From 6ce1560d35f63a458fead11ac865bc39cea9bc46 Mon Sep 17 00:00:00 2001 From: James Morse Date: Fri, 2 Sep 2022 15:48:17 +0000 Subject: [PATCH] x86/resctrl: Switch over to the resctrl mbps_val list Updates to resctrl's software controller follow the same path as other configuration updates, but they don't modify the hardware state. rdtgroup_schemata_write() uses parse_line() and the resource's parse_ctrlval() function to stage the configuration. resctrl_arch_update_domains() then updates the mbps_val[] array instead, and resctrl_arch_update_domains() skips the rdt_ctrl_update() call that would update hardware. This complicates the interface between resctrl's filesystem parts and architecture specific code. It should be possible for mba_sc to be completely implemented by the filesystem parts of resctrl. This would allow it to work on a second architecture with no additional code. resctrl_arch_update_domains() using the mbps_val[] array prevents this. Change parse_bw() to write the configuration value directly to the mbps_val[] array in the domain structure. Change rdtgroup_schemata_write() to skip the call to resctrl_arch_update_domains(), meaning all the mba_sc specific code in resctrl_arch_update_domains() can be removed. On the read-side, show_doms() and update_mba_bw() are changed to read the mbps_val[] array from the domain structure. With this, resctrl_arch_get_config() no longer needs to consider mba_sc resources. Signed-off-by: James Morse Signed-off-by: Borislav Petkov Reviewed-by: Jamie Iles Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Tested-by: Xin Hao Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Link: https://lore.kernel.org/r/20220902154829.30399-10-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 44 ++++++++++++++--------- arch/x86/kernel/cpu/resctrl/monitor.c | 10 +++--- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 27 ++++++++++---- 3 files changed, 52 insertions(+), 29 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c index 87666275eed9..bf9d73c5be14 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -61,6 +61,7 @@ int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, struct rdt_domain *d) { struct resctrl_staged_config *cfg; + u32 closid = data->rdtgrp->closid; struct rdt_resource *r = s->res; unsigned long bw_val; @@ -72,6 +73,12 @@ int parse_bw(struct rdt_parse_data *data, struct resctrl_schema *s, if (!bw_validate(data->buf, &bw_val, r)) return -EINVAL; + + if (is_mba_sc(r)) { + d->mbps_val[closid] = bw_val; + return 0; + } + cfg->new_ctrl = bw_val; cfg->have_new_ctrl = true; @@ -261,14 +268,13 @@ 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, bool mba_sc) + cpumask_var_t cpu_mask) { struct rdt_domain *dom = &hw_dom->d_resctrl; - u32 *dc = !mba_sc ? hw_dom->ctrl_val : hw_dom->mbps_val; - if (cfg->new_ctrl != dc[idx]) { + if (cfg->new_ctrl != hw_dom->ctrl_val[idx]) { cpumask_set_cpu(cpumask_any(&dom->cpu_mask), cpu_mask); - dc[idx] = cfg->new_ctrl; + hw_dom->ctrl_val[idx] = cfg->new_ctrl; return true; } @@ -284,14 +290,12 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) enum resctrl_conf_type t; cpumask_var_t cpu_mask; struct rdt_domain *d; - bool mba_sc; int cpu; u32 idx; if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL)) return -ENOMEM; - mba_sc = is_mba_sc(r); msr_param.res = NULL; list_for_each_entry(d, &r->domains, list) { hw_dom = resctrl_to_arch_dom(d); @@ -301,7 +305,7 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) continue; idx = get_config_index(closid, t); - if (!apply_config(hw_dom, cfg, idx, cpu_mask, mba_sc)) + if (!apply_config(hw_dom, cfg, idx, cpu_mask)) continue; if (!msr_param.res) { @@ -315,11 +319,7 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid) } } - /* - * Avoid writing the control msr with control values when - * MBA software controller is enabled - */ - if (cpumask_empty(cpu_mask) || mba_sc) + if (cpumask_empty(cpu_mask)) goto done; cpu = get_cpu(); /* Update resource control msr on this CPU if it's in cpu_mask. */ @@ -406,6 +406,14 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of, list_for_each_entry(s, &resctrl_schema_all, list) { r = s->res; + + /* + * Writes to mba_sc resources update the software controller, + * not the control MSR. + */ + if (is_mba_sc(r)) + continue; + ret = resctrl_arch_update_domains(r, rdtgrp->closid); if (ret) goto out; @@ -433,9 +441,7 @@ u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d, struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d); u32 idx = get_config_index(closid, type); - if (!is_mba_sc(r)) - return hw_dom->ctrl_val[idx]; - return hw_dom->mbps_val[idx]; + return hw_dom->ctrl_val[idx]; } static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid) @@ -450,8 +456,12 @@ static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int clo if (sep) seq_puts(s, ";"); - ctrl_val = resctrl_arch_get_config(r, dom, closid, - schema->conf_type); + if (is_mba_sc(r)) + ctrl_val = dom->mbps_val[closid]; + else + ctrl_val = resctrl_arch_get_config(r, dom, closid, + schema->conf_type); + seq_printf(s, r->format_str, dom->id, max_data_width, ctrl_val); sep = true; diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c index 497cadf3285d..16028b2f756a 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -447,13 +447,11 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm) hw_dom_mba = resctrl_to_arch_dom(dom_mba); cur_bw = pmbm_data->prev_bw; - user_bw = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE); + user_bw = dom_mba->mbps_val[closid]; delta_bw = pmbm_data->delta_bw; - /* - * resctrl_arch_get_config() chooses the mbps/ctrl value to return - * based on is_mba_sc(). For now, reach into the hw_dom. - */ - cur_msr_val = hw_dom_mba->ctrl_val[closid]; + + /* MBA resource doesn't support CDP */ + cur_msr_val = resctrl_arch_get_config(r_mba, dom_mba, closid, CDP_NONE); /* * For Ctrl groups read data from child monitor groups. diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index f7ebd019e7a5..55d8a12287c3 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1356,11 +1356,13 @@ static int rdtgroup_size_show(struct kernfs_open_file *of, struct seq_file *s, void *v) { struct resctrl_schema *schema; + enum resctrl_conf_type type; struct rdtgroup *rdtgrp; struct rdt_resource *r; struct rdt_domain *d; unsigned int size; int ret = 0; + u32 closid; bool sep; u32 ctrl; @@ -1386,8 +1388,11 @@ static int rdtgroup_size_show(struct kernfs_open_file *of, goto out; } + closid = rdtgrp->closid; + list_for_each_entry(schema, &resctrl_schema_all, list) { r = schema->res; + type = schema->conf_type; sep = false; seq_printf(s, "%*s:", max_name_width, schema->name); list_for_each_entry(d, &r->domains, list) { @@ -1396,9 +1401,12 @@ static int rdtgroup_size_show(struct kernfs_open_file *of, if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { size = 0; } else { - ctrl = resctrl_arch_get_config(r, d, - rdtgrp->closid, - schema->conf_type); + if (is_mba_sc(r)) + ctrl = d->mbps_val[closid]; + else + ctrl = resctrl_arch_get_config(r, d, + closid, + type); if (r->rid == RDT_RESOURCE_MBA) size = ctrl; else @@ -2818,14 +2826,19 @@ static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid) } /* Initialize MBA resource with default values. */ -static void rdtgroup_init_mba(struct rdt_resource *r) +static void rdtgroup_init_mba(struct rdt_resource *r, u32 closid) { struct resctrl_staged_config *cfg; struct rdt_domain *d; list_for_each_entry(d, &r->domains, list) { + if (is_mba_sc(r)) { + d->mbps_val[closid] = MBA_MAX_MBPS; + continue; + } + cfg = &d->staged_config[CDP_NONE]; - cfg->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl; + cfg->new_ctrl = r->default_ctrl; cfg->have_new_ctrl = true; } } @@ -2840,7 +2853,9 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp) list_for_each_entry(s, &resctrl_schema_all, list) { r = s->res; if (r->rid == RDT_RESOURCE_MBA) { - rdtgroup_init_mba(r); + rdtgroup_init_mba(r, rdtgrp->closid); + if (is_mba_sc(r)) + continue; } else { ret = rdtgroup_init_cat(s, rdtgrp->closid); if (ret < 0)