kernel.git/arch/powerpc/platforms/pseries, branch linux-5.8.y

powerpc/pseries: Avoid using addr_to_pfn in real mode

2020-10-29T09:08:16Z

[ Upstream commit 4ff753feab021242144818b9a3ba011238218145 ] When an UE or memory error exception is encountered the MCE handler tries to find the pfn using addr_to_pfn() which takes effective address as an argument, later pfn is used to poison the page where memory error occurred, recent rework in this area made addr_to_pfn to run in real mode, which can be fatal as it may try to access memory outside RMO region. Have two helper functions to separate things to be done in real mode and virtual mode without changing any functionality. This also fixes the following error as the use of addr_to_pfn is now moved to virtual mode. Without this change following kernel crash is seen on hitting UE. [ 485.128036] Oops: Kernel access of bad area, sig: 11 [#1] [ 485.128040] LE SMP NR_CPUS=2048 NUMA pSeries [ 485.128047] Modules linked in: [ 485.128067] CPU: 15 PID: 6536 Comm: insmod Kdump: loaded Tainted: G OE 5.7.0 #22 [ 485.128074] NIP: c00000000009b24c LR: c0000000000398d8 CTR: c000000000cd57c0 [ 485.128078] REGS: c000000003f1f970 TRAP: 0300 Tainted: G OE (5.7.0) [ 485.128082] MSR: 8000000000001003 CR: 28008284 XER: 00000001 [ 485.128088] CFAR: c00000000009b190 DAR: c0000001fab00000 DSISR: 40000000 IRQMASK: 1 [ 485.128088] GPR00: 0000000000000001 c000000003f1fbf0 c000000001634300 0000b0fa01000000 [ 485.128088] GPR04: d000000002220000 0000000000000000 00000000fab00000 0000000000000022 [ 485.128088] GPR08: c0000001fab00000 0000000000000000 c0000001fab00000 c000000003f1fc14 [ 485.128088] GPR12: 0000000000000008 c000000003ff5880 d000000002100008 0000000000000000 [ 485.128088] GPR16: 000000000000ff20 000000000000fff1 000000000000fff2 d0000000021a1100 [ 485.128088] GPR20: d000000002200000 c00000015c893c50 c000000000d49b28 c00000015c893c50 [ 485.128088] GPR24: d0000000021a0d08 c0000000014e5da8 d0000000021a0818 000000000000000a [ 485.128088] GPR28: 0000000000000008 000000000000000a c0000000017e2970 000000000000000a [ 485.128125] NIP [c00000000009b24c] __find_linux_pte+0x11c/0x310 [ 485.128130] LR [c0000000000398d8] addr_to_pfn+0x138/0x170 [ 485.128133] Call Trace: [ 485.128135] Instruction dump: [ 485.128138] 3929ffff 7d4a3378 7c883c36 7d2907b4 794a1564 7d294038 794af082 3900ffff [ 485.128144] 79291f24 790af00e 78e70020 7d095214 <7c69502a> 2fa30000 419e011c 70690040 [ 485.128152] ---[ end trace d34b27e29ae0e340 ]--- Fixes: 9ca766f9891d ("powerpc/64s/pseries: machine check convert to use common event code") Signed-off-by: Ganesh Goudar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200724063946.21378-1-ganeshgr@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/papr_scm: Add PAPR command family to pass-through command-set

2020-10-29T09:08:01Z

[ Upstream commit 13135b461cf205941308984bd3271ec7d403dc40 ] Add NVDIMM_FAMILY_PAPR to the list of valid 'dimm_family_mask' acceptable by papr_scm. This is needed as since commit 92fe2aa859f5 ("libnvdimm: Validate command family indices") libnvdimm performs a validation of 'nd_cmd_pkg.nd_family' received as part of ND_CMD_CALL processing to ensure only known command families can use the general ND_CMD_CALL pass-through functionality. Without this change the ND_CMD_CALL pass-through targeting NVDIMM_FAMILY_PAPR error out with -EINVAL. Fixes: 92fe2aa859f5 ("libnvdimm: Validate command family indices") Signed-off-by: Vaibhav Jain Reviewed-by: Ira Weiny Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200913211904.24472-1-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory

