ...) Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-28powerpc/kexec: Disable hard IRQ before kexecPhileas Fogg
commit 8520e443aa56cc157b015205ea53e7b9fc831291 upstream. Disable hard IRQ before kexec a new kernel image. Not doing it can result in corrupted data in the memory segments reserved for the new kernel. Signed-off-by: Phileas Fogg <phileas-fogg@mail.ru> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17KVM: PPC: 44x: fix DCR read/writeAlexander Graf
commit e43a028752fed049e4bd94ef895542f96d79fa74 upstream. When remembering the direction of a DCR transaction, we should write to the same variable that we interpret on later when doing vcpu_run again. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: CAI Qian <caiqian@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17powerpc: Add missing NULL terminator to avoid boot panic on PPC40xGabor Juhos
commit e6449c9b2d90c1bd9a5985bf05ddebfd1631cd6b upstream. The missing NULL terminator can cause a panic on PPC405 boards during boot: Linux/PowerPC load: console=ttyS0,115200 root=/dev/mtdblock1 rootfstype=squashfs,jffs2 noinitrd init=/etc/preinit Finalizing device tree... flat tree at 0x6a5160 bootconsole [udbg0] enabled Page fault in user mode with in_atomic() = 1 mm = (null) NIP = c0275f50 MSR = fffffffe Oops: Weird page fault, sig: 11 [#1] PowerPC 40x Platform Modules linked in: NIP: c0275f50 LR: c0275f60 CTR: c0280000 REGS: c0275eb0 TRAP: 636f7265 Not tainted (3.7.1) MSR: fffffffe <VEC,VSX,EE,PR,FP,ME,SE,BE,IR,DR,PMM,RI> CR: c06a6190 XER: 00000001 TASK = c02662a8[0] 'swapper' THREAD: c0274000 GPR00: c0275ec0 c000c658 c027c4bf 00000000 c0275ee0 c000a0ec c020a1a8 c020a1f0 GPR08: c020f631 c020f404 c025f078 c025f080 c0275f10 Call Trace: ---[ end trace 31fd0ba7d8756001 ]--- Kernel panic - not syncing: Attempted to kill the idle task! The panic happens since commit 9597abe00c1bab2aedce6b49866bf6d1e81c9eed (sections: fix section conflicts in arch/powerpc), however the root cause of this is that the NULL terminator were not added in commit a4f740cf33f7f6c164bbde3c0cdbcc77b0c4997c (of/flattree: Add of_flat_dt_match() helper function). Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17powerpc/vdso: Remove redundant locking in update_vsyscall_tz()Shan Hai
commit ce73ec6db47af84d1466402781ae0872a9e7873c upstream. The locking in update_vsyscall_tz() is not only unnecessary because the vdso code copies the data unproteced in __kernel_gettimeofday() but also introduces a hard to reproduce race condition between update_vsyscall() and update_vsyscall_tz(), which causes user space process to loop forever in vdso code. The following patch removes the locking from update_vsyscall_tz(). Locking is not only unnecessary because the vdso code copies the data unprotected in __kernel_gettimeofday() but also erroneous because updating the tb_update_count is not atomic and introduces a hard to reproduce race condition between update_vsyscall() and update_vsyscall_tz(), which further causes user space process to loop forever in vdso code. The below scenario describes the race condition, x==0 Boot CPU other CPU proc_P: x==0 timer interrupt update_vsyscall x==1 x++;sync settimeofday update_vsyscall_tz x==2 x++;sync x==3 sync;x++ sync;x++ proc_P: x==3 (loops until x becomes even) Because the ++ operator would be implemented as three instructions and not atomic on powerpc. A similar change was made for x86 in commit 6c260d58634 ("x86: vdso: Remove bogus locking in update_vsyscall_tz") Signed-off-by: Shan Hai <shan.hai@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-17powerpc: Fix CONFIG_RELOCATABLE=y CONFIG_CRASH_DUMP=n buildAnton Blanchard
commit 11ee7e99f35ecb15f59b21da6a82d96d2cd3fcc8 upstream. If we build a kernel with CONFIG_RELOCATABLE=y CONFIG_CRASH_DUMP=n, the kernel fails when we run at a non zero offset. It turns out we were incorrectly wrapping some of the relocatable kernel code with CONFIG_CRASH_DUMP. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-03powerpc/eeh: Lock module while handling EEH eventGavin Shan
