1/* SPDX-License-Identifier: GPL-2.0 */ 2#ifndef _ASM_X86_RESCTRL_H 3#define _ASM_X86_RESCTRL_H 4 5#ifdef CONFIG_X86_CPU_RESCTRL 6 7#include <linux/sched.h> 8#include <linux/jump_label.h> 9 10/* 11 * This value can never be a valid CLOSID, and is used when mapping a 12 * (closid, rmid) pair to an index and back. On x86 only the RMID is 13 * needed. The index is a software defined value. 14 */ 15#define X86_RESCTRL_EMPTY_CLOSID ((u32)~0) 16 17/** 18 * struct resctrl_pqr_state - State cache for the PQR MSR 19 * @cur_rmid: The cached Resource Monitoring ID 20 * @cur_closid: The cached Class Of Service ID 21 * @default_rmid: The user assigned Resource Monitoring ID 22 * @default_closid: The user assigned cached Class Of Service ID 23 * 24 * The upper 32 bits of MSR_IA32_PQR_ASSOC contain closid and the 25 * lower 10 bits rmid. The update to MSR_IA32_PQR_ASSOC always 26 * contains both parts, so we need to cache them. This also 27 * stores the user configured per cpu CLOSID and RMID. 28 * 29 * The cache also helps to avoid pointless updates if the value does 30 * not change. 31 */ 32struct resctrl_pqr_state { 33 u32 cur_rmid; 34 u32 cur_closid; 35 u32 default_rmid; 36 u32 default_closid; 37}; 38 39DECLARE_PER_CPU(struct resctrl_pqr_state, pqr_state); 40 41extern bool rdt_alloc_capable; 42extern bool rdt_mon_capable; 43 44DECLARE_STATIC_KEY_FALSE(rdt_enable_key); 45DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key); 46DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); 47 48static inline bool resctrl_arch_alloc_capable(void) 49{ 50 return rdt_alloc_capable; 51} 52 53static inline void resctrl_arch_enable_alloc(void) 54{ 55 static_branch_enable_cpuslocked(&rdt_alloc_enable_key); 56 static_branch_inc_cpuslocked(&rdt_enable_key); 57} 58 59static inline void resctrl_arch_disable_alloc(void) 60{ 61 static_branch_disable_cpuslocked(&rdt_alloc_enable_key); 62 static_branch_dec_cpuslocked(&rdt_enable_key); 63} 64 65static inline bool resctrl_arch_mon_capable(void) 66{ 67 return rdt_mon_capable; 68} 69 70static inline void resctrl_arch_enable_mon(void) 71{ 72 static_branch_enable_cpuslocked(&rdt_mon_enable_key); 73 static_branch_inc_cpuslocked(&rdt_enable_key); 74} 75 76static inline void resctrl_arch_disable_mon(void) 77{ 78 static_branch_disable_cpuslocked(&rdt_mon_enable_key); 79 static_branch_dec_cpuslocked(&rdt_enable_key); 80} 81 82/* 83 * __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR 84 * 85 * Following considerations are made so that this has minimal impact 86 * on scheduler hot path: 87 * - This will stay as no-op unless we are running on an Intel SKU 88 * which supports resource control or monitoring and we enable by 89 * mounting the resctrl file system. 90 * - Caches the per cpu CLOSid/RMID values and does the MSR write only 91 * when a task with a different CLOSid/RMID is scheduled in. 92 * - We allocate RMIDs/CLOSids globally in order to keep this as 93 * simple as possible. 94 * Must be called with preemption disabled. 95 */ 96static inline void __resctrl_sched_in(struct task_struct *tsk) 97{ 98 struct resctrl_pqr_state *state = this_cpu_ptr(&pqr_state); 99 u32 closid = state->default_closid; 100 u32 rmid = state->default_rmid; 101 u32 tmp; 102 103 /* 104 * If this task has a closid/rmid assigned, use it. 105 * Else use the closid/rmid assigned to this cpu. 106 */ 107 if (static_branch_likely(&rdt_alloc_enable_key)) { 108 tmp = READ_ONCE(tsk->closid); 109 if (tmp) 110 closid = tmp; 111 } 112 113 if (static_branch_likely(&rdt_mon_enable_key)) { 114 tmp = READ_ONCE(tsk->rmid); 115 if (tmp) 116 rmid = tmp; 117 } 118 119 if (closid != state->cur_closid || rmid != state->cur_rmid) { 120 state->cur_closid = closid; 121 state->cur_rmid = rmid; 122 wrmsr(MSR_IA32_PQR_ASSOC, rmid, closid); 123 } 124} 125 126static inline unsigned int resctrl_arch_round_mon_val(unsigned int val) 127{ 128 unsigned int scale = boot_cpu_data.x86_cache_occ_scale; 129 130 /* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */ 131 val /= scale; 132 return val * scale; 133} 134 135static inline void resctrl_arch_set_closid_rmid(struct task_struct *tsk, 136 u32 closid, u32 rmid) 137{ 138 WRITE_ONCE(tsk->closid, closid); 139 WRITE_ONCE(tsk->rmid, rmid); 140} 141 142static inline bool resctrl_arch_match_closid(struct task_struct *tsk, u32 closid) 143{ 144 return READ_ONCE(tsk->closid) == closid; 145} 146 147static inline bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 ignored, 148 u32 rmid) 149{ 150 return READ_ONCE(tsk->rmid) == rmid; 151} 152 153static inline void resctrl_sched_in(struct task_struct *tsk) 154{ 155 if (static_branch_likely(&rdt_enable_key)) 156 __resctrl_sched_in(tsk); 157} 158 159static inline u32 resctrl_arch_system_num_rmid_idx(void) 160{ 161 /* RMID are independent numbers for x86. num_rmid_idx == num_rmid */ 162 return boot_cpu_data.x86_cache_max_rmid + 1; 163} 164 165static inline void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid) 166{ 167 *rmid = idx; 168 *closid = X86_RESCTRL_EMPTY_CLOSID; 169} 170 171static inline u32 resctrl_arch_rmid_idx_encode(u32 ignored, u32 rmid) 172{ 173 return rmid; 174} 175 176/* x86 can always read an rmid, nothing needs allocating */ 177struct rdt_resource; 178static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, int evtid) 179{ 180 might_sleep(); 181 return NULL; 182}; 183 184static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, int evtid, 185 void *ctx) { }; 186 187void resctrl_cpu_detect(struct cpuinfo_x86 *c); 188 189#else 190 191static inline void resctrl_sched_in(struct task_struct *tsk) {} 192static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {} 193 194#endif /* CONFIG_X86_CPU_RESCTRL */ 195 196#endif /* _ASM_X86_RESCTRL_H */ 197