/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_RESCTRL_SCHED_H #define _ASM_X86_RESCTRL_SCHED_H #ifdef CONFIG_X86_RESCTRL #include #include #define IA32_PQR_ASSOC 0x0c8f /** * struct resctrl_pqr_state - State cache for the PQR MSR * @cur_rmid: The cached Resource Monitoring ID * @cur_closid: The cached Class Of Service ID * @default_rmid: The user assigned Resource Monitoring ID * @default_closid: The user assigned cached Class Of Service ID * * The upper 32 bits of IA32_PQR_ASSOC contain closid and the * lower 10 bits rmid. The update to IA32_PQR_ASSOC always * contains both parts, so we need to cache them. This also * stores the user configured per cpu CLOSID and RMID. * * The cache also helps to avoid pointless updates if the value does * not change. */ struct resctrl_pqr_state { u32 cur_rmid; u32 cur_closid; u32 default_rmid; u32 default_closid; }; DECLARE_PER_CPU(struct resctrl_pqr_state, pqr_state); DECLARE_STATIC_KEY_FALSE(rdt_enable_key); DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key); DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); /* * __resctrl_sched_in() - Writes the task's CLOSid/RMID to IA32_PQR_MSR * * Following considerations are made so that this has minimal impact * on scheduler hot path: * - This will stay as no-op unless we are running on an Intel SKU * which supports resource control or monitoring and we enable by * mounting the resctrl file system. * - Caches the per cpu CLOSid/RMID values and does the MSR write only * when a task with a different CLOSid/RMID is scheduled in. * - We allocate RMIDs/CLOSids globally in order to keep this as * simple as possible. * Must be called with preemption disabled. */ static void __resctrl_sched_in(void) { struct resctrl_pqr_state *state = this_cpu_ptr(&pqr_state); u32 closid = state->default_closid; u32 rmid = state->default_rmid; /* * If this task has a closid/rmid assigned, use it. * Else use the closid/rmid assigned to this cpu. */ if (static_branch_likely(&rdt_alloc_enable_key)) { if (current->closid) closid = current->closid; } if (static_branch_likely(&rdt_mon_enable_key)) { if (current->rmid) rmid = current->rmid; } if (closid != state->cur_closid || rmid != state->cur_rmid) { state->cur_closid = closid; state->cur_rmid = rmid; wrmsr(IA32_PQR_ASSOC, rmid, closid); } } static inline void resctrl_sched_in(void) { if (static_branch_likely(&rdt_enable_key)) __resctrl_sched_in(); } #else static inline void resctrl_sched_in(void) {} #endif /* CONFIG_X86_RESCTRL */ #endif /* _ASM_X86_RESCTRL_SCHED_H */