The ICU is an IRQ chip found in Armada CP110. It currently has 207 wired
inputs. Its purpose is to aggregate all CP interrupts and report them to
the AP through MSIs. The ICU writes into GIC registers (AP side) by way
of the interconnect. These interrupts can be of several groups:
- SecuRe (SR);
- Non-SecuRe (NSR);
- System Error Interrupts (SEI);
- RAM Error Interrupts (REI);
- ...
Each ICU wired interrupt can be of any of these groups. The group is
encoded in the MSI payload.
Until now, only the non-secure interrupts (NSR) were handled by the ICU
driver. Interrupts of another group could work by chance because the
ICU driver does not erase all ATF configuration; it only erases the
configuration for NSR interrupts.
This series aims at adding support for the System Error Interrupts
(SEI). For this purpose, the ICU driver is a bit reworked to separate
the ICU 'generic' configuration from the NSR-related handling. Then,
the SEI driver (part of the GIC) is introduced and finally, support for
SEI interrupts are also added to the ICU driver.
The SEI driver is a bit different than its cousin the GICP because it
must handle MSIs from the CPs, as well as wired interrupts from the AP
itself. MSIs and wired interrupts will automatically update two
registers (GICP_SECR0/GICP_SECR1) that will trigger a single top-level
interrupt (SPI #32).
As this is my first contribution in the IRQ subsystem I might have
missed some specificities or misunderstood the API, please do not
hesitate to correct me if I'm wrong.
Also, for the sake of understandability (and because I love ASCII art),
this is a try to explain the ICU/SEI architecture:
+----------------------------------------------------------------------+
| |
| |
| SPIa SPIb SPIz SPI 32 |
| ^ ^ ^ ^ |
| | | . . . | | |
| | | | | |
| | | . . . | | |
| +------------------------+ +---------------------------------+ |
| | | | | | | | | |
| | | | | | | SEI | | |
| | | | . . . | | | ________|_______ | |
| | | | | | | /___SEI_SECR_____\ | |
| | |____|___________| | | / | \\ | |
| | \_GICP_SETSPI _/ | | / | \\ | |
| | || | | / ... | \\ | |
| | GICP || | | | | \\ | |
| +----------------||------+ +--|----------|------------||-----+ |
| || | | || |
| || | ... | || |
| || | | || |
| || | | || |
| \\_______ int 0 ... int 20 // |
| \_NSR__ \ // |
| \\ ____________________// |
| \\ /________SEI_________/ |
| AP 806 \\// |
| || |
+---------------------------------||-----------------------------------+
||
|| Interconnect
||\
||\\______
|| \______ <---> Others CP 110
||
+---------------------------------||-----------------------------------+
| || |
| CP 110 || |
| || |
| +-------------------------||------------------------+ |
| | || MSI | |
| | ICU || | |
| | /--------------/ \------\ | |
| | / /-------/ \ | |
| | / / / \ | |
| | / / / . . . \ | |
| | / / / \ | |
| | NSR NSR SEI NSR | |
| | | | | | | |
| +----^-------^-------^-----------------^------------+ |
| | | | | |
| | | | . . . | |
| | | | | |
| int 0 int 1 int 2 int 206 |
| |
| |
+----------------------------------------------------------------------+
Thank you,
Miquèl
Changes since v4:
=================
* Rebased on top of v4-19-rc1
ICU driver
----------
* Updated the commit message of the patch adding SEI support in the
ICU driver, to explain a bit more how this is possible and what
changed.
* Replaced all the icu->is_legacy conditional by static keys so that
the information of what bindings are in use are global to the driver
and the overhead of the branching minimal when it comes to new
bindings (more likely to happen) once DT will be moved.
* Removed some pointless changes and moved other changes from patch 9
(adding SEI support in the ICU) in patch 6 (supporting ICU
subnodes).
* After having discussed with Marc Zingier about how to properly check
in the ->translate() function the value of the interrupt type (from
the fwspec structure), realized actually there was a mismatch
between the type of interrupt received by the ICU (level) and the
type of interrupt sent to the SEI (edge). Discussions are on going
about how to handle such situation, for now I just forced the *type
parameter.
