The following commit has been merged into the x86/cache branch of tip: Commit-ID: 1d81d15db39c2b517bc58f63008c6255dd08aafe Gitweb: https://git.kernel.org/tip/1d81d15db39c2b517bc58f63008c6255dd08aafe Author: James Morse <james.morse@xxxxxxx> AuthorDate: Fri, 02 Sep 2022 15:48:25 Committer: Borislav Petkov <bp@xxxxxxx> CommitterDate: Fri, 23 Sep 2022 14:22:20 +02:00 x86/resctrl: Move mbm_overflow_count() into resctrl_arch_rmid_read() resctrl_arch_rmid_read() is intended as the function that an architecture agnostic resctrl filesystem driver can use to read a value in bytes from a counter. Currently the function returns the MBM values in chunks directly from hardware. When reading a bandwidth counter, mbm_overflow_count() must be used to correct for any possible overflow. mbm_overflow_count() is architecture specific, its behaviour should be part of resctrl_arch_rmid_read(). Move the mbm_overflow_count() calls into resctrl_arch_rmid_read(). This allows the resctrl filesystems's prev_msr to be removed in favour of the architecture private version. Signed-off-by: James Morse <james.morse@xxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Reviewed-by: Jamie Iles <quic_jiles@xxxxxxxxxxx> Reviewed-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxx> Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Tested-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx> Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxx> Tested-by: Cristian Marussi <cristian.marussi@xxxxxxx> Link: https://lore.kernel.org/r/20220902154829.30399-18-james.morse@xxxxxxx --- arch/x86/kernel/cpu/resctrl/internal.h | 2 +- arch/x86/kernel/cpu/resctrl/monitor.c | 35 ++++++++++++++----------- 2 files changed, 20 insertions(+), 17 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 1d2e7bd..8039e8a 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -281,7 +281,6 @@ struct rftype { /** * struct mbm_state - status for each MBM counter in each domain * @chunks: Total data moved (multiply by rdt_group.mon_scale to get bytes) - * @prev_msr: Value of IA32_QM_CTR for this RMID last time we read it * @prev_bw_chunks: Previous chunks value read for bandwidth calculation * @prev_bw: The most recent bandwidth in MBps * @delta_bw: Difference between the current and previous bandwidth @@ -289,7 +288,6 @@ struct rftype { */ struct mbm_state { u64 chunks; - u64 prev_msr; u64 prev_bw_chunks; u32 prev_bw; u32 delta_bw; diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 262141b..862a446 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -167,9 +167,20 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, struct rdt_domain *d, memset(am, 0, sizeof(*am)); } +static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width) +{ + u64 shift = 64 - width, chunks; + + chunks = (cur_msr << shift) - (prev_msr << shift); + return chunks >> shift; +} + int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, u32 rmid, enum resctrl_event_id eventid, u64 *val) { + struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); + struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); + struct arch_mbm_state *am; u64 msr_val; if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask)) @@ -191,7 +202,13 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, if (msr_val & RMID_VAL_UNAVAIL) return -EINVAL; - *val = msr_val; + am = get_arch_mbm_state(hw_dom, rmid, eventid); + if (am) { + *val = mbm_overflow_count(am->prev_msr, msr_val, hw_res->mbm_width); + am->prev_msr = msr_val; + } else { + *val = msr_val; + } return 0; } @@ -322,19 +339,10 @@ void free_rmid(u32 rmid) list_add_tail(&entry->list, &rmid_free_lru); } -static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width) -{ - u64 shift = 64 - width, chunks; - - chunks = (cur_msr << shift) - (prev_msr << shift); - return chunks >> shift; -} - static int __mon_event_count(u32 rmid, struct rmid_read *rr) { - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r); struct mbm_state *m; - u64 chunks, tval = 0; + u64 tval = 0; if (rr->first) resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid); @@ -363,13 +371,10 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr) if (rr->first) { memset(m, 0, sizeof(struct mbm_state)); - m->prev_msr = tval; return 0; } - chunks = mbm_overflow_count(m->prev_msr, tval, hw_res->mbm_width); - m->chunks += chunks; - m->prev_msr = tval; + m->chunks += tval; rr->val += get_corrected_mbm_count(rmid, m->chunks);
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