xref: /linux/include/linux/resctrl.h (revision c9f016e72b5cc7d4d68fac51f8e72c8c7a69c06e)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _RESCTRL_H
3 #define _RESCTRL_H
4 
5 #include <linux/cacheinfo.h>
6 #include <linux/kernel.h>
7 #include <linux/list.h>
8 #include <linux/pid.h>
9 
10 /* CLOSID, RMID value used by the default control group */
11 #define RESCTRL_RESERVED_CLOSID		0
12 #define RESCTRL_RESERVED_RMID		0
13 
14 #define RESCTRL_PICK_ANY_CPU		-1
15 
16 #ifdef CONFIG_PROC_CPU_RESCTRL
17 
18 int proc_resctrl_show(struct seq_file *m,
19 		      struct pid_namespace *ns,
20 		      struct pid *pid,
21 		      struct task_struct *tsk);
22 
23 #endif
24 
25 /* max value for struct rdt_domain's mbps_val */
26 #define MBA_MAX_MBPS   U32_MAX
27 
28 /**
29  * enum resctrl_conf_type - The type of configuration.
30  * @CDP_NONE:	No prioritisation, both code and data are controlled or monitored.
31  * @CDP_CODE:	Configuration applies to instruction fetches.
32  * @CDP_DATA:	Configuration applies to reads and writes.
33  */
34 enum resctrl_conf_type {
35 	CDP_NONE,
36 	CDP_CODE,
37 	CDP_DATA,
38 };
39 
40 #define CDP_NUM_TYPES	(CDP_DATA + 1)
41 
42 /*
43  * Event IDs, the values match those used to program IA32_QM_EVTSEL before
44  * reading IA32_QM_CTR on RDT systems.
45  */
46 enum resctrl_event_id {
47 	QOS_L3_OCCUP_EVENT_ID		= 0x01,
48 	QOS_L3_MBM_TOTAL_EVENT_ID	= 0x02,
49 	QOS_L3_MBM_LOCAL_EVENT_ID	= 0x03,
50 };
51 
52 /**
53  * struct resctrl_staged_config - parsed configuration to be applied
54  * @new_ctrl:		new ctrl value to be loaded
55  * @have_new_ctrl:	whether the user provided new_ctrl is valid
56  */
57 struct resctrl_staged_config {
58 	u32			new_ctrl;
59 	bool			have_new_ctrl;
60 };
61 
62 enum resctrl_domain_type {
63 	RESCTRL_CTRL_DOMAIN,
64 	RESCTRL_MON_DOMAIN,
65 };
66 
67 /**
68  * struct rdt_domain_hdr - common header for different domain types
69  * @list:		all instances of this resource
70  * @id:			unique id for this instance
71  * @type:		type of this instance
72  * @cpu_mask:		which CPUs share this resource
73  */
74 struct rdt_domain_hdr {
75 	struct list_head		list;
76 	int				id;
77 	enum resctrl_domain_type	type;
78 	struct cpumask			cpu_mask;
79 };
80 
81 /**
82  * struct rdt_ctrl_domain - group of CPUs sharing a resctrl control resource
83  * @hdr:		common header for different domain types
84  * @plr:		pseudo-locked region (if any) associated with domain
85  * @staged_config:	parsed configuration to be applied
86  * @mbps_val:		When mba_sc is enabled, this holds the array of user
87  *			specified control values for mba_sc in MBps, indexed
88  *			by closid
89  */
90 struct rdt_ctrl_domain {
91 	struct rdt_domain_hdr		hdr;
92 	struct pseudo_lock_region	*plr;
93 	struct resctrl_staged_config	staged_config[CDP_NUM_TYPES];
94 	u32				*mbps_val;
95 };
96 
97 /**
98  * struct rdt_mon_domain - group of CPUs sharing a resctrl monitor resource
99  * @hdr:		common header for different domain types
100  * @ci:			cache info for this domain
101  * @rmid_busy_llc:	bitmap of which limbo RMIDs are above threshold
102  * @mbm_total:		saved state for MBM total bandwidth
103  * @mbm_local:		saved state for MBM local bandwidth
104  * @mbm_over:		worker to periodically read MBM h/w counters
105  * @cqm_limbo:		worker to periodically read CQM h/w counters
106  * @mbm_work_cpu:	worker CPU for MBM h/w counters
107  * @cqm_work_cpu:	worker CPU for CQM h/w counters
108  */
109 struct rdt_mon_domain {
110 	struct rdt_domain_hdr		hdr;
111 	struct cacheinfo		*ci;
112 	unsigned long			*rmid_busy_llc;
113 	struct mbm_state		*mbm_total;
114 	struct mbm_state		*mbm_local;
115 	struct delayed_work		mbm_over;
116 	struct delayed_work		cqm_limbo;
117 	int				mbm_work_cpu;
118 	int				cqm_work_cpu;
119 };
120 
121 /**
122  * struct resctrl_cache - Cache allocation related data
123  * @cbm_len:		Length of the cache bit mask
124  * @min_cbm_bits:	Minimum number of consecutive bits to be set.
