kernel / fs / resctrl / internal.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FS_RESCTRL_INTERNAL_H
#define _FS_RESCTRL_INTERNAL_H

#include <linux/resctrl.h>
#include <linux/kernfs.h>
#include <linux/fs_context.h>
#include <linux/tick.h>

#define CQM_LIMBOCHECK_INTERVAL	1000

/**
 * cpumask_any_housekeeping() - Choose any CPU in @mask, preferring those that
 *			        aren't marked nohz_full
 * @mask:	The mask to pick a CPU from.
 * @exclude_cpu:The CPU to avoid picking.
 *
 * Returns a CPU from @mask, but not @exclude_cpu. If there are housekeeping
 * CPUs that don't use nohz_full, these are preferred. Pass
 * RESCTRL_PICK_ANY_CPU to avoid excluding any CPUs.
 *
 * When a CPU is excluded, returns >= nr_cpu_ids if no CPUs are available.
 */
static inline unsigned int
cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu)
{
	unsigned int cpu;

	/* Try to find a CPU that isn't nohz_full to use in preference */
	if (tick_nohz_full_enabled()) {
		cpu = cpumask_any_andnot_but(mask, tick_nohz_full_mask, exclude_cpu);
		if (cpu < nr_cpu_ids)
			return cpu;
	}

	return cpumask_any_but(mask, exclude_cpu);
}

struct rdt_fs_context {
	struct kernfs_fs_context	kfc;
	bool				enable_cdpl2;
	bool				enable_cdpl3;
	bool				enable_mba_mbps;
	bool				enable_debug;
};

static inline struct rdt_fs_context *rdt_fc2context(struct fs_context *fc)
{
	struct kernfs_fs_context *kfc = fc->fs_private;

	return container_of(kfc, struct rdt_fs_context, kfc);
}

/**
 * struct mon_evt - Entry in the event list of a resource
 * @evtid:		event id
 * @name:		name of the event
 * @configurable:	true if the event is configurable
 * @list:		entry in &rdt_resource->evt_list
 */
struct mon_evt {
	enum resctrl_event_id	evtid;
	char			*name;
	bool			configurable;
	struct list_head	list;
};

/**
 * struct mon_data - Monitoring details for each event file.
 * @list:            Member of the global @mon_data_kn_priv_list list.
 * @rid:             Resource id associated with the event file.
 * @evtid:           Event id associated with the event file.
 * @sum:             Set when event must be summed across multiple
 *                   domains.
 * @domid:           When @sum is zero this is the domain to which
 *                   the event file belongs. When @sum is one this
 *                   is the id of the L3 cache that all domains to be
 *                   summed share.
 *
 * Pointed to by the kernfs kn->priv field of monitoring event files.
 * Readers and writers must hold rdtgroup_mutex.
 */
struct mon_data {
	struct list_head	list;
	enum resctrl_res_level	rid;
	enum resctrl_event_id	evtid;
	int			domid;
	bool			sum;
};

/**
 * struct rmid_read - Data passed across smp_call*() to read event count.
 * @rgrp:  Resource group for which the counter is being read. If it is a parent
 *	   resource group then its event count is summed with the count from all
 *	   its child resource groups.
 * @r:	   Resource describing the properties of the event being read.
 * @d:	   Domain that the counter should be read from. If NULL then sum all
 *	   domains in @r sharing L3 @ci.id
 * @evtid: Which monitor event to read.
 * @first: Initialize MBM counter when true.
 * @ci_id: Cacheinfo id for L3. Only set when @d is NULL. Used when summing domains.
 * @err:   Error encountered when reading counter.
 * @val:   Returned value of event counter. If @rgrp is a parent resource group,
 *	   @val includes the sum of event counts from its child resource groups.
 *	   If @d is NULL, @val includes the sum of all domains in @r sharing @ci.id,
 *	   (summed across child resource groups if @rgrp is a parent resource group).
 * @arch_mon_ctx: Hardware monitor allocated for this read request (MPAM only).
 */
struct rmid_read {
	struct rdtgroup		*rgrp;
	struct rdt_resource	*r;
	struct rdt_mon_domain	*d;
	enum resctrl_event_id	evtid;
	bool			first;
	unsigned int		ci_id;
	int			err;
	u64			val;
	void			*arch_mon_ctx;
};

extern struct list_head resctrl_schema_all;

extern bool resctrl_mounted;

enum rdt_group_type {
	RDTCTRL_GROUP = 0,
	RDTMON_GROUP,
	RDT_NUM_GROUP,
};

