linux/arch/x86/include/asm/resctrl.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_RESCTRL_H
#define _ASM_X86_RESCTRL_H

#ifdef CONFIG_X86_CPU_RESCTRL

#include <linux/sched.h>
#include <linux/jump_label.h>

/*
 * This value can never be a valid CLOSID, and is used when mapping a
 * (closid, rmid) pair to an index and back. On x86 only the RMID is
 * needed. The index is a software defined value.
 */
#define X86_RESCTRL_EMPTY_CLOSID …

/**
 * struct resctrl_pqr_state - State cache for the PQR MSR
 * @cur_rmid:		The cached Resource Monitoring ID
 * @cur_closid:	The cached Class Of Service ID
 * @default_rmid:	The user assigned Resource Monitoring ID
 * @default_closid:	The user assigned cached Class Of Service ID
 *
 * The upper 32 bits of MSR_IA32_PQR_ASSOC contain closid and the
 * lower 10 bits rmid. The update to MSR_IA32_PQR_ASSOC always
 * contains both parts, so we need to cache them. This also
 * stores the user configured per cpu CLOSID and RMID.
 *
 * The cache also helps to avoid pointless updates if the value does
 * not change.
 */
struct resctrl_pqr_state { … };

DECLARE_PER_CPU(struct resctrl_pqr_state, pqr_state);

extern bool rdt_alloc_capable;
extern bool rdt_mon_capable;

DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);

static inline bool resctrl_arch_alloc_capable(void)
{ … }

static inline void resctrl_arch_enable_alloc(void)
{ … }

static inline void resctrl_arch_disable_alloc(void)
{ … }

static inline bool resctrl_arch_mon_capable(void)
{ … }

static inline void resctrl_arch_enable_mon(void)
{ … }

static inline void resctrl_arch_disable_mon(void)
{ … }

/*
 * __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR
 *
 * Following considerations are made so that this has minimal impact
 * on scheduler hot path:
 * - This will stay as no-op unless we are running on an Intel SKU
 *   which supports resource control or monitoring and we enable by
 *   mounting the resctrl file system.
 * - Caches the per cpu CLOSid/RMID values and does the MSR write only
 *   when a task with a different CLOSid/RMID is scheduled in.
 * - We allocate RMIDs/CLOSids globally in order to keep this as
 *   simple as possible.
 * Must be called with preemption disabled.
 */
static inline void __resctrl_sched_in(struct task_struct *tsk)
{ … }

static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
{ … }

static inline void resctrl_arch_set_closid_rmid(struct task_struct *tsk,
						u32 closid, u32 rmid)
{ … }

static inline bool resctrl_arch_match_closid(struct task_struct *tsk, u32 closid)
{ … }

static inline bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 ignored,
					   u32 rmid)
{ … }

static inline void resctrl_sched_in(struct task_struct *tsk)
{ … }

static inline u32 resctrl_arch_system_num_rmid_idx(void)
{ … }

static inline void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid)
{ … }

static inline u32 resctrl_arch_rmid_idx_encode(u32 ignored, u32 rmid)
{ … }

/* x86 can always read an rmid, nothing needs allocating */
struct rdt_resource;
static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, int evtid)
{
	might_sleep();
	return NULL;
};

static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, int evtid,
					     void *ctx) { };

void resctrl_cpu_detect(struct cpuinfo_x86 *c);

#else

static inline void resctrl_sched_in(struct task_struct *tsk) {}
static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {}

#endif /* CONFIG_X86_CPU_RESCTRL */

#endif /* _ASM_X86_RESCTRL_H */