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* powerpc: use machine_subsys_initcall() for opal_hmi_handler_init()Li Zhong2014-09-091-1/+2
| | | | | | | | As opal_message_init() uses machine_early_initcall(powernv, ), and opal_hmi_handler_init() depends on that early initcall, so it also needs use machine_* to check the machine_id. Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
* powerpc/pseries: Fix endian issues in memory hotplugThomas Falcon2014-09-091-17/+19
| | | | | | | | Values acquired from Open Firmware are in 32-bit big endian format and need to be handled on little endian architectures. This patch ensures values are in cpu endian when hotplugging memory. Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
* Merge branch 'next' of ↵Linus Torvalds2014-08-147-24/+49
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull more powerpc updates from Ben Herrenschmidt: "Here are some more powerpc bits for 3.17, essentially fixes. The biggest series, also aimed at -stable, is from Aneesh and is the result of weeks and weeks of debugging to find out why the heck or THP implementation was occasionally triggering multi-hit errors in our level 1 TLB. It ended up being a combination of issues including subtleties as to how we should invalidate those special 'MPSS' pages we use to allow the use of 16M pages inside 4K/64K "base page size" segments (you really have to love our MMU !) Another interesting one in the "OMG" category is the series from Michael adding memory barriers to spin_is_locked(). That's also the result of many days of debugging to figure out why the semaphore code would occasionally crash in ways that made no sense. It ended up being some creative lock stacking that was defeated by the fact that our locks allow a load inside the locked section to be re-ordered with the load of the lock value itself (I'm still of two mind about whether to kill that once and for all by putting a heavier barrier back into our lock implementation...). The fixes come with a long explanation in the cset comments, feel free to read it if you feel like having a headache today" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits) powerpc/thp: Add tracepoints to track hugepage invalidate powerpc/mm: Use read barrier when creating real_pte powerpc/thp: Use ACCESS_ONCE when loading pmdp powerpc/thp: Invalidate with vpn in loop powerpc/thp: Handle combo pages in invalidate powerpc/thp: Invalidate old 64K based hash page mapping before insert of 4k pte powerpc/thp: Don't recompute vsid and ssize in loop on invalidate powerpc/thp: Add write barrier after updating the valid bit powerpc: reorder per-cpu NUMA information's initialization powerpc/perf/hv-24x7: Use kmem_cache_free powerpc/pseries/hvcserver: Fix endian issue in hvcs_get_partner_info powerpc: Hard disable interrupts in xmon powerpc: remove duplicate definition of TEXASR_FS powerpc/pseries: Avoid deadlock on removing ddw powerpc/pseries: Failure on removing device node powerpc/boot: Use correct zlib types for comparison powerpc/powernv: Interface to register/unregister opal dump region printk: Add function to return log buffer address and size powerpc: Add POWER8 features to CPU_FTRS_POSSIBLE/ALWAYS powerpc/ppc476: Disable BTAC ...