commit feadf7c0a1a7c08c74bebb4a13b755f8c40e3bbc upstream. The EEH core is talking with the PCI device driver to determine the action (purely reset, or PCI device removal). During the period, the driver might be unloaded and in turn causes kernel crash as follows: EEH: Detected PCI bus error on PHB#4-PE#10000 EEH: This PCI device has failed 3 times in the last hour lpfc 0004:01:00.0: 0:2710 PCI channel disable preparing for reset Unable to handle kernel paging request for data at address 0x00000490 Faulting instruction address: 0xd00000000e682c90 cpu 0x1: Vector: 300 (Data Access) at [c000000fc75ffa20] pc: d00000000e682c90: .lpfc_io_error_detected+0x30/0x240 [lpfc] lr: d00000000e682c8c: .lpfc_io_error_detected+0x2c/0x240 [lpfc] sp: c000000fc75ffca0 msr: 8000000000009032 dar: 490 dsisr: 40000000 current = 0xc000000fc79b88b0 paca = 0xc00000000edb0380 softe: 0 irq_happened: 0x00 pid = 3386, comm = eehd enter ? for help [c000000fc75ffca0] c000000fc75ffd30 (unreliable) [c000000fc75ffd30] c00000000004fd3c .eeh_report_error+0x7c/0xf0 [c000000fc75ffdc0] c00000000004ee00 .eeh_pe_dev_traverse+0xa0/0x180 [c000000fc75ffe70] c00000000004ffd8 .eeh_handle_event+0x68/0x300 [c000000fc75fff00] c0000000000503a0 .eeh_event_handler+0x130/0x1a0 [c000000fc75fff90] c000000000020138 .kernel_thread+0x54/0x70 1:mon> The patch increases the reference of the corresponding driver modules while EEH core does the negotiation with PCI device driver so that the corresponding driver modules can't be unloaded during the period and we're safe to refer the callbacks. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [ herton: backported for 3.5, adjusted driver assignments, return 0 instead of NULL, assume dev is not NULL ] Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-13powerpc/eeh: Fix crash on converting OF node to edevGavin Shan
commit 1e38b7140185e384da216aff66a711df09b5afc9 upstream. The kernel crash was reported by Alexy. He was testing some feature with private kernel, in which Alexy added some code in pci_pm_reset() to read the CSR after writting it. The bug could be reproduced on Fiber Channel card (Fibre Channel: Emulex Corporation Saturn-X: LightPulse Fibre Channel Host Adapter (rev 03)) by the following commands. # echo 1 > /sys/devices/pci0004:01/0004:01:00.0/reset # rmmod lpfc # modprobe lpfc The history behind the test case is that those additional config space reading operations in pci_pm_reset() would cause EEH error, but we didn't detect EEH error until "modprobe lpfc". For the case, all the PCI devices on PCI bus (0004:01) were removed and added after PE reset. Then the EEH devices would be figured out again based on the OF nodes. Unfortunately, there were some child OF nodes under PCI device (0004:01:00.0), but they didn't have attached PCI_DN since they're invisible from PCI domain. However, we were still trying to convert OF node to EEH device without checking on the attached PCI_DN. Eventually, it caused the kernel crash as follows: Unable to handle kernel paging request for data at address 0x00000030 Faulting instruction address: 0xc00000000004d888 cpu 0x0: Vector: 300 (Data Access) at [c000000fc797b950] pc: c00000000004d888: .eeh_add_device_tree_early+0x78/0x140 lr: c00000000004d880: .eeh_add_device_tree_early+0x70/0x140 sp: c000000fc797bbd0 msr: 8000000000009032 dar: 30 dsisr: 40000000 current = 0xc000000fc78d9f70 paca = 0xc00000000edb0000 softe: 0 irq_happened: 0x00 pid = 2951, comm = eehd enter ? for help [c000000fc797bc50] c00000000004d848 .eeh_add_device_tree_early+0x38/0x140 [c000000fc797bcd0] c00000000004d848 .eeh_add_device_tree_early+0x38/0x140 [c000000fc797bd50] c000000000051b54 .pcibios_add_pci_devices+0x34/0x190 [c000000fc797bde0] c00000000004fb10 .eeh_reset_device+0x100/0x160 [c000000fc797be70] c0000000000502dc .eeh_handle_event+0x19c/0x300 [c000000fc797bf00] c000000000050570 .eeh_event_handler+0x130/0x1a0 [c000000fc797bf90] c000000000020138 .kernel_thread+0x54/0x70 The patch changes of_node_to_eeh_dev() and just returns NULL if the passed OF node doesn't have attached PCI_DN. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02powerpc/85xx: p1022ds: fix DIU/LBC switching with NAND enabledTimur Tabi
