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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-08 11:34:32 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-08 11:34:32 -0700 |
commit | 10c8e0562057b5d64ea170feab148e1550420030 (patch) | |
tree | cfd387208c85e893c93d24e324d147eb6e9abfc9 /Documentation/arm | |
parent | d4e1f5a14e17d4f0e8034c0967511884bcb12fba (diff) | |
parent | 3e528cb7bae00ba0d73def6645d0f2fa906ee3e8 (diff) |
Merge tag 'drivers-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver changes from Olof Johansson:
"A handful of driver-related changes. We've had a bunch of them going
in through other branches as well, so it's only a part of what we
really have this release.
Larger pieces are:
- Removal of a now unused PWM driver for atmel
[ This includes AVR32 changes that have been appropriately acked ]
- Performance counter support for the arm CCN interconnect
- OMAP mailbox driver cleanups and consolidation
- PCI and SATA PHY drivers for SPEAr 13xx platforms
- Redefinition (with backwards compatibility!) of PCI DT bindings for
Tegra to better model regulators/power"
Note: this merge also fixes up the semantic conflict with the new
calling convention for devm_phy_create(), see commit f0ed817638b5 ("phy:
core: Let node ptr of PHY point to PHY and not of PHY provider") that
came in through Greg's USB tree.
Semantic merge patch by Stephen Rothwell <sfr@canb.auug.org.au> through
the next tree.
* tag 'drivers-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (38 commits)
bus: arm-ccn: Fix error handling at event allocation
mailbox/omap: add a parent structure for every IP instance
mailbox/omap: remove the private mailbox structure
mailbox/omap: consolidate OMAP mailbox driver
mailbox/omap: simplify the fifo assignment by using macros
mailbox/omap: remove omap_mbox_type_t from mailbox ops
mailbox/omap: remove OMAP1 mailbox driver
mailbox/omap: use devm_* interfaces
bus: ARM CCN: add PERF_EVENTS dependency
bus: ARM CCN PMU driver
PCI: spear: Remove spear13xx_pcie_remove()
PCI: spear: Fix Section mismatch compilation warning for probe()
ARM: tegra: Remove legacy PCIe power supply properties
PCI: tegra: Remove deprecated power supply properties
PCI: tegra: Implement accurate power supply scheme
ARM: SPEAr13xx: Update defconfigs
ARM: SPEAr13xx: Add pcie and miphy DT nodes
ARM: SPEAr13xx: Add bindings and dt node for misc block
ARM: SPEAr13xx: Fix static mapping table
phy: Add drivers for PCIe and SATA phy on SPEAr13xx
...
Diffstat (limited to 'Documentation/arm')
-rw-r--r-- | Documentation/arm/CCN.txt | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/Documentation/arm/CCN.txt b/Documentation/arm/CCN.txt new file mode 100644 index 000000000000..0632b3aad83e --- /dev/null +++ b/Documentation/arm/CCN.txt @@ -0,0 +1,52 @@ +ARM Cache Coherent Network +========================== + +CCN-504 is a ring-bus interconnect consisting of 11 crosspoints +(XPs), with each crosspoint supporting up to two device ports, +so nodes (devices) 0 and 1 are connected to crosspoint 0, +nodes 2 and 3 to crosspoint 1 etc. + +PMU (perf) driver +----------------- + +The CCN driver registers a perf PMU driver, which provides +description of available events and configuration options +in sysfs, see /sys/bus/event_source/devices/ccn*. + +The "format" directory describes format of the config, config1 +and config2 fields of the perf_event_attr structure. The "events" +directory provides configuration templates for all documented +events, that can be used with perf tool. For example "xp_valid_flit" +is an equivalent of "type=0x8,event=0x4". Other parameters must be +explicitly specified. For events originating from device, "node" +defines its index. All crosspoint events require "xp" (index), +"port" (device port number) and "vc" (virtual channel ID) and +"dir" (direction). Watchpoints (special "event" value 0xfe) also +require comparator values ("cmp_l" and "cmp_h") and "mask", being +index of the comparator mask. + +Masks are defined separately from the event description +(due to limited number of the config values) in the "cmp_mask" +directory, with first 8 configurable by user and additional +4 hardcoded for the most frequent use cases. + +Cycle counter is described by a "type" value 0xff and does +not require any other settings. + +Example of perf tool use: + +/ # perf list | grep ccn + ccn/cycles/ [Kernel PMU event] +<...> + ccn/xp_valid_flit/ [Kernel PMU event] +<...> + +/ # perf stat -C 0 -e ccn/cycles/,ccn/xp_valid_flit,xp=1,port=0,vc=1,dir=1/ \ + sleep 1 + +The driver does not support sampling, therefore "perf record" will +not work. Also notice that only single cpu is being selected +("-C 0") - this is because perf framework does not support +"non-CPU related" counters (yet?) so system-wide session ("-a") +would try (and in most cases fail) to set up the same event +per each CPU. |