[PATCH v1 09/31] x86/resctrl: Add a resctrl helper to reset all the resources

James Morse
2024-03-21T16:51:58Z

On umount(), resctrl resets each resource back to its default
configuration. It only ever does this for all resources in one go.

reset_all_ctrls() is architecture specific as it works with struct
rdt_hw_resource.

Add an architecture helper to reset all resources.

Signed-off-by: James Morse <james.morse@arm.com>
---
arch/x86/include/asm/resctrl.h | 2 ++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 +++++++++++-----
2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h
index f61382258743..5f6a5375bb4a 100644
--- a/arch/x86/include/asm/resctrl.h
+++ b/arch/x86/include/asm/resctrl.h
@@ -15,6 +15,8 @@
*/
#define X86_RESCTRL_EMPTY_CLOSID ((u32)~0)

+void resctrl_arch_reset_resources(void);
+
/**
* struct resctrl_pqr_state - State cache for the PQR MSR
* @cur_rmid: The cached Resource Monitoring ID
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1a49c9918f8d..13c24cb18d76 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2859,6 +2859,14 @@ static int reset_all_ctrls(struct rdt_resource *r)
return 0;
}

+void resctrl_arch_reset_resources(void)
+{
+ struct rdt_resource *r;
+
+ for_each_capable_rdt_resource(r)
+ reset_all_ctrls(r);
+}
+
/*
* Move tasks from one to the other group. If @from is NULL, then all tasks
* in the systems are moved unconditionally (used for teardown).
@@ -2968,16 +2976,14 @@ static void rmdir_all_sub(void)

static void rdt_kill_sb(struct super_block *sb)
{
- struct rdt_resource *r;
-
cpus_read_lock();
mutex_lock(&rdtgroup_mutex);

rdt_disable_ctx();

- /*Put everything back to default values. */
- for_each_alloc_capable_rdt_resource(r)
- reset_all_ctrls(r);
+ /* Put everything back to default values. */
+ resctrl_arch_reset_resources();
+
rmdir_all_sub();
rdt_pseudo_lock_release();
rdtgroup_default.mode = RDT_MODE_SHAREABLE;
--
2.39.2