commit 896c01cb4bb3cfc2c0ea9873fa7a9f8bd0a7c8d8 upstream. In order for indirect mode on the PIXIS to work properly, both chip selects need to be set to GPCM mode, otherwise writes to the chip select base addresses will not actually post to the local bus -- they'll go to the NAND controller instead. Therefore, we need to set BR0 and BR1 to GPCM mode before switching to indirect mode. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-02powerpc/85xx: p1022ds: disable the NAND flash node if video is enabledTimur Tabi
commit 6269f2584a359766f53005c676daff8aee60cbed upstream. The Freescale P1022 has a unique pin muxing "feature" where the DIU video controller's video signals are muxed with 24 of the local bus address signals. When the DIU is enabled, the bulk of the local bus is disabled, preventing access to memory-mapped devices like NAND flash and the pixis FPGA. Therefore, if the DIU is going to be enabled, then memory-mapped devices on the localbus, like NAND flash, need to be disabled. This patch is similar to "powerpc/85xx: p1022ds: disable the NOR flash node if video is enabled", except that it disables the NAND flash node instead. This PIXIS node needs to remain enabled because it is used by platform code to switch into indirect mode. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14powerpc: Make sure IPI handlers see data written by IPI sendersPaul Mackerras
commit 9fb1b36ca1234e64a5d1cc573175303395e3354d upstream. We have been observing hangs, both of KVM guest vcpu tasks and more generally, where a process that is woken doesn't properly wake up and continue to run, but instead sticks in TASK_WAKING state. This happens because the update of rq->wake_list in ttwu_queue_remote() is not ordered with the update of ipi_message in smp_muxed_ipi_message_pass(), and the reading of rq->wake_list in scheduler_ipi() is not ordered with the reading of ipi_message in smp_ipi_demux(). Thus it is possible for the IPI receiver not to see the updated rq->wake_list and therefore conclude that there is nothing for it to do. In order to make sure that anything done before smp_send_reschedule() is ordered before anything done in the resulting call to scheduler_ipi(), this adds barriers in smp_muxed_message_pass() and smp_ipi_demux(). The barrier in smp_muxed_message_pass() is a full barrier to ensure that there is a full ordering between the smp_send_reschedule() caller and scheduler_ipi(). In smp_ipi_demux(), we use xchg() rather than xchg_local() because xchg() includes release and acquire barriers. Using xchg() rather than xchg_local() makes sense given that ipi_message is not just accessed locally. This moves the barrier between setting the message and calling the cause_ipi() function into the individual cause_ipi implementations. Most of them -- those that used outb, out_8 or similar -- already had a full barrier because out_8 etc. include a sync before the MMIO store. This adds an explicit barrier in the two remaining cases. These changes made no measurable difference to the speed of IPIs as measured using a simple ping-pong latency test across two CPUs on different cores of a POWER7 machine. The analysis of the reason why processes were not waking up properly is due to Milton Miller. Reported-by: Milton Miller <miltonm@bga.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14powerpc: Restore correct DSCR in context switchAnton Blanchard
commit 714332858bfd40dcf8f741498336d93875c23aa7 upstream. During a context switch we always restore the per thread DSCR value. If we aren't doing explicit DSCR management (ie thread.dscr_inherit == 0) and the default DSCR changed while the process has been sleeping we end up with the wrong value. Check thread.dscr_inherit and select the default DSCR or per thread DSCR as required. This was found with the following test case, when running with more threads than CPUs (ie forcing context switching): http://ozlabs.org/~anton/junkcode/dscr_default_test.c With the four patches applied I can run a combination of all test cases successfully at the same time: http://ozlabs.org/~anton/junkcode/dscr_default_test.c http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14powerpc: Fix DSCR inheritance in copy_thread()Anton Blanchard