* Removed bitmap_allocate_region() calls with
find_first_free()/set_bit() and same for the free counterpart.
SEI driver
----------
* Tried to make this driver fit as much as possible the "cascaded
irqchip" design, instead of the mix between "cascaded" and
"hierarchy" I used until now. This implied to change a bit the
->probe() but as well the ->translate() callback. However, Marc said
in the ->alloc() function it was bad to "allocate a GIC interrupt
that matches the SEI hwirq". I first understood the allocation was
wrong, but figured out finally it could not work without it, so I
kept this function call, but with 0 instead.
* Protected from concurrent accesses the ->mask()/->unmask() callbacks
with a mutex as they are hitting the same hardware register.
* As the bindings have changed (see below), changed the compatible in
the driver and attached to it some platform data to represent the
list of wired interrupts vs. the MSI ones.
* Added a ->map() callback for wired IRQs, simplifying the ->alloc()
callback for MSIs.
* The chained IRQ handler used a bitmap (array of unsigned long, that
are 32-bit quantities under 32-bit architectures, or 64-bit
quantities under 64-bit architectures). We used readl() to fill it
(32-bit reads on all architectures). Using readl and iterating over
bitmap[0], bitmap[1] is wrong, so I added an u32 pointer taking
bitmap address, so that bitmap could be filled with readl() calls
properly.
* Reworded the cascaded interrupt loop so that only one call to
irq_find_mapping() is done.
ICU bindigns
------------
* Even if none of the bindings listed there have ever been supported
in Linux, they were mentioned in the bindings before, so re-adding SR
and REI to the list now.
SEI Bindings
------------
* Renamed the compatible "marvell,armada-8k-sei" to
"marvell,ap806-sei" as there might be other AP using this IP with a
different wired/MSI interrupt layout.
* Removed the addition of "marvell,cp-wired/msi-interrupt-ranges" as
these should not appear in the DT and are instead available to the
driver under the form of platform data depending on the compatible.
Changes since v3:
=================
* Added an helper to create MSI tree domains.
ICU driver
----------
* Updated the code to use this helper.
* Removed the use of a regmap for the ICU subnodes.
* Squashed patches "irqchip/irq-mvebu-icu: make irq_domain local" and
"irqchip/irq-mvebu-icu: disociate ICU and NSR".
* Fixed a regression: when using old bindings, no platform data was
available for the NSR subset, preventing the ICU driver to probe
correctly.
* Removed the stale comment in a commit log about using linear (instead
of tree) domains.
* Pass a driver structure (called msi_domain) to mvebu_icu_init()
intead of an IRQ domain from which the above structure was derived
from.
SEI driver
----------
* Renamed the 'number' member of the mvebu_sei_interrupt_range structure
into 'size' in the SEI driver.
* Used _relaxed accessors.
* Simplified the 'over' checking around the sei and sei->ap_domain
pointers.
* Do not write GICP_SECR register if the irqmap read has no bit set
(ie. nothing to clear, do not do the writel operation).
* Moved irq_set_chained_handler() and irq_set_handler_data() at the end
of the probe.
* Simplified the chained handler with only one inner loop after having
created a bitmap of the pending interrupts.
Changes since v2:
=================
* Rebased on top of v4.18-rc1
platform-msi:
-------------
* New patch to allow using MSI tree domains.
irqchip/irq-mvebu-sei: add new driver for Marvell SEI
------------------------------------------------------
* Updated commit message with Marc comments
* Wrote two functions to fill ->irq_set_type() in the irq_chip
structures, one accepting only rising edge interrupts (for MSI),
another one accepting only high level interrupts (for wired IRQ).
* Changed the spin lock protecting the allocated SEIs bitmap into a
mutex.
* Changed the bitmap allocation line to respect the actual number of
MSIs instead of pretending having SEI_IRQ_COUNT (64) MSI available.
* I did not split the code to have one function per domain because it
would duplicate a _lot_ of code. Requested some advices instead.
* Stopped using the fwnode when creating the AP (wired) IRQ domain.
* Implemented the AP IRQ domain ->match() hook.
* Used marvell,sei-xx-ranges properties to get the relevant IRQ numbers
from DT. 'xx' is either 'ap' or 'cp'.
irqchip/irq-mvebu-icu: add support for System Error Interrupts (SEI)
---------------------------------------------------------------------
* Added a patch to ease the creation of tree domains (changes in the
core).
