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Diffstat (limited to 'drivers/soc/marvell/octeontx2-ccu/README')
| -rw-r--r-- | drivers/soc/marvell/octeontx2-ccu/README | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/soc/marvell/octeontx2-ccu/README b/drivers/soc/marvell/octeontx2-ccu/README new file mode 100644 index 000000000000..015d94fe06b0 --- /dev/null +++ b/drivers/soc/marvell/octeontx2-ccu/README @@ -0,0 +1,97 @@ + +OCTEONTX2 Cache Controller Unit (CCU) +------------------------------------- + +The Cache Controller Unit allows partitioning the LLC ways into +different partitions (mparid) and associate them with a cpu or a +set of CPUs. + +This driver creates a debugfs directory (ccu) in /sys/kernel/debug +with the following files + $ ls /sys/kernel/debug/ccu + config counter cpumask mparid waymask + +mparid - Create a new parition ID. Valid values are 0 - 255. +waymask - Set the LLC ways that will be masked for the associated mparid. + CCU has 14 LTG ways and 20 DTG ways. The mask value is as follows + [13:0] - LTG Ways + [33:14] - DTG Ways +cpumask - Set the CPU mask to which the LLC way partitioning will be applied. +config - Write 1 to enable the CCU partitioning with values set in the files + mparid, waymask and cpumask. + Read prints the cache configuration. +counter - Prints the Allocate and Hit counter values for the MPARIDs that + are configured. + +Usage Steps +----------- + 1. Create a new parition + $ echo <mparid> > /sys/kernel/debug/ccu/mparid + + 2. Set the LLC ways that need to be masked. + $ echo <waymask> > /sys/kernel/debug/ccu/waymask + + 3. Set cpumask to which waymasking will be applied to. + $ echo <cpu-mask> > /sys/kernel/debug/ccu/cpumask + + 4. Enable this configuration + $ echo 1 > /sys/kernel/debug/ccu/config + +The above 4 steps can be repeated the with different mparid, waymask and +cpumask values. Finally the hardware configuration can be read by + $ cat /sys/kernel/debug/ccu/config + +To check the Allocate and Hit counter for the configured MPARIDs + $ cat /sys/kernel/debug/ccu/counter + +Example +------- +Lets create mparid 10, with all LTG ways masked and associate it with cpus 12-23 + $ echo 10 > /sys/kernel/debug/ccu/mparid + $ echo 0x3fff > /sys/kernel/debug/ccu/waymask + $ echo 0xfff000 > /sys/kernel/debug/ccu/cpumask + $ echo 1 > /sys/kernel/debug/ccu/config + + $ cat /sys/kernel/debug/ccu/config + core:0 mparid:0 waymask:0x0 + core:1 mparid:0 waymask:0x0 + core:2 mparid:0 waymask:0x0 + core:3 mparid:0 waymask:0x0 + core:4 mparid:0 waymask:0x0 + core:5 mparid:0 waymask:0x0 + core:6 mparid:0 waymask:0x0 + core:7 mparid:0 waymask:0x0 + core:8 mparid:0 waymask:0x0 + core:9 mparid:0 waymask:0x0 + core:10 mparid:0 waymask:0x0 + core:11 mparid:0 waymask:0x0 + core:12 mparid:10 waymask:0x3fff + core:13 mparid:10 waymask:0x3fff + core:14 mparid:10 waymask:0x3fff + core:15 mparid:10 waymask:0x3fff + core:16 mparid:10 waymask:0x3fff + core:17 mparid:10 waymask:0x3fff + core:18 mparid:10 waymask:0x3fff + core:19 mparid:10 waymask:0x3fff + core:20 mparid:10 waymask:0x3fff + core:21 mparid:10 waymask:0x3fff + core:22 mparid:10 waymask:0x3fff + core:23 mparid:10 waymask:0x3fff + + $ cat /sys/kernel/debug/ccu/counter + CCU:0 TAD:0 MPARID:0 ALLOC:0x20a469e HIT:0x1ca8fa09 + CCU:0 TAD:1 MPARID:0 ALLOC:0x20a48ea HIT:0x32dc7712 + CCU:1 TAD:0 MPARID:0 ALLOC:0x20a45ee HIT:0x326f8834 + CCU:1 TAD:1 MPARID:0 ALLOC:0x20a470e HIT:0x19aa9ce8 + CCU:2 TAD:0 MPARID:0 ALLOC:0x20a4719 HIT:0x3204242a + CCU:2 TAD:1 MPARID:0 ALLOC:0x20a474f HIT:0x32234456 + CCU:3 TAD:0 MPARID:0 ALLOC:0x20a45a2 HIT:0x19e723c9 + CCU:3 TAD:1 MPARID:0 ALLOC:0x20a46c2 HIT:0x1aae638a + CCU:0 TAD:0 MPARID:10 ALLOC:0x8 HIT:0x2a1 + CCU:0 TAD:1 MPARID:10 ALLOC:0xb HIT:0x273 + CCU:1 TAD:0 MPARID:10 ALLOC:0x13 HIT:0x22d + CCU:1 TAD:1 MPARID:10 ALLOC:0xb HIT:0x26d + CCU:2 TAD:0 MPARID:10 ALLOC:0x11 HIT:0x206 + CCU:2 TAD:1 MPARID:10 ALLOC:0x10 HIT:0x1f2 + CCU:3 TAD:0 MPARID:10 ALLOC:0x10 HIT:0x2b2 + CCU:3 TAD:1 MPARID:10 ALLOC:0x14 HIT:0x26f |