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#ifndef _ASM_X86_INTEL_RDT_SCHED_H
#define _ASM_X86_INTEL_RDT_SCHED_H
#ifdef CONFIG_INTEL_RDT
#include <linux/sched.h>
#include <linux/jump_label.h>
#define IA32_PQR_ASSOC 0x0c8f
/**
* struct intel_pqr_state - State cache for the PQR MSR
* @rmid: The cached Resource Monitoring ID
* @closid: The 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.
*
* The cache also helps to avoid pointless updates if the value does
* not change.
*/
struct intel_pqr_state {
u32 rmid;
u32 closid;
};
DECLARE_PER_CPU(struct intel_pqr_state, pqr_state);
DECLARE_PER_CPU_READ_MOSTLY(int, cpu_closid);
DECLARE_STATIC_KEY_FALSE(rdt_enable_key);
/*
* intel_rdt_sched_in() - Writes the task's CLOSid 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 and we enable by mounting the
* resctrl file system.
* - Caches the per cpu CLOSid values and does the MSR write only
* when a task with a different CLOSid is scheduled in.
*
* Must be called with preemption disabled.
*/
static inline void intel_rdt_sched_in(void)
{
if (static_branch_likely(&rdt_enable_key)) {
struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);
int closid;
/*
* If this task has a closid assigned, use it.
* Else use the closid assigned to this cpu.
*/
closid = current->closid;
if (closid == 0)
closid = this_cpu_read(cpu_closid);
if (closid != state->closid) {
state->closid = closid;
wrmsr(IA32_PQR_ASSOC, state->rmid, closid);
}
}
}
#else
static inline void intel_rdt_sched_in(void) {}
#endif /* CONFIG_INTEL_RDT */
#endif /* _ASM_X86_INTEL_RDT_SCHED_H */
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