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40fc735b78
x86's RMID are independent of the CLOSID. An RMID can be allocated, used and freed without considering the CLOSID. MPAM's equivalent feature is PMG, which is not an independent number, it extends the CLOSID/PARTID space. For MPAM, only PMG-bits worth of 'RMID' can be allocated for a single CLOSID. i.e. if there is 1 bit of PMG space, then each CLOSID can have two monitor groups. To allow resctrl to disambiguate RMID values for different CLOSID, everything in resctrl that keeps an RMID value needs to know the CLOSID too. This will always be ignored on x86. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Reviewed-by: Xin Hao <xhao@linux.alibaba.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Babu Moger <babu.moger@amd.com> Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64 Link: https://lore.kernel.org/r/20240213184438.16675-6-james.morse@arm.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
114 lines
3.2 KiB
C
114 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_X86_RESCTRL_H
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#define _ASM_X86_RESCTRL_H
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#ifdef CONFIG_X86_CPU_RESCTRL
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#include <linux/sched.h>
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#include <linux/jump_label.h>
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/*
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* This value can never be a valid CLOSID, and is used when mapping a
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* (closid, rmid) pair to an index and back. On x86 only the RMID is
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* needed. The index is a software defined value.
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*/
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#define X86_RESCTRL_EMPTY_CLOSID ((u32)~0)
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/**
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* struct resctrl_pqr_state - State cache for the PQR MSR
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* @cur_rmid: The cached Resource Monitoring ID
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* @cur_closid: The cached Class Of Service ID
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* @default_rmid: The user assigned Resource Monitoring ID
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* @default_closid: The user assigned cached Class Of Service ID
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*
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* The upper 32 bits of MSR_IA32_PQR_ASSOC contain closid and the
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* lower 10 bits rmid. The update to MSR_IA32_PQR_ASSOC always
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* contains both parts, so we need to cache them. This also
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* stores the user configured per cpu CLOSID and RMID.
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*
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* The cache also helps to avoid pointless updates if the value does
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* not change.
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*/
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struct resctrl_pqr_state {
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u32 cur_rmid;
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u32 cur_closid;
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u32 default_rmid;
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u32 default_closid;
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};
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DECLARE_PER_CPU(struct resctrl_pqr_state, pqr_state);
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DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
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DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);
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DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);
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/*
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* __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR
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*
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* Following considerations are made so that this has minimal impact
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* on scheduler hot path:
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* - This will stay as no-op unless we are running on an Intel SKU
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* which supports resource control or monitoring and we enable by
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* mounting the resctrl file system.
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* - Caches the per cpu CLOSid/RMID values and does the MSR write only
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* when a task with a different CLOSid/RMID is scheduled in.
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* - We allocate RMIDs/CLOSids globally in order to keep this as
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* simple as possible.
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* Must be called with preemption disabled.
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*/
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static inline void __resctrl_sched_in(struct task_struct *tsk)
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{
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struct resctrl_pqr_state *state = this_cpu_ptr(&pqr_state);
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u32 closid = state->default_closid;
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u32 rmid = state->default_rmid;
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u32 tmp;
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/*
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* If this task has a closid/rmid assigned, use it.
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* Else use the closid/rmid assigned to this cpu.
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*/
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if (static_branch_likely(&rdt_alloc_enable_key)) {
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tmp = READ_ONCE(tsk->closid);
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if (tmp)
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closid = tmp;
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}
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if (static_branch_likely(&rdt_mon_enable_key)) {
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tmp = READ_ONCE(tsk->rmid);
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if (tmp)
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rmid = tmp;
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}
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if (closid != state->cur_closid || rmid != state->cur_rmid) {
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state->cur_closid = closid;
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state->cur_rmid = rmid;
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wrmsr(MSR_IA32_PQR_ASSOC, rmid, closid);
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}
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}
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static inline unsigned int resctrl_arch_round_mon_val(unsigned int val)
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{
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unsigned int scale = boot_cpu_data.x86_cache_occ_scale;
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/* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
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val /= scale;
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return val * scale;
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}
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static inline void resctrl_sched_in(struct task_struct *tsk)
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{
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if (static_branch_likely(&rdt_enable_key))
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__resctrl_sched_in(tsk);
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}
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void resctrl_cpu_detect(struct cpuinfo_x86 *c);
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#else
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static inline void resctrl_sched_in(struct task_struct *tsk) {}
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static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {}
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#endif /* CONFIG_X86_CPU_RESCTRL */
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#endif /* _ASM_X86_RESCTRL_H */
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