commit 1021cb268b3025573c4811f1dee4a11260c4507b upstream. If the default DSCR is non zero we set thread.dscr_inherit in copy_thread() meaning the new thread and all its children will ignore future updates to the default DSCR. This is not intended and is a change in behaviour that a number of our users have hit. We just need to inherit thread.dscr and thread.dscr_inherit from the parent which ends up being much simpler. This was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_default_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14powerpc: Keep thread.dscr and thread.dscr_inherit in syncAnton Blanchard
commit 00ca0de02f80924dfff6b4f630e1dff3db005e35 upstream. When we update the DSCR either via emulation of mtspr(DSCR) or via a change to dscr_default in sysfs we don't update thread.dscr. We will eventually update it at context switch time but there is a period where thread.dscr is incorrect. If we fork at this point we will copy the old value of thread.dscr into the child. To avoid this, always keep thread.dscr in sync with reality. This issue was found with the following testcase: http://ozlabs.org/~anton/junkcode/dscr_inherit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-14powerpc: Update DSCR on all CPUs when writing sysfs dscr_defaultAnton Blanchard
commit 1b6ca2a6fe56e7697d57348646e07df08f43b1bb upstream. Writing to dscr_default in sysfs doesn't actually change the DSCR - we rely on a context switch on each CPU to do the work. There is no guarantee we will get a context switch in a reasonable amount of time so fire off an IPI to force an immediate change. This issue was found with the following test case: http://ozlabs.org/~anton/junkcode/dscr_explicit_test.c Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-09powerpc/85xx: use the BRx registers to enable indirect mode on the P1022DSTimur Tabi
commit 6bd825f02966be8ba544047cab313d6032c23819 upstream. In order to enable the DIU video controller on the P1022DS, the FPGA needs to be switched to "indirect mode", where the localbus is disabled and the FPGA is accessed via writes to localbus chip select signals CS0 and CS1. To obtain the address of CS0 and CS1, the platform driver uses an "indirect pixis mode" device tree node. This node assumes that the localbus 'ranges' property is sorted in chip-select order. That is, reg value 0 maps to CS0, reg value 1 maps to CS1, etc. This is how the 'ranges' property is supposed to be arranged. Unfortunately, the 'ranges' property is often mis-arranged, and not just on the P1022DS. Linux normally does not care, since it does not program the localbus. But the indirect-mode code on the P1022DS does care. The "proper" fix is to have U-Boot fix the 'ranges' property, but this would be too cumbersome. The names and 'reg' properties of all the localbus devices would also need to be updated, and determining which localbus device maps to which chip select is board-specific. Instead, we determine the CS0/CS1 base addresses the same way that U-boot does -- by reading the BRx registers directly and mapping them to physical addresses. This code is simpler and more reliable, and it does not require a U-boot or device tree change. Since the indirect pixis device tree node is no longer needed, the node is deleted from the DTS. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-09powerpc/eeh: Check handle_eeh_events() return valueKleber Sacilotto de Souza
commit 10db8d212864cb6741df7d7fafda5ab6661f6f88 upstream. Function eeh_event_handler() dereferences the pointer returned by handle_eeh_events() without checking, causing a crash if NULL was returned, which is expected in some situations. This patch fixes this bug by checking for the value returned by handle_eeh_events() before dereferencing it. Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-09powerpc: Add "memory" attribute for mfmsr()Tiejun Chen
commit b416c9a10baae6a177b4f9ee858b8d309542fbef upstream. Add "memory" attribute in inline assembly language as a compiler barrier to make sure 4.6.x GCC don't reorder mfmsr(). Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-08-09powerpc/ftrace: Fix assembly trampoline register usageroger blofeld