/**
 * enum rdtgrp_mode - Mode of a RDT resource group
 * @RDT_MODE_SHAREABLE: This resource group allows sharing of its allocations
 * @RDT_MODE_EXCLUSIVE: No sharing of this resource group's allocations allowed
 * @RDT_MODE_PSEUDO_LOCKSETUP: Resource group will be used for Pseudo-Locking
 * @RDT_MODE_PSEUDO_LOCKED: No sharing of this resource group's allocations
 *                          allowed AND the allocations are Cache Pseudo-Locked
 * @RDT_NUM_MODES: Total number of modes
 *
 * The mode of a resource group enables control over the allowed overlap
 * between allocations associated with different resource groups (classes
 * of service). User is able to modify the mode of a resource group by
 * writing to the "mode" resctrl file associated with the resource group.
 *
 * The "shareable", "exclusive", and "pseudo-locksetup" modes are set by
 * writing the appropriate text to the "mode" file. A resource group enters
 * "pseudo-locked" mode after the schemata is written while the resource
 * group is in "pseudo-locksetup" mode.
 */
enum rdtgrp_mode {
	RDT_MODE_SHAREABLE = 0,
	RDT_MODE_EXCLUSIVE,
	RDT_MODE_PSEUDO_LOCKSETUP,
	RDT_MODE_PSEUDO_LOCKED,

	/* Must be last */
	RDT_NUM_MODES,
};

/**
 * struct mongroup - store mon group's data in resctrl fs.
 * @mon_data_kn:		kernfs node for the mon_data directory
 * @parent:			parent rdtgrp
 * @crdtgrp_list:		child rdtgroup node list
 * @rmid:			rmid for this rdtgroup
 */
struct mongroup {
	struct kernfs_node	*mon_data_kn;
	struct rdtgroup		*parent;
	struct list_head	crdtgrp_list;
	u32			rmid;
};

/**
 * struct rdtgroup - store rdtgroup's data in resctrl file system.
 * @kn:				kernfs node
 * @rdtgroup_list:		linked list for all rdtgroups
 * @closid:			closid for this rdtgroup
 * @cpu_mask:			CPUs assigned to this rdtgroup
 * @flags:			status bits
 * @waitcount:			how many cpus expect to find this
 *				group when they acquire rdtgroup_mutex
 * @type:			indicates type of this rdtgroup - either
 *				monitor only or ctrl_mon group
 * @mon:			mongroup related data
 * @mode:			mode of resource group
 * @mba_mbps_event:		input monitoring event id when mba_sc is enabled
 * @plr:			pseudo-locked region
 */
struct rdtgroup {
	struct kernfs_node		*kn;
	struct list_head		rdtgroup_list;
	u32				closid;
	struct cpumask			cpu_mask;
	int				flags;
	atomic_t			waitcount;
	enum rdt_group_type		type;
	struct mongroup			mon;
	enum rdtgrp_mode		mode;
	enum resctrl_event_id		mba_mbps_event;
	struct pseudo_lock_region	*plr;
};

/* rdtgroup.flags */
#define	RDT_DELETED		1

/* rftype.flags */
#define RFTYPE_FLAGS_CPUS_LIST	1

/*
 * Define the file type flags for base and info directories.
 */
#define RFTYPE_INFO			BIT(0)

#define RFTYPE_BASE			BIT(1)

#define RFTYPE_CTRL			BIT(4)

#define RFTYPE_MON			BIT(5)

#define RFTYPE_TOP			BIT(6)

#define RFTYPE_RES_CACHE		BIT(8)

#define RFTYPE_RES_MB			BIT(9)

#define RFTYPE_DEBUG			BIT(10)

#define RFTYPE_CTRL_INFO		(RFTYPE_INFO | RFTYPE_CTRL)

#define RFTYPE_MON_INFO			(RFTYPE_INFO | RFTYPE_MON)

#define RFTYPE_TOP_INFO			(RFTYPE_INFO | RFTYPE_TOP)

#define RFTYPE_CTRL_BASE		(RFTYPE_BASE | RFTYPE_CTRL)

#define RFTYPE_MON_BASE			(RFTYPE_BASE | RFTYPE_MON)

/* List of all resource groups */
extern struct list_head rdt_all_groups;

extern int max_name_width;

/**
 * struct rftype - describe each file in the resctrl file system
 * @name:	File name
 * @mode:	Access mode
 * @kf_ops:	File operations
 * @flags:	File specific RFTYPE_FLAGS_* flags
 * @fflags:	File specific RFTYPE_* flags
 * @seq_show:	Show content of the file
 * @write:	Write to the file
 */
struct rftype {
	char			*name;
	umode_t			mode;
	const struct kernfs_ops	*kf_ops;
	unsigned long		flags;
	unsigned long		fflags;

	int (*seq_show)(struct kernfs_open_file *of,
			struct seq_file *sf, void *v);
	/*
	 * write() is the generic write callback which maps directly to
	 * kernfs write operation and overrides all other operations.
	 * Maximum write size is determined by ->max_write_len.
	 */
	ssize_t (*write)(struct kernfs_open_file *of,
			 char *buf, size_t nbytes, loff_t off);
};