125  *			The value 0 means the architecture can support
126  *			zero CBM.
127  * @shareable_bits:	Bitmask of shareable resource with other
128  *			executing entities
129  * @arch_has_sparse_bitmasks:	True if a bitmask like f00f is valid.
130  * @arch_has_per_cpu_cfg:	True if QOS_CFG register for this cache
131  *				level has CPU scope.
132  */
133 struct resctrl_cache {
134 	unsigned int	cbm_len;
135 	unsigned int	min_cbm_bits;
136 	unsigned int	shareable_bits;
137 	bool		arch_has_sparse_bitmasks;
138 	bool		arch_has_per_cpu_cfg;
139 };
140 
141 /**
142  * enum membw_throttle_mode - System's memory bandwidth throttling mode
143  * @THREAD_THROTTLE_UNDEFINED:	Not relevant to the system
144  * @THREAD_THROTTLE_MAX:	Memory bandwidth is throttled at the core
145  *				always using smallest bandwidth percentage
146  *				assigned to threads, aka "max throttling"
147  * @THREAD_THROTTLE_PER_THREAD:	Memory bandwidth is throttled at the thread
148  */
149 enum membw_throttle_mode {
150 	THREAD_THROTTLE_UNDEFINED = 0,
151 	THREAD_THROTTLE_MAX,
152 	THREAD_THROTTLE_PER_THREAD,
153 };
154 
155 /**
156  * struct resctrl_membw - Memory bandwidth allocation related data
157  * @min_bw:		Minimum memory bandwidth percentage user can request
158  * @bw_gran:		Granularity at which the memory bandwidth is allocated
159  * @delay_linear:	True if memory B/W delay is in linear scale
160  * @arch_needs_linear:	True if we can't configure non-linear resources
161  * @throttle_mode:	Bandwidth throttling mode when threads request
162  *			different memory bandwidths
163  * @mba_sc:		True if MBA software controller(mba_sc) is enabled
164  * @mb_map:		Mapping of memory B/W percentage to memory B/W delay
165  */
166 struct resctrl_membw {
167 	u32				min_bw;
168 	u32				bw_gran;
169 	u32				delay_linear;
170 	bool				arch_needs_linear;
171 	enum membw_throttle_mode	throttle_mode;
172 	bool				mba_sc;
173 	u32				*mb_map;
174 };
175 
176 struct rdt_parse_data;
177 struct resctrl_schema;
178 
179 enum resctrl_scope {
180 	RESCTRL_L2_CACHE = 2,
181 	RESCTRL_L3_CACHE = 3,
182 	RESCTRL_L3_NODE,
183 };
184 
185 /**
186  * struct rdt_resource - attributes of a resctrl resource
187  * @rid:		The index of the resource
188  * @alloc_capable:	Is allocation available on this machine
189  * @mon_capable:	Is monitor feature available on this machine
190  * @num_rmid:		Number of RMIDs available
191  * @ctrl_scope:		Scope of this resource for control functions
192  * @mon_scope:		Scope of this resource for monitor functions
193  * @cache:		Cache allocation related data
194  * @membw:		If the component has bandwidth controls, their properties.
195  * @ctrl_domains:	RCU list of all control domains for this resource
196  * @mon_domains:	RCU list of all monitor domains for this resource
197  * @name:		Name to use in "schemata" file.
198  * @data_width:		Character width of data when displaying
199  * @default_ctrl:	Specifies default cache cbm or memory B/W percent.
200  * @format_str:		Per resource format string to show domain value
201  * @parse_ctrlval:	Per resource function pointer to parse control values
202  * @evt_list:		List of monitoring events
203  * @fflags:		flags to choose base and info files
204  * @cdp_capable:	Is the CDP feature available on this resource
205  */
206 struct rdt_resource {
207 	int			rid;
208 	bool			alloc_capable;
209 	bool			mon_capable;
210 	int			num_rmid;
211 	enum resctrl_scope	ctrl_scope;
212 	enum resctrl_scope	mon_scope;
213 	struct resctrl_cache	cache;
214 	struct resctrl_membw	membw;
215 	struct list_head	ctrl_domains;
216 	struct list_head	mon_domains;
217 	char			*name;
218 	int			data_width;
219 	u32			default_ctrl;
220 	const char		*format_str;
221 	int			(*parse_ctrlval)(struct rdt_parse_data *data,
222 						 struct resctrl_schema *s,
223 						 struct rdt_ctrl_domain *d);
224 	struct list_head	evt_list;
225 	unsigned long		fflags;
226 	bool			cdp_capable;
227 };
228 
229 /**
230  * struct resctrl_schema - configuration abilities of a resource presented to
231  *			   user-space
232  * @list:	Member of resctrl_schema_all.
233  * @name:	The name to use in the "schemata" file.
234  * @conf_type:	Whether this schema is specific to code/data.
235  * @res:	The resource structure exported by the architecture to describe
236  *		the hardware that is configured by this schema.