commit fd5a42980e1cf327b7240adf5e7b51ea41c23437 upstream. Just like the module loader, ftrace needs to be updated to use r12 instead of r11 with newer gcc's. Signed-off-by: Roger Blofeld <blofeldus@yahoo.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc: Fix build of some debug irq codeBenjamin Herrenschmidt
commit 21b2de341270bd7bb7a811027ffe63276d9b3b75 upstream. There was a typo, checking for CONFIG_TRACE_IRQFLAG instead of CONFIG_TRACE_IRQFLAGS causing some useful debug code to not be built This in turns causes a build error on BookE 64-bit due to incorrect semicolons at the end of a couple of macros, so let's fix that too Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc: More fixes for lazy IRQ vs. idleBenjamin Herrenschmidt
commit be2cf20a5ad31ebb13562c1c866ecc626fbd721e upstream. Looks like we still have issues with pSeries and Cell idle code vs. the lazy irq state. In fact, the reset fixes that went upstream are exposing the problem more by causing BUG_ON() to trigger (which this patch turns into a WARN_ON instead). We need to be careful when using a variant of low power state that has the side effect of turning interrupts back on, to properly set all the SW & lazy state to look as if everything is enabled before we enter the low power state with MSR:EE off as we will return with MSR:EE on. If not, we have a discrepancy of state which can cause things to go very wrong later on. This patch moves the logic into a helper and uses it from the pseries and cell idle code. The power4/970 idle code already got things right (in assembly even !) so I'm not touching it. The power7 "bare metal" idle code is subtly different and correct. Remains PA6T and some hypervisor based Cell platforms which have questionable code in there, but they are mostly dead platforms so I'll fix them when I manage to get final answers from the respective maintainers about how the low power state actually works on them. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc/xmon: Use cpumask iterator to avoid warningAnton Blanchard
commit bc1d7702910c7c7e88eb60b58429dbfe293683ce upstream. We have a bug report where the kernel hits a warning in the cpumask code: WARNING: at include/linux/cpumask.h:107 Which is: WARN_ON_ONCE(cpu >= nr_cpumask_bits); The backtrace is: cpu_cmd cmds xmon_core xmon die xmon is iterating through 0 to NR_CPUS. I'm not sure why we are still open coding this but iterating above nr_cpu_ids is definitely a bug. This patch iterates through all possible cpus, in case we issue a system reset and CPUs in an offline state call in. Perhaps the old code was trying to handle CPUs that were in the partition but were never started (eg kexec into a kernel with an nr_cpus= boot option). They are going to die way before we get into xmon since we haven't set any kernel state up for them. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc/kvm: sldi should be sldMichael Neuling
commit 2f584a146a2965b82fce89b8d2f95dc5cfe468d0 upstream. Since we are taking a registers, this should never have been an sldi. Talking to paulus offline, this is the correct fix. Was introduced by: commit 19ccb76a1938ab364a412253daec64613acbf3df Author: Paul Mackerras <paulus@samba.org> Date: Sat Jul 23 17:42:46 2011 +1000 Talking to paulus, this shouldn't be a literal. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc: check_and_cede_processor() never cedesAnton Blanchard
commit 0b17ba7258db83cd02da560884e053b85de371f2 upstream. Commit f948501b36c6 ("Make hard_irq_disable() actually hard-disable interrupts") caused check_and_cede_processor to stop working. ->irq_happened will never be zero right after a hard_irq_disable so the compiler removes the call to cede_processor completely. The bug was introduced back in the lazy interrupt handling rework of 3.4 but was hidden until recently because hard_irq_disable did nothing. This issue will eventually appear in 3.4 stable since the hard_irq_disable fix is marked stable, so mark this one for stable too. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc/pseries: Fix software invalidate TCEMichael Neuling
