From e3ca96e479c91d6ee657d3caa5092a6a3a620f9f Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Fri, 8 Mar 2024 13:38:45 -0800 Subject: x86/resctrl: Pass domain to target CPU reset_all_ctrls() and resctrl_arch_update_domains() use on_each_cpu_mask() to call rdt_ctrl_update() on potentially one CPU from each domain. But this means rdt_ctrl_update() needs to figure out which domain to apply changes to. Doing so requires a search of all domains in a resource, which can only be done safely if cpus_lock is held. Both callers do hold this lock, but there isn't a way for a function called on another CPU via IPI to verify this. Commit c0d848fcb09d ("x86/resctrl: Remove lockdep annotation that triggers false positive") removed the incorrect assertions. Add the target domain to the msr_param structure and call rdt_ctrl_update() for each domain separately using smp_call_function_single(). This means that rdt_ctrl_update() doesn't need to search for the domain and get_domain_from_cpu() can safely assert that the cpus_lock is held since the remaining callers do not use IPI. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: James Morse Reviewed-by: Babu Moger Tested-by: Maciej Wieczor-Retman Link: https://lore.kernel.org/r/20240308213846.77075-2-tony.luck@intel.com --- arch/x86/kernel/cpu/resctrl/core.c | 17 +++++--------- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 38 ++++++------------------------- arch/x86/kernel/cpu/resctrl/internal.h | 2 ++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 ++-------- 4 files changed, 17 insertions(+), 52 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 83e40341583e..acf52aa185e0 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -362,6 +362,8 @@ struct rdt_domain *get_domain_from_cpu(int cpu, struct rdt_resource *r) { struct rdt_domain *d; + lockdep_assert_cpus_held(); + list_for_each_entry(d, &r->domains, list) { /* Find the domain that contains this CPU */ if (cpumask_test_cpu(cpu, &d->cpu_mask)) @@ -378,19 +380,11 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *r) void rdt_ctrl_update(void *arg) { + struct rdt_hw_resource *hw_res; struct msr_param *m = arg; - struct rdt_hw_resource *hw_res = resctrl_to_arch_res(m->res); - struct rdt_resource *r = m->res; - int cpu = smp_processor_id(); - struct rdt_domain *d; - d = get_domain_from_cpu(cpu, r); - if (d) { - hw_res->msr_update(d, m, r); - return; - } - pr_warn_once("cpu %d not found in any domain for resource %s\n", - cpu, r->name); + hw_res = resctrl_to_arch_res(m->res); + hw_res->msr_update(m->dom, m, m->res); } /* @@ -463,6 +457,7 @@ static int domain_setup_ctrlval(struct rdt_resource *r, struct rdt_domain *d) hw_dom->ctrl_val = dc; setup_default_ctrlval(r, dc); + m.dom = d; m.low = 0; m.high = hw_res->num_closid; hw_res->msr_update(d, &m, r); diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 7997b47743a2..165d8d453c04 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -272,22 +272,6 @@ static u32 get_config_index(u32 closid, enum resctrl_conf_type type) } } -static bool apply_config(struct rdt_hw_domain *hw_dom, - struct resctrl_staged_config *cfg, u32 idx, - cpumask_var_t cpu_mask) -{ - struct rdt_domain *dom = &hw_dom->d_resctrl; - - if (cfg->new_ctrl != hw_dom->ctrl_val[idx]) { - cpumask_set_cpu(cpumask_any(&dom->cpu_mask), cpu_mask); - hw_dom->ctrl_val[idx] = cfg->new_ctrl; - - return true; - } - - return false; -} - int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d, u32 closid, enum resctrl_conf_type t, u32 cfg_val) { @@ -302,6 +286,7 @@ int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d, hw_dom->ctrl_val[idx] = cfg_val; msr_param.res = r; + msr_param.dom = d; msr_param.low = idx; msr_param.high = idx + 1; hw_res->msr_update(d, &msr_param, r); @@ -315,48 +300,39 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) struct rdt_hw_domain *hw_dom; struct msr_param msr_param; enum resctrl_conf_type t; - cpumask_var_t cpu_mask; struct rdt_domain *d; u32 idx; /* Walking r->domains, ensure it can't race with cpuhp */ lockdep_assert_cpus_held(); - if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) - return -ENOMEM; - - msr_param.res = NULL; list_for_each_entry(d, &r->domains, list) { hw_dom = resctrl_to_arch_dom(d); + msr_param.res = NULL; for (t = 0; t < CDP_NUM_TYPES; t++) { cfg = &hw_dom->d_resctrl.staged_config[t]; if (!cfg->have_new_ctrl) continue; idx = get_config_index(closid, t); - if (!apply_config(hw_dom, cfg, idx, cpu_mask)) + if (cfg->new_ctrl == hw_dom->ctrl_val[idx]) continue; + hw_dom->ctrl_val[idx] = cfg->new_ctrl; if (!msr_param.res) { msr_param.low = idx; msr_param.high = msr_param.low + 1; msr_param.res = r; + msr_param.dom = d; } else { msr_param.low = min(msr_param.low, idx); msr_param.high = max(msr_param.high, idx + 1); } } + if (msr_param.res) + smp_call_function_any(&d->cpu_mask, rdt_ctrl_update, &msr_param, 1); } - if (cpumask_empty(cpu_mask)) - goto done; - - /* Update resource control msr on all the CPUs. */ - on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1); - -done: - free_cpumask_var(cpu_mask); - return 0; } diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index 1a8687f8073a..ab2d315f7a2e 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -379,11 +379,13 @@ static inline struct rdt_hw_domain *resctrl_to_arch_dom(struct rdt_domain *r) /** * struct msr_param - set a range of MSRs from a domain * @res: The resource to use + * @dom: The domain to update * @low: Beginning index from base MSR * @high: End index */ struct msr_param { struct rdt_resource *res; + struct rdt_domain *dom; u32 low; u32 high; }; diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 011e17efb1a6..02f213f1c51c 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2813,16 +2813,12 @@ static int reset_all_ctrls(struct rdt_resource *r) struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r); struct rdt_hw_domain *hw_dom; struct msr_param msr_param; - cpumask_var_t cpu_mask; struct rdt_domain *d; int i; /* Walking r->domains, ensure it can't race with cpuhp */ lockdep_assert_cpus_held(); - if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) - return -ENOMEM; - msr_param.res = r; msr_param.low = 0; msr_param.high = hw_res->num_closid; @@ -2834,17 +2830,13 @@ static int reset_all_ctrls(struct rdt_resource *r) */ list_for_each_entry(d, &r->domains, list) { hw_dom = resctrl_to_arch_dom(d); - cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask); for (i = 0; i < hw_res->num_closid; i++) hw_dom->ctrl_val[i] = r->default_ctrl; + msr_param.dom = d; + smp_call_function_any(&d->cpu_mask, rdt_ctrl_update, &msr_param, 1); } - /* Update CBM on all the CPUs in cpu_mask */ - on_each_cpu_mask(cpu_mask, rdt_ctrl_update, &msr_param, 1); - - free_cpumask_var(cpu_mask); - return 0; } -- cgit v1.2.3