[PATCH v5 21/40] x86/resctrl: Change mon_event_config_{read,write}() to be arch helpers

From: James Morse
Date: Fri Oct 04 2024 - 14:09:31 EST

mon_event_config_{read,write}() are called via IPI and access model
specific registers to do their work.

To support another architecture, this needs abstracting.

Rename mon_event_config_{read,write}() to have a "resctrl_arch_"
prefix, and move their struct mon_config_info parameter into
<linux/resctrl.h>. This allows another architecture to supply an
implementation of these.

As struct mon_config_info is now exposed globally, give it a 'resctrl_'
prefix. MPAM systems need access to the domain to do this work, add
the resource and domain to struct resctrl_mon_config_info.

Co-developed-by: Dave Martin <Dave.Martin@xxxxxxx>
Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
Tested-by: Carl Worth <carl@xxxxxxxxxxxxxxxxxxxxxx> # arm64
Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
Reviewed-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
---
Changes since v3:
* Added comments over the read/write helper to explain the type of the void
pointer.

Changes since v1:
* [Whitespace only] Re-tabbed struct resctrl_mon_config_info in
<linux/resctrl.h> to fit the prevailing style.

Non-functional change.

* [Commit message only] Reword to align with the actual naming of the
definitions and destination header file.
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 34 +++++++++++++-------------
include/linux/resctrl.h | 25 +++++++++++++++++++
2 files changed, 42 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 9294bf74f3a8..304fdf199de7 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1571,11 +1571,6 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
return ret;
}

-struct mon_config_info {
- u32 evtid;
- u32 mon_config;
-};
-
#define INVALID_CONFIG_INDEX UINT_MAX

/**
@@ -1600,9 +1595,9 @@ static inline unsigned int mon_event_config_index_get(u32 evtid)
}
}

-static void mon_event_config_read(void *info)
+void resctrl_arch_mon_event_config_read(void *info)
{
- struct mon_config_info *mon_info = info;
+ struct resctrl_mon_config_info *mon_info = info;
unsigned int index;
u64 msrval;

@@ -1617,14 +1612,15 @@ static void mon_event_config_read(void *info)
mon_info->mon_config = msrval & MAX_EVT_CONFIG_BITS;
}

-static void mondata_config_read(struct rdt_mon_domain *d, struct mon_config_info *mon_info)
+static void mondata_config_read(struct resctrl_mon_config_info *mon_info)
{
- smp_call_function_any(&d->hdr.cpu_mask, mon_event_config_read, mon_info, 1);
+ smp_call_function_any(&mon_info->d->hdr.cpu_mask,
+ resctrl_arch_mon_event_config_read, mon_info, 1);
}

static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid)
{
- struct mon_config_info mon_info;
+ struct resctrl_mon_config_info mon_info;
struct rdt_mon_domain *dom;
bool sep = false;

@@ -1635,9 +1631,11 @@ static int mbm_config_show(struct seq_file *s, struct rdt_resource *r, u32 evtid
if (sep)
seq_puts(s, ";");

- memset(&mon_info, 0, sizeof(struct mon_config_info));
+ memset(&mon_info, 0, sizeof(struct resctrl_mon_config_info));
+ mon_info.r = r;
+ mon_info.d = dom;
mon_info.evtid = evtid;
- mondata_config_read(dom, &mon_info);
+ mondata_config_read(&mon_info);

seq_printf(s, "%d=0x%02x", dom->hdr.id, mon_info.mon_config);
sep = true;
@@ -1670,9 +1668,9 @@ static int mbm_local_bytes_config_show(struct kernfs_open_file *of,
return 0;
}

-static void mon_event_config_write(void *info)
+void resctrl_arch_mon_event_config_write(void *info)
{
- struct mon_config_info *mon_info = info;
+ struct resctrl_mon_config_info *mon_info = info;
unsigned int index;

index = mon_event_config_index_get(mon_info->evtid);
@@ -1686,14 +1684,16 @@ static void mon_event_config_write(void *info)
static void mbm_config_write_domain(struct rdt_resource *r,
struct rdt_mon_domain *d, u32 evtid, u32 val)
{
- struct mon_config_info mon_info = {0};
+ struct resctrl_mon_config_info mon_info = {0};

/*
* Read the current config value first. If both are the same then
* no need to write it again.
*/
+ mon_info.r = r;
+ mon_info.d = d;
mon_info.evtid = evtid;
- mondata_config_read(d, &mon_info);
+ mondata_config_read(&mon_info);
if (mon_info.mon_config == val)
return;

@@ -1705,7 +1705,7 @@ static void mbm_config_write_domain(struct rdt_resource *r,
* are scoped at the domain level. Writing any of these MSRs
* on one CPU is observed by all the CPUs in the domain.
*/
- smp_call_function_any(&d->hdr.cpu_mask, mon_event_config_write,
+ smp_call_function_any(&d->hdr.cpu_mask, resctrl_arch_mon_event_config_write,
&mon_info, 1);

/*
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 224a14d9aa7a..0072c2e5947f 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -271,6 +271,13 @@ struct resctrl_cpu_defaults {
u32 rmid;
};

+struct resctrl_mon_config_info {
+ struct rdt_resource *r;
+ struct rdt_mon_domain *d;
+ u32 evtid;
+ u32 mon_config;
+};
+
/**
* resctrl_arch_sync_cpu_closid_rmid() - Refresh this CPU's CLOSID and RMID.
* Call via IPI.
@@ -315,6 +322,24 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);

bool __init resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);

+/**
+ * resctrl_arch_mon_event_config_write() - Write the config for a counter.
+ * @info: struct resctrl_mon_config_info describing the resource, domain
+ * and event.
+ *
+ * Must be called on a CPU that is a member of the specified domain.
+ */
+void resctrl_arch_mon_event_config_write(void *info);
+
+/**
+ * resctrl_arch_mon_event_config_read() - Read the config for a counter.
+ * @info: struct resctrl_mon_config_info describing the resource, domain
+ * and event.
+ *
+ * Must be called on a CPU that is a member of the specified domain.
+ */
+void resctrl_arch_mon_event_config_read(void *info);
+
/*
* Update the ctrl_val and apply this config right now.
* Must be called on one of the domain's CPUs.
--
2.39.2