237  * @num_closid:	The number of closid that can be used with this schema. When
238  *		features like CDP are enabled, this will be lower than the
239  *		hardware supports for the resource.
240  */
241 struct resctrl_schema {
242 	struct list_head		list;
243 	char				name[8];
244 	enum resctrl_conf_type		conf_type;
245 	struct rdt_resource		*res;
246 	u32				num_closid;
247 };
248 
249 /* The number of closid supported by this resource regardless of CDP */
250 u32 resctrl_arch_get_num_closid(struct rdt_resource *r);
251 u32 resctrl_arch_system_num_rmid_idx(void);
252 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
253 
254 /*
255  * Update the ctrl_val and apply this config right now.
256  * Must be called on one of the domain's CPUs.
257  */
258 int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_ctrl_domain *d,
259 			    u32 closid, enum resctrl_conf_type t, u32 cfg_val);
260 
261 u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_ctrl_domain *d,
262 			    u32 closid, enum resctrl_conf_type type);
263 int resctrl_online_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d);
264 int resctrl_online_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d);
265 void resctrl_offline_ctrl_domain(struct rdt_resource *r, struct rdt_ctrl_domain *d);
266 void resctrl_offline_mon_domain(struct rdt_resource *r, struct rdt_mon_domain *d);
267 void resctrl_online_cpu(unsigned int cpu);
268 void resctrl_offline_cpu(unsigned int cpu);
269 
270 /**
271  * resctrl_arch_rmid_read() - Read the eventid counter corresponding to rmid
272  *			      for this resource and domain.
273  * @r:			resource that the counter should be read from.
274  * @d:			domain that the counter should be read from.
275  * @closid:		closid that matches the rmid. Depending on the architecture, the
276  *			counter may match traffic of both @closid and @rmid, or @rmid
277  *			only.
278  * @rmid:		rmid of the counter to read.
279  * @eventid:		eventid to read, e.g. L3 occupancy.
280  * @val:		result of the counter read in bytes.
281  * @arch_mon_ctx:	An architecture specific value from
282  *			resctrl_arch_mon_ctx_alloc(), for MPAM this identifies
283  *			the hardware monitor allocated for this read request.
284  *
285  * Some architectures need to sleep when first programming some of the counters.
286  * (specifically: arm64's MPAM cache occupancy counters can return 'not ready'
287  *  for a short period of time). Call from a non-migrateable process context on
288  * a CPU that belongs to domain @d. e.g. use smp_call_on_cpu() or
289  * schedule_work_on(). This function can be called with interrupts masked,
290  * e.g. using smp_call_function_any(), but may consistently return an error.
291  *
292  * Return:
293  * 0 on success, or -EIO, -EINVAL etc on error.
294  */
295 int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_mon_domain *d,
296 			   u32 closid, u32 rmid, enum resctrl_event_id eventid,
297 			   u64 *val, void *arch_mon_ctx);
298 
299 /**
300  * resctrl_arch_rmid_read_context_check()  - warn about invalid contexts
301  *
302  * When built with CONFIG_DEBUG_ATOMIC_SLEEP generate a warning when
303  * resctrl_arch_rmid_read() is called with preemption disabled.
304  *
305  * The contract with resctrl_arch_rmid_read() is that if interrupts
306  * are unmasked, it can sleep. This allows NOHZ_FULL systems to use an
307  * IPI, (and fail if the call needed to sleep), while most of the time
308  * the work is scheduled, allowing the call to sleep.
309  */
resctrl_arch_rmid_read_context_check(void)310 static inline void resctrl_arch_rmid_read_context_check(void)
311 {
312 	if (!irqs_disabled())
313 		might_sleep();
314 }
315 
316 /**
317  * resctrl_arch_reset_rmid() - Reset any private state associated with rmid
318  *			       and eventid.
319  * @r:		The domain's resource.
320  * @d:		The rmid's domain.
321  * @closid:	closid that matches the rmid. Depending on the architecture, the
322  *		counter may match traffic of both @closid and @rmid, or @rmid only.
323  * @rmid:	The rmid whose counter values should be reset.
324  * @eventid:	The eventid whose counter values should be reset.
325  *
326  * This can be called from any CPU.
327  */
328 void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_mon_domain *d,
329 			     u32 closid, u32 rmid,
330 			     enum resctrl_event_id eventid);
331 
332 /**
333  * resctrl_arch_reset_rmid_all() - Reset all private state associated with
334  *				   all rmids and eventids.
335  * @r:		The resctrl resource.
336  * @d:		The domain for which all architectural counter state will
337  *		be cleared.
338  *
339  * This can be called from any CPU.
340  */
341 void resctrl_arch_reset_rmid_all(struct rdt_resource *r, struct rdt_mon_domain *d);
342 
343 extern unsigned int resctrl_rmid_realloc_threshold;
344 extern unsigned int resctrl_rmid_realloc_limit;
345 
346 #endif /* _RESCTRL_H */
347