commit bc6dc752f35488160ffac07ae91bed1bddaea32a upstream. The following added support for powernv but broke pseries/BML: 1f1616e powerpc/powernv: Add TCE SW invalidation support TCE_PCI_SW_INVAL was split into FREE and CREATE flags but the tests in the pseries code were not updated to reflect this. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc: Fix uninitialised error in numa.cMichael Neuling
commit 82b2521d257b5c0efd51821cf5fa306e53bbb6ba upstream. chroma_defconfig currently gives me this with gcc 4.6: arch/powerpc/mm/numa.c:638:13: error: 'dm' may be used uninitialized in this function [-Werror=uninitialized] It's a bogus warning/error since of_get_drconf_memory() only writes it anyway. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16powerpc/ftrace: Do not trace restore_interrupts()Steven Rostedt
commit 2d773aa4810d4a612d1c879faacc38594cc3f841 upstream. As I was adding code that affects all archs, I started testing function tracer against PPC64 and found that it currently locks up with 3.4 kernel. I figured it was due to tracing a function that shouldn't be, so I went through the following process to bisect to find the culprit: cat /debug/tracing/available_filter_functions > t num=`wc -l t` sed -ne "1,${num}p" t > t1 let num=num+1 sed -ne "${num},$p" t > t2 cat t1 > /debug/tracing/set_ftrace_filter echo function /debug/tracing/current_tracer <failed? bisect t1, if not bisect t2> It finally came down to this function: restore_interrupts() I'm not sure why this locks up the system. It just seems to prevent scheduling from occurring. Interrupts seem to still work, as I can ping the box. But all user processes freeze. When restore_interrupts() is not traced, function tracing works fine. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-22Make hard_irq_disable() actually hard-disable interruptsPaul Mackerras
commit f948501b36c6b3d9352ce212a197098a7e958971 upstream. At present, hard_irq_disable() does nothing on powerpc because of this code in include/linux/interrupt.h: #ifndef hard_irq_disable #define hard_irq_disable() do { } while(0) #endif So we need to make our hard_irq_disable be a macro. It was previously a macro until commit 7230c56441 ("powerpc: Rework lazy-interrupt handling") changed it to a static inline function. Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -- arch/powerpc/include/asm/hw_irq.h | 3 +++ 1 file changed, 3 insertions(+)
2012-06-17powerpc: Fix kernel panic during kernel module loadSteffen Rumler
commit 3c75296562f43e6fbc6cddd3de948a7b3e4e9bcf upstream. This fixes a problem which can causes kernel oopses while loading a kernel module. According to the PowerPC EABI specification, GPR r11 is assigned the dedicated function to point to the previous stack frame. In the powerpc-specific kernel module loader, do_plt_call() (in arch/powerpc/kernel/module_32.c), GPR r11 is also used to generate trampoline code. This combination crashes the kernel, in the case where the compiler chooses to use a helper function for saving GPRs on entry, and the module loader has placed the .init.text section far away from the .text section, meaning that it has to generate a trampoline for functions in the .init.text section to call the GPR save helper. Because the trampoline trashes r11, references to the stack frame using r11 can cause an oops. The fix just uses GPR r12 instead of GPR r11 for generating the trampoline code. According to the statements from Freescale, this is safe from an EABI perspective. I've tested the fix for kernel 2.6.33 on MPC8541. Signed-off-by: Steffen Rumler <steffen.rumler.ext@nsn.com> [paulus@samba.org: reworded the description] Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-17powerpc/time: Sanity check of decrementer expiration is necessaryPaul Mackerras