| * powerpc/thp: Don't recompute vsid and ssize in loop on invalidateAneesh Kumar K.V2014-08-131-14/+6Star
| | | | | | | | | | | | | | | | | | | | The segment identifier and segment size will remain the same in the loop, So we can compute it outside. We also change the hugepage_invalidate interface so that we can use it the later patch CC: <stable@vger.kernel.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/pseries/hvcserver: Fix endian issue in hvcs_get_partner_infoThomas Falcon2014-08-131-2/+2
| | | | | | | | | | | | | | | | | | A buffer returned by H_VTERM_PARTNER_INFO contains device information in big endian format, causing problems for little endian architectures. This patch ensures that they are in cpu endian. Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/pseries: Avoid deadlock on removing ddwGavin Shan2014-08-131-6/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function remove_ddw() could be called in of_reconfig_notifier and we potentially remove the dynamic DMA window property, which invokes of_reconfig_notifier again. Eventually, it leads to the deadlock as following backtrace shows. The patch fixes the above issue by deferring releasing the dynamic DMA window property while releasing the device node. ============================================= [ INFO: possible recursive locking detected ] 3.16.0+ #428 Tainted: G W --------------------------------------------- drmgr/2273 is trying to acquire lock: ((of_reconfig_chain).rwsem){.+.+..}, at: [<c000000000091890>] \ .__blocking_notifier_call_chain+0x40/0x78 but task is already holding lock: ((of_reconfig_chain).rwsem){.+.+..}, at: [<c000000000091890>] \ .__blocking_notifier_call_chain+0x40/0x78 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((of_reconfig_chain).rwsem); lock((of_reconfig_chain).rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by drmgr/2273: #0: (sb_writers#4){.+.+.+}, at: [<c0000000001cbe70>] \ .vfs_write+0xb0/0x1f8 #1: ((of_reconfig_chain).rwsem){.+.+..}, at: [<c000000000091890>] \ .__blocking_notifier_call_chain+0x40/0x78 stack backtrace: CPU: 17 PID: 2273 Comm: drmgr Tainted: G W 3.16.0+ #428 Call Trace: [c0000000137e7000] [c000000000013d9c] .show_stack+0x88/0x148 (unreliable) [c0000000137e70b0] [c00000000083cd34] .dump_stack+0x7c/0x9c [c0000000137e7130] [c0000000000b8afc] .__lock_acquire+0x128c/0x1c68 [c0000000137e7280] [c0000000000b9a4c] .lock_acquire+0xe8/0x104 [c0000000137e7350] [c00000000083588c] .down_read+0x4c/0x90 [c0000000137e73e0] [c000000000091890] .__blocking_notifier_call_chain+0x40/0x78 [c0000000137e7490] [c000000000091900] .blocking_notifier_call_chain+0x38/0x48 [c0000000137e7520] [c000000000682a28] .of_reconfig_notify+0x34/0x5c [c0000000137e75b0] [c000000000682a9c] .of_property_notify+0x4c/0x54 [c0000000137e7650] [c000000000682bf0] .of_remove_property+0x30/0xd4 [c0000000137e76f0] [c000000000052a44] .remove_ddw+0x144/0x168 [c0000000137e7790] [c000000000053204] .iommu_reconfig_notifier+0x30/0xe0 [c0000000137e7820] [c00000000009137c] .notifier_call_chain+0x6c/0xb4 [c0000000137e78c0] [c0000000000918ac] .__blocking_notifier_call_chain+0x5c/0x78 [c0000000137e7970] [c000000000091900] .blocking_notifier_call_chain+0x38/0x48 [c0000000137e7a00] [c000000000682a28] .of_reconfig_notify+0x34/0x5c [c0000000137e7a90] [c000000000682e14] .of_detach_node+0x44/0x1fc [c0000000137e7b40] [c0000000000518e4] .ofdt_write+0x3ac/0x688 [c0000000137e7c20] [c000000000238430] .proc_reg_write+0xb8/0xd4 [c0000000137e7cd0] [c0000000001cbeac] .vfs_write+0xec/0x1f8 [c0000000137e7d70] [c0000000001cc3b0] .SyS_write+0x58/0xa0 [c0000000137e7e30] [c00000000000a064] syscall_exit+0x0/0x98 Cc: stable@vger.kernel.org Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/pseries: Failure on removing device nodeGavin Shan2014-08-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While running command "drmgr -c phb -r -s 'PHB 528'", following backtrace jumped out because the target device node isn't marked with OF_DETACHED by of_detach_node(), which caused by error returned from memory hotplug related reconfig notifier when disabling CONFIG_MEMORY_HOTREMOVE. The patch fixes it. ERROR: Bad of_node_put() on /pci@800000020000210/ethernet@0 CPU: 14 PID: 2252 Comm: drmgr Tainted: G W 3.16.0+ #427 Call Trace: [c000000012a776a0] [c000000000013d9c] .show_stack+0x88/0x148 (unreliable) [c000000012a77750] [c00000000083cd34] .dump_stack+0x7c/0x9c [c000000012a777d0] [c0000000006807c4] .of_node_release+0x58/0xe0 [c000000012a77860] [c00000000038a7d0] .kobject_release+0x174/0x1b8 [c000000012a77900] [c00000000038a884] .kobject_put+0x70/0x78 [c000000012a77980] [c000000000681680] .of_node_put+0x28/0x34 [c000000012a77a00] [c000000000681ea8] .