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arm_mpam: Add quirk framework

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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: Gavin Shan <gshan@redhat.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Zeng Heng <zengheng4@huawei.com>
Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com>
Tested-by: Jesse Chick <jessechick@os.amperecomputing.com>
Reviewed-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Co-developed-by: Ben Horgan <ben.horgan@arm.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Co-developed-by: James Morse <james.morse@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
This commit is contained in:
Shanker Donthineni
2026-03-13 14:46:12 +00:00
committed by James Morse
parent fb481ec086
commit fa7745218c
2 changed files with 57 additions and 0 deletions
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32
drivers/resctrl/mpam_devices.c
View File

@@ -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);
}

25
drivers/resctrl/mpam_internal.h
View File

@@ -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;