kernel_samsung_a53x/include/linux/cpuhotplug.h
Mark Rutland 3a368fd114 arm64/arm: xen: enlighten: Fix KPTI checks
[ Upstream commit 20f3b8eafe0ba5d3c69d5011a9b07739e9645132 ]

When KPTI is in use, we cannot register a runstate region as XEN
requires that this is always a valid VA, which we cannot guarantee. Due
to this, xen_starting_cpu() must avoid registering each CPU's runstate
region, and xen_guest_init() must avoid setting up features that depend
upon it.

We tried to ensure that in commit:

  f88af7229f6f22ce (" xen/arm: do not setup the runstate info page if kpti is enabled")

... where we added checks for xen_kernel_unmapped_at_usr(), which wraps
arm64_kernel_unmapped_at_el0() on arm64 and is always false on 32-bit
arm.

Unfortunately, as xen_guest_init() is an early_initcall, this happens
before secondary CPUs are booted and arm64 has finalized the
ARM64_UNMAP_KERNEL_AT_EL0 cpucap which backs
arm64_kernel_unmapped_at_el0(), and so this can subsequently be set as
secondary CPUs are onlined. On a big.LITTLE system where the boot CPU
does not require KPTI but some secondary CPUs do, this will result in
xen_guest_init() intializing features that depend on the runstate
region, and xen_starting_cpu() registering the runstate region on some
CPUs before KPTI is subsequent enabled, resulting the the problems the
aforementioned commit tried to avoid.

Handle this more robsutly by deferring the initialization of the
runstate region until secondary CPUs have been initialized and the
ARM64_UNMAP_KERNEL_AT_EL0 cpucap has been finalized. The per-cpu work is
moved into a new hotplug starting function which is registered later
when we're certain that KPTI will not be used.

Fixes: f88af7229f6f ("xen/arm: do not setup the runstate info page if kpti is enabled")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Bertrand Marquis <bertrand.marquis@arm.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-18 11:42:55 +01:00

