Commit fa774521 authored by Shanker Donthineni's avatar Shanker Donthineni Committed by James Morse
Browse files

arm_mpam: Add quirk framework 



The MPAM specification includes the MPAMF_IIDR, which serves to uniquely
identify the MSC implementation through a combination of implementer
details, product ID, variant, and revision. Certain hardware issues/errata
can be resolved using software workarounds.

Introduce a quirk framework to allow workarounds to be enabled based on the
MPAMF_IIDR value.

Tested-by: default avatarGavin Shan <gshan@redhat.com>
Tested-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: default avatarZeng Heng <zengheng4@huawei.com>
Tested-by: default avatarPunit Agrawal <punit.agrawal@oss.qualcomm.com>
Tested-by: default avatarJesse Chick <jessechick@os.amperecomputing.com>
Reviewed-by: default avatarZeng Heng <zengheng4@huawei.com>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarJonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Signed-off-by: default avatarShanker Donthineni <sdonthineni@nvidia.com>
Co-developed-by: default avatarBen Horgan <ben.horgan@arm.com>
Signed-off-by: default avatarBen Horgan <ben.horgan@arm.com>
Co-developed-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
parent fb481ec0

drivers/resctrl/mpam_devices.c

+32 −0
Original line number Diff line number Diff line
@@ -630,6 +630,30 @@ static struct mpam_msc_ris *mpam_get_or_create_ris(struct mpam_msc *msc, 
	return ERR_PTR(-ENOENT);

}



static const struct mpam_quirk mpam_quirks[] = {

	{ NULL } /* Sentinel */

};



static void mpam_enable_quirks(struct mpam_msc *msc)

{

	const struct mpam_quirk *quirk;



	for (quirk = &mpam_quirks[0]; quirk->iidr_mask; quirk++) {

		int err = 0;



		if (quirk->iidr != (msc->iidr & quirk->iidr_mask))

			continue;



		if (quirk->init)

			err = quirk->init(msc, quirk);



		if (err)

			continue;



		mpam_set_quirk(quirk->workaround, msc);

	}

}



/*

 * IHI009A.a has this nugget: "If a monitor does not support automatic behaviour

 * of NRDY, software can use this bit for any purpose" - so hardware might not
@@ -864,8 +888,11 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) 
	/* Grab an IDR value to find out how many RIS there are */

	mutex_lock(&msc->part_sel_lock);

	idr = mpam_msc_read_idr(msc);

	msc->iidr = mpam_read_partsel_reg(msc, IIDR);

	mutex_unlock(&msc->part_sel_lock);



	mpam_enable_quirks(msc);



	msc->ris_max = FIELD_GET(MPAMF_IDR_RIS_MAX, idr);



	/* Use these values so partid/pmg always starts with a valid value */
@@ -1972,6 +1999,7 @@ static bool mpam_has_cmax_wd_feature(struct mpam_props *props) 
 * resulting safe value must be compatible with both. When merging values in

 * the tree, all the aliasing resources must be handled first.

 * On mismatch, parent is modified.

 * Quirks on an MSC will apply to all MSC in that class.

 */

static void __props_mismatch(struct mpam_props *parent,

			     struct mpam_props *child, bool alias)
@@ -2091,6 +2119,7 @@ static void __props_mismatch(struct mpam_props *parent, 
 * nobble the class feature, as we can't configure all the resources.

 * e.g. The L3 cache is composed of two resources with 13 and 17 portion

 * bitmaps respectively.

 * Quirks on an MSC will apply to all MSC in that class.

 */

static void

__class_props_mismatch(struct mpam_class *class, struct mpam_vmsc *vmsc)
@@ -2104,6 +2133,9 @@ __class_props_mismatch(struct mpam_class *class, struct mpam_vmsc *vmsc) 
	dev_dbg(dev, "Merging features for class:0x%lx &= vmsc:0x%lx\n",

		(long)cprops->features, (long)vprops->features);



	/* Merge quirks */

	class->quirks |= vmsc->msc->quirks;



	/* Take the safe value for any common features */

	__props_mismatch(cprops, vprops, false);

}

drivers/resctrl/mpam_internal.h

+25 −0
Original line number Diff line number Diff line
@@ -85,6 +85,8 @@ struct mpam_msc { 
	u8			pmg_max;

	unsigned long		ris_idxs;

	u32			ris_max;

	u32			iidr;

	u16			quirks;



	/*

	 * error_irq_lock is taken when registering/unregistering the error
@@ -216,6 +218,28 @@ struct mpam_props { 
#define mpam_set_feature(_feat, x)	__set_bit(_feat, (x)->features)

#define mpam_clear_feature(_feat, x)	__clear_bit(_feat, (x)->features)



/* Workaround bits for msc->quirks */

enum mpam_device_quirks {

	MPAM_QUIRK_LAST

};



#define mpam_has_quirk(_quirk, x)	((1 << (_quirk) & (x)->quirks))

#define mpam_set_quirk(_quirk, x)	((x)->quirks |= (1 << (_quirk)))



struct mpam_quirk {

	int (*init)(struct mpam_msc *msc, const struct mpam_quirk *quirk);



	u32 iidr;

	u32 iidr_mask;



	enum mpam_device_quirks workaround;

};



#define MPAM_IIDR_MATCH_ONE	(FIELD_PREP_CONST(MPAMF_IIDR_PRODUCTID,   0xfff) | \

				 FIELD_PREP_CONST(MPAMF_IIDR_VARIANT,     0xf)	 | \

				 FIELD_PREP_CONST(MPAMF_IIDR_REVISION,    0xf)	 | \

				 FIELD_PREP_CONST(MPAMF_IIDR_IMPLEMENTER, 0xfff))



/* The values for MSMON_CFG_MBWU_FLT.RWBW */

enum mon_filter_options {

	COUNT_BOTH	= 0,
@@ -259,6 +283,7 @@ struct mpam_class { 


	struct mpam_props	props;

	u32			nrdy_usec;

	u16			quirks;

	u8			level;

	enum mpam_class_types	type;