[PATCH v2 00/16] Add System Error Interrupt support to Armada SoCs

From: Miquel Raynal
Date: Tue May 22 2018 - 04:49:03 EST

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,
MiquÃl


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"


Miquel Raynal (16):
dt-bindings/interrupt-controller: fix Marvell ICU length in the
example
arm64: dts: marvell: fix CP110 ICU node size
irqchip/irq-mvebu-icu: fix wrong private data retrieval
irqchip/irq-mvebu-icu: clarify the reset operation of configured
interrupts
irqchip/irq-mvebu-icu: switch to regmap
irqchip/irq-mvebu-icu: make irq_domain local
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

.../bindings/interrupt-controller/marvell,icu.txt | 83 +++-
.../bindings/interrupt-controller/marvell,sei.txt | 50 +++
arch/arm64/Kconfig.platforms | 1 +
arch/arm64/boot/dts/marvell/armada-ap806.dtsi | 19 +
arch/arm64/boot/dts/marvell/armada-cp110.dtsi | 123 +++---
drivers/irqchip/Kconfig | 3 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-mvebu-icu.c | 301 ++++++++++++---
drivers/irqchip/irq-mvebu-sei.c | 422 +++++++++++++++++++++
9 files changed, 872 insertions(+), 131 deletions(-)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/marvell,sei.txt
create mode 100644 drivers/irqchip/irq-mvebu-sei.c

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2.14.1