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 extern unsigned int rdt_mon_features;
48
49 DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
50 DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
51 DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
52
resctrl_arch_alloc_capable(void)53 static inline bool resctrl_arch_alloc_capable(void)
54 {
55 return rdt_alloc_capable;
56 }
57
resctrl_arch_enable_alloc(void)58 static inline void resctrl_arch_enable_alloc(void)
59 {
60 static_branch_enable_cpuslocked(&rdt_alloc_enable_key);
61 static_branch_inc_cpuslocked(&rdt_enable_key);
62 }
63
resctrl_arch_disable_alloc(void)64 static inline void resctrl_arch_disable_alloc(void)
65 {
66 static_branch_disable_cpuslocked(&rdt_alloc_enable_key);
67 static_branch_dec_cpuslocked(&rdt_enable_key);
68 }
69
resctrl_arch_mon_capable(void)70 static inline bool resctrl_arch_mon_capable(void)
71 {
72 return rdt_mon_capable;
73 }
74
resctrl_arch_enable_mon(void)75 static inline void resctrl_arch_enable_mon(void)
76 {
77 static_branch_enable_cpuslocked(&rdt_mon_enable_key);
78 static_branch_inc_cpuslocked(&rdt_enable_key);
79 }
80
resctrl_arch_disable_mon(void)81 static inline void resctrl_arch_disable_mon(void)
82 {
83 static_branch_disable_cpuslocked(&rdt_mon_enable_key);
84 static_branch_dec_cpuslocked(&rdt_enable_key);
85 }
86
resctrl_arch_is_llc_occupancy_enabled(void)87 static inline bool resctrl_arch_is_llc_occupancy_enabled(void)
88 {
89 return (rdt_mon_features & (1 << QOS_L3_OCCUP_EVENT_ID));
90 }
91
resctrl_arch_is_mbm_total_enabled(void)92 static inline bool resctrl_arch_is_mbm_total_enabled(void)
93 {
94 return (rdt_mon_features & (1 << QOS_L3_MBM_TOTAL_EVENT_ID));
95 }
96
resctrl_arch_is_mbm_local_enabled(void)97 static inline bool resctrl_arch_is_mbm_local_enabled(void)
98 {
99 return (rdt_mon_features & (1 << QOS_L3_MBM_LOCAL_EVENT_ID));
100 }
101
102 /*
103 * __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR
104 *
105 * Following considerations are made so that this has minimal impact
106 * on scheduler hot path:
107 * - This will stay as no-op unless we are running on an Intel SKU
108 * which supports resource control or monitoring and we enable by
109 * mounting the resctrl file system.
110 * - Caches the per cpu CLOSid/RMID values and does the MSR write only
111 * when a task with a different CLOSid/RMID is scheduled in.
112 * - We allocate RMIDs/CLOSids globally in order to keep this as
113 * simple as possible.
114 * Must be called with preemption disabled.
115 */
__resctrl_sched_in(struct task_struct * tsk)116 static inline void __resctrl_sched_in(struct task_struct *tsk)
117 {
118 struct resctrl_pqr_state *state = this_cpu_ptr(&pqr_state);
119 u32 closid = READ_ONCE(state->default_closid);
120 u32 rmid = READ_ONCE(state->default_rmid);
121 u32 tmp;
122
123 /*
124 * If this task has a closid/rmid assigned, use it.
125 * Else use the closid/rmid assigned to this cpu.
126 */
127 if (static_branch_likely(&rdt_alloc_enable_key)) {
128 tmp = READ_ONCE(tsk->closid);
129 if (tmp)
130 closid = tmp;
131 }
132
133 if (static_branch_likely(&rdt_mon_enable_key)) {
134 tmp = READ_ONCE(tsk->rmid);
135 if (tmp)
136 rmid = tmp;
137 }
138
139 if (closid != state->cur_closid || rmid != state->cur_rmid) {
140 state->cur_closid = closid;
141 state->cur_rmid = rmid;
142 wrmsr(MSR_IA32_PQR_ASSOC, rmid, closid);
143 }
144 }
145
resctrl_arch_round_mon_val(unsigned int val)146 static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
147 {
148 unsigned int scale = boot_cpu_data.x86_cache_occ_scale;
149
150 /* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
151 val /= scale;
152 return val * scale;
153 }
154
resctrl_arch_set_cpu_default_closid_rmid(int cpu,u32 closid,u32 rmid)155 static inline void resctrl_arch_set_cpu_default_closid_rmid(int cpu, u32 closid,
156 u32 rmid)
157 {
158 WRITE_ONCE(per_cpu(pqr_state.default_closid, cpu), closid);
159 WRITE_ONCE(per_cpu(pqr_state.default_rmid, cpu), rmid);
160 }
161
resctrl_arch_set_closid_rmid(struct task_struct * tsk,u32 closid,u32 rmid)162 static inline void resctrl_arch_set_closid_rmid(struct task_struct *tsk,
163 u32 closid, u32 rmid)
164 {
165 WRITE_ONCE(tsk->closid, closid);
166 WRITE_ONCE(tsk->rmid, rmid);
167 }
168
resctrl_arch_match_closid(struct task_struct * tsk,u32 closid)169 static inline bool resctrl_arch_match_closid(struct task_struct *tsk, u32 closid)
170 {
171 return READ_ONCE(tsk->closid) == closid;
172 }
173
resctrl_arch_match_rmid(struct task_struct * tsk,u32 ignored,u32 rmid)174 static inline bool resctrl_arch_match_rmid(struct task_struct *tsk, u32 ignored,
175 u32 rmid)
176 {
177 return READ_ONCE(tsk->rmid) == rmid;
178 }
179
resctrl_arch_sched_in(struct task_struct * tsk)180 static inline void resctrl_arch_sched_in(struct task_struct *tsk)
181 {
182 if (static_branch_likely(&rdt_enable_key))
183 __resctrl_sched_in(tsk);
184 }
185
resctrl_arch_rmid_idx_decode(u32 idx,u32 * closid,u32 * rmid)186 static inline void resctrl_arch_rmid_idx_decode(u32 idx, u32 *closid, u32 *rmid)
187 {
188 *rmid = idx;
189 *closid = X86_RESCTRL_EMPTY_CLOSID;
190 }
191
resctrl_arch_rmid_idx_encode(u32 ignored,u32 rmid)192 static inline u32 resctrl_arch_rmid_idx_encode(u32 ignored, u32 rmid)
193 {
194 return rmid;
195 }
196
197 /* x86 can always read an rmid, nothing needs allocating */
198 struct rdt_resource;
resctrl_arch_mon_ctx_alloc(struct rdt_resource * r,enum resctrl_event_id evtid)199 static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r,
200 enum resctrl_event_id evtid)
201 {
202 might_sleep();
203 return NULL;
204 }
205
resctrl_arch_mon_ctx_free(struct rdt_resource * r,enum resctrl_event_id evtid,void * ctx)206 static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r,
207 enum resctrl_event_id evtid,
208 void *ctx) { }
209
210 void resctrl_cpu_detect(struct cpuinfo_x86 *c);
211
212 #else
213
resctrl_arch_sched_in(struct task_struct * tsk)214 static inline void resctrl_arch_sched_in(struct task_struct *tsk) {}
resctrl_cpu_detect(struct cpuinfo_x86 * c)215 static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {}
216
217 #endif /* CONFIG_X86_CPU_RESCTRL */
218
219 #endif /* _ASM_X86_RESCTRL_H */
220