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/jump_label.h> 8 #include <linux/percpu.h> 9 #include <linux/resctrl_types.h> 10 #include <linux/sched.h> 11 12 #include <asm/msr.h> 13 14 /* 15 * This value can never be a valid CLOSID, and is used when mapping a 16 * (closid, rmid) pair to an index and back. On x86 only the RMID is 17 * needed. The index is a software defined value. 18 */ 19 #define X86_RESCTRL_EMPTY_CLOSID ((u32)~0) 20 21 /** 22 * struct resctrl_pqr_state - State cache for the PQR MSR 23 * @cur_rmid: The cached Resource Monitoring ID 24 * @cur_closid: The cached Class Of Service ID 25 * @default_rmid: The user assigned Resource Monitoring ID 26 * @default_closid: The user assigned cached Class Of Service ID 27 * 28 * The upper 32 bits of MSR_IA32_PQR_ASSOC contain closid and the 29 * lower 10 bits rmid. The update to MSR_IA32_PQR_ASSOC always 30 * contains both parts, so we need to cache them. This also 31 * stores the user configured per cpu CLOSID and RMID. 32 * 33 * The cache also helps to avoid pointless updates if the value does 34 * not change. 35 */ 36 struct resctrl_pqr_state { 37 u32 cur_rmid; 38 u32 cur_closid; 39 u32 default_rmid; 40 u32 default_closid; 41 }; 42 43 DECLARE_PER_CPU(struct resctrl_pqr_state, pqr_state); 44 45 extern bool rdt_alloc_capable; 46 extern bool rdt_mon_capable; 47 48 DECLARE_STATIC_KEY_FALSE(rdt_enable_key); 49 DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key); 50 DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); 51 52 static inline bool resctrl_arch_alloc_capable(void) 53 { 54 return rdt_alloc_capable; 55 } 56 57 static inline void resctrl_arch_enable_alloc(void) 58 { 59 static_branch_enable_cpuslocked(&rdt_alloc_enable_key); 60 static_branch_inc_cpuslocked(&rdt_enable_key); 61 } 62 63 static inline void resctrl_arch_disable_alloc(void) 64 { 65 static_branch_disable_cpuslocked(&rdt_alloc_enable_key); 66 static_branch_dec_cpuslocked(&rdt_enable_key); 67 } 68 69 static inline bool resctrl_arch_mon_capable(void) 70 { 71 return rdt_mon_capable; 72 } 73 74 static inline void resctrl_arch_enable_mon(void) 75 { 76 static_branch_enable_cpuslocked(&rdt_mon_enable_key); 77 static_branch_inc_cpuslocked(&rdt_enable_key); 78 } 79 80 static inline void resctrl_arch_disable_mon(void) 81 { 82 static_branch_disable_cpuslocked(&rdt_mon_enable_key); 83 static_branch_dec_cpuslocked(&rdt_enable_key); 84 } 85 86 /* 87 * __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR 88 * 89 * Following considerations are made so that this has minimal impact 90 * on scheduler hot path: 91 * - This will stay as no-op unless we are running on an Intel SKU 92 * which supports resource control or monitoring and we enable by 93 * mounting the resctrl file system. 94 * - Caches the per cpu CLOSid/RMID values and does the MSR write only 95 * when a task with a different CLOSid/RMID is scheduled in. 96 * - We allocate RMIDs/CLOSids globally in order to keep this as 97 * simple as possible. 98 * Must be called with preemption disabled. 99 */ 100 static inline void __resctrl_sched_in(struct task_struct *tsk) 101 { 102 struct resctrl_pqr_state *state = this_cpu_ptr(&pqr_state); 103 u32 closid = READ_ONCE(state->default_closid); 104 u32 rmid = READ_ONCE(state->default_rmid); 105 u32 tmp; 106 107 /* 108 * If this task has a closid/rmid assigned, use it. 109 * Else use the closid/rmid assigned to this cpu. 110 */ 111 if (static_branch_likely(&rdt_alloc_enable_key)) { 112 tmp = READ_ONCE(tsk->closid); 113 if (tmp) 114 closid = tmp; 115 } 116 117 if (static_branch_likely(&rdt_mon_enable_key)) { 118 tmp = READ_ONCE(tsk->rmid); 119 if (tmp) 120 rmid = tmp; 121 } 122 123 if (closid != state->cur_closid || rmid != state->cur_rmid) { 124 state->cur_closid = closid; 125 state->cur_rmid = rmid; 126 wrmsr(MSR_IA32_PQR_ASSOC, rmid, closid); 127 } 128 } 129 130 static inline unsigned int resctrl_arch_round_mon_val(unsigned int val) 131 { 132 unsigned int scale = boot_cpu_data.x86_cache_occ_scale; 133 134 /* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */ 135 val /= scale; 136 return val * scale; 137 } 138 139 static inline void resctrl_arch_set_cpu_default_closid_rmid(int cpu, u32 closid, 140 u32 rmid) 141 { 142 WRITE_ONCE(per_cpu(pqr_state.default_closid, cpu), closid); 143 WRITE_ONCE(per_cpu(pqr_state.default_rmid, cpu), rmid); 144 } 145 146 static inline void resctrl_arch_set_closid_rmid(struct task_struct *tsk, 147 u32 closid, u32 rmid) 148 { 149 WRITE_ONCE(tsk->closid, closid); 150 WRITE_ONCE(tsk->rmid, rmid); 151 } 152 153 static inline bool resctrl_arch_match_closid(struct task_struct *tsk, u32 closid) 154 { 155 return READ_ONCE(tsk->closid) == closid; 156 } 157 158 static inline bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 ignored, 159 u32 rmid) 160 { 161 return READ_ONCE(tsk->rmid) == rmid; 162 } 163 164 static inline void resctrl_arch_sched_in(struct task_struct *tsk) 165 { 166 if (static_branch_likely(&rdt_enable_key)) 167 __resctrl_sched_in(tsk); 168 } 169 170 static inline void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid) 171 { 172 *rmid = idx; 173 *closid = X86_RESCTRL_EMPTY_CLOSID; 174 } 175 176 static inline u32 resctrl_arch_rmid_idx_encode(u32 ignored, u32 rmid) 177 { 178 return rmid; 179 } 180 181 /* x86 can always read an rmid, nothing needs allocating */ 182 struct rdt_resource; 183 static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, 184 enum resctrl_event_id evtid) 185 { 186 might_sleep(); 187 return NULL; 188 } 189 190 static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, 191 enum resctrl_event_id evtid, 192 void *ctx) { } 193 194 void resctrl_cpu_detect(struct cpuinfo_x86 *c); 195 196 #else 197 198 static inline void resctrl_arch_sched_in(struct task_struct *tsk) {} 199 static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {} 200 201 #endif /* CONFIG_X86_CPU_RESCTRL */ 202 203 #endif /* _ASM_X86_RESCTRL_H */ 204