x86/resctrl: Add a helper to read a closid's configuration

Functions like show_doms() reach into the architecture's private
structure to retrieve the configuration from the struct rdt_hw_resource.

The hardware configuration may look completely different to the
values resctrl gets from user-space. The staged configuration and
resctrl_arch_update_domains() allow the architecture to convert or
translate these values.

Resctrl shouldn't read or write the ctrl_val[] values directly. Add
a helper to read the current configuration. This will allow another
architecture to scale the bitmaps if necessary, and possibly use
controls that don't take the user-space control format at all.

Of the remaining functions that access ctrl_val[] directly,
apply_config() is part of the architecture-specific code, and is
called via resctrl_arch_update_domains(). reset_all_ctrls() will be an
architecture specific helper.

update_mba_bw() manipulates both ctrl_val[], mbps_val[] and the
hardware. The mbps_val[] that matches the mba_sc state of the resource
is changed, but the other is left unchanged. Abstracting this is the
subject of later patches that affect set_mba_sc() too.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jamie Iles <jamie@nuviainc.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lkml.kernel.org/r/20210728170637.25610-17-james.morse@arm.com

diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 8cde76d..4da08ba 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -401,22 +401,30 @@ out:
        return ret ?: nbytes;
 }
 
+void resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
+                            u32 closid, u32 *value)
+{
+       struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
+
+       if (!is_mba_sc(r))
+               *value = hw_dom->ctrl_val[closid];
+       else
+               *value = hw_dom->mbps_val[closid];
+}
+
 static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid)
 {
        struct rdt_resource *r = schema->res;
-       struct rdt_hw_domain *hw_dom;
        struct rdt_domain *dom;
        bool sep = false;
        u32 ctrl_val;
 
        seq_printf(s, "%*s:", max_name_width, schema->name);
        list_for_each_entry(dom, &r->domains, list) {
-               hw_dom = resctrl_to_arch_dom(dom);
                if (sep)
                        seq_puts(s, ";");
 
-               ctrl_val = (!is_mba_sc(r) ? hw_dom->ctrl_val[closid] :
-                           hw_dom->mbps_val[closid]);
+               resctrl_arch_get_config(r, dom, closid, &ctrl_val);
                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 26a0948..e45e715 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -442,8 +442,12 @@ 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 = hw_dom_mba->mbps_val[closid];
+       resctrl_arch_get_config(r_mba, dom_mba, closid, &user_bw);
        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];
 
        /*

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 4b6de76..6b2be56 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -910,27 +910,27 @@ static int rdt_bit_usage_show(struct kernfs_open_file *of,
        int i, hwb, swb, excl, psl;
        enum rdtgrp_mode mode;
        bool sep = false;
-       u32 *ctrl;
+       u32 ctrl_val;
 
        mutex_lock(&rdtgroup_mutex);
        hw_shareable = r->cache.shareable_bits;
        list_for_each_entry(dom, &r->domains, list) {
                if (sep)
                        seq_putc(seq, ';');
-               ctrl = resctrl_to_arch_dom(dom)->ctrl_val;
                sw_shareable = 0;
                exclusive = 0;
                seq_printf(seq, "%d=", dom->id);
-               for (i = 0; i < closids_supported(); i++, ctrl++) {
+               for (i = 0; i < closids_supported(); i++) {
                        if (!closid_allocated(i))
                                continue;
+                       resctrl_arch_get_config(r, dom, i, &ctrl_val);
                        mode = rdtgroup_mode_by_closid(i);
                        switch (mode) {
                        case RDT_MODE_SHAREABLE:
-                               sw_shareable |= *ctrl;
+                               sw_shareable |= ctrl_val;
                                break;
                        case RDT_MODE_EXCLUSIVE:
-                               exclusive |= *ctrl;
+                               exclusive |= ctrl_val;
                                break;
                        case RDT_MODE_PSEUDO_LOCKSETUP:
                        /*
@@ -1188,7 +1188,6 @@ static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d
 {
        enum rdtgrp_mode mode;
        unsigned long ctrl_b;
-       u32 *ctrl;
        int i;
 
        /* Check for any overlap with regions used by hardware directly */
@@ -1199,9 +1198,8 @@ static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d
        }
 
