[PATCH 16/28] x86/intel_rdt: Prepare to add RDT monitor cpus file support

From: Vikas Shivappa
Date: Tue Jul 25 2017 - 17:18:39 EST


Separate the ctrl cpus file handling from the generic cpus file handling
and convert the per cpu closid from u32 to a struct which will be used
later to add rmid to the same struct. Also cleanup some name space.

Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/intel_rdt_sched.h | 4 +-
arch/x86/kernel/cpu/intel_rdt.c | 6 +-
arch/x86/kernel/cpu/intel_rdt.h | 2 -
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 103 +++++++++++++++++--------------
4 files changed, 62 insertions(+), 53 deletions(-)

diff --git a/arch/x86/include/asm/intel_rdt_sched.h b/arch/x86/include/asm/intel_rdt_sched.h
index 1d8d45a..2c704d2 100644
--- a/arch/x86/include/asm/intel_rdt_sched.h
+++ b/arch/x86/include/asm/intel_rdt_sched.h
@@ -26,7 +26,7 @@ struct intel_pqr_state {
};

DECLARE_PER_CPU(struct intel_pqr_state, pqr_state);
-DECLARE_PER_CPU_READ_MOSTLY(int, cpu_closid);
+DECLARE_PER_CPU_READ_MOSTLY(struct intel_pqr_state, rdt_cpu_default);
DECLARE_STATIC_KEY_FALSE(rdt_alloc_enable_key);

/*
@@ -54,7 +54,7 @@ static inline void intel_rdt_sched_in(void)
*/
closid = current->closid;
if (closid == 0)
- closid = this_cpu_read(cpu_closid);
+ closid = this_cpu_read(rdt_cpu_default.closid);

if (closid != state->closid) {
state->closid = closid;
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index eab2467..cd48ec9 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -39,8 +39,6 @@
/* Mutex to protect rdtgroup access. */
DEFINE_MUTEX(rdtgroup_mutex);

-DEFINE_PER_CPU_READ_MOSTLY(int, cpu_closid);
-
/*
* The cached intel_pqr_state is strictly per CPU and can never be
* updated from a remote CPU. Functions which modify the state
@@ -49,6 +47,8 @@
*/
DEFINE_PER_CPU(struct intel_pqr_state, pqr_state);

+DEFINE_PER_CPU_READ_MOSTLY(struct intel_pqr_state, rdt_cpu_default);
+
/*
* Used to store the max resource name width and max resource data width
* to display the schemata in a tabular format
@@ -500,7 +500,7 @@ static void clear_closid(int cpu)
{
struct intel_pqr_state *state = this_cpu_ptr(&pqr_state);

- per_cpu(cpu_closid, cpu) = 0;
+ per_cpu(rdt_cpu_default.closid, cpu) = 0;
state->closid = 0;
wrmsr(IA32_PQR_ASSOC, state->rmid, 0);
}
diff --git a/arch/x86/kernel/cpu/intel_rdt.h b/arch/x86/kernel/cpu/intel_rdt.h
index b2a2de3..6f07047 100644
--- a/arch/x86/kernel/cpu/intel_rdt.h
+++ b/arch/x86/kernel/cpu/intel_rdt.h
@@ -320,8 +320,6 @@ enum {
unsigned int full;
};

-DECLARE_PER_CPU_READ_MOSTLY(int, cpu_closid);
-
void rdt_ctrl_update(void *arg);
struct rdtgroup *rdtgroup_kn_lock_live(struct kernfs_node *kn);
void rdtgroup_kn_unlock(struct kernfs_node *kn);
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index d02596e9..7f8f52d 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -181,13 +181,16 @@ static int rdtgroup_cpus_show(struct kernfs_open_file *of,
/*
* This is safe against intel_rdt_sched_in() called from __switch_to()
* because __switch_to() is executed with interrupts disabled. A local call
- * from rdt_update_closid() is proteced against __switch_to() because
+ * from update_closid() is proteced against __switch_to() because
* preemption is disabled.
*/
-static void rdt_update_cpu_closid(void *closid)
+static void update_cpu_closid(void *info)
{
- if (closid)
- this_cpu_write(cpu_closid, *(int *)closid);
+ struct rdtgroup *r = info;
+
+ if (r)
+ this_cpu_write(rdt_cpu_default.closid, r->closid);
+
/*
* We cannot unconditionally write the MSR because the current
* executing task might have its own closid selected. Just reuse
@@ -199,28 +202,62 @@ static void rdt_update_cpu_closid(void *closid)
/*
* Update the PGR_ASSOC MSR on all cpus in @cpu_mask,
*
- * Per task closids must have been set up before calling this function.
- *
- * The per cpu closids are updated with the smp function call, when @closid
- * is not NULL. If @closid is NULL then all affected percpu closids must
- * have been set up before calling this function.
+ * Per task closids/rmids must have been set up before calling this function.
*/
static void
-rdt_update_closid(const struct cpumask *cpu_mask, int *closid)
+update_closid(const struct cpumask *cpu_mask, struct rdtgroup *r)
{
int cpu = get_cpu();

if (cpumask_test_cpu(cpu, cpu_mask))
- rdt_update_cpu_closid(closid);
- smp_call_function_many(cpu_mask, rdt_update_cpu_closid, closid, 1);
+ update_cpu_closid(r);
+ smp_call_function_many(cpu_mask, update_cpu_closid, r, 1);
put_cpu();
}