commit 860aed25a1f0936d4852ab936252b47cd1e630f1 upstream. This reverts 68568add2c ("powerpc/time: Remove unnecessary sanity check of decrementer expiration"). We do need to check whether we have reached the expiration time of the next event, because we sometimes get an early decrementer interrupt, most notably when we set the decrementer to 1 in arch_irq_work_raise(). The effect of not having the sanity check is that if timer_interrupt() gets called early, we leave the decrementer set to its maximum value, which means we then don't get any more decrementer interrupts for about 4 seconds (or longer, depending on timebase frequency). I saw these pauses as a consequence of getting a stray hypervisor decrementer interrupt left over from exiting a KVM guest. This isn't quite a straight revert because of changes to the surrounding code, but it restores the same algorithm as was previously used. Acked-by: Anton Blanchard <anton@samba.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-01powerpc: Fix broken cpu_idle_wait() implementationThomas Gleixner
commit 9cd75e13de2dcf32ecc21c7f277cff3c0ced059e upstream. commit 771dae818 (powerpc/cpuidle: Add cpu_idle_wait() to allow switching of idle routines) implemented cpu_idle_wait() for powerpc. The changelog says: "The equivalent routine for x86 is in arch/x86/kernel/process.c but the powerpc implementation is different.": Unfortunately the changelog is completely useless as it does not tell _WHY_ it is different. Aside of being different the implementation is patently wrong. The rescheduling IPI is async. That means that there is no guarantee, that the other cores have executed the IPI when cpu_idle_wait() returns. But that's the whole purpose of this function: to guarantee that no CPU uses the old idle handler anymore. Use the smp_functional_call() based implementation, which fulfils the requirements. [ This code is going to replaced by a core version to remove all the pointless copies in arch/*, but this one should go to stable ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Cc: Trinabh Gupta <g.trinabh@gmail.com> Cc: Arun R Bharadwaj <arun.r.bharadwaj@gmail.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Link: http://lkml.kernel.org/r/20120507175651.980164748@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-16KVM: PPC: Book3S HV: Fix bug leading to deadlock in guest HPT updatesPaul Mackerras
When handling the H_BULK_REMOVE hypercall, we were forgetting to invalidate and unlock the hashed page table entry (HPTE) in the case where the page had been paged out. This fixes it by clearing the first doubleword of the HPTE in that case. This fixes a regression introduced in commit a92bce95f0 ("KVM: PPC: Book3S HV: Keep HPTE locked when invalidating"). The effect of the regression is that the host kernel will sometimes hang when under memory pressure. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-16powerpc/kvm: Fix VSID usage in 64-bit "PR" KVMBenjamin Herrenschmidt
The code forgot to scramble the VSIDs the way we normally do and was basically using the "proto VSID" directly with the MMU. This means that in practice, KVM used random VSIDs that could collide with segments used by other user space programs. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [agraf: simplify ppc32 case] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-16KVM: PPC: Book3S: PR: Fix hsrr codeAlexander Graf
When jumping back into the kernel to code that knows that it would be using HSRR registers instead of SRR registers, we need to make sure we pass it all information on where to jump to in HSRR registers. Unfortunately, we used r10 to store the information to distinguish between the HSRR and SRR case. That register got clobbered in between though, rendering the later comparison invalid. Instead, let's use cr1 to store this information. That way we don't need yet another register and everyone's happy. This fixes PR KVM on POWER7 bare metal for me. Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-16KVM: PPC: Fix PR KVM on POWER7 bare metalAlexander Graf
When running on a system that is HV capable, some interrupts use HSRR SPRs instead of the normal SRR SPRs. These are also used in the Linux handlers to jump back to code after an interrupt got processed. Unfortunately, in our "jump back to the real host handler after we've done the context switch" code, we were only setting the SRR SPRs, rendering Linux to jump back to some invalid IP after it's processed the interrupt. This fixes random crashes on p7 opal mode with PR KVM for me. Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-16KVM: PPC: Book3S: PR: Handle EMUL_ASSISTAlexander Graf