__of_get_next_child+0x64/0x70 [c000000012a77a90] [c000000000682138] .of_find_node_by_path+0x1b8/0x20c [c000000012a77b40] [c000000000051840] .ofdt_write+0x308/0x688 [c000000012a77c20] [c000000000238430] .proc_reg_write+0xb8/0xd4 [c000000012a77cd0] [c0000000001cbeac] .vfs_write+0xec/0x1f8 [c000000012a77d70] [c0000000001cc3b0] .SyS_write+0x58/0xa0 [c000000012a77e30] [c00000000000a064] syscall_exit+0x0/0x98 Cc: stable@vger.kernel.org Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/powernv: Interface to register/unregister opal dump regionVasant Hegde2014-08-132-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | PowerNV platform is capable of capturing host memory region when system crashes (because of host/firmware). We have new OPAL API to register/ unregister memory region to be captured when system crashes. This patch adds support for new API. Also during boot time we register kernel log buffer and unregister before doing kexec. Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * powerpc/powernv: Fix IOMMU group lostGavin Shan2014-08-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we take full hotplug to recover from EEH errors, PCI buses could be involved. For the case, the child devices of involved PCI buses can't be attached to IOMMU group properly, which is caused by commit 3f28c5a ("powerpc/powernv: Reduce multi-hit of iommu_add_device()"). When adding the PCI devices of the newly created PCI buses to the system, the IOMMU group is expected to be added in (C). (A) fails to bind the IOMMU group because bus->is_added is false. (B) fails because the device doesn't have binding IOMMU table yet. bus->is_added is set to true at end of (C) and pdev->is_added is set to true at (D). pcibios_add_pci_devices() pci_scan_bridge() pci_scan_child_bus() pci_scan_slot() pci_scan_single_device() pci_scan_device() pci_device_add() pcibios_add_device() A: Ignore device_add() B: Ignore pcibios_fixup_bus() pcibios_setup_bus_devices() pcibios_setup_device() C: Hit pcibios_finish_adding_to_bus() pci_bus_add_devices() pci_bus_add_device() D: Add device If the parent PCI bus isn't involved in hotplug, the IOMMU group is expected to be bound in (B). (A) should fail as the sysfs entries aren't populated. The patch fixes the issue by reverting commit 3f28c5a and remove WARN_ON() in iommu_add_device() to allow calling the function even the specified device already has associated IOMMU group. Cc: <stable@vger.kernel.org> # 3.16+ Reported-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Acked-by: Wei Yang <weiyang@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linuxLinus Torvalds2014-08-146-21/+10Star
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull device tree updates from Grant Likely: "The branch contains the following device tree changes the v3.17 merge window: Group changes to the device tree. In preparation for adding device tree overlay support, OF_DYNAMIC is reworked so that a set of device tree changes can be prepared and applied to the tree all at once. OF_RECONFIG notifiers see the most significant change here so that users always get a consistent view of the tree. Notifiers generation is moved from before a change to after it, and notifiers for a group of changes are emitted after the entire block of changes have been applied Automatic console selection from DT. Console drivers can now use of_console_check() to see if the device node is specified as a console device. If so then it gets added as a preferred console. UART devices get this support automatically when uart_add_one_port() is called. DT unit tests no longer depend on pre-loaded data in the device tree. Data is loaded dynamically at the start of unit tests, and then unloaded again when the tests have completed. Also contains a few bugfixes for reserved regions and early memory setup" * tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux: (21 commits) of: Fixing OF Selftest build error drivers: of: add automated assignment of reserved regions to client devices of: Use proper types for checking memory overflow of: typo fix in __of_prop_dup() Adding selftest testdata dynamically into live tree of: Add todo tasklist for Devicetree of: Transactional DT support. of: Reorder device tree changes and notifiers of: Move dynamic node fixups out of powerpc and into common code of: Make sure attached nodes don't carry along extra children of: Make devicetree sysfs update functions consistent. of: Create unlocked versions of node and property add/remove functions OF: Utility helper functions for dynamic nodes of: Move CONFIG_OF_DYNAMIC code into a separate file of: rename of_aliases_mutex to just of_mutex of/platform: Fix of_platform_device_destroy iteration of devices of: Migrate of_find_node_by_name() users to for_each_node_by_name() tty: Update hypervisor tty drivers to use core stdout parsing code. arm/versatile: Add the uart as the stdout device. of: Enable console on serial ports specified by /chosen/stdout-path ...