/**
 * struct mbm_state - status for each MBM counter in each domain
 * @prev_bw_bytes: Previous bytes value read for bandwidth calculation
 * @prev_bw:	The most recent bandwidth in MBps
 */
struct mbm_state {
	u64	prev_bw_bytes;
	u32	prev_bw;
};

extern struct mutex rdtgroup_mutex;

static inline const char *rdt_kn_name(const struct kernfs_node *kn)
{
	return rcu_dereference_check(kn->name, lockdep_is_held(&rdtgroup_mutex));
}

extern struct rdtgroup rdtgroup_default;

extern struct dentry *debugfs_resctrl;

extern enum resctrl_event_id mba_mbps_default_event;

void rdt_last_cmd_clear(void);

void rdt_last_cmd_puts(const char *s);

__printf(1, 2)
void rdt_last_cmd_printf(const char *fmt, ...);

struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn);

void rdtgroup_kn_unlock(struct kernfs_node *kn);

int rdtgroup_kn_mode_restrict(struct rdtgroup *r, const char *name);

int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
			     umode_t mask);

ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
				char *buf, size_t nbytes, loff_t off);

int rdtgroup_schemata_show(struct kernfs_open_file *of,
			   struct seq_file *s, void *v);

ssize_t rdtgroup_mba_mbps_event_write(struct kernfs_open_file *of,
				      char *buf, size_t nbytes, loff_t off);

int rdtgroup_mba_mbps_event_show(struct kernfs_open_file *of,
				 struct seq_file *s, void *v);

bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_ctrl_domain *d,
			   unsigned long cbm, int closid, bool exclusive);

unsigned int rdtgroup_cbm_to_size(struct rdt_resource *r, struct rdt_ctrl_domain *d,
				  unsigned long cbm);

enum rdtgrp_mode rdtgroup_mode_by_closid(int closid);

int rdtgroup_tasks_assigned(struct rdtgroup *r);

int closids_supported(void);

void closid_free(int closid);

int alloc_rmid(u32 closid);

void free_rmid(u32 closid, u32 rmid);

void resctrl_mon_resource_exit(void);

void mon_event_count(void *info);

int rdtgroup_mondata_show(struct seq_file *m, void *arg);

void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,
		    struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,
		    cpumask_t *cpumask, int evtid, int first);

int resctrl_mon_resource_init(void);

void mbm_setup_overflow_handler(struct rdt_mon_domain *dom,
				unsigned long delay_ms,
				int exclude_cpu);

void mbm_handle_overflow(struct work_struct *work);

bool is_mba_sc(struct rdt_resource *r);

void cqm_setup_limbo_handler(struct rdt_mon_domain *dom, unsigned long delay_ms,
			     int exclude_cpu);

void cqm_handle_limbo(struct work_struct *work);

bool has_busy_rmid(struct rdt_mon_domain *d);

void __check_limbo(struct rdt_mon_domain *d, bool force_free);

void resctrl_file_fflags_init(const char *config, unsigned long fflags);

void rdt_staged_configs_clear(void);

bool closid_allocated(unsigned int closid);

int resctrl_find_cleanest_closid(void);

#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK
int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);

int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp);

bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm);

bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d);

int rdt_pseudo_lock_init(void);

void rdt_pseudo_lock_release(void);

int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp);

void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp);

#else
static inline int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp)
{
	return -EOPNOTSUPP;
}

static inline int rdtgroup_locksetup_exit(struct rdtgroup *rdtgrp)
{
	return -EOPNOTSUPP;
}

static inline bool rdtgroup_cbm_overlaps_pseudo_locked(struct rdt_ctrl_domain *d, unsigned long cbm)
{
	return false;
}

static inline bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d)
{
	return false;
}

static inline int rdt_pseudo_lock_init(void) { return 0; }
static inline void rdt_pseudo_lock_release(void) { }
static inline int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp)
{
	return -EOPNOTSUPP;
}

static inline void rdtgroup_pseudo_lock_remove(struct rdtgroup *rdtgrp) { }
#endif /* CONFIG_RESCTRL_FS_PSEUDO_LOCK */

#endif /* _FS_RESCTRL_INTERNAL_H */