419 lines
13 KiB
C
Executable file

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __CPUHOTPLUG_H
#define __CPUHOTPLUG_H
#include <linux/types.h>
/*
* CPU-up CPU-down
*
* BP AP BP AP
*
* OFFLINE OFFLINE
* | ^
* v |
* BRINGUP_CPU->AP_OFFLINE BRINGUP_CPU <- AP_IDLE_DEAD (idle thread/play_dead)
* | AP_OFFLINE
* v (IRQ-off) ,---------------^
* AP_ONLNE | (stop_machine)
* | TEARDOWN_CPU <- AP_ONLINE_IDLE
* | ^
* v |
* AP_ACTIVE AP_ACTIVE
*/
enum cpuhp_state {
CPUHP_INVALID = -1,
CPUHP_OFFLINE = 0,
CPUHP_CREATE_THREADS,
CPUHP_PERF_PREPARE,
CPUHP_PERF_X86_PREPARE,
CPUHP_PERF_X86_AMD_UNCORE_PREP,
CPUHP_PERF_POWER,
CPUHP_PERF_SUPERH,
CPUHP_X86_HPET_DEAD,
CPUHP_X86_APB_DEAD,
CPUHP_X86_MCE_DEAD,
CPUHP_VIRT_NET_DEAD,
CPUHP_SLUB_DEAD,
CPUHP_DEBUG_OBJ_DEAD,
CPUHP_MM_WRITEBACK_DEAD,
CPUHP_MM_VMSTAT_DEAD,
CPUHP_SOFTIRQ_DEAD,
CPUHP_NET_MVNETA_DEAD,
CPUHP_CPUIDLE_DEAD,
CPUHP_ARM64_FPSIMD_DEAD,
CPUHP_ARM_OMAP_WAKE_DEAD,
CPUHP_IRQ_POLL_DEAD,
CPUHP_BLOCK_SOFTIRQ_DEAD,
CPUHP_ACPI_CPUDRV_DEAD,
CPUHP_S390_PFAULT_DEAD,
CPUHP_BLK_MQ_DEAD,
CPUHP_FS_BUFF_DEAD,
CPUHP_PRINTK_DEAD,
CPUHP_MM_MEMCQ_DEAD,
CPUHP_PERCPU_CNT_DEAD,
CPUHP_RADIX_DEAD,
CPUHP_PAGE_ALLOC_DEAD,
CPUHP_NET_DEV_DEAD,
CPUHP_PCI_XGENE_DEAD,
CPUHP_IOMMU_INTEL_DEAD,
CPUHP_LUSTRE_CFS_DEAD,
CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,
CPUHP_PADATA_DEAD,
CPUHP_WORKQUEUE_PREP,
CPUHP_POWER_NUMA_PREPARE,
CPUHP_HRTIMERS_PREPARE,
CPUHP_PROFILE_PREPARE,
CPUHP_X2APIC_PREPARE,
CPUHP_SMPCFD_PREPARE,
CPUHP_RELAY_PREPARE,
CPUHP_SLAB_PREPARE,
CPUHP_MD_RAID5_PREPARE,
CPUHP_RCUTREE_PREP,
CPUHP_CPUIDLE_COUPLED_PREPARE,
CPUHP_POWERPC_PMAC_PREPARE,
CPUHP_POWERPC_MMU_CTX_PREPARE,
CPUHP_XEN_PREPARE,
CPUHP_XEN_EVTCHN_PREPARE,
CPUHP_ARM_SHMOBILE_SCU_PREPARE,
CPUHP_SH_SH3X_PREPARE,
CPUHP_NET_FLOW_PREPARE,
CPUHP_TOPOLOGY_PREPARE,
CPUHP_NET_IUCV_PREPARE,
CPUHP_ARM_BL_PREPARE,
CPUHP_TRACE_RB_PREPARE,
CPUHP_MM_ZS_PREPARE,
CPUHP_MM_ZSWP_MEM_PREPARE,
CPUHP_MM_ZSWP_POOL_PREPARE,
CPUHP_KVM_PPC_BOOK3S_PREPARE,
CPUHP_ZCOMP_PREPARE,
CPUHP_TIMERS_PREPARE,
CPUHP_MIPS_SOC_PREPARE,
CPUHP_BP_PREPARE_DYN,
CPUHP_BP_PREPARE_DYN_END = CPUHP_BP_PREPARE_DYN + 20,
CPUHP_BRINGUP_CPU,
CPUHP_AP_IDLE_DEAD,
CPUHP_AP_OFFLINE,
CPUHP_AP_SCHED_STARTING,
CPUHP_AP_RCUTREE_DYING,
CPUHP_AP_CPU_PM_STARTING,
CPUHP_AP_IRQ_GIC_STARTING,
CPUHP_AP_IRQ_HIP04_STARTING,
CPUHP_AP_IRQ_ARMADA_XP_STARTING,
CPUHP_AP_IRQ_BCM2836_STARTING,
CPUHP_AP_IRQ_MIPS_GIC_STARTING,
CPUHP_AP_IRQ_RISCV_STARTING,
CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
CPUHP_AP_ARM_MVEBU_COHERENCY,
CPUHP_AP_MICROCODE_LOADER,
CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,
CPUHP_AP_PERF_X86_STARTING,
CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
CPUHP_AP_PERF_X86_CQM_STARTING,
CPUHP_AP_PERF_X86_CSTATE_STARTING,
CPUHP_AP_PERF_XTENSA_STARTING,
CPUHP_AP_MIPS_OP_LOONGSON3_STARTING,
CPUHP_AP_ARM_SDEI_STARTING,
CPUHP_AP_ARM_VFP_STARTING,
CPUHP_AP_ARM64_DEBUG_MONITORS_STARTING,
CPUHP_AP_PERF_ARM_HW_BREAKPOINT_STARTING,
CPUHP_AP_PERF_ARM_ACPI_STARTING,
CPUHP_AP_PERF_ARM_STARTING,
CPUHP_AP_ARM_L2X0_STARTING,
CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
CPUHP_AP_ARM_ARCH_TIMER_STARTING,
CPUHP_AP_ARM_GLOBAL_TIMER_STARTING,
CPUHP_AP_JCORE_TIMER_STARTING,
CPUHP_AP_ARM_TWD_STARTING,
CPUHP_AP_QCOM_TIMER_STARTING,
CPUHP_AP_TEGRA_TIMER_STARTING,
CPUHP_AP_ARMADA_TIMER_STARTING,
CPUHP_AP_MARCO_TIMER_STARTING,
CPUHP_AP_MIPS_GIC_TIMER_STARTING,
CPUHP_AP_ARC_TIMER_STARTING,
CPUHP_AP_RISCV_TIMER_STARTING,
CPUHP_AP_CLINT_TIMER_STARTING,
CPUHP_AP_CSKY_TIMER_STARTING,
CPUHP_AP_TI_GP_TIMER_STARTING,
CPUHP_AP_HYPERV_TIMER_STARTING,
CPUHP_AP_KVM_STARTING,
CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
CPUHP_AP_KVM_ARM_VGIC_STARTING,
CPUHP_AP_KVM_ARM_TIMER_STARTING,
/* Must be the last timer callback */
CPUHP_AP_DUMMY_TIMER_STARTING,
CPUHP_AP_ARM_XEN_STARTING,
CPUHP_AP_ARM_XEN_RUNSTATE_STARTING,
CPUHP_AP_ARM_CORESIGHT_STARTING,
CPUHP_AP_ARM_CORESIGHT_CTI_STARTING,
CPUHP_AP_ARM64_ISNDEP_STARTING,
CPUHP_AP_SMPCFD_DYING,
CPUHP_AP_X86_TBOOT_DYING,
CPUHP_AP_ARM_CACHE_B15_RAC_DYING,