| * \ Merge branch 'devicetree/next-overlay' into devicetree/nextGrant Likely2014-08-111-1/+1
| |\ \ | | | | | | | | | | | | | | | | Conflicts: drivers/of/testcase-data/testcases.dts
| | * | of: Reorder device tree changes and notifiersGrant Likely2014-07-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, devicetree reconfig notifiers get emitted before the change is applied to the tree, but that behaviour is problematic if the receiver wants the determine the new state of the tree. The current users don't care, but the changeset code to follow will be making multiple changes at once. Reorder notifiers to get emitted after the change has been applied to the tree so that callbacks see the new tree state. At the same time, fixup the existing callbacks to expect the new order. There are a few callbacks that compare the old and new values of a changed property. Put both property pointers into the of_prop_reconfig structure. The current notifiers also allow the notifier callback to fail and cancel the change to the tree, but that feature isn't actually used. It really isn't valid to ignore a tree modification provided by firmware anyway, so remove the ability to cancel a change to the tree. Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Nathan Fontenot <nfont@austin.ibm.com>
| * | | Merge branch 'devicetree/next-console' into devicetree/nextGrant Likely2014-08-115-20/+9Star
| |\ \ \ | | |/ / | |/| |
| | * | of: Migrate of_find_node_by_name() users to for_each_node_by_name()Grant Likely2014-06-265-20/+9Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a bunch of users open coding the for_each_node_by_name() by calling of_find_node_by_name() directly instead of using the macro. This is getting in the way of some cleanups, and the possibility of removing of_find_node_by_name() entirely. Clean it up so that all the users are consistent. Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Takashi Iwai <tiwai@suse.de>
* | | | Merge tag 'modules-next-for-linus' of ↵Linus Torvalds2014-08-112-4/+4
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "This finally applies the stricter sysfs perms checking we pulled out before last merge window. A few stragglers are fixed (thanks linux-next!)" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs files arch/powerpc/platforms/powernv/opal-elog.c: fix world-writable sysfs files drivers/video/fbdev/s3c2410fb.c: don't make debug world-writable. ARM: avoid ARM binutils leaking ELF local symbols scripts: modpost: Remove numeric suffix pattern matching scripts: modpost: fix compilation warning sysfs: disallow world-writable files. module: return bool from within_module*() module: add within_module() function modules: Fix build error in moduleloader.h
| * | | arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs filesRusty Russell2014-08-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | If you don't have a store function, you're not writable anyway! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | | arch/powerpc/platforms/powernv/opal-elog.c: fix world-writable sysfs filesRusty Russell2014-08-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If you don't have a store function, you're not writable anyway! Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
* | | | arch/powerpc: replace obsolete strict_strto* callsDaniel Walter2014-08-092-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace strict_strto calls with more appropriate kstrto calls Signed-off-by: Daniel Walter <dwalter@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | lib/scatterlist: make ARCH_HAS_SG_CHAIN an actual KconfigLaura Abbott2014-08-093-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than have architectures #define ARCH_HAS_SG_CHAIN in an architecture specific scatterlist.h, make it a proper Kconfig option and use that instead. At same time, remove the header files are are now mostly useless and just include asm-generic/scatterlist.h. [sfr@canb.auug.org.au: powerpc files now need asm/dma.h] Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [powerpc] Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'next' of ↵Linus Torvalds2014-08-0740-522/+1587