2020-10-29T09:07:55Z

[ Upstream commit eae9eec476d13fad9af6da1f44a054ee02b7b161 ] POWER secure guests (i.e., guests which use the Protected Execution Facility) need to use SWIOTLB to be able to do I/O with the hypervisor, but they don't need the SWIOTLB memory to be in low addresses since the hypervisor doesn't have any addressing limitation. This solves a SWIOTLB initialization problem we are seeing in secure guests with 128 GB of RAM: they are configured with 4 GB of crashkernel reserved memory, which leaves no space for SWIOTLB in low addresses. To do this, we use mostly the same code as swiotlb_init(), but allocate the buffer using memblock_alloc() instead of memblock_alloc_low(). Fixes: 2efbc58f157a ("powerpc/pseries/svm: Force SWIOTLB for secure guests") Signed-off-by: Thiago Jung Bauermann Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200818221126.391073-1-bauerman@linux.ibm.com Signed-off-by: Sasha Levin

pseries/drmem: don't cache node id in drmem_lmb struct

2020-10-29T09:07:52Z

[ Upstream commit e5e179aa3a39c818db8fbc2dce8d2cd24adaf657 ] At memory hot-remove time we can retrieve an LMB's nid from its corresponding memory_block. There is no need to store the nid in multiple locations. Note that lmb_to_memblock() uses find_memory_block() to get the corresponding memory_block. As find_memory_block() runs in sub-linear time this approach is negligibly slower than what we do at present. In exchange for this lookup at hot-remove time we no longer need to call memory_add_physaddr_to_nid() during drmem_init() for each LMB. On powerpc, memory_add_physaddr_to_nid() is a linear search, so this spares us an O(n^2) initialization during boot. On systems with many LMBs that initialization overhead is palpable and disruptive. For example, on a box with 249854 LMBs we're seeing drmem_init() take upwards of 30 seconds to complete: [ 53.721639] drmem: initializing drmem v2 [ 80.604346] watchdog: BUG: soft lockup - CPU#65 stuck for 23s! [swapper/0:1] [ 80.604377] Modules linked in: [ 80.604389] CPU: 65 PID: 1 Comm: swapper/0 Not tainted 5.6.0-rc2+ #4 [ 80.604397] NIP: c0000000000a4980 LR: c0000000000a4940 CTR: 0000000000000000 [ 80.604407] REGS: c0002dbff8493830 TRAP: 0901 Not tainted (5.6.0-rc2+) [ 80.604412] MSR: 8000000002009033 CR: 44000248 XER: 0000000d [ 80.604431] CFAR: c0000000000a4a38 IRQMASK: 0 [ 80.604431] GPR00: c0000000000a4940 c0002dbff8493ac0 c000000001904400 c0003cfffffede30 [ 80.604431] GPR04: 0000000000000000 c000000000f4095a 000000000000002f 0000000010000000 [ 80.604431] GPR08: c0000bf7ecdb7fb8 c0000bf7ecc2d3c8 0000000000000008 c00c0002fdfb2001 [ 80.604431] GPR12: 0000000000000000 c00000001e8ec200 [ 80.604477] NIP [c0000000000a4980] hot_add_scn_to_nid+0xa0/0x3e0 [ 80.604486] LR [c0000000000a4940] hot_add_scn_to_nid+0x60/0x3e0 [ 80.604492] Call Trace: [ 80.604498] [c0002dbff8493ac0] [c0000000000a4940] hot_add_scn_to_nid+0x60/0x3e0 (unreliable) [ 80.604509] [c0002dbff8493b20] [c000000000087c10] memory_add_physaddr_to_nid+0x20/0x60 [ 80.604521] [c0002dbff8493b40] [c0000000010d4880] drmem_init+0x25c/0x2f0 [ 80.604530] [c0002dbff8493c10] [c000000000010154] do_one_initcall+0x64/0x2c0 [ 80.604540] [c0002dbff8493ce0] [c0000000010c4aa0] kernel_init_freeable+0x2d8/0x3a0 [ 80.604550] [c0002dbff8493db0] [c000000000010824] kernel_init+0x2c/0x148 [ 80.604560] [c0002dbff8493e20] [c00000000000b648] ret_from_kernel_thread+0x5c/0x74 [ 80.604567] Instruction dump: [ 80.604574] 392918e8 e9490000 e90a000a e92a0000 80ea000c 1d080018 3908ffe8 7d094214 [ 80.604586] 7fa94040 419d00dc e9490010 714a0088 <2faa0008> 409e00ac e9490000 7fbe5040 [ 89.047390] drmem: 249854 LMB(s) With a patched kernel on the same machine we're no longer seeing the soft lockup. drmem_init() now completes in negligible time, even when the LMB count is large. Fixes: b2d3b5ee66f2 ("powerpc/pseries: Track LMB nid instead of using device tree") Signed-off-by: Scott Cheloha Reviewed-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200811015115.63677-1-cheloha@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/pseries: Fix missing of_node_put() in rng_init()

