Commit bc740420 authored by James Morse's avatar James Morse Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Drop __init/__exit on assorted symbols 



Because ARM's MPAM controls are probed using MMIO, resctrl can't be
initialised until enough CPUs are online to have determined the system-wide
supported num_closid. Arm64 also supports 'late onlined secondaries', where
only a subset of CPUs are online during boot.

These two combine to mean the MPAM driver may not be able to initialise
resctrl until user-space has brought 'enough' CPUs online.

To allow MPAM to initialise resctrl after __init text has been free'd, remove
all the __init markings from resctrl.

The existing __exit markings cause these functions to be removed by the linker
as it has never been possible to build resctrl as a module. MPAM has an error
interrupt which causes the driver to reset and disable itself. Remove the
__exit markings to allow the MPAM driver to tear down resctrl when an error
occurs.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarFenghua Yu <fenghuay@nvidia.com>
Tested-by: default avatarFenghua Yu <fenghuay@nvidia.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: default avatarPeter Newman <peternewman@google.com>
Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64
Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64
Tested-by: default avatarBabu Moger <babu.moger@amd.com>
Tested-by: default avatarTony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/20250515165855.31452-10-james.morse@arm.com
parent 8c992e24

arch/x86/kernel/cpu/resctrl/core.c

+3 −3
Original line number Diff line number Diff line
@@ -737,7 +737,7 @@ struct rdt_options { 
	bool	force_off, force_on;

};



static struct rdt_options rdt_options[]  __initdata = {

static struct rdt_options rdt_options[]  __ro_after_init = {

	RDT_OPT(RDT_FLAG_CMT,	    "cmt",	X86_FEATURE_CQM_OCCUP_LLC),

	RDT_OPT(RDT_FLAG_MBM_TOTAL, "mbmtotal", X86_FEATURE_CQM_MBM_TOTAL),

	RDT_OPT(RDT_FLAG_MBM_LOCAL, "mbmlocal", X86_FEATURE_CQM_MBM_LOCAL),
@@ -777,7 +777,7 @@ static int __init set_rdt_options(char *str) 
}

__setup("rdt", set_rdt_options);



bool __init rdt_cpu_has(int flag)

bool rdt_cpu_has(int flag)

{

	bool ret = boot_cpu_has(flag);

	struct rdt_options *o;
@@ -797,7 +797,7 @@ bool __init rdt_cpu_has(int flag) 
	return ret;

}



__init bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)

bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt)

{

	if (!rdt_cpu_has(X86_FEATURE_BMEC))

		return false;

arch/x86/kernel/cpu/resctrl/internal.h

+2 −2
Original line number Diff line number Diff line
@@ -472,13 +472,13 @@ int alloc_rmid(u32 closid); 
void free_rmid(u32 closid, u32 rmid);

int rdt_get_mon_l3_config(struct rdt_resource *r);

void resctrl_mon_resource_exit(void);

bool __init rdt_cpu_has(int flag);

bool rdt_cpu_has(int flag);

void mon_event_count(void *info);

int rdtgroup_mondata_show(struct seq_file *m, void *arg);

void mon_event_read(struct rmid_read *rr, struct rdt_resource *r,

		    struct rdt_mon_domain *d, struct rdtgroup *rdtgrp,

		    cpumask_t *cpumask, int evtid, int first);

int __init resctrl_mon_resource_init(void);

int resctrl_mon_resource_init(void);

void mbm_setup_overflow_handler(struct rdt_mon_domain *dom,

				unsigned long delay_ms,

				int exclude_cpu);

arch/x86/kernel/cpu/resctrl/monitor.c

+1 −1
Original line number Diff line number Diff line
@@ -1204,7 +1204,7 @@ static __init int snc_get_config(void) 
 *

 * Returns 0 for success, or -ENOMEM.

 */

int __init resctrl_mon_resource_init(void)

int resctrl_mon_resource_init(void)

{

	struct rdt_resource *r = resctrl_arch_get_resource(RDT_RESOURCE_L3);

	int ret;

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+4 −4
Original line number Diff line number Diff line
@@ -4144,7 +4144,7 @@ static void rdtgroup_destroy_root(void) 
	rdtgroup_default.kn = NULL;

}



static void __init rdtgroup_setup_default(void)

static void rdtgroup_setup_default(void)

{

	mutex_lock(&rdtgroup_mutex);
@@ -4376,7 +4376,7 @@ void resctrl_offline_cpu(unsigned int cpu) 
 *

 * Return: 0 on success or -errno

 */

int __init resctrl_init(void)

int resctrl_init(void)

{

	int ret = 0;
@@ -4433,7 +4433,7 @@ int __init resctrl_init(void) 
	return ret;

}



static bool __exit resctrl_online_domains_exist(void)

static bool resctrl_online_domains_exist(void)

{

	struct rdt_resource *r;
@@ -4471,7 +4471,7 @@ static bool __exit resctrl_online_domains_exist(void) 
 * resctrl_arch_get_resource() must continue to return struct rdt_resources

 * with the correct rid field to ensure the filesystem can be unmounted.

 */

void __exit resctrl_exit(void)

void resctrl_exit(void)

{

	cpus_read_lock();

	WARN_ON_ONCE(resctrl_online_domains_exist());

include/linux/resctrl.h

+3 −3
Original line number Diff line number Diff line
@@ -358,7 +358,7 @@ u32 resctrl_arch_get_num_closid(struct rdt_resource *r); 
u32 resctrl_arch_system_num_rmid_idx(void);

int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);



__init bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);

bool resctrl_arch_is_evt_configurable(enum resctrl_event_id evt);



/**

 * resctrl_arch_mon_event_config_write() - Write the config for an event.
@@ -514,7 +514,7 @@ void resctrl_arch_reset_all_ctrls(struct rdt_resource *r); 
extern unsigned int resctrl_rmid_realloc_threshold;

extern unsigned int resctrl_rmid_realloc_limit;



int __init resctrl_init(void);

void __exit resctrl_exit(void);

int resctrl_init(void);

void resctrl_exit(void);



#endif /* _RESCTRL_H */