+static int cpus_ctrl_write(struct rdtgroup *rdtgrp, cpumask_var_t newmask,
+ cpumask_var_t tmpmask)
+{
+ struct rdtgroup *r;
+
+ /* Check whether cpus are dropped from this group */
+ cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
+ if (cpumask_weight(tmpmask)) {
+ /* Can't drop from default group */
+ if (rdtgrp == &rdtgroup_default)
+ return -EINVAL;
+
+ /* Give any dropped cpus to rdtgroup_default */
+ cpumask_or(&rdtgroup_default.cpu_mask,
+ &rdtgroup_default.cpu_mask, tmpmask);
+ update_closid(tmpmask, &rdtgroup_default);
+ }
+
+ /*
+ * If we added cpus, remove them from previous group that owned them
+ * and update per-cpu closid
+ */
+ cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
+ if (cpumask_weight(tmpmask)) {
+ list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
+ if (r == rdtgrp)
+ continue;
+ cpumask_andnot(&r->cpu_mask, &r->cpu_mask, tmpmask);
+ }
+ update_closid(tmpmask, rdtgrp);
+ }
+
+ /* Done pushing/pulling - update this group with new mask */
+ cpumask_copy(&rdtgrp->cpu_mask, newmask);
+
+ return 0;
+}
+
static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
char *buf, size_t nbytes, loff_t off)
{
cpumask_var_t tmpmask, newmask;
- struct rdtgroup *rdtgrp, *r;
+ struct rdtgroup *rdtgrp;
int ret;

if (!buf)
@@ -254,36 +291,10 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of,
goto unlock;
}

- /* Check whether cpus are dropped from this group */
- cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask);
- if (cpumask_weight(tmpmask)) {
- /* Can't drop from default group */
- if (rdtgrp == &rdtgroup_default) {
- ret = -EINVAL;
- goto unlock;
- }
- /* Give any dropped cpus to rdtgroup_default */
- cpumask_or(&rdtgroup_default.cpu_mask,
- &rdtgroup_default.cpu_mask, tmpmask);
- rdt_update_closid(tmpmask, &rdtgroup_default.closid);
- }
-
- /*
- * If we added cpus, remove them from previous group that owned them
- * and update per-cpu closid
- */
- cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask);
- if (cpumask_weight(tmpmask)) {
- list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) {
- if (r == rdtgrp)
- continue;
- cpumask_andnot(&r->cpu_mask, &r->cpu_mask, tmpmask);
- }
- rdt_update_closid(tmpmask, &rdtgrp->closid);
- }
-
- /* Done pushing/pulling - update this group with new mask */
- cpumask_copy(&rdtgrp->cpu_mask, newmask);
+ if (rdtgrp->type == RDTCTRL_GROUP)
+ ret = cpus_ctrl_write(rdtgrp, newmask, tmpmask);
+ else
+ ret = -EINVAL;

unlock:
rdtgroup_kn_unlock(of->kn);
@@ -1103,7 +1114,7 @@ static void rmdir_all_sub(void)
}
/* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
get_online_cpus();
- rdt_update_closid(cpu_online_mask, &rdtgroup_default.closid);
+ update_closid(cpu_online_mask, &rdtgroup_default);
put_online_cpus();

kernfs_remove(kn_info);
@@ -1360,13 +1371,13 @@ static int rdtgroup_rmdir(struct kernfs_node *kn)

/* Update per cpu closid of the moved CPUs first */
for_each_cpu(cpu, &rdtgrp->cpu_mask)
- per_cpu(cpu_closid, cpu) = closid;
+ per_cpu(rdt_cpu_default.closid, cpu) = closid;
/*
* Update the MSR on moved CPUs and CPUs which have moved
* task running on them.
*/
cpumask_or(tmpmask, tmpmask, &rdtgrp->cpu_mask);
- rdt_update_closid(tmpmask, NULL);
+ update_closid(tmpmask, NULL);

rdtgrp->flags = RDT_DELETED;
closid_free(rdtgrp->closid);
--
1.9.1