2020-10-29T09:07:51Z

[ Upstream commit 67c3e59443f5fc77be39e2ce0db75fbfa78c7965 ] The call to of_find_compatible_node() returns a node pointer with refcount incremented thus it must be explicitly decremented here before returning. Fixes: a489043f4626 ("powerpc/pseries: Implement arch_get_random_long() based on H_RANDOM") Signed-off-by: Nicholas Mc Guire Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1530522496-14816-1-git-send-email-hofrat@osadl.org Signed-off-by: Sasha Levin

powerpc/pseries: Do not initiate shutdown when system is running on UPS

2020-08-26T09:49:18Z

commit 90a9b102eddf6a3f987d15f4454e26a2532c1c98 upstream. As per PAPR we have to look for both EPOW sensor value and event modifier to identify the type of event and take appropriate action. In LoPAPR v1.1 section 10.2.2 includes table 136 "EPOW Action Codes": SYSTEM_SHUTDOWN 3 The system must be shut down. An EPOW-aware OS logs the EPOW error log information, then schedules the system to be shut down to begin after an OS defined delay internal (default is 10 minutes.) Then in section 10.3.2.2.8 there is table 146 "Platform Event Log Format, Version 6, EPOW Section", which includes the "EPOW Event Modifier": For EPOW sensor value = 3 0x01 = Normal system shutdown with no additional delay 0x02 = Loss of utility power, system is running on UPS/Battery 0x03 = Loss of system critical functions, system should be shutdown 0x04 = Ambient temperature too high All other values = reserved We have a user space tool (rtas_errd) on LPAR to monitor for EPOW_SHUTDOWN_ON_UPS. Once it gets an event it initiates shutdown after predefined time. It also starts monitoring for any new EPOW events. If it receives "Power restored" event before predefined time it will cancel the shutdown. Otherwise after predefined time it will shutdown the system. Commit 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown") changed our handling of the "on UPS/Battery" case, to immediately shutdown the system. This breaks existing setups that rely on the userspace tool to delay shutdown and let the system run on the UPS. Fixes: 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown") Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Vasant Hegde [mpe: Massage change log and add PAPR references] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/hotplug-cpu: wait indefinitely for vCPU death

2020-08-26T09:49:17Z

[ Upstream commit 801980f6497946048709b9b09771a1729551d705 ] For a power9 KVM guest with XIVE enabled, running a test loop where we hotplug 384 vcpus and then unplug them, the following traces can be seen (generally within a few loops) either from the unplugged vcpu: cpu 65 (hwid 65) Ready to die... Querying DEAD? cpu 66 (66) shows 2 list_del corruption. next->prev should be c00a000002470208, but was c00a000002470048 ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:56! Oops: Exception in kernel mode, sig: 5 [#1] LE SMP NR_CPUS=2048 NUMA pSeries Modules linked in: fuse nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 ... CPU: 66 PID: 0 Comm: swapper/66 Kdump: loaded Not tainted 4.18.0-221.el8.ppc64le #1 NIP: c0000000007ab50c LR: c0000000007ab508 CTR: 00000000000003ac REGS: c0000009e5a17840 TRAP: 0700 Not tainted (4.18.0-221.el8.ppc64le) MSR: 800000000282b033 CR: 28000842 XER: 20040000 ... NIP __list_del_entry_valid+0xac/0x100 LR __list_del_entry_valid+0xa8/0x100 Call Trace: __list_del_entry_valid+0xa8/0x100 (unreliable) free_pcppages_bulk+0x1f8/0x940 free_unref_page+0xd0/0x100 xive_spapr_cleanup_queue+0x148/0x1b0 xive_teardown_cpu+0x1bc/0x240 pseries_mach_cpu_die+0x78/0x2f0 cpu_die+0x48/0x70 arch_cpu_idle_dead+0x20/0x40 do_idle+0x2f4/0x4c0 cpu_startup_entry+0x38/0x40 start_secondary+0x7bc/0x8f0 start_secondary_prolog+0x10/0x14 or on the worker thread handling the unplug: pseries-hotplug-cpu: Attempting to remove CPU , drc index: 1000013a Querying DEAD? cpu 314 (314) shows 2 BUG: Bad page state in process kworker/u768:3 pfn:95de1 cpu 314 (hwid 314) Ready to die... page:c00a000002577840 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 flags: 0x5ffffc00000000() raw: 005ffffc00000000 5deadbeef0000100 5deadbeef0000200 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffff7f 0000000000000000 page dumped because: nonzero mapcount Modules linked in: kvm xt_CHECKSUM ipt_MASQUERADE xt_conntrack ... CPU: 0 PID: 548 Comm: kworker/u768:3 Kdump: loaded Not tainted 4.18.0-224.el8.bz1856588.ppc64le #1 Workqueue: pseries hotplug workque pseries_hp_work_fn Call Trace: dump_stack+0xb0/0xf4 (unreliable) bad_page+0x12c/0x1b0 free_pcppages_bulk+0x5bc/0x940 page_alloc_cpu_dead+0x118/0x120 cpuhp_invoke_callback.constprop.5+0xb8/0x760 _cpu_down+0x188/0x340 cpu_down+0x5c/0xa0 cpu_subsys_offline+0x24/0x40 device_offline+0xf0/0x130 dlpar_offline_cpu+0x1c4/0x2a0 dlpar_cpu_remove+0xb8/0x190 dlpar_cpu_remove_by_index+0x12c/0x150 dlpar_cpu+0x94/0x800 pseries_hp_work_fn+0x128/0x1e0 process_one_work+0x304/0x5d0 worker_thread+0xcc/0x7a0 kthread+0x1ac/0x1c0 ret_from_kernel_thread+0x5c/0x80 The latter trace is due to the following sequence: page_alloc_cpu_dead drain_pages drain_pages_zone free_pcppages_bulk where drain_pages() in this case is called under the assumption that the unplugged cpu is no longer executing. To ensure that is the case, and early call is made to __cpu_die()->pseries_cpu_die(), which runs a loop that waits for the cpu to reach a halted state by polling its status via query-cpu-stopped-state RTAS calls. It only polls for 25 iterations before giving up, however, and in the trace above this results in the following being printed only .1 seconds after the hotplug worker thread begins processing the unplug request: pseries-hotplug-cpu: Attempting to remove CPU , drc index: 1000013a Querying DEAD? cpu 314 (314) shows 2 At that point the worker thread assumes the unplugged CPU is in some unknown/dead state and procedes with the cleanup, causing the race with the XIVE cleanup code executed by the unplugged CPU. Fix this by waiting indefinitely, but also making an effort to avoid spurious lockup messages by allowing for rescheduling after polling the CPU status and printing a warning if we wait for longer than 120s. Fixes: eac1e731b59ee ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Suggested-by: Michael Ellerman Signed-off-by: Michael Roth Tested-by: Greg Kurz Reviewed-by: Thiago Jung Bauermann Reviewed-by: Greg Kurz [mpe: Trim oopses in change log slightly for readability] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200811161544.10513-1-mdroth@linux.vnet.ibm.com Signed-off-by: Sasha Levin