In addition to normal "priviledged instruction" traps, we can also receive "emulation assist" traps on newer hardware that has the HV bit set. Handle that one the same way as a privileged instruction, including the instruction fetching. That way we don't execute old instructions that we happen to still leave in that field when an emul assist trap comes. This fixes -M mac99 / -M g3beige on p7 bare metal for me. Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-12powerpc/irq: Fix another case of lazy IRQ state getting out of syncBenjamin Herrenschmidt
So we have another case of paca->irq_happened getting out of sync with the HW irq state. This can happen when a perfmon interrupt occurs while soft disabled, as it will return to a soft disabled but hard enabled context while leaving a stale PACA_IRQ_HARD_DIS flag set. This patch fixes it, and also adds a test for the condition of those flags being out of sync in arch_local_irq_restore() when CONFIG_TRACE_IRQFLAGS is enabled. This helps catching those gremlins faster (and so far I can't seem see any anymore, so that's good news). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-09Merge git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Avi Kivity: "Two asynchronous page fault fixes (one guest, one host), a powerpc page refcount fix, and an ia64 build fix." * git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: ia64: fix build due to typo KVM: PPC: Book3S HV: Fix refcounting of hugepages KVM: Do not take reference to mm during async #PF KVM: ensure async PF event wakes up vcpu from halt
2012-05-09Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc fixes from Benjamin Herrenschmidt: "Here are a couple of last minute fixes for 3.4 for regressions introduced by my rewrite of the lazy irq masking code." * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc/irq: Make alignment & program interrupt behave the same powerpc/irq: Fix bug with new lazy IRQ handling code
2012-05-09powerpc/irq: Make alignment & program interrupt behave the sameBenjamin Herrenschmidt
Alignment was the last user of the ENABLE_INTS macro, which we can now remove. All non-syscall exceptions now disable interrupts on entry, they get re-enabled conditionally from C code. Don't unconditionally re-enable in program check either, check the original context. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-09powerpc/irq: Fix bug with new lazy IRQ handling codeBenjamin Herrenschmidt
We had a case where we could turn on hard interrupts while leaving the PACA_IRQ_HARD_DIS bit set in the PACA. This can in turn cause a BUG_ON() to hit in __check_irq_replay() due to interrupt state getting out of sync. The assembly code was also way too convoluted. Instead, we now leave it to the C code to do the right thing which ends up being smaller and more readable. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-05-08KVM: PPC: Book3S HV: Fix refcounting of hugepagesDavid Gibson
The H_REGISTER_VPA hcall implementation in HV Power KVM needs to pin some guest memory pages into host memory so that they can be safely accessed from usermode. It does this used get_user_pages_fast(). When the VPA is unregistered, or the VCPUs are cleaned up, these pages are released using put_page(). However, the get_user_pages() is invoked on the specific memory are of the VPA which could lie within hugepages. In case the pinned page is huge, we explicitly find the head page of the compound page before calling put_page() on it. At least with the latest kernel, this is not correct. put_page() already handles finding the correct head page of a compound, and also deals with various counts on the individual tail page which are important for transparent huge pages. We don't support transparent hugepages on Power, but even so, bypassing this count maintenance can lead (when the VM ends) to a hugepage being released back to the pool with a non-zero mapcount on one of the tail pages. This can then lead to a bad_page() when the page is released from the hugepage pool. This removes the explicit compound_head() call to correct this bug. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>