* Changed the code accordingly to use tree domains.
* Created a couple of helpers to do the bitmap allocation/release.
* Removed the .offset_clr_a[hl] entries of the sei_subset_data
structure to avoid confusion. These registers actually exist, but
are not used here because the upper block (SEI) only supports
edge-MSI and not level-MSI like the NSR one.
dt-bindings/interrupt-controller: update Marvell ICU bindings
--------------------------------------------------------------
* Explained better in the commit message that backward compatibility
is not broken.
* Changed subnodes names to be 'interrupt-controller' as requested.
* Added a range associated to each sub-node (as well as in the DT).
* Replaced spaces by tabs.
* Merged the SEI's subnodes so that there is only one SEI node and no
subnodes anymore.
Changes since v1:
=================
General
-------
* Spelling/function names/comments.
* Added Reviewed-by tags.
* Rebased on top of Marc Zyngier level-MSI series (tip:irq/core).
SEI
---
* Change the license for GPL-2.0 only in irq-mvebu-sei.c C file.
* Used alphabetic ordering when adding SEI driver in Makefile.
* Re-ordered register definitions by increasing offset.
* s/NB/COUNT/ in register definitions.
* avoid enabling all interrupt by default.
* fixed mask/unmask functions using the wrong hwirq number.
* removed hackish doorbell mechanism.
* Removed the ->xlate hook assigned for CP MSIs.
* Used devm_*() helpers.
* s/top_level_spi/parent_irq/ in probe.
* Added forgotten of_node_put(child).
* Reset the SEI registers before registering the IRQ domains.
* Introduced new DT property "marvell,sei-ranges" instead of using
"reg" to declare the range of MSI interrupts vs. wired interrupts in
the SEI subnodes.
* Finally did not change the ->alloc() about the fwspec->param[1]
line (to be checked by Marc).
ICU
---
* Updated the ICU documentation so the legacy bindings are still
documented somewhere.
* Added stable tags on the commit fixing the CP110 ICU node size.
* Removed the "syscon" compatible from the ICU node, instead the
syscon is created at probe time.
* s/user data/private data/ in the title of commit
"irqchip/irq-mvebu-icu: fix wrong user data retrieval"
Marc Zyngier (1):
genirq/msi: Allow creation of a tree-based irqdomain for platform-msi
Miquel Raynal (13):
dt-bindings/interrupt-controller: fix Marvell ICU length in the
example
irqchip/irq-mvebu-icu: fix wrong private data retrieval
irqchip/irq-mvebu-icu: clarify the reset operation of configured
interrupts
irqchip/irq-mvebu-icu: disociate ICU and NSR
irqchip/irq-mvebu-icu: support ICU subnodes
irqchip/irq-mvebu-sei: add new driver for Marvell SEI
arm64: marvell: enable SEI driver
irqchip/irq-mvebu-icu: add support for System Error Interrupts (SEI)
dt-bindings/interrupt-controller: update Marvell ICU bindings
dt-bindings/interrupt-controller: add documentation for Marvell SEI
controller
arm64: dts: marvell: add AP806 SEI subnode
arm64: dts: marvell: use new bindings for CP110 interrupts
arm64: dts: marvell: add CP110 ICU SEI subnode
.../interrupt-controller/marvell,icu.txt | 87 +++-
.../interrupt-controller/marvell,sei.txt | 36 ++
arch/arm64/Kconfig.platforms | 1 +
arch/arm64/boot/dts/marvell/armada-ap806.dtsi | 9 +
arch/arm64/boot/dts/marvell/armada-cp110.dtsi | 125 +++--
drivers/base/platform-msi.c | 14 +-
drivers/irqchip/Kconfig | 3 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-mvebu-icu.c | 260 ++++++++--
drivers/irqchip/irq-mvebu-sei.c | 475 ++++++++++++++++++
include/linux/msi.h | 17 +-
11 files changed, 896 insertions(+), 132 deletions(-)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/marvell,sei.txt
create mode 100644 drivers/irqchip/irq-mvebu-sei.c
--
2.17.1