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc updates from Ben Herrenschmidt: "This is the powerpc new goodies for 3.17. The short story: The biggest bit is Michael removing all of pre-POWER4 processor support from the 64-bit kernel. POWER3 and rs64. This gets rid of a ton of old cruft that has been bitrotting in a long while. It was broken for quite a few versions already and nobody noticed. Nobody uses those machines anymore. While at it, he cleaned up a bunch of old dusty cabinets, getting rid of a skeletton or two. Then, we have some base VFIO support for KVM, which allows assigning of PCI devices to KVM guests, support for large 64-bit BARs on "powernv" platforms, support for HMI (Hardware Management Interrupts) on those same platforms, some sparse-vmemmap improvements (for memory hotplug), There is the usual batch of Freescale embedded updates (summary in the merge commit) and fixes here or there, I think that's it for the highlights" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (102 commits) powerpc/eeh: Export eeh_iommu_group_to_pe() powerpc/eeh: Add missing #ifdef CONFIG_IOMMU_API powerpc: Reduce scariness of interrupt frames in stack traces powerpc: start loop at section start of start in vmemmap_populated() powerpc: implement vmemmap_free() powerpc: implement vmemmap_remove_mapping() for BOOK3S powerpc: implement vmemmap_list_free() powerpc: Fail remap_4k_pfn() if PFN doesn't fit inside PTE powerpc/book3s: Fix endianess issue for HMI handling on napping cpus. powerpc/book3s: handle HMIs for cpus in nap mode. powerpc/powernv: Invoke opal call to handle hmi. powerpc/book3s: Add basic infrastructure to handle HMI in Linux. powerpc/iommu: Fix comments with it_page_shift powerpc/powernv: Handle compound PE in config accessors powerpc/powernv: Handle compound PE for EEH powerpc/powernv: Handle compound PE powerpc/powernv: Split ioda_eeh_get_state() powerpc/powernv: Allow to freeze PE powerpc/powernv: Enable M64 aperatus for PHB3 powerpc/eeh: Aux PE data for error log ...
| * | | | powerpc/powernv: Invoke opal call to handle hmi.Mahesh Salgaonkar2014-08-054-7/+219
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we hit the HMI in Linux, invoke opal call to handle/recover from HMI errors in real mode and then in virtual mode during check_irq_replay() invoke opal_poll_events()/opal_do_notifier() to retrieve HMI event from OPAL and act accordingly. Now that we are ready to handle HMI interrupt directly in linux, remove the HMI interrupt registration with firmware. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/book3s: Add basic infrastructure to handle HMI in Linux.Mahesh Salgaonkar2014-08-052-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements basic infrastructure to handle HMI in Linux host. The design is to invoke opal handle hmi in real mode for recovery and set irq_pending when we hit HMI. During check_irq_replay pull opal hmi event and print hmi info on console. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Handle compound PE in config accessorsGavin Shan2014-08-051-28/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The PCI config accessors check for PE frozen state and clear it if EEH isn't functional. The patch handles compound PE in config accessors if PHB supports it. For consistency, all PEs will be put into frozen state if any one in compound group gets frozen by hardware. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Handle compound PE for EEHGavin Shan2014-08-051-47/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch handles compound PE for EEH backend. If one specific PE in compound group has been frozen, we enforces to freeze all PEs in the group. If we're enable DMA or MMIO for one PE in compound group, DMA or MMIO of all PEs in the group will be enabled. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Handle compound PEGavin Shan2014-08-052-0/+146
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch introduces 3 PHB callbacks: compound PE state retrieval, force freezing and unfreezing compound PE. The PCI config accessors and PowerNV EEH backend can use them in subsequent patches. We don't export the capability of compound PE to EEH core, which helps avoiding more complexity to EEH core. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Split ioda_eeh_get_state()Gavin Shan2014-08-051-80/+104
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function ioda_eeh_get_state() is used to fetch EEH state for PHB or PE. We're going to support compound PE and the function becomes more complicated with that. The patch splits the function into two functions for PHB and PE cases separately to improve readability. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Allow to freeze PEGavin Shan2014-08-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch synchronizes header file with firmware to have new OPAL API opal_pci_eeh_freeze_set(), which is used to freeze the specified PE in order to support "compound" PE. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Enable M64 aperatus for PHB3Guo Chao2014-08-052-21/+300
