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Add the following workarounds: > > - Introduce a dedicated ACPI HID to identify the Graviton5 CMN variant. > - Derive the DTC domain from the XP node ID, since the unit info > register reports it as zero. > - Set the DTC logical ID from the XP's logical ID, since the node info > register's logical ID field is also zeroed. > > Signed-off-by: Aviv Bakal Thanks for the patch. It seems surprisingly clean approach. And thanks to Robin for answering to Sashiko bot! The patch looks good to me, Reviewed-by: Ilkka Koskinen Cheers, Ilkka > --- > drivers/perf/arm-cmn.c | 32 +++++++++++++++++++++++++++++++- > 1 file changed, 31 insertions(+), 1 deletion(-) > > diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c > index f1978a53d1c1..3fb71d9a57eb 100644 > --- a/drivers/perf/arm-cmn.c > +++ b/drivers/perf/arm-cmn.c > @@ -31,7 +31,8 @@ > #define CMN_CHILD_NODE_ADDR GENMASK(29, 0) > #define CMN_CHILD_NODE_EXTERNAL BIT(31) > > -#define CMN_MAX_DIMENSION 12 > +/* Some implementations use a mesh larger than the architectural max of 12 */ > +#define CMN_MAX_DIMENSION 14 > #define CMN_MAX_XPS (CMN_MAX_DIMENSION * CMN_MAX_DIMENSION) > #define CMN_MAX_DTMS (CMN_MAX_XPS + (CMN_MAX_DIMENSION - 1) * 4) > > @@ -214,6 +215,8 @@ enum cmn_part { > PART_CMN700 = 0x43c, > PART_CI700 = 0x43a, > PART_CMN_S3 = 0x43e, > + /* Synthetic part number, overridden to PART_CMN_S3 during discovery */ > + PART_GRAVITON5 = 0xa5, > }; > > /* CMN-600 r0px shouldn't exist in silicon, thankfully */ > @@ -2250,6 +2253,18 @@ static unsigned int arm_cmn_dtc_domain(struct arm_cmn *cmn, void __iomem *xp_reg > return FIELD_GET(CMN_DTM_UNIT_INFO_DTC_DOMAIN, readl_relaxed(xp_region + offset)); > } > > +static unsigned int arm_cmn_graviton5_dtc_domain(u16 xp_id) > +{ > + unsigned int x = (xp_id >> 7) & 0xf; > + unsigned int y = (xp_id >> 3) & 0xf; > + > + /* > + * The unit info register reads as zero; derive the DTC domain from > + * the XP's mesh coordinates over the 10x14 mesh. > + */ > + return (x / 5) + (y / 7) * 2; > +} > + > static void arm_cmn_init_node_info(struct arm_cmn *cmn, u32 offset, struct arm_cmn_node *node) > { > int level; > @@ -2295,6 +2310,7 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) > u64 reg; > int i, j; > size_t sz; > + bool graviton5_workaround = false; > > arm_cmn_init_node_info(cmn, rgn_offset, &cfg); > if (cfg.type != CMN_TYPE_CFG) > @@ -2305,6 +2321,13 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) > reg = readq_relaxed(cfg_region + CMN_CFGM_PERIPH_ID_01); > part = FIELD_GET(CMN_CFGM_PID0_PART_0, reg); > part |= FIELD_GET(CMN_CFGM_PID1_PART_1, reg) << 8; > + > + /* Graviton5 has a customised CMN-S3 which needs some fixups */ > + if (cmn->part == PART_GRAVITON5) { > + cmn->part = PART_CMN_S3; > + graviton5_workaround = true; > + } > + > /* 600AE is close enough that it's not really worth more complexity */ > if (part == PART_CMN600AE) > part = PART_CMN600; > @@ -2394,6 +2417,8 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) > > if (cmn->part == PART_CMN600) > xp->dtc = -1; > + else if (graviton5_workaround) > + xp->dtc = arm_cmn_graviton5_dtc_domain(xp->id); > else > xp->dtc = arm_cmn_dtc_domain(cmn, xp_region); > > @@ -2472,6 +2497,10 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset) > > switch (dn->type) { > case CMN_TYPE_DTC: > + if (graviton5_workaround) { > + /* Node info logical ID is zeroed; use the XP's */ > + dn->logid = xp->logid; > + } > cmn->num_dtcs++; > dn++; > break; > @@ -2687,6 +2716,7 @@ static const struct acpi_device_id arm_cmn_acpi_match[] = { > { "ARMHC650" }, > { "ARMHC700" }, > { "ARMHC003" }, > + { "AMZN0070", PART_GRAVITON5 }, > {} > }; > MODULE_DEVICE_TABLE(acpi, arm_cmn_acpi_match); > -- > 2.47.3 > >