        /* Check for overlap with other resource groups */
-       ctrl = resctrl_to_arch_dom(d)->ctrl_val;
-       for (i = 0; i < closids_supported(); i++, ctrl++) {
-               ctrl_b = *ctrl;
+       for (i = 0; i < closids_supported(); i++) {
+               resctrl_arch_get_config(r, d, i, (u32 *)&ctrl_b);
                mode = rdtgroup_mode_by_closid(i);
                if (closid_allocated(i) && i != closid &&
                    mode != RDT_MODE_PSEUDO_LOCKSETUP) {
@@ -1269,12 +1267,12 @@ bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_domain *d,
  */
 static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
 {
-       struct rdt_hw_domain *hw_dom;
        int closid = rdtgrp->closid;
        struct resctrl_schema *s;
        struct rdt_resource *r;
        bool has_cache = false;
        struct rdt_domain *d;
+       u32 ctrl;
 
        list_for_each_entry(s, &resctrl_schema_all, list) {
                r = s->res;
@@ -1282,10 +1280,8 @@ static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)
                        continue;
                has_cache = true;
                list_for_each_entry(d, &r->domains, list) {
-                       hw_dom = resctrl_to_arch_dom(d);
-                       if (rdtgroup_cbm_overlaps(s, d,
-                                                 hw_dom->ctrl_val[closid],
-                                                 rdtgrp->closid, false)) {
+                       resctrl_arch_get_config(r, d, closid, &ctrl);
+                       if (rdtgroup_cbm_overlaps(s, d, ctrl, closid, false)) {
                                rdt_last_cmd_puts("Schemata overlaps\n");
                                return false;
                        }
@@ -1417,7 +1413,6 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
                              struct seq_file *s, void *v)
 {
        struct resctrl_schema *schema;
-       struct rdt_hw_domain *hw_dom;
        struct rdtgroup *rdtgrp;
        struct rdt_resource *r;
        struct rdt_domain *d;
@@ -1453,15 +1448,13 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
                sep = false;
                seq_printf(s, "%*s:", max_name_width, schema->name);
                list_for_each_entry(d, &r->domains, list) {
-                       hw_dom = resctrl_to_arch_dom(d);
                        if (sep)
                                seq_putc(s, ';');
                        if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
                                size = 0;
                        } else {
-                               ctrl = (!is_mba_sc(r) ?
-                                               hw_dom->ctrl_val[rdtgrp->closid] :
-                                               hw_dom->mbps_val[rdtgrp->closid]);
+                               resctrl_arch_get_config(r, d, rdtgrp->closid,
+                                                       &ctrl);
                                if (r->rid == RDT_RESOURCE_MBA)
                                        size = ctrl;
                                else
@@ -2759,7 +2752,7 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
        u32 used_b = 0, unused_b = 0;
        unsigned long tmp_cbm;
        enum rdtgrp_mode mode;
-       u32 peer_ctl, *ctrl;
+       u32 peer_ctl, ctrl_val;
        int i;
 
        rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp);
@@ -2767,8 +2760,7 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
        cfg->have_new_ctrl = false;
        cfg->new_ctrl = r->cache.shareable_bits;
        used_b = r->cache.shareable_bits;
-       ctrl = resctrl_to_arch_dom(d)->ctrl_val;
-       for (i = 0; i < closids_supported(); i++, ctrl++) {
+       for (i = 0; i < closids_supported(); i++) {
                if (closid_allocated(i) && i != closid) {
                        mode = rdtgroup_mode_by_closid(i);
                        if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
@@ -2784,12 +2776,13 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
                         * with an exclusive group.
                         */
                        if (d_cdp)
-                               peer_ctl = resctrl_to_arch_dom(d_cdp)->ctrl_val[i];
+                               resctrl_arch_get_config(r_cdp, d_cdp, i, &peer_ctl);
                        else
                                peer_ctl = 0;
-                       used_b |= *ctrl | peer_ctl;
+                       resctrl_arch_get_config(r, d, i, &ctrl_val);
+                       used_b |= ctrl_val | peer_ctl;
                        if (mode == RDT_MODE_SHAREABLE)
-                               cfg->new_ctrl |= *ctrl | peer_ctl;
+                               cfg->new_ctrl |= ctrl_val | peer_ctl;
                }
        }
        if (d->plr && d->plr->cbm > 0)

diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index be58811..3a23094 100644 (file)
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -200,5 +200,7 @@ struct resctrl_schema {
 /* The number of closid supported by this resource regardless of CDP */
 u32 resctrl_arch_get_num_closid(struct rdt_resource *r);
 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
+void resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
+                            u32 closid, u32 *value);
 
 #endif /* _RESCTRL_H */