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables M64 aperatus for PHB3. We already had platform hook (ppc_md.pcibios_window_alignment) to affect the PCI resource assignment done in PCI core so that each PE's M32 resource was built on basis of M32 segment size. Similarly, we're using that for M64 assignment on basis of M64 segment size. * We're using last M64 BAR to cover M64 aperatus, and it's shared by all 256 PEs. * We don't support P7IOC yet. However, some function callbacks are added to (struct pnv_phb) so that we can reuse them on P7IOC in future. * PE, corresponding to PCI bus with large M64 BAR device attached, might span multiple M64 segments. We introduce "compound" PE to cover the case. The compound PE is a list of PEs and the master PE is used as before. The slave PEs are just for MMIO isolation. Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/eeh: Aux PE data for error logGavin Shan2014-08-052-14/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch allows PE (struct eeh_pe) instance to have auxillary data, whose size is configurable on basis of platform. For PowerNV, the auxillary data will be used to cache PHB diag-data for that PE (frozen PE or fenced PHB). In turn, we can retrieve the diag-data at any later points. It's useful for the case of VFIO PCI devices where the error log should be cached, and then be retrieved by the guest at later point. Also, it can avoid PHB diag-data overwritting if another frozen PE reported and the previous diag-data isn't fetched by guest. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/eeh: Make diag-data not endian dependentGavin Shan2014-08-052-44/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's followup of commit ddf0322a ("powerpc/powernv: Fix endianness problems in EEH"). The patch helps to get non-endian-dependent diag-data. Cc: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/eeh: Replace pr_warning() with pr_warn()Gavin Shan2014-08-053-23/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pr_warn() is equal to pr_warning(), but the former is a bit more formal according to commit fc62f2f ("kernel.h: add pr_warn for symmetry to dev_warn, netdev_warn"). The patch replaces pr_warning() with pr_warn(). Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/eeh: Selectively enable IO for error logGavin Shan2014-08-052-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to the experiment I did, PCI config access is blocked on P7IOC frozen PE by hardware, but PHB3 doesn't do that. That means we always get 0xFF's while dumping PCI config space of the frozen PE on P7IOC. We don't have the problem on PHB3. So we have to enable I/O prioir to collecting error log. Otherwise, meaningless 0xFF's are always returned. The patch fixes it by EEH flag (EEH_ENABLE_IO_FOR_LOG), which is selectively set to indicate the case for: P7IOC on PowerNV platform, pSeries platform. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/eeh: Refactor EEH flag accessorsGavin Shan2014-08-053-6/+5Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are multiple global EEH flags. Almost each flag has its own accessor, which doesn't make sense. The patch refactors EEH flag accessors so that they look unified: eeh_add_flag(): Add EEH flag eeh_clear_flag(): Clear EEH flag eeh_has_flag(): Check if one specific flag has been set eeh_enabled(): Check if EEH functionality has been enabled Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Fix IOMMU table for VFIO devGavin Shan2014-08-051-9/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On PHB3, PCI devices can bypass IOMMU for DMA access. If we pass through one PCI device, whose hose driver ever enable the bypass mode, pdev->dev.archdata.dma_data.iommu_table_base isn't IOMMU table. However, EEH needs access the IOMMU table when the device is owned by guest. The patch fixes pdev->dev.archdata.dma_data.iommu_table when passing through the device to guest in pnv_pci_ioda2_set_bypass(). Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/pci: Reorder pci bus/bridge unregistration during PHB removalTyrel Datwyler2014-08-051-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit bcdde7e made __sysfs_remove_dir() recursive and introduced a BUG_ON during PHB removal while attempting to delete the power managment attribute group of the bus. This is a result of tearing the bridge and bus devices down out of order in remove_phb_dynamic. Since, the the bus resides below the bridge in the sysfs device tree it should be torn down first. This patch simply moves the device_unregister call for the PHB bridge device after the device_unregister call for the PHB bus. Fixes: bcdde7e221a8 ("sysfs: make __sysfs_remove_dir() recursive") Cc: stable@vger.kernel.org Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/powernv: Update dev->dma_mask in pci_set_dma_mask() pathBrian W Hart2014-08-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | powerpc defines various machine-specific routines for handling pci_set_dma_mask(). The routines for machine "PowerNV" may neglect to set dev->dma_mask. This could confuse anyone (e.g. drivers) that consult dev->dma_mask to find the current mask. Set the dma_mask in the PowerNV leaf routine. Signed-off-by: Brian W. Hart <hartb@linux.vnet.ibm.com> CC: <stable@vger.kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/eeh: sysfs entries lostMike Qiu2014-08-052-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sysfs entries are lost because of commit 2213fb1 ("powerpc/eeh: Skip eeh sysfs when eeh is disabled"). That commit added condition to create sysfs entries with EEH_ENABLED, which isn't populated when trying to create sysfs entries on PowerNV platform during system boot time. The patch fixes the issue by: * Reoder EEH initialization functions so that they're same on PowerNV/pSeries. * Cache PE's primary bus by PowerNV platform instead of EEH core to avoid kernel crash caused by the function reorder. Another benefit with this is to avoid one eeh_probe_mode_dev() in EEH core. Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | powerpc/eeh: Avoid event on passed PEGavin Shan2014-08-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We must not handle EEH error on devices which are passed to somebody else. Instead, we expect that the frozen device owner detects an EEH error and recovers from it. This avoids EEH error handling on passed through devices so the device owner gets a chance to handle them. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | Merge remote-tracking branch 'scott/next' into nextBenjamin Herrenschmidt2014-08-053-1/+46
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Scott writes: Highlights include e6500 hardware threading support, an e6500 TLB erratum workaround, corenet error reporting, support for a new board, and some minor fixes.
| | * | | | powerpc/t2080rdb: Add T2080RDB board supportShengzhou Liu2014-07-312-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | T2080PCIe-RDB is a Freescale Reference Design Board that hosts T2080 SoC. The board feature overview: Processor: - T2080 SoC integrating four 64-bit dual-threads e6500 cores up to 1.8GHz DDR Memory: - Single memory controller capable of supporting DDR3 and DDR3-LP devices - 72bit 4GB DDR3-LP SODIMM in slot Ethernet interfaces: - Two 1Gbps RGMII ports on-board - Two 10Gbps SFP+ ports on-board - Two 10Gbps Base-T ports on-board Accelerator: - DPAA components consist of FMan, BMan, QMan, PME, DCE and SEC IFC/Local Bus - NOR: 128MB 16-bit NOR flash - NAND: 1GB 8-bit NAND flash - CPLD: for system controlling with programable header on-board eSPI: - 64MB N25Q512 SPI flash USB: - Two USB2.0 ports with internal PHY (both Type-A) PCIe: - One PCIe x4 goldfinger(support SR-IOV) - One PCIe x4 slot - One PCIe x2 end-point device (C293 crypto co-processor) SATA: - Two SATA 2.0 ports on-board SDHC: - support a MicroSD/TF card on-board I2C: - Four I2C controllers. UART: - Dual 4-pins UART serial ports Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
| | * | | | powerpc/e6500: Add support for hardware threadsAndy Fleming2014-07-301-0/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The general idea is that each core will release all of its threads into the secondary thread startup code, which will eventually wait in the secondary core holding area, for the appropriate bit in the PACA to be set. The kick_cpu function pointer will set that bit in the PACA, and thus "release" the core/thread to boot. We also need to do a few things that U-Boot normally does for CPUs (like enable branch prediction). Signed-off-by: Andy Fleming <afleming@freescale.com> [scottwood@freescale.com: various changes, including only enabling threads if Linux wants to kick them] Signed-off-by: Scott Wood <scottwood@freescale.com>