pseries: Fix 64 bit logical memory block panic

2020-08-21T11:15:01Z

commit 89c140bbaeee7a55ed0360a88f294ead2b95201b upstream. Booting with a 4GB LMB size causes us to panic: qemu-system-ppc64: OS terminated: OS panic: Memory block size not suitable: 0x0 Fix pseries_memory_block_size() to handle 64 bit LMBs. Cc: stable@vger.kernel.org Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200715000820.1255764-1-anton@ozlabs.org Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/hotplug-cpu: Remove double free in error path

2020-08-19T06:26:49Z

[ Upstream commit a0ff72f9f5a780341e7ff5e9ba50a0dad5fa1980 ] In the unlikely event that the device tree lacks a /cpus node, find_dlpar_cpus_to_add() oddly frees the cpu_drcs buffer it has been passed before returning an error. Its only caller also frees the buffer on error. Remove the less conventional kfree() of a caller-supplied buffer from find_dlpar_cpus_to_add(). Fixes: 90edf184b9b7 ("powerpc/pseries: Add CPU dlpar add functionality") Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190919231633.1344-1-nathanl@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/rtas: don't online CPUs for partition suspend

2020-08-19T06:26:35Z

[ Upstream commit ec2fc2a9e9bbad9023aab65bc472ce7a3ca8608f ] Partition suspension, used for hibernation and migration, requires that the OS place all but one of the LPAR's processor threads into one of two states prior to calling the ibm,suspend-me RTAS function: * the architected offline state (via RTAS stop-self); or * the H_JOIN hcall, which does not return until the partition resumes execution Using H_CEDE as the offline mode, introduced by commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state"), means that any threads which are offline from Linux's point of view must be moved to one of those two states before a partition suspension can proceed. This was eventually addressed in commit 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation"), which added code to temporarily bring up any offline processor threads so they can call H_JOIN. Conceptually this is fine, but the implementation has had multiple races with cpu hotplug operations initiated from user space[1][2][3], the error handling is fragile, and it generates user-visible cpu hotplug events which is a lot of noise for a platform feature that's supposed to minimize disruption to workloads. With commit 3aa565f53c39 ("powerpc/pseries: Add hooks to put the CPU into an appropriate offline state") reverted, this code becomes unnecessary, so remove it. Since any offline CPUs now are truly offline from the platform's point of view, it is no longer necessary to bring up CPUs only to have them call H_JOIN and then go offline again upon resuming. Only active threads are required to call H_JOIN; stopped threads can be left alone. [1] commit a6717c01ddc2 ("powerpc/rtas: use device model APIs and serialization during LPM") [2] commit 9fb603050ffd ("powerpc/rtas: retry when cpu offline races with suspend/migration") [3] commit dfd718a2ed1f ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration") Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation") Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200612051238.1007764-3-nathanl@linux.ibm.com Signed-off-by: Sasha Levin