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2022-11-09arm64: paravirt: remove conduit check in has_pv_steal_clockUsama Arif1-4/+0
arm_smccc_1_1_invoke() which is called later on in the function will return failure if there's no conduit (or pre-SMCCC 1.1), hence the check is unnecessary. Suggested-by: Steven Price <steven.price@arm.com> Signed-off-by: Usama Arif <usama.arif@bytedance.com> Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20221104061659.4116508-1-usama.arif@bytedance.com Signed-off-by: Will Deacon <will@kernel.org>
2022-05-17arm64: paravirt: Use RCU read locks to guard stolen_timePrakruthi Deepak Heragu1-8/+21
During hotplug, the stolen time data structure is unmapped and memset. There is a possibility of the timer IRQ being triggered before memset and stolen time is getting updated as part of this timer IRQ handler. This causes the below crash in timer handler - [ 3457.473139][ C5] Unable to handle kernel paging request at virtual address ffffffc03df05148 ... [ 3458.154398][ C5] Call trace: [ 3458.157648][ C5] para_steal_clock+0x30/0x50 [ 3458.162319][ C5] irqtime_account_process_tick+0x30/0x194 [ 3458.168148][ C5] account_process_tick+0x3c/0x280 [ 3458.173274][ C5] update_process_times+0x5c/0xf4 [ 3458.178311][ C5] tick_sched_timer+0x180/0x384 [ 3458.183164][ C5] __run_hrtimer+0x160/0x57c [ 3458.187744][ C5] hrtimer_interrupt+0x258/0x684 [ 3458.192698][ C5] arch_timer_handler_virt+0x5c/0xa0 [ 3458.198002][ C5] handle_percpu_devid_irq+0xdc/0x414 [ 3458.203385][ C5] handle_domain_irq+0xa8/0x168 [ 3458.208241][ C5] gic_handle_irq.34493+0x54/0x244 [ 3458.213359][ C5] call_on_irq_stack+0x40/0x70 [ 3458.218125][ C5] do_interrupt_handler+0x60/0x9c [ 3458.223156][ C5] el1_interrupt+0x34/0x64 [ 3458.227560][ C5] el1h_64_irq_handler+0x1c/0x2c [ 3458.232503][ C5] el1h_64_irq+0x7c/0x80 [ 3458.236736][ C5] free_vmap_area_noflush+0x108/0x39c [ 3458.242126][ C5] remove_vm_area+0xbc/0x118 [ 3458.246714][ C5] vm_remove_mappings+0x48/0x2a4 [ 3458.251656][ C5] __vunmap+0x154/0x278 [ 3458.255796][ C5] stolen_time_cpu_down_prepare+0xc0/0xd8 [ 3458.261542][ C5] cpuhp_invoke_callback+0x248/0xc34 [ 3458.266842][ C5] cpuhp_thread_fun+0x1c4/0x248 [ 3458.271696][ C5] smpboot_thread_fn+0x1b0/0x400 [ 3458.276638][ C5] kthread+0x17c/0x1e0 [ 3458.280691][ C5] ret_from_fork+0x10/0x20 As a fix, introduce rcu lock to update stolen time structure. Fixes: 75df529bec91 ("arm64: paravirt: Initialize steal time when cpu is online") Cc: stable@vger.kernel.org Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu> Link: https://lore.kernel.org/r/20220513174654.362169-1-quic_eberman@quicinc.com Signed-off-by: Will Deacon <will@kernel.org>
2021-03-11x86/paravirt: Switch time pvops functions to use static_call()Juergen Gross1-4/+9
The time pvops functions are the only ones left which might be used in 32-bit mode and which return a 64-bit value. Switch them to use the static_call() mechanism instead of pvops, as this allows quite some simplification of the pvops implementation. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210311142319.4723-5-jgross@suse.com
2020-09-17arm64: paravirt: Initialize steal time when cpu is onlineAndrew Jones1-11/+15
Steal time initialization requires mapping a memory region which invokes a memory allocation. Doing this at CPU starting time results in the following trace when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at mm/slab.h:498 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5+ #1 Call trace: dump_backtrace+0x0/0x208 show_stack+0x1c/0x28 dump_stack+0xc4/0x11c ___might_sleep+0xf8/0x130 __might_sleep+0x58/0x90 slab_pre_alloc_hook.constprop.101+0xd0/0x118 kmem_cache_alloc_node_trace+0x84/0x270 __get_vm_area_node+0x88/0x210 get_vm_area_caller+0x38/0x40 __ioremap_caller+0x70/0xf8 ioremap_cache+0x78/0xb0 memremap+0x9c/0x1a8 init_stolen_time_cpu+0x54/0xf0 cpuhp_invoke_callback+0xa8/0x720 notify_cpu_starting+0xc8/0xd8 secondary_start_kernel+0x114/0x180 CPU1: Booted secondary processor 0x0000000001 [0x431f0a11] However we don't need to initialize steal time at CPU starting time. We can simply wait until CPU online time, just sacrificing a bit of accuracy by returning zero for steal time until we know better. While at it, add __init to the functions that are only called by pv_time_init() which is __init. Signed-off-by: Andrew Jones <drjones@redhat.com> Fixes: e0685fa228fd ("arm64: Retrieve stolen time as paravirtualized guest") Cc: stable@vger.kernel.org Reviewed-by: Steven Price <steven.price@arm.com> Link: https://lore.kernel.org/r/20200916154530.40809-1-drjones@redhat.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-05-20firmware: smccc: Drop smccc_version enum and use ARM_SMCCC_VERSION_1_x insteadSudeep Holla1-1/+1
Instead of maintaining 2 sets of enums/macros for tracking SMCCC version, let us drop smccc_version enum and use ARM_SMCCC_VERSION_1_x directly instead. This is in preparation to drop smccc_version here and move it separately under drivers/firmware/smccc. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Etienne Carriere <etienne.carriere@st.com> Reviewed-by: Steven Price <steven.price@arm.com> Reviewed-by: Etienne Carriere <etienne.carriere@st.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200518091222.27467-5-sudeep.holla@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2019-10-21arm64: Retrieve stolen time as paravirtualized guestSteven Price1-0/+140
Enable paravirtualization features when running under a hypervisor supporting the PV_TIME_ST hypercall. For each (v)CPU, we ask the hypervisor for the location of a shared page which the hypervisor will use to report stolen time to us. We set pv_time_ops to the stolen time function which simply reads the stolen value from the shared page for a VCPU. We guarantee single-copy atomicity using READ_ONCE which means we can also read the stolen time for another VCPU than the currently running one while it is potentially being updated by the hypervisor. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174Thomas Gleixner1-8/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 655 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-03x86/paravirt: Use a single ops structureJuergen Gross1-2/+2
Instead of using six globally visible paravirt ops structures combine them in a single structure, keeping the original structures as sub-structures. This avoids the need to assemble struct paravirt_patch_template at runtime on the stack each time apply_paravirt() is being called (i.e. when loading a module). [ tglx: Made the struct and the initializer tabular for readability sake ] Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: xen-devel@lists.xenproject.org Cc: virtualization@lists.linux-foundation.org Cc: akataria@vmware.com Cc: rusty@rustcorp.com.au Cc: boris.ostrovsky@oracle.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/20180828074026.820-9-jgross@suse.com
2015-12-21arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_opsStefano Stabellini1-0/+25
Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM64. Necessary duplication of paravirt.h and paravirt.c with ARM. The only paravirt interface supported is pv_time_ops.steal_clock, so no runtime pvops patching needed. This allows us to make use of steal_account_process_tick for stolen ticks accounting. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com>