Commit ec5d30b4 authored by James Morse's avatar James Morse Committed by Zeng Heng
Browse files

arm_mpam: resctrl: Call resctrl_exit() in the event of errors 

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/snapshot/v6.7-rc2



---------------------------

All of MPAMs errors indicate a software bug, e.g. an out-of-bounds
partid has been generated. When this happens, the mpam driver
is disabled.

If resctrl_init() succeeded, also call resctrl_exit() to
remove resctrl.

If the filesystem was mounted in its traditional place, it is
no longer possible for processes to find it as the mount point
has been removed. If the filesystem was mounted elsewhere, it
will appear that all CPU and domains are offline. User-space
will not be able to update the hardware.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarZeng Heng <zengheng4@huawei.com>
parent 591b8d61

drivers/platform/mpam/mpam_devices.c

+2 −0
Original line number Diff line number Diff line
@@ -2240,6 +2240,8 @@ static irqreturn_t mpam_disable_thread(int irq, void *dev_id) 
	}

	mutex_unlock(&mpam_cpuhp_state_lock);



	mpam_resctrl_exit();



	static_branch_disable(&mpam_enabled);



	mpam_unregister_irqs();

drivers/platform/mpam/mpam_internal.h

+1 −0
Original line number Diff line number Diff line
@@ -313,6 +313,7 @@ int mpam_resctrl_online_cpu(unsigned int cpu); 
int mpam_resctrl_offline_cpu(unsigned int cpu);



int mpam_resctrl_setup(void);

void mpam_resctrl_exit(void);



/*

 * MPAM MSCs have the following register layout. See:

drivers/platform/mpam/mpam_resctrl.c

+17 −0
Original line number Diff line number Diff line
@@ -41,6 +41,12 @@ static struct mpam_class *mbm_total_class; 
 */

static bool cdp_enabled;



/*

 * If resctrl_init() succeeded, resctrl_exit() can be used to remove support

 * for the filesystem in the event of an error.

 */

static bool resctrl_enabled;



/* A dummy mon context to use when the monitors were allocated up front */

u32 __mon_is_rmid_idx = USE_RMID_IDX;

void *mon_is_rmid_idx = &__mon_is_rmid_idx;
@@ -825,11 +831,22 @@ int mpam_resctrl_setup(void) 
		}



		err = resctrl_init();

		if (!err)

			WRITE_ONCE(resctrl_enabled, true);

	}



	return err;

}



void mpam_resctrl_exit(void)

{

	if (!READ_ONCE(resctrl_enabled))

		return;



	WRITE_ONCE(resctrl_enabled, false);

	resctrl_exit();

}



u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,

			    u32 closid, enum resctrl_conf_type type)

{