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Diffstat (limited to 'include/linux/rseq_types.h')
| -rw-r--r-- | include/linux/rseq_types.h | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/include/linux/rseq_types.h b/include/linux/rseq_types.h new file mode 100644 index 000000000000..332dc14b81c9 --- /dev/null +++ b/include/linux/rseq_types.h @@ -0,0 +1,164 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_RSEQ_TYPES_H +#define _LINUX_RSEQ_TYPES_H + +#include <linux/irq_work_types.h> +#include <linux/types.h> +#include <linux/workqueue_types.h> + +#ifdef CONFIG_RSEQ +struct rseq; + +/** + * struct rseq_event - Storage for rseq related event management + * @all: Compound to initialize and clear the data efficiently + * @events: Compound to access events with a single load/store + * @sched_switch: True if the task was scheduled and needs update on + * exit to user + * @ids_changed: Indicator that IDs need to be updated + * @user_irq: True on interrupt entry from user mode + * @has_rseq: True if the task has a rseq pointer installed + * @error: Compound error code for the slow path to analyze + * @fatal: User space data corrupted or invalid + * @slowpath: Indicator that slow path processing via TIF_NOTIFY_RESUME + * is required + * + * @sched_switch and @ids_changed must be adjacent and the combo must be + * 16bit aligned to allow a single store, when both are set at the same + * time in the scheduler. + */ +struct rseq_event { + union { + u64 all; + struct { + union { + u32 events; + struct { + u8 sched_switch; + u8 ids_changed; + u8 user_irq; + }; + }; + + u8 has_rseq; + u8 __pad; + union { + u16 error; + struct { + u8 fatal; + u8 slowpath; + }; + }; + }; + }; +}; + +/** + * struct rseq_ids - Cache for ids, which need to be updated + * @cpu_cid: Compound of @cpu_id and @mm_cid to make the + * compiler emit a single compare on 64-bit + * @cpu_id: The CPU ID which was written last to user space + * @mm_cid: The MM CID which was written last to user space + * + * @cpu_id and @mm_cid are updated when the data is written to user space. + */ +struct rseq_ids { + union { + u64 cpu_cid; + struct { + u32 cpu_id; + u32 mm_cid; + }; + }; +}; + +/** + * struct rseq_data - Storage for all rseq related data + * @usrptr: Pointer to the registered user space RSEQ memory + * @len: Length of the RSEQ region + * @sig: Signature of critial section abort IPs + * @event: Storage for event management + * @ids: Storage for cached CPU ID and MM CID + */ +struct rseq_data { + struct rseq __user *usrptr; + u32 len; + u32 sig; + struct rseq_event event; + struct rseq_ids ids; +}; + +#else /* CONFIG_RSEQ */ +struct rseq_data { }; +#endif /* !CONFIG_RSEQ */ + +#ifdef CONFIG_SCHED_MM_CID + +#define MM_CID_UNSET BIT(31) +#define MM_CID_ONCPU BIT(30) +#define MM_CID_TRANSIT BIT(29) + +/** + * struct sched_mm_cid - Storage for per task MM CID data + * @active: MM CID is active for the task + * @cid: The CID associated to the task either permanently or + * borrowed from the CPU + */ +struct sched_mm_cid { + unsigned int active; + unsigned int cid; +}; + +/** + * struct mm_cid_pcpu - Storage for per CPU MM_CID data + * @cid: The CID associated to the CPU either permanently or + * while a task with a CID is running + */ +struct mm_cid_pcpu { + unsigned int cid; +}____cacheline_aligned_in_smp; + +/** + * struct mm_mm_cid - Storage for per MM CID data + * @pcpu: Per CPU storage for CIDs associated to a CPU + * @percpu: Set, when CIDs are in per CPU mode + * @transit: Set to MM_CID_TRANSIT during a mode change transition phase + * @max_cids: The exclusive maximum CID value for allocation and convergence + * @irq_work: irq_work to handle the affinity mode change case + * @work: Regular work to handle the affinity mode change case + * @lock: Spinlock to protect against affinity setting which can't take @mutex + * @mutex: Mutex to serialize forks and exits related to this mm + * @nr_cpus_allowed: The number of CPUs in the per MM allowed CPUs map. The map + * is growth only. + * @users: The number of tasks sharing this MM. Separate from mm::mm_users + * as that is modified by mmget()/mm_put() by other entities which + * do not actually share the MM. + * @pcpu_thrs: Threshold for switching back from per CPU mode + * @update_deferred: A deferred switch back to per task mode is pending. + */ +struct mm_mm_cid { + /* Hotpath read mostly members */ + struct mm_cid_pcpu __percpu *pcpu; + unsigned int percpu; + unsigned int transit; + unsigned int max_cids; + + /* Rarely used. Moves @lock and @mutex into the second cacheline */ + struct irq_work irq_work; + struct work_struct work; + + raw_spinlock_t lock; + struct mutex mutex; + + /* Low frequency modified */ + unsigned int nr_cpus_allowed; + unsigned int users; + unsigned int pcpu_thrs; + unsigned int update_deferred; +}____cacheline_aligned_in_smp; +#else /* CONFIG_SCHED_MM_CID */ +struct mm_mm_cid { }; +struct sched_mm_cid { }; +#endif /* !CONFIG_SCHED_MM_CID */ + +#endif |