CPUHP_AP_ONLINE,
CPUHP_TEARDOWN_CPU,
CPUHP_AP_ONLINE_IDLE,
CPUHP_AP_SMPBOOT_THREADS,
CPUHP_AP_X86_VDSO_VMA_ONLINE,
CPUHP_AP_IRQ_AFFINITY_ONLINE,
CPUHP_AP_BLK_MQ_ONLINE,
CPUHP_AP_ARM_MVEBU_SYNC_CLOCKS,
CPUHP_AP_X86_INTEL_EPB_ONLINE,
CPUHP_AP_PERF_ONLINE,
CPUHP_AP_PERF_X86_ONLINE,
CPUHP_AP_PERF_X86_UNCORE_ONLINE,
CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
CPUHP_AP_PERF_X86_AMD_POWER_ONLINE,
CPUHP_AP_PERF_X86_RAPL_ONLINE,
CPUHP_AP_PERF_X86_CQM_ONLINE,
CPUHP_AP_PERF_X86_CSTATE_ONLINE,
CPUHP_AP_PERF_S390_CF_ONLINE,
CPUHP_AP_PERF_S390_SF_ONLINE,
CPUHP_AP_PERF_ARM_CCI_ONLINE,
CPUHP_AP_PERF_ARM_CCN_ONLINE,
CPUHP_AP_PERF_ARM_HISI_DDRC_ONLINE,
CPUHP_AP_PERF_ARM_HISI_HHA_ONLINE,
CPUHP_AP_PERF_ARM_HISI_L3_ONLINE,
CPUHP_AP_PERF_ARM_L2X0_ONLINE,
CPUHP_AP_PERF_ARM_QCOM_L2_ONLINE,
CPUHP_AP_PERF_ARM_QCOM_L3_ONLINE,
CPUHP_AP_PERF_ARM_APM_XGENE_ONLINE,
CPUHP_AP_PERF_ARM_CAVIUM_TX2_UNCORE_ONLINE,
CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_CORE_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_THREAD_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_TRACE_IMC_ONLINE,
CPUHP_AP_PERF_POWERPC_HV_24x7_ONLINE,
CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
CPUHP_AP_WATCHDOG_ONLINE,
CPUHP_AP_WORKQUEUE_ONLINE,
CPUHP_AP_RCUTREE_ONLINE,
CPUHP_AP_BASE_CACHEINFO_ONLINE,
CPUHP_AP_ONLINE_DYN,
CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
CPUHP_AP_X86_HPET_ONLINE,
CPUHP_AP_X86_KVM_CLK_ONLINE,
CPUHP_AP_DTPM_CPU_ONLINE,
CPUHP_AP_ACTIVE,
CPUHP_ANDROID_RESERVED_1,
CPUHP_ANDROID_RESERVED_2,
CPUHP_ANDROID_RESERVED_3,
CPUHP_ANDROID_RESERVED_4,
CPUHP_ONLINE,
};
int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu), bool multi_instance);
int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name,
bool invoke,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu),
bool multi_instance);
/**
* cpuhp_setup_state - Setup hotplug state callbacks with calling the callbacks
* @state: The state for which the calls are installed
* @name: Name of the callback (will be used in debug output)
* @startup: startup callback function
* @teardown: teardown callback function
*
* Installs the callback functions and invokes the startup callback on
* the present cpus which have already reached the @state.
*/
static inline int cpuhp_setup_state(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state(state, name, true, startup, teardown, false);
}
static inline int cpuhp_setup_state_cpuslocked(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state_cpuslocked(state, name, true, startup,
teardown, false);
}
/**
* cpuhp_setup_state_nocalls - Setup hotplug state callbacks without calling the
* callbacks
* @state: The state for which the calls are installed
* @name: Name of the callback.
* @startup: startup callback function
* @teardown: teardown callback function
*
* Same as @cpuhp_setup_state except that no calls are executed are invoked
* during installation of this callback. NOP if SMP=n or HOTPLUG_CPU=n.
*/
static inline int cpuhp_setup_state_nocalls(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state(state, name, false, startup, teardown,
false);
}
static inline int cpuhp_setup_state_nocalls_cpuslocked(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu),
int (*teardown)(unsigned int cpu))
{
return __cpuhp_setup_state_cpuslocked(state, name, false, startup,
teardown, false);
}
/**
* cpuhp_setup_state_multi - Add callbacks for multi state
* @state: The state for which the calls are installed
* @name: Name of the callback.
* @startup: startup callback function
* @teardown: teardown callback function
*
* Sets the internal multi_instance flag and prepares a state to work as a multi
* instance callback. No callbacks are invoked at this point. The callbacks are
* invoked once an instance for this state are registered via
* @cpuhp_state_add_instance or @cpuhp_state_add_instance_nocalls.
*/
static inline int cpuhp_setup_state_multi(enum cpuhp_state state,
const char *name,
int (*startup)(unsigned int cpu,
struct hlist_node *node),
