From: James Morse james.morse@arm.com
rdt_enable_key is switched when resctrl is mounted. It was also previously used to prevent a second mount of the filesystem.
Any other architecture that wants to support resctrl has to provide identical static keys.
Now that there are helpers for enabling and disabling the alloc/mon keys, resctrl doesn't need to switch this extra key, it can be done by the arch code. Use the static-key increment and decrement helpers, and change resctrl to ensure the calls are balanced.
Signed-off-by: James Morse james.morse@arm.com Tested-by: Shaopeng Tan tan.shaopeng@fujitsu.com Tested-by: Peter Newman peternewman@google.com Tested-by: Babu Moger babu.moger@amd.com Reviewed-by: Shaopeng Tan tan.shaopeng@fujitsu.com Reviewed-by: Reinette Chatre reinette.chatre@intel.com Reviewed-by: Babu Moger babu.moger@amd.com --- arch/x86/include/asm/resctrl.h | 4 ++++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 11 +++++------ 2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h index 3c9137b6ad4f..b74aa34dc9e8 100644 --- a/arch/x86/include/asm/resctrl.h +++ b/arch/x86/include/asm/resctrl.h @@ -45,21 +45,25 @@ DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); static inline void resctrl_arch_enable_alloc(void) { static_branch_enable_cpuslocked(&rdt_alloc_enable_key); + static_branch_inc_cpuslocked(&rdt_enable_key); }
static inline void resctrl_arch_disable_alloc(void) { static_branch_disable_cpuslocked(&rdt_alloc_enable_key); + static_branch_dec_cpuslocked(&rdt_enable_key); }
static inline void resctrl_arch_enable_mon(void) { static_branch_enable_cpuslocked(&rdt_mon_enable_key); + static_branch_inc_cpuslocked(&rdt_enable_key); }
static inline void resctrl_arch_disable_mon(void) { static_branch_disable_cpuslocked(&rdt_mon_enable_key); + static_branch_dec_cpuslocked(&rdt_enable_key); }
/* diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 8cc5a0937fa8..74a8494a0c91 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2677,10 +2677,8 @@ static int rdt_get_tree(struct fs_context *fc) if (rdt_mon_capable) resctrl_arch_enable_mon();
- if (rdt_alloc_capable || rdt_mon_capable) { - static_branch_enable_cpuslocked(&rdt_enable_key); + if (rdt_alloc_capable || rdt_mon_capable) resctrl_mounted = true; - }
if (is_mbm_enabled()) { r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; @@ -2951,9 +2949,10 @@ static void rdt_kill_sb(struct super_block *sb) rdtgroup_default.mode = RDT_MODE_SHAREABLE; schemata_list_destroy(); rdtgroup_destroy_root(); - resctrl_arch_disable_alloc(); - resctrl_arch_disable_mon(); - static_branch_disable_cpuslocked(&rdt_enable_key); + if (rdt_alloc_capable) + resctrl_arch_disable_alloc(); + if (rdt_mon_capable) + resctrl_arch_disable_mon(); resctrl_mounted = false; kernfs_kill_sb(sb); mutex_unlock(&rdtgroup_mutex);