| * | | | | powerpc/pseries: Switch pseries drivers to use machine_xxx_initcall()Michael Ellerman2014-07-2811-23/+19Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A lot of the code in platforms/pseries is using non-machine initcalls. That means if a kernel built with pseries support runs on another platform, for example powernv, the initcalls will still run. Most of these cases are OK, though sometimes only due to luck. Some were having more effect: * hcall_inst_init - Checking FW_FEATURE_LPAR which is set on ps3 & celleb. * mobility_sysfs_init - created sysfs files unconditionally - but no effect due to ENOSYS from rtas_ibm_suspend_me() * apo_pm_init - created sysfs, allows write - nothing checks the value written to though * alloc_dispatch_log_kmem_cache - creating kmem_cache on non-pseries machines Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | powerpc/powernv: Switch powernv drivers to use machine_xxx_initcall()Michael Ellerman2014-07-288-16/+14Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A lot of the code in platforms/powernv is using non-machine initcalls. That means if a kernel built with powernv support runs on another platform, for example pseries, the initcalls will still run. That is usually OK, because the initcalls will check for something in the device tree or elsewhere before doing anything, so on other platforms they will usually just return. But it's fishy for powernv code to be running on other platforms, so switch them all to be machine initcalls. If we want any of them to run on other platforms in future they should move to sysdev. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | powerpc: Remove CONFIG_POWER4Michael Ellerman2014-07-283-30/+26Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although the name CONFIG_POWER4 suggests that it controls support for power4 cpus, this symbol is actually misnamed. It is a historical wart from the powermac code, which used to support building a 32-bit kernel for power4. CONFIG_POWER4 was used in that context to guard code that was 64-bit only. In the powermac code we can just use CONFIG_PPC64 instead, and in other places it is a synonym for CONFIG_PPC_BOOK3S_64. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | powerpc: Remove power3 from commentsMichael Ellerman2014-07-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are still a few occurences where it remains, because it helps to explain something that persists. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | powerpc: Remove CONFIG_POWER3Michael Ellerman2014-07-281-4/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have dropped power3 support we can remove CONFIG_POWER3. The usage in pgtable_32.c was already dead code as CONFIG_POWER3 was not selectable on PPC32. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | Merge branch 'merge' into nextBenjamin Herrenschmidt2014-07-283-2/+4
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | Bring in some important fixes from the 3.16 branch
| * | | | | | powernv: Add OPAL tracepointsAnton Blanchard2014-07-113-9/+191
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Knowing how long we spend in firmware calls is an important part of minimising OS jitter. This patch adds tracepoints to each OPAL call. If tracepoints are enabled we branch out to a common routine that calls an entry and exit tracepoint. This allows us to write tools that monitor the frequency and duration of OPAL calls, eg: name count total(ms) min(ms) max(ms) avg(ms) period(ms) OPAL_HANDLE_INTERRUPT 5 0.199 0.037 0.042 0.040 12547.545 OPAL_POLL_EVENTS 204 2.590 0.012 0.036 0.013 2264.899 OPAL_PCI_MSI_EOI 2830 3.066 0.001 0.005 0.001 81.166 We use jump labels if configured, which means we only add a single nop instruction to every OPAL call when the tracepoints are disabled. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc/pseries: Optimise hcall tracepointsAnton Blanchard2014-07-111-22/+16Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we execute the hcall tracepoint entry and exit code out of line, we can use the same stack across both functions. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | | | | powerpc/pseries: Use jump labels for hcall tracepointsAnton Blanchard2014-07-112-41/+133
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hcall tracepoints add quite a few instructions to our hcall path: plpar_hcall: mr r2,r2 mfcr r0 stw r0,8(r1) b 164 <---- start ld r12,0(r2) std r12,32(r1) cmpdi r12,0 beq 164 <---- end ... We have an unconditional branch that gets noped out during boot and a load/compare/branch. We also store the tracepoint value to the stack for the hcall_exit path to use. By using jump labels we can simplify this to just a single nop that gets replaced with a branch when the tracepoint is enabled: plpar_hcall: mr r2,r2 mfcr r0 stw r0,8(r1) nop <---- ... If jump labels are not enabled, we fall back to the old method. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>