int (*teardown)(unsigned int cpu,
struct hlist_node *node))
{
return __cpuhp_setup_state(state, name, false,
(void *) startup,
(void *) teardown, true);
}
int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
bool invoke);
int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state,
struct hlist_node *node, bool invoke);
/**
* cpuhp_state_add_instance - Add an instance for a state and invoke startup
* callback.
* @state: The state for which the instance is installed
* @node: The node for this individual state.
*
* Installs the instance for the @state and invokes the startup callback on
* the present cpus which have already reached the @state. The @state must have
* been earlier marked as multi-instance by @cpuhp_setup_state_multi.
*/
static inline int cpuhp_state_add_instance(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_add_instance(state, node, true);
}
/**
* cpuhp_state_add_instance_nocalls - Add an instance for a state without
* invoking the startup callback.
* @state: The state for which the instance is installed
* @node: The node for this individual state.
*
* Installs the instance for the @state The @state must have been earlier
* marked as multi-instance by @cpuhp_setup_state_multi.
*/
static inline int cpuhp_state_add_instance_nocalls(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_add_instance(state, node, false);
}
static inline int
cpuhp_state_add_instance_nocalls_cpuslocked(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_add_instance_cpuslocked(state, node, false);
}
void __cpuhp_remove_state(enum cpuhp_state state, bool invoke);
void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke);
/**
* cpuhp_remove_state - Remove hotplug state callbacks and invoke the teardown
* @state: The state for which the calls are removed
*
* Removes the callback functions and invokes the teardown callback on
* the present cpus which have already reached the @state.
*/
static inline void cpuhp_remove_state(enum cpuhp_state state)
{
__cpuhp_remove_state(state, true);
}
/**
* cpuhp_remove_state_nocalls - Remove hotplug state callbacks without invoking
* teardown
* @state: The state for which the calls are removed
*/
static inline void cpuhp_remove_state_nocalls(enum cpuhp_state state)
{
__cpuhp_remove_state(state, false);
}
static inline void cpuhp_remove_state_nocalls_cpuslocked(enum cpuhp_state state)
{
__cpuhp_remove_state_cpuslocked(state, false);
}
/**
* cpuhp_remove_multi_state - Remove hotplug multi state callback
* @state: The state for which the calls are removed
*
* Removes the callback functions from a multi state. This is the reverse of
* cpuhp_setup_state_multi(). All instances should have been removed before
* invoking this function.
*/
static inline void cpuhp_remove_multi_state(enum cpuhp_state state)
{
__cpuhp_remove_state(state, false);
}
int __cpuhp_state_remove_instance(enum cpuhp_state state,
struct hlist_node *node, bool invoke);
/**
* cpuhp_state_remove_instance - Remove hotplug instance from state and invoke
* the teardown callback
* @state: The state from which the instance is removed
* @node: The node for this individual state.
*
* Removes the instance and invokes the teardown callback on the present cpus
* which have already reached the @state.
*/
static inline int cpuhp_state_remove_instance(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_remove_instance(state, node, true);
}
/**
* cpuhp_state_remove_instance_nocalls - Remove hotplug instance from state
* without invoking the reatdown callback
* @state: The state from which the instance is removed
* @node: The node for this individual state.
*
* Removes the instance without invoking the teardown callback.
*/
static inline int cpuhp_state_remove_instance_nocalls(enum cpuhp_state state,
struct hlist_node *node)
{
return __cpuhp_state_remove_instance(state, node, false);
}
#ifdef CONFIG_SMP
void cpuhp_online_idle(enum cpuhp_state state);
#else
static inline void cpuhp_online_idle(enum cpuhp_state state) { }
#endif
#endif